Ampere-hours to mAh Converter

One ampere-hour equals 1000 milliampere-hours (mAh). To convert ampere-hours to milliampere-hours, multiply by 1000; to go back the other way, multiply by 0.001 instead.

The converter above does it as you type and shows the working underneath, so you can check the arithmetic rather than take the number on trust.

What ampere-hours and milliampere-hours actually measure

Ampere-hour (Ah) — An amp-hour is one amp sustained for an hour — 3,600 coulombs. Car and deep-cycle battery capacity.

Milliampere-hour (mAh) — A milliamp-hour is a thousandth of an amp-hour. Phone, laptop and power bank capacity ratings.

Ampere-hours to mAh conversion table

The most common values, worked out in advance. Anything not listed can be typed straight into the converter.

How to convert ampere-hours to milliampere-hours by hand

Multiply the number of ampere-hours by 1000.

For example, 25 Ah × 1000 = 25000 mAh.

Going the other way, divide by 1000 — or multiply by 0.001, which is the same thing and easier to do in your head.

Everything runs in your browser

There is no server involved in the calculation. The numbers you type never leave your device, nothing is logged, and the page keeps working with no connection once it has loaded. That is not a marketing line — it is simply how the tool is built, because a calculation like this has no reason to touch a network.