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Resistance Converter

Converters · Added 15 August 2026

Convert electrical resistance between ohms and every practical prefix, from the milliohms of a contact or a shunt to the gigaohms of insulation testing. Resistance in ohms describes opposition to direct current; its AC counterpart, impedance, shares the unit but carries a phase as well.

Result

1 kΩ in ohm

1,000 Ω

1 kΩ = 1,000 Ω

The same value in every unit

Ohm (Ω)
1,000
Microohm (µΩ)
1,000,000,000
Milliohm (mΩ)
1,000,000
Kiloohm (kΩ)
1
Megaohm (MΩ)
0.001
Gigaohm (GΩ)
0.000001
Abohm (abΩ)
1,000,000,000,000
Statohm (statΩ)
1.1127e-9

Resistance in ohms is what a component opposes direct current with. The AC equivalent is impedance, which shares the unit but also carries a phase — a capacitor's opposition to current changes with frequency, and a plain ohm value cannot describe it.

How to use the resistance converter

  1. 1Enter the resistance value you have.
  2. 2Pick the unit it is in and the unit you want.
  3. 3The table shows the same resistance in every unit at once.
  4. 4Swap the units to reverse the direction.
  5. 5For Ohm's law, pair this with the voltage and current converters.

Examples

A common resistor

Input
4.7 kΩ
Result
4,700 Ω · 0.0047 MΩ

Yellow-violet-red on the colour code.

Contact resistance

Input
5 mΩ
Result
0.005 Ω · 5,000 µΩ

Connector and switch contact resistance is measured in milliohms — small, but it dissipates real heat at high current.

Insulation testing

Input
500 MΩ
Result
0.5 GΩ · 500,000 kΩ

Insulation resistance testers read in the megohm-to-gigohm range.

About the resistance converter

What resistance is, physically

Resistance is the extent to which a material impedes charge flow, converting electrical energy into heat as it does so. Microscopically it is the scattering of charge carriers by the atomic lattice and its imperfections. A material's resistivity is an intrinsic property; the resistance of an actual component then depends on its shape — proportional to length, inversely proportional to cross-sectional area.

That geometric relationship explains a great deal of practical wiring. Doubling a cable's length doubles its resistance; doubling its cross-sectional area halves it. It is why long runs need thicker cable to hold voltage drop within limits, and why a nearly-broken strand in a connector heats up — the current is forced through a much smaller area at that point.

The unit honours Georg Ohm, whose 1827 work establishing the relationship between voltage, current and resistance was initially dismissed by his contemporaries. It took the better part of two decades to be accepted, by which time it had become the foundation of circuit analysis.

Why the range of values is so wide

Practical resistance spans more than twelve orders of magnitude, and each end has its own measurement problems. At the low end — contact resistance, shunts, busbar joints, battery internal resistance — values in milliohms and microohms are swamped by the resistance of the test leads themselves. Measuring them requires a four-wire Kelvin connection, where separate pairs of leads carry the current and sense the voltage so the leads' own resistance drops out of the reading.

At the high end, insulation resistance and semiconductor leakage paths run to megohms and gigohms. Here the difficulty is that ordinary multimeters cannot apply enough voltage to produce a measurable current, so insulation testers apply hundreds of volts deliberately. They also reveal faults that a low-voltage test misses entirely, since insulation can measure fine at 9 V and break down at working voltage.

In the middle, where most circuit design happens, the practical constraints are power dissipation and tolerance rather than measurement. A resistor's ohm value tells you nothing about how much power it can dissipate before failing — that is a separate rating, and choosing a resistor by value alone while ignoring its wattage is one of the most common beginner mistakes in electronics.

Frequently asked questions

What is Ohm's law?
Voltage equals current times resistance, V = IR. Rearranged, resistance is voltage divided by current, and current is voltage divided by resistance. Knowing any two of the three gives the third, which makes it the single most-used relationship in electrical work. It holds for ohmic materials — most metals at constant temperature — and not for components like diodes and transistors, whose resistance changes with the conditions applied.
What is the difference between resistance and impedance?
Resistance opposes direct current and dissipates energy as heat. Impedance is the AC generalisation: it includes resistance plus reactance from capacitance and inductance, and it varies with frequency. Both are measured in ohms, but impedance also has a phase angle describing how far current lags or leads voltage. A capacitor has near-infinite resistance to DC and low impedance at high frequency — a single ohm value cannot express that.
Does resistance change with temperature?
Yes, substantially. Metals become more resistive as they warm — copper by roughly 0.4% per degree Celsius — because thermal vibration scatters the charge carriers more. Semiconductors typically go the other way, becoming less resistive as more carriers are freed. This is exploited deliberately in temperature sensors: a platinum RTD is a resistor whose predictable temperature coefficient is the measurement, and a thermistor is chosen for a large, non-linear response.
Why do resistors come in odd values like 4.7 kΩ?
They follow the E-series, logarithmic sequences designed so that consecutive values are separated by roughly the component's tolerance. The E12 series — 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 — covers a decade in twelve steps suited to 10% tolerance parts. The point is even coverage in percentage terms rather than round numbers, so any target value is within tolerance of a stocked one. Tighter tolerance parts use denser series such as E24, E96 and E192.

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