All tools

Find an exact age in years, months and days from a date of birth — plus the next birthday countdown.

Work out the monthly instalment on a loan, with total interest and a full amortisation schedule.

Five percentage calculations in one place — including percentage change and reverse percentages.

Add or remove GST at any rate, with the CGST and SGST split shown separately.

Find the sale price and the amount saved, or work backwards to the discount percentage.

Calculate Body Mass Index in metric or imperial units, with the WHO category and healthy weight range.

Calculate simple interest and maturity value from principal, rate and time.

Project growth with any compounding frequency, with optional regular monthly contributions.

Solve for payment, loan amount or tenure, and see total cost with a repayment schedule.

Count the days, weeks and months between two dates — with or without weekends.

Work out the tip and the total, split it between any number of people, and round it off.

Project what a monthly investment could grow to, with an optional annual step-up.

Work out what a fixed deposit matures to, with any compounding frequency and the effective yield.

Find the maturity value of a recurring deposit from the monthly instalment, rate and term.

Project a Public Provident Fund balance over 15 years or more, with a year-by-year table.

Break an annual CTC into its components and estimate the monthly take-home pay.

Estimate gratuity under the Payment of Gratuity Act from last drawn salary and years of service.

Find the compound annual growth rate between two values, and the absolute return alongside it.

Compare the old and new regimes on your income, with slabs, rebate, surcharge and cess shown.

Project an Employees' Provident Fund balance from basic pay, contributions and years of service.

Find the exempt portion of your house rent allowance, and how much of it stays taxable.

Estimate the tax deducted from each payslip, and what remains for the rest of the year.

Compare the corpus you are on track to build against the one your retirement actually needs.

See what an amount will cost later, and what today's money will still be able to buy.

Project what a single investment grows to, with the year-by-year path shown.

Model a systematic withdrawal plan and find out whether the corpus lasts the distance.

Estimate how much you could borrow from your income, obligations, rate and tenure.

See what a lump-sum prepayment saves, comparing a shorter tenure against a lower EMI.

Estimate your BMR and daily calorie needs with a choice of recognised formulas.

Work out what a trip costs in fuel, in km/l, mpg or l/100km, split between passengers.

A full scientific calculator with trigonometry, logarithms, powers and memory keys.

Work out a credit-weighted CGPA across any number of subjects, with optional percentage conversion.

Find margin and markup from cost and price, or price for a target of either.

Find the mean, median, mode and range of a list of numbers, pasted in any format.

Calculate sample or population standard deviation with the full working shown.

Add, subtract, multiply and divide fractions and mixed numbers, with exact results.

Simplify a ratio, share an amount in proportion, or solve for a missing term.

Find the sales volume that covers your fixed costs, and what a target profit needs.

Work out return on investment, with an annualised figure when you supply a period.

Find the score you need on the final exam to reach the overall grade you want.

Solve ax² + bx + c = 0 with roots, discriminant, vertex and factored form.

Add and subtract durations, or find the time between two clock times including overnight.

Full monthly housing cost — principal, interest, tax, insurance, HOA and PMI.

Auto loan payment including sales tax, trade-in, fees and negative equity.

What you will have, what you must save, or how long it takes to reach a goal.

Compare avalanche and snowball strategies across all your debts at once.

Add up everything you own and owe to get a single financial position.

Add or remove US sales tax with stacked state, county, city and district rates.

Add VAT to a net figure or extract it from a gross one, at any rate.

Basal metabolic rate from three equations at once, with the spread shown.

Total daily energy expenditure across every activity level, with a macro split.

Four clinical formulas plus the healthy BMI range, with the disagreement shown.

Add or subtract days, weeks, months and years, or count down to a date.

The exact age gap between two people in years, months, days and weeks.

Weekly timesheet — clock in and out, deduct breaks, split overtime and pay.

Convert pay between hourly, daily, weekly, monthly and annual — both directions.

Measure real fuel efficiency from distance and fuel used — km/l, mpg and l/100km.

Estimate a monthly bill from appliance usage, on flat or slab tariffs.

Work out floor or plot area from measurements, add a waste allowance and cost the material.

How much paint a room needs, from its dimensions, the openings, the coats and the spread rate.

Concrete volume for a slab, footing, wall or column, with bags or a cement, sand and aggregate split.

Solve pace, time or distance, with a split table and equivalent times at other race distances.

Resize without distortion, identify the ratio of any size, or fit an image inside a box.

Work out how many tiles and boxes a floor or wall needs, grout joints included.

Estimate body fat percentage from tape measurements or from height and weight.

Find the highest common factor and lowest common multiple of two or more numbers, with the factorisation shown.

Count arrangements and selections — nPr, nCr, with or without repetition — with exact results and the formula shown.

Project a National Pension System corpus, the lump sum you may take at exit, and the pension the rest buys.

Rank packs of different sizes by what they actually cost per gram, millilitre or item.

Apparent temperature from the published heat index and wind chill formulas, with the dew point.

Solve a triangle from any three parts — sides, angles, area, altitudes and the ambiguous case.

Convert between rise-in-12, degrees and percent, and get rafter lengths and true roof area.

Slope, angle, distance, midpoint and the equation of the line through two points.

Enter any two of voltage, current, resistance and power to get the other two.

Read a resistor's value from its bands, or find the bands for a value you need.

Work out the series resistor an LED needs, and what to actually buy for it.

Combine up to ten resistors in parallel or series into one equivalent value.

Find the output of a two-resistor divider, or the resistor that hits a target voltage.

How long a battery lasts at a given draw, with realistic usable capacity.

Decode the three-digit marking on a capacitor into pF, nF and µF at once.

Time constant, charge curve and filter corner frequency for a resistor and capacitor.

Resonant frequency of an LC circuit, or the inductor or capacitor to reach one.

How long a file takes to download, with bits and bytes kept straight.

How many people to survey for a given margin of error and confidence level.

Solve C₁V₁ = C₂V₂ for stock volume, final volume or either concentration.

Voltage lost along a cable run, from its gauge, length, current and temperature.

Convert between ratios and decibels, and between dBm, dBW, dBV and dBu.

Convert frequency to wavelength and back, with antenna lengths worked out.

Frequency of any musical note, or the nearest note to any frequency, at your tuning.

Pixel density, panel size and viewing distance from a resolution and a diagonal.

Gear ratio, output speed and torque for a train of up to four stages.

Compare two tyre sizes for diameter, clearance and speedometer error.

Board feet from thickness, width and length, with waste and cost worked out.

Work a flight out from the floor-to-floor height: riser count, riser height, run and stringer length.

Convert between a value, its z-score, its percentile and the tail probabilities, in either direction.

Convert between kW, kVA, kVAr and line current for single- and three-phase supplies, with power factor.

Capacity and contents for cylindrical, rectangular and capsule tanks, including partial fill by depth.

Rescale a whole ingredient list by servings or a multiplier, keeping quantities as kitchen fractions.

Weight of bar, tube, plate and angle in any alloy, per piece, per metre and for the whole order.

Determinant, inverse, transpose, product, sum and scalar multiple for matrices up to 6×6.

Size a solar array from your electricity use: panel count, kWp, roof area and annual generation.

Size an air conditioner for a room, with the adjustments for sun, ceiling height, occupants and kitchens.

Work out the mass to weigh, the concentration you made, or the volume a mass will give.

Estimate a one-rep max from a set, across six formulas, with the training percentages.

Posts, rails, pickets and concrete for a run of fence, with gates taken out of the length.

Displacement from bore, stroke and cylinder count, with the bore/stroke ratio and compression.

Sunrise, sunset, solar noon and the three twilights for any date and coordinates.

Convert a bread recipe between weights and baker's percentages, with hydration worked out.

The nth term and the sum of an arithmetic or geometric sequence, or identify one from its terms.

Build a confidence interval for a mean or a proportion, with the margin of error.

Fit a least-squares line to your data points, with R², significance and prediction.

Add, subtract, dot and cross two vectors, with magnitudes, angle and projection.

Probability of exactly, at most or at least k successes in n independent trials.

Find the ISO week for a date, or the dates in a given week, with the week-year.

Five training zones from your age or measured maximum, by percentage or Karvonen.

Convert lamp output to illuminance over an area, or find the lumens a space needs.

Delay and reverb times in milliseconds for every note value at a given tempo.

Work out volumetric weight and which of it or actual weight a courier will bill.

Ramp run, gradient and landings for a given rise, against ADA or UK Part M limits.

Balances a reaction into the smallest whole-number coefficients, and recounts every atom.

The Moon's phase, illuminated percentage and age for any date, with the next four phase dates.

Rolls needed for a room, counted in drops and allowing for the pattern repeat.

Solves PV = nRT for pressure, volume, moles or temperature, in whatever units you have.

Solves exponential decay for the amount left, the time taken, or the half-life itself.

pH, pOH and ion concentrations for strong and weak acids and bases, with pKw that moves with temperature.

Solves Q = mcΔT for heat, mass, specific heat or temperature change, and warns when a phase change breaks it.

Range, peak height, flight time and impact for a projectile launched at a speed and angle.

Dew point, wet bulb and absolute humidity from a temperature and a humidity reading, with the temperature a surface starts sweating at.

Count the significant figures in a number, round to a given number of them, or propagate them correctly through a calculation.

Compares renting and buying as net worth over time, with the renter investing the deposit and the monthly difference.

Works back from the income you want to the hourly rate you have to charge, after unpaid hours, expenses and tax.

Static compression ratio from bore, stroke, chamber, gasket, deck and piston volumes — plus the dynamic ratio a camshaft actually delivers.

Astable frequency and duty cycle, monostable pulse width, or the resistor pair that hits a frequency you name.

Inverting and non-inverting gain from the feedback resistors, with output clipping, bandwidth and the slew rate limit.

Turns ratio from voltages or windings, with secondary current, primary draw and the impedance ratio it presents.

Power from torque and RPM, or either from the other two, in hp, kW and PS — with a wheel-to-crank estimate.

Near and far focus limits, hyperfocal distance and the diffraction ceiling for a given format, lens and aperture.

Bedtimes or wake-up times that land between sleep cycles, with the time it takes you to fall asleep counted in.

Your attendance so far, how many classes you must attend in a row to reach the requirement, and how many you can still miss.

Belt length from two pulleys and a centre distance, or the centre distance from a belt you already have, with wrap angles.

Works out what an hour in the room costs, from the number of people in it and what their time is worth.

Estimates how long an electric car takes to charge, what the electricity costs and how much range it buys.

Live word, sentence and paragraph counts with reading time and keyword density.

Count characters with and without spaces, with live limits for tweets, SEO tags and SMS.

Convert text between upper, lower, title, sentence, camel, snake, kebab and more.

Strip duplicate lines from a list, with options for case sensitivity and trimming.

Sort lines alphabetically, numerically, by length or randomly, ascending or descending.

Strip extra spaces, blank lines, line breaks, HTML tags, punctuation and smart quotes.

Generate placeholder paragraphs, sentences, words or list items for mockups.

Compare two versions of a text and see exactly which lines were added, removed or left alone.

Turn a title into a clean URL slug, with accents transliterated and symbols spelled out.

Convert Markdown to clean HTML, or HTML back to Markdown, with a live preview.

Score any text with six readability formulas at once and see where they disagree.

Replace text across a whole document, matching plain text or a regular expression.

Translate text to Morse code and back, and hear it played at a real sending speed.

Shift letters by any amount, decode with ROT13, or try all 25 shifts at once to crack a puzzle.

Spell anything out as Alfa Bravo Charlie, or turn phonetic words back into text.

Break text down character by character — code point, bytes, escapes, and the invisible ones.

Shuffle a list or draw winners from it, with the full draw order shown so the result can be checked.

Hard-wrap text at a column width, or join wrapped lines back into paragraphs.

Find what two lists share, what only one side has, and how far they overlap.

Score how alike two strings are using Levenshtein, Jaro-Winkler and Dice.

A timed copy test that reports net and gross words per minute alongside accuracy.

Converts text to uncontracted Grade 1 braille and back, with the dot numbers for every cell and the full reference tables.

Retimes an SRT or VTT file by a fixed offset, by frame rate, or from two points you know the correct times for.

Pretty-print, minify and inspect JSON with precise error positions.

Check JSON validity and get a structural summary — depth, key count and type breakdown.

Encode text to Base64 and decode it back, with full Unicode and URL-safe support.

Percent-encode and decode URLs and query parameters, with a query string breakdown.

Generate cryptographically random UUIDs in bulk, with formatting options.

Convert Unix timestamps to human dates and back, in local time and UTC.

Test regular expressions live with highlighted matches, capture groups and replace.

Decode a JSON Web Token's header, payload and claims, and see whether it has expired.

Generate SHA-256, SHA-384, SHA-512 or SHA-1 digests of text or a file, and verify a checksum.

Generate a strong random password with your own length and character rules, and see its real entropy.

Beautify and indent HTML markup, or minify it for production.

Format CSS with consistent indentation, or minify it for delivery.

Convert CSV to JSON or JSON back to CSV, with proper quoted-field handling.

Convert JSON to YAML or YAML back to JSON, with the ambiguous values quoted.

Turn a JSON sample into TypeScript interfaces, with optional and union types inferred.

Build or decode a cron expression, in plain English, with the next run times.

Build a robots.txt with per-crawler rules, and get it checked for the usual mistakes.

Generate JSON-LD structured data for articles, businesses, products, events and more.

Audit a page's title, description and social tags from its HTML, with card previews.

Check any two colours against the WCAG contrast thresholds, with passing shades suggested.

Search every HTTP status code — what it means, when to return it, and whether it caches.

Work out the network, broadcast, mask and usable host range for any IPv4 CIDR block.

Convert Unix file permissions between the octal number, the symbolic string and a tick-box grid.

Create a QR code for a link, Wi-Fi network, contact card or any text, and download it as SVG.

Build a linear, radial or conic CSS gradient visually and copy the declaration.

Build a layered CSS box-shadow with live preview, including inset and multi-layer depth.

Beautify or minify a SQL query, with clause breaks, indented subqueries and keyword casing.

Indent or minify XML and check it is well-formed, without disturbing mixed content or CDATA.

Draw whole or decimal numbers in any range, with or without repeats, from the browser secure RNG.

Escape HTML characters to entities and decode them back, in named, decimal or hex form.

Generate EAN-13, EAN-8 and UPC-A barcodes as scalable SVG, with the check digit worked out.

Build a flex layout against a live preview and copy CSS containing only the properties you changed.

Build a Markdown table in a grid or from pasted CSV, with column alignment and pipes escaped for you.

Build a grid visually — tracks, gaps, alignment and cell spans — and copy the CSS it produces.

Build a fluid clamp() that scales a size between two viewport widths.

Build a CSS easing curve, see it drawn, and read the progress at each moment.

Round corners individually, including the elliptical eight-value form.

Arithmetic and bitwise operations on 8 to 64-bit integers, in any base.

Searchable ASCII reference with decimal, hex, octal, binary and escapes.

Find the Content-Type for any file extension, and what to send with it.

Infer a JSON Schema from a sample document, with the guesses spelled out.

Escape or unescape a string for JSON, JavaScript, SQL, a shell, CSV or a regular expression.

Work out the specificity of any selector, with a part-by-part breakdown and a winner when you compare several.

Compare two JSON documents by structure — key order and formatting ignored, type changes called out.

Turn a list of URLs into a valid sitemap.xml, with the fields Google ignores switched off by default.

Enumerate every case of a boolean expression, with working columns and an equivalence check.

Order two versions, sort a list, or test whether a version satisfies a caret or tilde range.

Read and write durations like PT1H30M, and convert them to seconds, minutes or hours.

Convert .env, .ini and .properties files to JSON, and back again.

Convert internationalised domain names between their Unicode and xn-- forms, with a mixed-script warning.

Compute a keyed HMAC over a message with SHA-1, SHA-256, SHA-384 or SHA-512.

See how two colours look under protanopia, deuteranopia, tritanopia and greyscale.

Expand, compress and inspect an IPv6 address, with its scope and integer value.

Build a linked table of contents from the headings in a Markdown document.

Encode and decode Base32 in both the RFC 4648 and Crockford alphabets.

Reformat a MAC address between notations and read the flags in its first byte.

Generate a typographic size scale from a base size and a ratio, with CSS output.

Turn a curl command into fetch, axios, Python requests or Node https code.

Break a user-agent string into browser, engine, OS and device — and what it cannot tell you.

Encrypt a message with a passphrase using AES-256-GCM, and decrypt it back again.

Builds a Content-Security-Policy header and warns about the settings that quietly defeat it.

Shows what a password's character count hides — the patterns that make it guessable.

Runs a JSONPath expression against a document and shows every match with the path it came from.

Turns a list of old and new URLs into server redirect rules, and finds the loops and chains first.

Splits a URL into its components with the query string decoded into a table, and flags the encoding and credential problems in it.

What service conventionally runs on a TCP or UDP port, whether it encrypts, and whether exposing it to the internet is a bad idea.

Shows the sign, exponent and significand bits of a float or double, and the exact decimal value those bits stand for.

Parses raw email headers into the delivery path with hop timings, the SPF, DKIM and DMARC results, and the identity mismatches worth noticing.

Usable capacity, redundancy cost and fault tolerance for RAID 0, 1, 5, 6, 10, 50 and 60, in both decimal TB and binary TiB.

Convert JSON to XML or XML back to JSON, with attributes, text nodes and arrays mapped by a stated convention.

Build a @keyframes block and its shorthand from a preset, with a live preview and a reduced-motion guard.

Turn a docker run command into a compose.yaml service, with the flags that have no Compose equivalent listed rather than dropped.

Converts TOML config to JSON and back, with a parser that reports the line it failed on rather than guessing.

Shrink JPG, PNG and WebP files with a quality slider and a live size preview.

Resize images by pixels or percentage, with the aspect ratio locked by default.

Crop an image to any region or a fixed aspect ratio, by dragging or by exact pixels.

Convert JPG photographs to lossless PNG files, several at a time.

Convert PNG files to JPG, choosing the quality and the colour that replaces transparency.

Turn an image into a Base64 data URI ready to paste into CSS or HTML.

Generate a full favicon set at every size a modern site needs.

Click any point in an image to read its colour, and pull out the palette behind it.

Stamp text across your photos — one corner mark or tiled over the whole frame — without uploading them.

Turn a picture in quarter steps or mirror it, with a preview of the file you will download.

See the EXIF data hidden in a photo, including whether it records where it was taken.

Strip editor metadata, comments and scripts from an SVG, and round its coordinates.

Rasterises SVG markup or a .svg file to a PNG at any size, with a transparent background.

Pixelates, blurs or blacks out parts of an image by overwriting the pixels underneath.

Cuts a picture into a grid of tiles that reassemble exactly, with presets for profile grids and a download for each piece.

Draw a placeholder image at any size and colour in your browser, and download it as PNG, JPEG or WebP.

Combines several pictures into one file — side by side, stacked, or in a grid, with control over order and spacing.

Turn a set of images into a single PDF with page size, orientation and margin control.

Convert between millimetres, metres, kilometres, inches, feet, yards and miles.

Convert grams, kilograms, tonnes, ounces, pounds and stones in one step.

Convert between Celsius, Fahrenheit and Kelvin instantly.

Convert km/h, mph, m/s, knots and Mach.

Convert bytes, KB, MB, GB and TB — with binary and decimal units kept separate.

Convert seconds, minutes, hours, days, weeks, months and years.

Convert square metres, square feet, acres, hectares and more.

Convert litres, millilitres, cubic metres, gallons, pints and cups.

Convert a date and time between any two cities, with daylight saving handled for that date.

Convert between bar, psi, pascal, atmosphere, mmHg and eleven other pressure units.

Convert between binary, octal, decimal, hexadecimal and any base from 2 to 36.

Convert numbers to Roman numerals and back, with the subtractive rules enforced.

Convert cups, spoons, grams and ounces for real ingredients, using their actual density.

Write numbers out in words, in the international or Indian numbering system.

Convert between mpg, L/100km and km/L — including the US and imperial gallon difference.

Convert joules, kilowatt-hours, calories, BTU, therms, electronvolts and more.

Convert watts, kilowatts, horsepower, BTU per hour and tons of refrigeration.

Convert newtons, kilogram-force, pound-force, dynes, kips and poundals.

Convert newton metres, pound-force feet, kilogram-force metres and inch-pounds.

Convert degrees, radians, gradians, turns, arcminutes, arcseconds and mils.

Convert m/s², g-force, ft/s², and rates of speed change like km/h per second.

Convert kg/m³, g/cm³, lb/ft³, lb/gal and other density units.

Convert hertz, kilohertz, megahertz, gigahertz, RPM, rad/s and BPM.

Convert Mbps to MB/s and between every bit, byte, decimal and binary rate unit.

Convert coulombs, amp-hours, milliamp-hours, faradays and elementary charges.

Convert volts, millivolts, microvolts, kilovolts, megavolts and CGS units.

Convert amperes, milliamps, microamps, kiloamps and CGS current units.

Convert ohms, milliohms, kilohms, megohms, gigohms and CGS resistance units.

Convert lux, foot-candles, phots and other units of light falling on a surface.

Convert ppm, ppb, percent, per mille, mg/kg and mg/L concentration units.

Convert oven temperatures between Celsius, Fahrenheit, gas mark and fan settings.

Work out molar mass from a chemical formula, then convert between grams and moles.

Convert sieverts, grays, becquerels, curies and rem — each within its own quantity.

Convert px, rem, em, pt, %, vw and vh against a root font size you set.

Convert one colour between hex, RGB, HSL, HSV and CMYK, with hue-rotated sets alongside.

Convert text to binary, octal, decimal or hex and back, as UTF-8 bytes or code points.

Convert volumetric flow between litres per minute, cubic metres per hour, GPM, CFM and more.

Every standard sheet size in millimetres, inches, points and pixels at the DPI you choose.

Convert AWG to millimetres and mm², both ways, with resistance per kilometre.

Convert a coordinate between decimal degrees, degrees-minutes-seconds and decimal minutes.

Convert dynamic viscosity in Pa·s, poise and reyn, or kinematic viscosity in m²/s and stokes.

Convert between UK, US, EU and Japanese shoe sizes, worked from foot length rather than a copied chart.

Convert between standard, scientific and engineering notation, with significant figures handled properly.

Convert magnetic flux density in tesla and gauss, or magnetic flux in webers and maxwells.

Convert ring sizes between US, UK, EU and Japanese scales, or from a measured circumference.

Convert thermal conductivity between W/(m·K), the two BTU forms and the calorie units, with every factor derived from exact definitions.

Convert between astronomical units, light-years, parsecs, lunar distances and kilometres, with the exact definitions marked.

Convert paper and fabric weight between g/m², oz/yd² and the US basis weights, where a pound means something different in every grade.

Swap one baking pan for another by volume, with the factor to multiply the recipe by and how the batter depth changes.