What Is a Milliamp-Hours to Watt-Hours Calculator?
A Milliamp-Hours to Watt-Hours Calculator (mAh to Wh Calculator) is a free online tool used to convert battery capacity from milliamp-hours (mAh) into watt-hours (Wh).
It is especially useful for comparing batteries, power banks, smartphones, laptops, portable electronics, solar batteries, and other battery-powered devices.
Milliamp-Hours to Watt-Hours Formula
To convert mAh to Wh, you need to know the battery voltage (V).
The formula is:
Wh = (mAh × V) ÷ 1,000
Where:
- mAh = battery capacity in milliamp-hours
- V = battery voltage in volts
- Wh = energy capacity in watt-hours
- 1,000 = conversion from milliamp-hours to amp-hours
Example
Suppose a battery has:
- Capacity: 5,000 mAh
- Voltage: 3.7 V
Calculation:
Wh = (5,000 × 3.7) ÷ 1,000
Wh = 18.5 Wh
Therefore, a 5,000 mAh, 3.7 V battery has approximately 18.5 Wh of energy capacity.
Quick mAh to Wh Examples
| Battery Capacity | Voltage | Energy |
|---|---|---|
| 1,000 mAh | 3.7 V | 3.7 Wh |
| 2,000 mAh | 3.7 V | 7.4 Wh |
| 5,000 mAh | 3.7 V | 18.5 Wh |
| 10,000 mAh | 3.7 V | 37 Wh |
| 20,000 mAh | 3.7 V | 74 Wh |
| 30,000 mAh | 3.7 V | 111 Wh |
Why Use a Milliamp-Hours to Watt-Hours Calculator?
A free mAh to Wh Calculator can help you:
- Compare batteries with different voltages
- Calculate power-bank energy capacity
- Estimate how much energy a battery stores
- Compare portable electronic devices
- Estimate battery runtime
- Calculate energy requirements for projects
- Evaluate batteries for solar and backup-power systems
- Convert battery specifications for travel or shipping requirements
mAh vs. Wh
The two units describe different things:
mAh (milliamp-hours) describes electrical charge capacity.
Wh (watt-hours) describes energy capacity.
This is why mAh alone is not enough to calculate Wh. You also need the battery’s voltage.
For example, two batteries could both have 10,000 mAh, but if their voltages are different, their total energy in Wh will also be different.
In short:
Watt-hours = (Milliamp-hours × Volts) ÷ 1,000
A Milliamp-Hours to Watt-Hours Calculator simply automates this calculation, making it fast and easy to determine the approximate energy capacity of a battery.
