Coulombs to Ampere-hours Converter
Enter the electric charge in coulombs below to convert it to ampere-hours.
Convert Coulombs to Ampere-hours
Enter a value in coulombs (C) to convert to ampere-hours (Ah).
Coulomb to Ampere-hour Conversion Table
Table showing various coulomb measurements converted to ampere-hours. Click any preset value or arrow to load it into the converter.
| Coulombs (C) | Ampere-hours (Ah) |
|---|---|
| 1 C | 0.000277778 Ah |
| 2 C | 0.000555556 Ah |
| 2.5 C | 0.000694444 Ah |
| 5 C | 0.0013889 Ah |
| 10 C | 0.0027778 Ah |
| 15 C | 0.0041667 Ah |
| 20 C | 0.0055556 Ah |
| 25 C | 0.0069444 Ah |
| 30 C | 0.0083333 Ah |
| 50 C | 0.0138889 Ah |
How to Convert Coulombs to Ampere-hours
To convert coulombs to ampere-hours, multiply the electric charge by the following conversion ratio: 0.000277778 ampere-hours/coulomb.
Since one coulomb is equal to 0.000277778 ampere-hours, you can use this simple formula to convert:
The electric charge in ampere-hours is equal to the electric charge in coulombs multiplied by 0.000277778.
For example, here's how to convert 5 coulombs to ampere-hours using the formula above.
How Many Ampere-hours Are in a Coulomb?
There are 0.000277778 ampere-hours in a coulomb, which is why we use this value in the formula above.
Our coulomb to ampere-hour calculator automatically converts your electric charge measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Coulombs and ampere-hours are both units used to measure electric charge. Keep reading to learn more about each unit.
What Is a Coulomb?
SI unit of electric charge (1 A·s). It serves as a primary reference unit for measuring electric charge across scientific and practical applications. [1]
The coulomb is classified as an International System of Units (SI) unit of electric charge. Coulombs can be abbreviated as C; for example, 1 coulomb can be written as 1 C.
As the primary coherent reference unit for electric charge in this category, all other electric charge units are mathematically anchored to the coulomb (C).
In practice, coulombs (C) are widely used across standard electric charge applications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.
What Is an Ampere-hour?
An ampere-hour is a unit of electric charge equal to 3,600 coulombs (C), the base unit for electric charge. Battery charge capacity unit equal to 3,600 Coulombs (1,000 mAh). [2]
The ampere-hour is classified as a standard unit of electric charge. Ampere-hours can be abbreviated as Ah; for example, 1 ampere-hour can be written as 1 Ah.
When working with ampere-hours (Ah) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, ampere-hours (Ah) are widely used across large-scale industrial, bulk, and macro-level electric charge specifications within international standard workflows, engineering documentation, and technical data sheets.
When converting electric charge between coulombs (C) and ampere-hours (Ah), keep full floating-point precision (1 C = 0.000277778 Ah; 1 Ah = 3,600 C) during intermediate calculations and round only the final ampere-hour figure to match your instrument tolerance.
More Coulomb & Ampere-hour Conversions
Need to calculate in the opposite direction? Use our ampere-hours to coulombs calculator to switch your starting unit immediately. You can also explore related tools such as converting ampere-hours to coulombs, converting milliampere-hours to ampere-hours, or converting kilowatt-hours to ampere-hours.
Convert from Coulombs
Frequently Asked Questions
References
- [1]NIST CUU StandardNIST CUU (Derived SI Unit: Coulomb (C))·Electric Charge Metrology Standard — Coulombs (C) to Ampere-hours (Ah)
- [2]NIST OWM SpecificationNIST OWM (SI Units — Electric Current)·Unit Specifications: Coulomb (C) & Ampere-hour (Ah)
- [3]NIST SP 811 ReferenceNIST SP 811 (NIST SP 811 App. B.9 (1 Ah = 3,600 C))·Conversion Factors & Mathematical Basis (C to Ah)