Convert electric charge between coulombs, milli/micro/nano-coulombs, ampere-hours and CGS units.
Electricity • 9 units
All 9 units on the Electric Charge Converter are defined against the Coulomb (C), so each result is one conversion factor away from a single reference rather than the end of a chain of roundings.
The conversion this page is most often opened for is ready before you type anything: 1 mAh = 3.6 C. Change either side and every row in the table recalculates with it.
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The most consequential misreading of this table is treating a milliamp-hour as a quantity of energy. It is a quantity of charge. Two cells both marked 3,000 mAh hold an identical 10,800 coulombs, but a lithium-ion cell at a nominal 3.7 V stores about 11.1 watt-hours while a NiMH cell at 1.2 V stores roughly 3.6 — three times less from the same headline number. Comparing batteries by mAh is only meaningful at equal voltage, which is why power banks are increasingly labelled in watt-hours, and why airline cabin limits are written that way too.
At the small end of the scale the picocoulomb is the working unit of sensor electronics. Piezoelectric accelerometers and force transducers are specified in charge per unit of input — pC/g, pC/N — because the crystal generates charge rather than voltage, and the charge amplifier reading it converts picocoulombs into volts through a known feedback capacitance. Electrostatic-discharge testing trades in the same currency: the human-body model charges 100 pF to 2 kV, which is 200 nC of charge, and it is that quantity rather than the voltage headline that decides whether a gate oxide survives.
One caution applies to every battery figure converted here. A cell's rated capacity is measured at a specified discharge current and temperature, usually a gentle one. Draw the same cell harder and the usable charge falls — the effect Peukert described for lead-acid batteries, which lithium chemistries show in milder form — while a cold cell delivers less again. Converting 3,000 mAh into 10,800 coulombs converts a test condition rather than a promise, and the gap between the two opens widest exactly when the load is heaviest.
Quick reference — 1 Milliampere-hour (mAh) is equal to:
| Coulomb | C | 3.600000 |
| Millicoulomb | mC | 3,600 |
| Microcoulomb | µC | 3,600,000 |
| Nanocoulomb | nC | 3,600,000,000 |
| Picocoulomb | pC | 3,600,000,000,000 |
| Ampere-hour | Ah | 0.001 |
| Abcoulomb (EMU) | abC | 0.36 |
| Faraday | F | 0.0000373114 |
9 units of electric charge, each a fixed multiple of the C. The table spans 96,485,330,000,000,000:1, from pC (1.0000e-12 C) to F (96485.3 C). Conversion is one multiplication into the base unit and one division out of it, with no lookup table and no approximation.
value_to = value_from × (factor_from ÷ factor_to)1 C = 1 C1 mC = 0.001 C1 µC = 0.000001 C1 nC = 0.000000001 C1 pC = 1.0000e-12 C1 Ah = 3600 C1 mAh = 3.6 C1 abC = 10 C1 F = 96485.3 Cwhere:
Assumptions: Factors are exact definitions. Full double precision is carried internally and rounding is applied only for display.
Result25 mAh = 90 C
Charge is current multiplied by time. The coulomb (C) is one ampere flowing for one second, which makes it a small quantity for practical purposes — hence this converter's wider units.
Battery capacity is the clearest example of the mismatch between the SI unit and the market. Cells are rated in milliamp-hours, not coulombs, and the conversion is simply a matter of seconds: one amp-hour is 3,600 coulombs, so a 3,000 mAh phone battery holds about 10,800 C. The faraday, roughly 96,485 C, belongs to a different world again — it is the charge needed to deposit one mole of a singly-charged ion, and it is the unit that makes electroplating calculations tractable.