mAh to Wh & Wh to mAh Calculator
Convert mAh to Wh instantly using battery voltage. Calculate watt-hours for lithium batteries, power banks and portable devices with accurate engineering formulas.
How to Use mAh to Wh Calculator
Converting milliamp-hours to watt-hours allows you to compare the true energy capacity of different batteries.
- 1Enter battery capacity. Enter battery capacity in milliamp-hours.
- 2Enter battery voltage. Input the battery operating voltage.
- 3Use the result. Use the result for battery comparison or power calculations.
This conversion is highly practical when evaluating power banks, portable devices, or calculating runtime requirements for electronic systems.
How to Calculate mAh to Wh Calculator
Watt-hours (Wh) is a measure of total electrical energy. To calculate watt-hours from milliamp-hours (mAh), you need to multiply the charge capacity by the operating voltage and divide by 1000.
Primary Formula
Amp-Hour Conversion Formula
If you need to find the capacity in Amp-hours (Ah) first, use this conversion:
Real-World Example Calculation
Given Parameters:
- Battery capacity: 5000 mAh
- Voltage: 3.7 V
Step 1 — Multiply capacity by voltage
5000 × 3.7 = 18,500
Step 2 — Divide by 1000
18,500 ÷ 1000 = 18.5
Walkthrough Final Verified Results
- Battery Capacity: 5000 mAh
- Operating Voltage: 3.7 V
- Total Energy: 18.5 Wh
Practical Applications
You can use this calculation for various everyday devices and systems:
- Power banks
- Smartphones
- Laptops
- Lithium-ion batteries
- Solar storage batteries
mAh to Wh Chart
Energy values vary with battery voltage. The table below assumes a nominal voltage of 3.7 V, which is standard for most single-cell lithium-ion batteries and power banks.
| Capacity (mAh) | Voltage (V) | Energy (Wh) |
|---|---|---|
| 1000 | 3.7 | 3.7 |
| 2000 | 3.7 | 7.4 |
| 3000 | 3.7 | 11.1 |
| 4000 | 3.7 | 14.8 |
| 5000 | 3.7 | 18.5 |
| 6000 | 3.7 | 22.2 |
| 8000 | 3.7 | 29.6 |
| 10000 | 3.7 | 37.0 |
| 15000 | 3.7 | 55.5 |
| 20000 | 3.7 | 74.0 |
| 30000 | 3.7 | 111.0 |
Note: Energy values vary with battery voltage. The table assumes a nominal voltage of 3.7 V.
How to Convert Wh to mAh
Multiply the energy in watt-hours by 1,000 and divide by the battery voltage to get milliamp-hours.
Example: a 37 Wh laptop battery cell pack at 3.7 V is 37 × 1,000 ÷ 3.7 = 10,000 mAh.
| Energy (Wh) | Voltage (V) | Capacity (mAh) |
|---|---|---|
| 5 | 3.70 | 1,351 |
| 10 | 3.70 | 2,703 |
| 20 | 3.70 | 5,405 |
| 37 | 3.70 | 10,000 |
| 50 | 3.70 | 13,514 |
| 74 | 3.70 | 20,000 |
| 100 | 3.70 | 27,027 |
mAh to Wh Calculator Frequently Asked Questions
Converting milliampere-hours to watt-hours is straightforward if you know the exact battery voltage. You must simply multiply the total mAh capacity by the operating voltage, then strictly divide that number by 1000. Formula: Wh = (mAh × Voltage) / 1000.
A standard 20000mAh portable power bank operating with normal 3.7-volt lithium-ion cells holds approximately 74 watt-hours of energy. Calculate this by multiplying the 20000 capacity rating by the 3.7 voltage, then dividing that total by exactly one thousand.
Yes, you can safely travel with a standard 10000mAh portable battery on commercial airplanes. Most airlines allow spare lithium batteries up to 100 watt-hours in carry-on baggage without approval. Power bank mAh ratings refer to the internal 3.6–3.7V cells, so a 10000mAh power bank holds about 37 watt-hours (10000 × 3.7 ÷ 1000), well under the limit.
Commercial airlines strictly monitor watt-hours instead of milliampere-hours because Wh represents the absolute total of stored energy. Since passenger devices run at vastly different voltages, the Wh metric provides regulators a reliable safety standard.
Most commercial flight operators enforce a maximum safety limit of strictly 100 watt-hours for portable battery packs. Because power bank mAh ratings refer to 3.7V lithium-ion cells, this limit equates to about 27,000mAh (100 × 1000 ÷ 3.7). Packs from 100 to 160 watt-hours usually require airline approval, and larger packs are generally not allowed as carry-on spares.
The standard conversion formula is mAh = (Wh × 1000) ÷ V, where Wh represents total stored energy in Watt-hours, 1,000 scales Amps to Milliamps, and V represents nominal system voltage in Volts. If battery capacity is measured in Ampere-hours (Ah), the simplified formula is Ah = Wh ÷ V, which is then multiplied by 1,000 to yield mAh.
