Current Converter
Convert electric current between ampere, kiloampere, milliampere, microampere and the CGS units biot, abampere and statampere. Pick two units, enter a value and read the result instantly.
Select two units to see the conversion factor.
This tool converts electric current (A) only. It is not electric charge (C), not current density (A/m or A/m²) and not voltage. For alternating current, enter the value you already have (RMS stays RMS, peak stays peak).
Electric Current Formula
Every current unit is a fixed multiple of the ampere. Result = value × (source factor ÷ target factor). Metric prefixes are exact powers of ten: 1 kA = 1,000 A, 1 mA = 0.001 A and 1 µA = 0.000001 A. The CGS units are also exact: 1 abampere = 1 biot = 10 A, and 1 statampere is one statcoulomb per second, 1/2,997,924,580 A.
What Is Electric Current?
Electric current is the rate at which electric charge flows past a point in a circuit. A current of one ampere (A) means one coulomb of charge passes every second, so I = Q ÷ t. In a metal wire the charge carriers are electrons; in a battery electrolyte, a plasma or a semiconductor they can be ions or holes. By convention the direction of current is the direction positive charge would flow, opposite to the drift of electrons.
Currents in practice cover an enormous range. A pacemaker or a sensor may draw microamperes, an LED indicator about 20 mA, a phone charger 1 to 3 A, a household branch circuit 15 to 20 A, an electric-arc furnace tens of kiloamperes and a lightning stroke around 30 kA on average. That spread is why the milliampere, microampere and kiloampere are used every day.
The biot and the abampere are the same unit, the electromagnetic CGS unit of current, exactly 10 A; the “EMU of current” and “CGS e.m. unit” are further names for it. The statampere, the “ESU of current” and the “CGS e.s. unit” are the electrostatic counterpart, about 3.34 × 10⁻¹⁰ A. You mainly meet them in older physics texts that use Gaussian units.
Do not confuse current with related quantities. Current is charge per time, so it is not the charge itself (Charge Converter). Current density is current per length or per area (Linear and Surface Current Density Converters). Current is also not voltage, the push that drives it (Electric Potential Converter).
Supported Units
This converter supports the following 11 current units. The last column gives the value of each unit in the base unit, the ampere. Several CGS names are identical in size: the biot, abampere, EMU of current and CGS e.m. unit are all 10 A, and the statampere, ESU of current and CGS e.s. unit are all the same electrostatic unit.
| Unit | Symbol | Value in A |
|---|---|---|
| Ampere | A | 1 |
| Kiloampere | kA | 1,000 |
| Milliampere | mA | 0.001 |
| Microampere | µA | 1e-6 |
| Biot | Bi | 10 |
| Abampere | abA | 10 |
| EMU of current | EMU | 10 |
| Statampere | statA | 3.335640952e-10 |
| ESU of current | ESU | 3.335640952e-10 |
| CGS e.m. unit | CGS e.m. | 10 |
| CGS e.s. unit | CGS e.s. | 3.335640952e-10 |
How to Use the Current Converter
- Type the electric current in the value box. Decimals and scientific notation such as 0.0025 or 2.5e-3 are accepted.
- Choose the From unit and the To unit.
- The result appears instantly, or press Convert Now. Very large or very small results are shown in scientific notation.
- Use Swap Units to reverse the conversion, Copy Result to copy the answer, open Show this value in all units for a full list, and Clear to start again.
Step-by-step by hand
- Find the size of each unit in the common base unit (A): 1 mA = 0.001 A and 1 A = 1 A.
- Divide the source size by the target size to get the conversion factor: 0.001 ÷ 1 = 0.001, so 1 mA = 0.001 A.
- Multiply by your value: 250 mA × 0.001 = 0.25 A.
Current can be positive or negative (a sign shows direction), so a minus sign is accepted. Zero is also valid.
Common Current Conversions
- Milliamperes to amperes: 250 mA equals 0.25 A.
- LED indicator: 20 mA equals 20,000 µA.
- 4–20 mA control loop: 4 mA equals 0.004 A and 20 mA equals 0.02 A.
- Lightning: 30 kA equals 30,000 A.
- Sensor leakage: 500 µA equals 0.5 mA.
- CGS to SI: 1 abampere equals 10 A, and 1 statampere equals 3.335640952e-10 A.
Milliampere to Other Current Units
Quick reference for frequently used values
| mA | Ampere (A) | Microampere (µA) | Abampere (abA) |
|---|---|---|---|
| 1 | 0.001 | 1,000 | 0.0001 |
| 4 | 0.004 | 4,000 | 0.0004 |
| 10 | 0.01 | 10,000 | 0.001 |
| 20 | 0.02 | 20,000 | 0.002 |
| 100 | 0.1 | 100,000 | 0.01 |
| 250 | 0.25 | 250,000 | 0.025 |
| 500 | 0.5 | 500,000 | 0.05 |
| 1,000 | 1 | 1,000,000 | 0.1 |
Where and Why This Conversion Is Used
- Electronics design: datasheets quote quiescent and leakage currents in µA, signal currents in mA and supply currents in A.
- Instrumentation: 4–20 mA current loops, sensor outputs and meter ranges.
- Power and safety: breaker and fuse ratings in A, fault and lightning currents in kA, and touch-current limits in mA.
- Batteries and chargers: charge and discharge currents and the C-rate of a cell.
- Physics education: moving between SI and the older CGS units.
Limitations
- For AC, RMS, peak and average values are different numbers. This tool changes units only and does not convert between them.
- A current in amperes cannot be converted to charge without a time, or to power without a voltage.
Important Differences Between Related Electrical Measurements
- Current, A is the rate of flow of charge. Charge, C is the amount that has flowed: 2 A for 30 s moves 60 C.
- Current vs current density: current is the total through a conductor. Current density is how crowded it is, per area (A/m²) or per width of a sheet (A/m). The same 10 A is a gentle density in a thick cable and a severe one in a thin wire.
- Current vs voltage: voltage (electric potential difference) is the push, current is the flow it drives. They are linked by resistance through Ohm’s law, I = V ÷ R.
- Current vs power: power is voltage times current (W = V × A). A current alone does not say how much power is delivered.
Each converter on this site changes units within one quantity only, and none of them mixes quantities. The related tools are: Charge, Current, Linear Charge Density, Surface Charge Density, Volume Charge Density, Linear Current Density, Surface Current Density, Electric Field Strength, Electric Potential, Electric Resistance, Electric Resistivity, Electric Conductance, Electric Conductivity, Electrostatic Capacitance and Inductance.