Amps to Milliamps Converter
Quick fact: 1 amp = 1,000 milliamps. To convert A to mA, simply multiply by 1,000.
Frequently Asked Questions
How many milliamps in an amp?
There are exactly 1,000 milliamps (mA) in 1 amp (A). The prefix "milli" means one-thousandth, so 1 mA = 0.001 A. This is an exact SI relationship — no rounding involved.
What is a milliamp?
A milliamp (mA) is one-thousandth of an ampere (0.001 A). It is commonly used to measure small electrical currents in electronics, such as LED circuits, sensor outputs, and battery charging rates.
Why use milliamps?
Milliamps are more practical for small devices. An LED typically draws about 20 mA — writing 0.02 A is less intuitive. Using milliamps avoids leading zeros and makes small currents easier to read and compare in circuit design and troubleshooting.
What is a safe current for humans?
The perception threshold is about 1 mA (a slight tingle). Currents above 10 mA can cause involuntary muscle contraction, making it impossible to let go. Currents above 100 mA (0.1 A) across the heart can be lethal. These thresholds vary by individual and the path through the body.
How to Convert Amps to Milliamps
Converting amps (A) to milliamps (mA) is straightforward because both are SI units of electric current:
- Note the amp value. For example, 0.5 A.
- Multiply by 1,000. Formula: mA = A × 1,000
- Result: 0.5 A × 1,000 = 500 mA
Amps to Milliamps Formula
Since the prefix "milli" means 10-3 (one-thousandth), multiplying by 1,000 converts any amp value to milliamps. This is an exact conversion — no approximation or rounding is needed.
Amps to Milliamps Conversion Table
| Amps (A) | Milliamps (mA) | Typical Use |
|---|---|---|
| 0.001 A | 1 mA | Human perception threshold |
| 0.005 A | 5 mA | Small sensor current |
| 0.02 A | 20 mA | Standard LED current |
| 0.05 A | 50 mA | USB low-power device |
| 0.1 A | 100 mA | Dangerous current level |
| 0.5 A | 500 mA | USB 2.0 max output |
| 1 A | 1,000 mA | Phone charger (standard) |
| 2 A | 2,000 mA | Tablet charger |
| 5 A | 5,000 mA | High-power USB-C charging |
Amps to Milliamps Examples
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All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.
