Amperes to Milliamperes Converter
Enter the electric current in amperes below to convert it to milliamperes.
Convert Amperes to Milliamperes
Enter a value in amperes (A) to convert to milliamperes (mA).
Ampere to Milliampere Conversion Table
Table showing various ampere measurements converted to milliamperes. Click any preset value or arrow to load it into the converter.
How to Convert Amperes to Milliamperes
To convert amperes to milliamperes, multiply the electric current by the following conversion ratio: 1,000 milliamperes/ampere.
Since one ampere is equal to 1,000 milliamperes, you can use this simple formula to convert:
The electric current in milliamperes is equal to the electric current in amperes multiplied by 1,000.
For example, here's how to convert 2.5 amperes to milliamperes using the formula above.
How Many Milliamperes Are in an Ampere?
There are 1,000 milliamperes in an ampere, which is why we use this value in the formula above.
Our ampere to milliampere calculator automatically converts your electric current measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Amperes and milliamperes are both units used to measure electric current. Keep reading to learn more about each unit.
What Is an Ampere?
Base SI unit of electric current. It serves as a primary reference unit for measuring electric current across scientific and practical applications. [1]
The ampere is classified as an International System of Units (SI) unit of electric current. Amperes can be abbreviated as A; for example, 1 ampere can be written as 1 A.
As the primary coherent reference unit for electric current in this category, all other electric current units are mathematically anchored to the ampere (A).
In practice, amperes (A) are widely used across standard electric current applications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.
What Is a Milliampere?
A milliampere is a unit of electric current equal to 1/1,000 of an ampere (0.001 A). One-thousandth of an Ampere (0.001 A). [2]
The milliampere is classified as a metric and SI-compatible unit of electric current. Milliamperes can be abbreviated as mA; for example, 1 milliampere can be written as 1 mA.
In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the milliampere (mA) a convenient decimal multiple of the ampere (A).
In practice, milliamperes (mA) are widely used across fine-tolerance laboratory, analytical, and micro-scale electric current measurements within SI metric workflows, engineering documentation, and technical data sheets.
When converting electric current between amperes (A) and milliamperes (mA), keep full floating-point precision (1 A = 1,000 mA; 1 mA = 0.001 A) during intermediate calculations and round only the final milliampere figure to match your instrument tolerance.
More Ampere & Milliampere Conversions
Need to calculate in the opposite direction? Use our milliamperes to amperes converter (mA to A) to switch your starting unit immediately. You can also explore related tools such as converting microamperes to milliamperes, or converting kiloamperes to amperes.
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Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Electric Current)·Electric Current Metrology Standard — Amperes (A) to Milliamperes (mA)
- [2]BIPM SpecificationBIPM (SI Base Unit: Ampere (A))·Unit Specifications: Ampere (A) & Milliampere (mA)
- [3]NIST SP 811 ReferenceNIST SP 811 (NIST SP 811 App. B.9 (Electricity & Magnetism))·Conversion Factors & Mathematical Basis (A to mA)