Amps To Milliamps
Convert amps to milliamps for current ratings on LED strips, microcontroller specs, charger outputs and small electronics. 1 A = 1000 mA — quick reference table.
Last updated: May 2026
Enter a value to see the conversion instantly.
Why this electronics conversion matters
Electrical values are often written in different scales depending on the part, meter or datasheet. A sensor may output millivolts while a reference circuit is discussed in volts. A resistor may be marked in kilo-ohms while the calculator or schematic expects raw ohms. This page handles that translation quickly. For the current example, 1 Amps equals 1000 Milliamps.
The formula is milliamps = amps × 1000. That matters in practical bench work because many errors come from reading the right number with the wrong prefix. Converting once before you wire, buy or tune a circuit is faster than troubleshooting after the fact.
Typical use cases
- Reading datasheets and comparing values with meter output
- Checking power supply settings, sensor ranges and resistor values
- Translating schematic notation into the unit scale shown by test equipment
A practical use case is verifying whether a module output, resistor value or frequency figure sits in the range a circuit expects.
Quick reference
| Amps | Milliamps |
|---|---|
| 1 | 1000 |
| 1 | 1000 |
| 10 | 10000 |
| 100 | 100000 |
| 1000 | 1000000 |
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Frequently Asked Questions
What current do GPIO pins on Arduino or Raspberry Pi supply?
GPIO pins source 20–40 mA maximum. Most sensors draw 1–15 mA; standard indicator LEDs draw 20 mA. Working in milliamps lets you total the draw across all connected devices and verify you are within the pin's limit before wiring anything.
Why are LED ratings in milliamps and not amps?
LEDs run at 5–30 mA — fractions of an amp. Using milliamps avoids the decimal places that cause wiring errors. A 20 mA indicator LED is clearer to spec and measure than 0.02 A, and most LED driver ICs list their current limit in mA on the datasheet.
How do I estimate battery runtime from a milliamp draw?
Divide the battery capacity in mAh by the average draw in mA. A 2000 mAh pack powering a 50 mA circuit runs roughly 40 hours. The real figure is 10–20% lower due to efficiency losses and voltage cutoff, so build in a safety margin for any battery-powered design.