Coulombs to milliampere-hours
Type a value in coulombs to see it in milliampere-hours straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the coulombs box.
- Read the result in milliampere-hours as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
mAh = C × 0.2777777778
Multiply the value in coulombs by 0.2777777778 to get milliampere-hours.
Example
To convert 25 C to milliampere-hours: 25 × 0.2777777778 = 6.94444 mAh.
Conversion table
| Coulombs (C) | Milliampere-hours (mAh) |
|---|---|
| 1 | 0.277778 |
| 2 | 0.555556 |
| 3 | 0.833333 |
| 5 | 1.38889 |
| 10 | 2.77778 |
| 20 | 5.55556 |
| 25 | 6.94444 |
| 50 | 13.8889 |
| 100 | 27.7778 |
| 250 | 69.4444 |
| 500 | 138.889 |
| 1,000 | 277.778 |
About the units
- Coulomb
- The SI unit of charge: the charge carried by a current of one ampere in one second, so 1 C = 1 A·s.
- Milliampere-hour
- One thousandth of an ampere-hour, exactly 3.6 coulombs, the figure printed on phone batteries and power banks.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many milliampere-hours are in one coulomb?
1 C = 0.277778 mAh exactly.
How do I convert coulombs to milliampere-hours?
Use mAh = C × 0.2777777778. For example, 25 C = 6.94444 mAh.
How many coulombs are in one milliampere-hour?
1 mAh = 3.6 C.
How do I convert battery mAh to watt-hours?
You need the battery voltage: Wh equals mAh times volts divided by 1000. A 5000 mAh battery at 3.7 V holds 18.5 Wh.
How many coulombs are in an ampere-hour?
Exactly 3600 coulombs, because an ampere-hour is one ampere flowing for 3600 seconds.