Charge Converter
Fast, accurate charge conversions, right in your browser.
The Charge Converter converts between coulombs, amp-hours, milliamp-hours, and other units of electric charge — commonly needed when comparing battery capacity ratings (usually given in mAh) against charge calculations that use the SI coulomb unit.
How to Convert
- Enter your charge value and select the starting unit
- Choose your target unit
- The converted result appears instantly
Frequently Asked Questions
What electric charge units does this converter support?
Common units include coulombs (C), milliamp-hours (mAh), and amp-hours (Ah).
How is mAh related to coulombs?
1 mAh equals 3.6 coulombs, based on the relationship between current, time, and charge.
Why are batteries rated in mAh instead of coulombs?
mAh (milliamp-hours) is a more practically sized and intuitive unit for consumer battery capacity, directly relating to how long a battery can supply a given current.
Is this useful for comparing phone or laptop battery capacity?
Yes — device batteries are almost universally rated in mAh, and this converter helps when cross-referencing specs that use coulombs or amp-hours instead.
Is this tool free to use?
Yes, completely free with no signup, no limits and no software to install.
Is my data saved anywhere?
No — conversions run in your browser and the values you enter are not stored or sent to a server.
How many mAh are in an Ah?
1,000 mAh equal one Ah (amp-hour).
Does higher mAh always mean a battery lasts longer?
Generally yes for the same device and usage pattern, but actual battery life also depends on voltage, the device's power draw, and battery efficiency — mAh alone doesn't capture total energy capacity without voltage.
Is this useful for EV or solar battery bank sizing?
Yes — larger battery systems are often specified in amp-hours, and converting to more familiar units helps with capacity planning and comparisons.
What is the relationship between charge and current?
Current (amps) is the rate of charge flow, while charge (coulombs or amp-hours) is the total accumulated quantity — similar to how power relates to energy over time.
