Electric Charge Converter – Coulombs to Ah and mAh in 3 Easy Steps
Electric Charge Converter
Use this electric charge converter: type a value into any field to instantly convert across all electrical charge measurements.
Use this free electric charge converter to switch between coulombs (C), ampere-hours (Ah), milliampere-hours (mAh) and faradays. Type a value into any box and the other three update instantly, which is handy for battery capacity, electrochemistry and physics problems.
Quick answer
1 ampere-hour = 3,600 coulombs, 1 mAh = 3.6 C, and 1 Ah = 1,000 mAh. One faraday = 96,485.33 C, the charge of one mole of electrons. So a 5,000 mAh power bank stores 5 Ah = 18,000 C = 0.1866 faradays of charge.
Table of Contents
Battery labels use mAh or Ah, physics uses coulombs, and chemistry uses faradays. They all measure the same thing, electric charge, just on different scales.
This electric charge converter links all four units, so you can move from a phone battery rating to coulombs or from an electrolysis problem to amp-hours in one step.
Electric Charge Conversion Formulas
- Coulombs = amps × seconds
- Coulombs = Ah × 3,600
- Coulombs = mAh × 3.6
- Ah = mAh ÷ 1,000
- Faradays = coulombs ÷ 96,485.33
Electric Charge Conversion Table
| mAh | Ah | Coulombs | Typical device |
|---|---|---|---|
| 250 | 0.25 | 900 | Small earbud battery |
| 1,000 | 1 | 3,600 | Older phone battery |
| 3,000 | 3 | 10,800 | Modern smartphone |
| 5,000 | 5 | 18,000 | Large phone or power bank |
| 20,000 | 20 | 72,000 | Large power bank |
| 60,000 | 60 | 216,000 | Car battery (60 Ah) |
How to Use the Electric Charge Converter
Step 1: Convert Coulombs to Ampere-Hours
Type a charge in Coulombs (C). 3,600 C equals 1 Ah, 1,000 mAh and 0.0373 faradays, because one amp flowing for one hour moves 3,600 coulombs.
Step 2: Convert a Battery’s mAh Rating
Type a battery rating in Milliampere-Hours (mAh). A 5,000 mAh power bank stores 5 Ah, 18,000 C and 0.1866 faradays.
Step 3: Check the Reference Matrix
The Base Conversion Reference Matrix lists the key constants: 1 Ah = 3,600 C, 1 mAh = 3.6 C, 1 faraday = 96,485.33 C and 1 Ah = 1,000 mAh. Press Clear Fields to reset.
mAh vs Wh: Charge vs Energy
mAh measures charge, not energy. To compare batteries with different voltages, convert to watt-hours: Wh = Ah × volts. A 5,000 mAh phone battery at 3.7 V holds 5 × 3.7 = 18.5 Wh. Many airlines allow power banks up to 100 Wh in cabin baggage without approval, which is about 27,000 mAh at 3.7 V.
Faradays in Electrochemistry
One faraday is the charge of one mole of electrons. In electrolysis, depositing one mole of copper (Cu²⁺ + 2e⁻ → Cu) needs 2 faradays, or about 192,971 C. At a current of 2 A, that takes 192,971 ÷ 2 = 96,485 seconds, roughly 26.8 hours.
Comparing Power Banks Fairly
Power bank capacity is printed at the internal cell voltage, usually 3.6–3.7 V, but USB outputs at 5 V or more. Some energy is also lost in the voltage converter. A 10,000 mAh power bank typically delivers roughly 6,000–7,000 mAh to a phone. Converting both the power bank and the phone battery with the electric charge converter, then to watt-hours, gives a more honest comparison.
Coulombs in Physics
The coulomb is the SI unit of charge. One coulomb is the charge moved by a current of one ampere in one second, and it equals the charge of about 6.24 × 10¹⁸ electrons. Physics formulas such as Coulomb’s law and Q = It expect charge in coulombs, so convert battery ratings before using them.
Estimating Battery Run Time
- Run time (hours) ≈ capacity (mAh) ÷ load current (mA).
- A 3,000 mAh battery powering a 150 mA device lasts about 20 hours.
- Real run time is usually lower because of conversion losses and battery ageing.
More electrical tools: the Electric Current Converter, the Linear Charge Density Converter and the Surface Charge Density Converter.
Frequently Asked Questions
How many coulombs are in 1 Ah?
One ampere-hour equals 3,600 coulombs.
How many coulombs is 1 mAh?
One milliampere-hour equals 3.6 coulombs.
How do I convert mAh to Ah?
Divide by 1,000. 5,000 mAh = 5 Ah.
What is a faraday of charge?
It is the charge of one mole of electrons, about 96,485.33 coulombs.
How do I convert mAh to watt-hours?
Multiply Ah by the battery voltage. 5,000 mAh at 3.7 V = 18.5 Wh.
Is my data stored?
No. The electric charge converter runs in your browser and nothing is saved.