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Electric Charge Converter

Converters · Added 15 August 2026

Convert electric charge between coulombs, the amp-hour units used for battery capacity, and the chemistry and physics units. The practical caution: milliamp-hours measure charge, not stored energy — two 5,000 mAh batteries at different voltages hold different amounts of energy.

Result

1 mAh in coulomb

3.6 C

1 mAh = 3.6 C

The same value in every unit

Coulomb (C)
3.6
Millicoulomb (mC)
3,600
Microcoulomb (µC)
3,600,000
Nanocoulomb (nC)
3,600,000,000
Picocoulomb (pC)
3,600,000,000,000
Kilocoulomb (kC)
0.0036
Amp-hour (Ah)
0.001
Milliamp-hour (mAh)
1
Faraday (per mole) (F)
0.0000373113708
Elementary charge (e)
2.2469e+19
Abcoulomb (abC)
0.36
Statcoulomb (franklin) (statC)
10,792,528,500

Milliamp-hours measure charge, not energy. To get energy, multiply by the cell voltage: a 5,000 mAh pack at 3.7 V holds 18.5 Wh, while the same 5,000 mAh at 12 V holds 60 Wh.

How to use the electric charge converter

  1. 1Enter the charge value you have.
  2. 2Pick the unit — mAh for a phone or power bank, Ah for a car battery.
  3. 3Choose the unit you want.
  4. 4The table shows the same charge in every unit at once.
  5. 5To get energy rather than charge, multiply by the voltage and use the energy converter.

Examples

A phone battery

Input
5,000 mAh
Result
5 Ah · 18,000 C

At 3.7 V nominal this is about 18.5 Wh of energy.

A car battery

Input
60 Ah
Result
216,000 C · 60,000 mAh

Car batteries are rated in amp-hours at a specified discharge rate.

Electroplating chemistry

Input
1 faraday
Result
96,485.33 C

The charge carried by one mole of electrons — the constant behind Faraday's laws of electrolysis.

About the electric charge converter

Charge, current and the relationship between them

Charge is a quantity of electricity; current is the rate at which it flows. The two are related exactly as distance and speed are: current is charge per unit time, so charge is current multiplied by time. An amp-hour is that multiplication written into a unit.

This is why battery capacity is a charge and not an energy. A battery holds a certain number of coulombs it can push around a circuit; how much work those coulombs do depends on the voltage driving them. Energy is charge times voltage, which is why watt-hours — not amp-hours — are the honest measure for comparing batteries of different chemistries.

The distinction has practical consequences whenever voltages differ. A 12 V 100 Ah battery and a 24 V 50 Ah battery both hold 1.2 kWh of energy despite one having twice the amp-hour rating. Comparing them on amp-hours alone would give exactly the wrong answer.

The chemistry connection

The faraday in this converter is not the farad — that is capacitance, a different quantity entirely. A faraday is the charge carried by one mole of electrons, about 96,485 coulombs, and it is the bridge between electricity and chemistry.

Faraday's laws of electrolysis state that the amount of substance transformed at an electrode is proportional to the charge passed. That relationship makes electroplating quantitatively predictable: knowing the charge, the ion's valency and its molar mass tells you exactly how much metal will be deposited. The same arithmetic governs anodising, electrorefining and industrial chlorine production.

It runs in reverse for batteries. A cell's theoretical capacity follows from the amount of active material and the number of electrons each reaction transfers, which is why battery chemistry research is largely a search for materials that move more electrons per gram. The gap between theoretical and actual capacity — usually substantial — is where the engineering lives.

Frequently asked questions

Is a 10,000 mAh power bank twice as good as a 5,000 mAh one?
In charge, yes. In usable energy delivered to your phone, not necessarily, because charge alone does not describe energy — you need the voltage too. A power bank's cells typically run at 3.7 V while USB output is 5 V, so an internal 10,000 mAh does not deliver 10,000 mAh at 5 V. After conversion losses, a 10,000 mAh bank commonly delivers around 6,000–6,500 mAh at USB voltage. Comparing watt-hours, where manufacturers publish them, is far more meaningful.
What is a coulomb?
The SI unit of electric charge: the charge transported by a current of one ampere in one second. Since the 2019 redefinition of the SI, it follows from the elementary charge being fixed at exactly 1.602176634 × 10⁻¹⁹ coulombs. One coulomb is therefore about 6.24 × 10¹⁸ elementary charges — a very large number of very small charges.
Why is an amp-hour 3,600 coulombs?
Because an ampere is defined as one coulomb per second, and an hour is 3,600 seconds. One amp flowing for one hour therefore transports 3,600 coulombs. The amp-hour survives in battery specifications because it maps directly onto how batteries are used — a device drawing a known current for a known time — in a way that raw coulombs do not.
Do battery capacity ratings hold at any discharge rate?
No, and this is why a rating is normally quoted alongside a discharge period. Drawing current faster than the rated rate generally yields less total charge, an effect described by Peukert's law and pronounced in lead-acid batteries. A 100 Ah car battery discharged over 20 hours delivers close to its rating; the same battery discharged in one hour delivers noticeably less. This converter changes units and does not model that behaviour.

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