Electric Charge Converter
Convert between Coulomb, millicoulomb, microcoulomb, ampere-hour, and milliampere-hour instantly.
Type in any field and the others update automatically.
Type in any field — the others update instantly.
Electric charge is the quantity of electricity itself, the thing that current carries along. The SI unit is the coulomb (C): one ampere flowing for one second moves one coulomb. For everyday electronics, though, the unit that actually matters is the ampere-hour, because that’s how battery capacity is sold.
Metric prefixes:
- 1 C = 1,000 mC (millicoulombs)
- 1 C = 1,000,000 µC (microcoulombs)
Ampere-hour units:
- 1 Ah = 3,600 C (one amp for one hour)
- 1 mAh = 3.6 C
Real-world charges:
- A phone battery: 3,000–5,000 mAh
- A car battery: 40–100 Ah
- A lightning bolt: about 5 C
The phone-to-car gap is bigger than it looks. A 4,000 mAh phone holds 4 Ah; a 60 Ah car battery holds fifteen times the charge, at a much higher voltage on top of that.
And that voltage point is the real trap: charge is not energy. A 5,000 mAh power bank and a 5,000 mAh phone cell do not store the same usable energy if they run at different voltages, because energy in watt-hours is charge times voltage. Comparing battery capacities in mAh across devices with different voltages tells you almost nothing. When you actually want to know what a battery can do, convert to watt-hours first.
How we build and check this converter
This converter runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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