mAh to Watt Hours Calculator
| mAh | 3.7V (Wh) | 5V (Wh) | 11.1V (Wh) |
|---|---|---|---|
| 2,000 | 7.40 | 10.00 | 22.20 |
| 5,000 | 18.50 | 25.00 | 55.50 |
| 10,000 | 37.00 | 50.00 | 111.00 |
| 20,000 | 74.00 | 100.00 | 222.00 |
| 27,000 | 99.90 | 135.00 | 299.70 |
mAh to Watt Hours Formula Explained
Voltage-Based Energy Conversion
The formula Wh = (mAh × V) ÷ 1000 converts milliamp hours to watt hours. The ÷1000 converts mAh to Ah. A 5000mAh battery at 3.7V stores 18.5Wh of energy.
Energy Density Calculations
Energy density is measured in Wh/kg or Wh/L. Converting mAh to Wh allows you to calculate and compare energy density across different battery form factors and chemistries.
Scientific Unit Conversion Accuracy
For maximum accuracy, use the exact nominal voltage from the battery datasheet. Different chemistries have different voltages: LiFePO4 = 3.2V, Li-ion = 3.7V, Li-polymer = 3.8V.
Why Watt Hours Are Used for Safety Regulations
FAA & Airline Battery Limits
The FAA specifies battery limits in Wh, not mAh: under 100Wh for carry-on (no restriction), 100-160Wh (airline approval required, max 2 spare batteries). Use this calculator to verify. For Wh to mAh conversion, see Wh to mAh converter.
Laptop and Drone Battery Ratings
Laptop batteries are often rated in mAh with multiple cells. A 6-cell laptop battery with 4400mAh cells at 11.1V = 48.84Wh. Drone batteries (e.g., DJI Mavic 3: 5000mAh @ 15.4V = 77Wh) must comply with airline regulations.