Electric Current Converter

Convert electric current values among common SI, metric and customary units. Electric current is the rate of electric charge flow. The ampere is an SI base unit, and prefixed units differ by powers of ten.

ValueSigned values are supported; scientific notation is accepted.Convert fromAmpere (A)Milliampere (mA)Microampere (µA)Nanoampere (nA)Kiloampere (kA)Convert toAmpere (A)Milliampere (mA)Microampere (µA)Nanoampere (nA)Kiloampere (kA)

Convert

Converted value2500 mA

SI-base value2.5 A

Multiply by1000

The displayed results apply to the default example. Enable JavaScript to convert other values.

How to use this converter

1. Enter the electric current value.
2. Select its current unit and the unit you want.
3. Select Convert. The page shows the converted value, the SI-base value and the direct multiplication factor.

Conversion formula

Converted value = entered value × source-to-SI factor ÷ target-to-SI factor.

Every option is represented by its factor to ampere (A). This one-base method keeps reciprocal conversions consistent. Calculations run in your browser, and old results are hidden when an input changes or validation fails.

Worked example

Convert 2.5 A to mA. Multiply by 1000; the result is 2500 mA. The same input equals 2.5 A in the SI-base unit.

Accuracy and limitations

A unit conversion does not establish safe conductor size, overcurrent protection or shock risk. Follow applicable electrical codes and qualified guidance.

The calculator retains more digits internally than it displays. Round the final value to the precision supported by your measurement. Very large and very small answers may use scientific notation.

Frequently asked questions

How many milliamperes are in one ampere?

There are 1,000 milliamperes in one ampere.

Can I reverse the conversion?

Yes. Swap the From and To selections. Because both units use the same SI base, the reverse factor is the reciprocal of the forward factor.

Why was my entry rejected?

Use digits with an optional decimal point or scientific notation. Blank values, commas, fractions, words and non-finite entries are rejected. Negative values are allowed when they express direction or polarity.

Review notes and sources

Reviewed October 4, 2026. The conversion factors, default example, zero or signed boundary behavior, invalid-input handling and recovery after an error were checked. Factors follow SI definitions and published conversion guidance from the NIST Guide to the SI and the BIPM SI Brochure. Explanations and examples are original.

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