Electric Charge Converter
Electric charge is the fundamental property of matter that governs electromagnetic interactions. The SI unit is the coulomb (C), defined as the amount of charge transported by one ampere of electric current flowing for one second. In practical applications, charge is often expressed in different units depending on context: battery manufacturers use milliampere-hours (mAh) and ampere-hours (Ah) because they directly express capacity in terms of current and time; electrochemists use the faraday, equal to Faraday's constant (approximately 96,485 coulombs), which represents the charge of one mole of electrons; and very small charges in electrostatics and precision electronics use nanocoulombs, microcoulombs, and millicoulombs. A typical smartphone battery might be rated at 3,000 mAh, which equals 10,800 coulombs or about 0.112 farads of charge capacity. Converting between these units is essential in battery specifications, electrical engineering, electrochemistry, and physics. This calculator converts instantly between coulombs, milliampere-hours, ampere-hours, faraday, and related units.
Electric charge conversion factors
All conversions below use SI and standard electrochemical definitions, with all units expressed relative to the coulomb (C).
| Unit | Symbol | Coulombs (C) |
|---|---|---|
| Nanocoulomb | nC | 0.000000001 |
| Microcoulomb | μC | 0.000001 |
| Millicoulomb | mC | 0.001 |
| Coulomb | C | 1 |
| Kilocoulomb | kC | 1,000 |
| Milliampere-hour | mAh | 3.6 |
| Ampere-hour | Ah | 3,600 |
| Faraday | F | 96,485.33 |
Electric charge converter: frequently asked questions
What is electric charge?
Electric charge is a fundamental property of matter that causes it to experience a force when placed in an electric field. It is measured in coulombs (C) in the SI system. One coulomb is defined as the amount of charge transported by one ampere of current in one second: 1 C = 1 A * s.
What is the relationship between coulombs and ampere-hours?
An ampere-hour (Ah) is a unit of electric charge commonly used in battery specifications. One ampere-hour equals the charge delivered by one ampere of current flowing for one hour, which is 3,600 coulombs. The milliampere-hour (mAh), one-thousandth of an ampere-hour, equals 3.6 coulombs. A battery rated at 1,000 mAh stores 3,600 coulombs of charge.
What is a faraday?
A faraday (F) is a unit of electric charge used in electrochemistry, equal to the charge required to liberate one mole of univalent ions in electrolysis. One faraday equals approximately 96,485 coulombs (Faraday's constant). It is primarily used in electrochemistry and less commonly in other applications.
What are nanocoulombs, microcoulombs, and millicoulombs?
These are prefixed versions of the coulomb: a nanocoulomb (nC) is 10^-9 coulombs, a microcoulomb (μC) is 10^-6 coulombs, and a millicoulomb (mC) is 10^-3 coulombs. They are used when dealing with very small charges, such as in electrostatic experiments or sensitive electronic measurements.
Why do battery manufacturers use milliampere-hours instead of coulombs?
The milliampere-hour (mAh) is more intuitive for battery users because it directly describes the product of current and time. A 1,000 mAh battery can theoretically deliver 1 ampere for 1 hour, or 0.5 amperes for 2 hours. Coulombs express the same information but in less familiar units for everyday applications.
Official sources
- SI Brochure (9th edition, 2019): The International System of Units. BIPM.
- NIST Special Publication 330: The International System of Units (SI).
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.