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ToolBoxGenie

Current Converter

Converters · Added 15 August 2026

Convert electric current between amperes and every SI prefix from nanoamps to megaamps, plus the older CGS units. The ampere is one of the seven SI base units, and since 2019 it has been defined by fixing the elementary charge exactly rather than by a force between wires.

Result

1 mA in ampere

0.001 A

1 mA = 0.001 A

The same value in every unit

Ampere (A)
0.001
Nanoampere (nA)
1,000,000
Microampere (µA)
1,000
Milliampere (mA)
1
Kiloampere (kA)
0.000001
Megaampere (MA)
1.0000e-9
Abampere (biot) (abA)
0.0001
Statampere (statA)
2,997,924.58

The ampere is one of the seven SI base units, and since the 2019 redefinition it follows from fixing the elementary charge exactly: one amp is one coulomb of charge passing a point every second.

How to use the current converter

  1. 1Enter the current value you have.
  2. 2Pick the unit it is in and the unit you want.
  3. 3The reference table shows the same current in every unit at once.
  4. 4Use the swap button to reverse the direction.
  5. 5For Ohm's law calculations, the voltage and resistance converters cover the other two quantities.

Examples

An LED

Input
20 mA
Result
0.02 A · 20,000 µA

A typical indicator LED forward current.

A domestic circuit

Input
32 A
Result
32,000 mA · 0.032 kA

A common rating for a kitchen ring or an EV charger circuit.

Leakage current

Input
5 µA
Result
0.005 mA · 5,000 nA

Semiconductor leakage and sensor bias currents live down here.

About the current converter

What a current actually is

An electric current is charge in motion — in a metal wire, the drift of free electrons through the lattice. The ampere measures the rate of that flow: one coulomb of charge passing a point every second, which is roughly 6.24 × 10¹⁸ electrons.

A surprising detail is how slowly those electrons actually move. Drift velocity in a typical household wire is on the order of a fraction of a millimetre per second — slower than walking pace by a wide margin. The lamp comes on immediately because the electromagnetic field propagates near the speed of light, setting electrons throughout the circuit moving almost at once. The individual charges crawl; the signal to start moving does not.

Conventional current is defined as flowing from positive to negative, which is the opposite of the actual electron flow in a metal. The convention was fixed by Benjamin Franklin before the electron was discovered, and by the time the direction was known it was too entrenched to change. Every circuit diagram in use still follows it, and no calculation is affected — only the mental picture.

Ranges and what they mean in practice

Current in practical work spans about fifteen orders of magnitude. Semiconductor leakage and biological signals sit in nanoamps and microamps. Signal electronics and LEDs work in milliamps. Domestic appliances draw single-digit to tens of amps, industrial motors hundreds, and welding equipment or electrolysis plants thousands.

Conductor sizing follows almost entirely from current rather than voltage, because resistive heating goes as current squared. This is why a thin wire is fine at high voltage and low current but dangerous at low voltage and high current, and why cable tables are indexed by amps. Voltage determines the insulation required; current determines the copper.

Measuring current is also fundamentally different from measuring voltage. A voltmeter connects across a component and ideally draws no current; an ammeter must be placed in series so the current flows through it, which means breaking the circuit. This is why clamp meters exist — they measure the magnetic field around a conductor and so read current without interrupting anything, which is far safer on live equipment.

Frequently asked questions

How is the ampere defined?
Since the SI revision that took effect in 2019, by fixing the elementary charge at exactly 1.602176634 × 10⁻¹⁹ coulombs. One ampere is then one coulomb of charge passing a point per second. The previous definition, in force from 1948, described the force between two infinitely long parallel conductors — elegant but impossible to realise directly in a laboratory, which is why it was replaced.
Is it current or voltage that is dangerous?
Current is what causes physiological harm, but voltage is what drives current through the body, so the question is not quite well-posed — you cannot have one without the other. The path through the body, the duration and skin resistance all matter enormously. This is a unit converter and not a source of electrical safety guidance; any work on live equipment should follow the relevant national standards and be done by a qualified person.
What is the difference between AC and DC current?
Direct current flows in one direction continuously; alternating current reverses direction periodically, fifty or sixty times a second on most mains supplies. Both are measured in amperes. An AC current figure is normally the RMS value, the equivalent DC current that would produce the same heating. Converting between units works identically for both.
What is an abampere?
The unit of current in the CGS electromagnetic system, equal to exactly 10 amperes. It also went by the name biot, after Jean-Baptiste Biot. Its counterpart statampere, from the electrostatic system, is about 3.34 × 10⁻¹⁰ amperes. Neither is used in current practice, but both appear in older physics texts and are included here for reading them.

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