Ampere to Milliampere Converter
1 ampere is exactly 1000 milliamperes. Convert amperes (A) to milliamperes (mA) below: type a value and the result updates as you type.
A to mA calculator
Result
Ampere to Milliampere conversion
1 A = 1000 mAone ampere in milliamperes
1 mA = 0.001 Aone milliampere in amperes
Ampere (A): SI base unit of electric current, defined by fixing the elementary charge e = 1.602176634 × 10⁻¹⁹ C.
Milliampere (mA): One thousandth of an ampere. Used for electronics and 4-20 mA sensor signals.
Source:SI Brochure, 9th edition (BIPM, 2019)
How to convert amperes to milliamperes
To convert amperes to milliamperes, multiply the number of amperes by 1000.
Formula
mA = A × 1000
Examples
- 5 A = 5 × 1000 = 5000 mA
- 25 A = 25 × 1000 = 25000 mA
- 100 A = 100 × 1000 = 100000 mA
Ampere to Milliampere conversion table
| Ampere (A) | Milliampere (mA) |
|---|---|
| 0.1 A | 100 mA |
| 0.5 A | 500 mA |
| 1 A | 1000 mA |
| 2 A | 2000 mA |
| 3 A | 3000 mA |
| 5 A | 5000 mA |
| 10 A | 10000 mA |
| 20 A | 20000 mA |
| 25 A | 25000 mA |
| 50 A | 50000 mA |
| 100 A | 100000 mA |
| 250 A | 250000 mA |
| 500 A | 500000 mA |
| 1000 A | 1000000 mA |
Values rounded to 10 significant digits where needed.
Frequently asked questions
- How many milliamperes are in one ampere?
- One ampere is exactly 1000 milliamperes.
- How do I convert milliamperes to amperes?
- To convert milliamperes to amperes, multiply the number of milliamperes by 0.001. The formula is A = mA × 0.001.
- Is this conversion exact?
- Yes. Both units have exact definitions and the factor 1000 is exact. Displayed results are only rounded when they have many decimal places.
- Which is larger, a ampere or a milliampere?
- A ampere is 1000 times larger than a milliampere. In other words, a milliampere is exactly 1/1000 of a ampere.