Convert Watt-Hours (Wh) to Milliamp-hours (mAh)
Airline battery rules (100 Wh, 160 Wh) are written in watt-hours, but powerbanks are sold in mAh. At the Li-ion nominal 3.7 V: mAh = Wh × 1000 ÷ 3.7, so 100 Wh ≈ 27,027 mAh.
Formula
1 Wh = 270.27027 mAh
To convert Wh to mAh, multiply the value by 270.27027.
Conversion Table
| Watt-Hours (Wh) | Milliamp-hours (mAh) |
|---|---|
| 1 Wh | 270.2703 mAh |
| 2 Wh | 540.5405 mAh |
| 5 Wh | 1351.3514 mAh |
| 10 Wh | 2702.7027 mAh |
| 15 Wh | 4054.0541 mAh |
| 20 Wh | 5405.4054 mAh |
| 27 Wh | 7297.2973 mAh |
| 37 Wh | 10000 mAh |
| 50 Wh | 13513.5135 mAh |
| 74 Wh | 20000 mAh |
| 100 Wh | 27027.027 mAh |
| 150 Wh | 40540.5405 mAh |
| 160 Wh | 43243.2432 mAh |
| 200 Wh | 54054.0541 mAh |
| 250 Wh | 67567.5676 mAh |
| 300 Wh | 81081.0811 mAh |
| 500 Wh | 135135.1351 mAh |
| 1000 Wh | 270270.2703 mAh |
| 2000 Wh | 540540.5405 mAh |
| 5000 Wh | 1351351.3514 mAh |
Common Wh to mAh Examples
- 10 Wh = 2702.7027 mAh
- 27 Wh = 7297.2973 mAh
- 37 Wh = 10000 mAh
- 50 Wh = 13513.5135 mAh
- 100 Wh = 27027.027 mAh
- 160 Wh = 43243.2432 mAh
- 200 Wh = 54054.0541 mAh
- 500 Wh = 135135.1351 mAh
About Wh to mAh
The two aviation thresholds translate like this: 100 Wh — the no-approval carry-on limit — is about 27,000 mAh, and 160 Wh — the maximum most airlines allow with approval — is about 43,200 mAh. That is exactly why the biggest mainstream "flight-safe" powerbanks are sold as 26,800 mAh.
Laptop batteries are usually labelled in Wh directly: a 13-inch laptop pack of 50–70 Wh corresponds to 13,500–19,000 mAh at 3.7 V. Wh is the honest, comparable number across devices — the same Wh at a different cell voltage yields a different mAh.
Frequently Asked Questions
How many mAh is the 100 Wh airline limit?
About 27,027 mAh at 3.7 V — which is why 26,800 mAh powerbanks are marketed as flight-safe.
Can I fly with a 30,000 mAh powerbank?
30,000 mAh ≈ 111 Wh, which is over the 100 Wh threshold — most airlines then require prior approval, so check before you fly.
Is the conversion from Wh to mAh exact?
The ratio 270.27027 is defined to high precision and is exact for most practical purposes. Rounding only matters when many decimal places are needed.
How do I convert Wh to mAh by hand?
Take the value in Wh and multiply the value by 270.27027. The result is the same value expressed in mAh.
What is the formula to convert Wh to mAh?
The formula is 1 Wh = 270.27027 mAh. To convert any value, multiply the value by 270.27027.
How much is 1 Wh in mAh?
1 Wh equals 270.27027 mAh. This ratio applies to every conversion between the two units.
Why are there different units for Battery Capacity?
Different regions and industries developed their own Battery Capacity standards over time. International trade and science later required conversion tools to bridge them.
What is the difference between Wh and mAh?
Both measure Battery Capacity, but they belong to different unit systems or scales, which is why a conversion factor is needed between them.