Power bank mAh to Wh: will it pass airport security?
Airlines do not limit power banks in mAh — they limit them in watt-hours (Wh). This power bank mAh to Wh calculator converts the capacity printed on your power bank into watt-hours and tells you straight away whether it can fly: allowed without approval, allowed only with the airline’s approval, or not allowed at all. It also checks the number you are carrying, because since 27 March 2026 the international rules allow no more than two power banks per person.
Type the mAh and the voltage from the label (or the Wh figure, if the label already shows it). The answer comes with the formula, the largest power bank you could take at that voltage, a table of common sizes from 5,000 to 50,000 mAh, and a short checklist of what the rules say about carrying and using it on board. The calculation runs in your browser.
How to use the Power Bank mAh to Wh Calculator & Flight Checker
- Find the capacity and voltage on the power bank’s label — for example “20000mAh 3.7V 74Wh”.
- Type the mAh and the voltage, or switch to Wh on the label and type the watt-hours.
- Enter how many power banks you are packing.
- Read the watt-hours and the verdict, and check the airline’s own rules if the result is over 100 Wh.
- Press Copy the result to keep the answer for the security queue.
Power Bank mAh to Wh Calculator & Flight Checker features
mAh ↔ Wh both ways
mAh × V ÷ 1000 = Wh, or Wh back to mAh at the cell voltage.
Three-tier verdict
Up to 100 Wh, over 100 Wh up to 160 Wh, and over 160 Wh, with what each means for a power bank.
Two-per-person check
Warns when you pack more than two power banks.
Size table
Common capacities at your voltage, with the 26,800 and 27,000 mAh sizes that sit just under 100 Wh.
Dated rules panel
ICAO, IATA and India’s DGCA rules as checked on 24 October 2026.
How to convert mAh to Wh
Watt-hours = milliamp-hours × volts ÷ 1000. The volts are the nominal voltage of the lithium-ion cells inside, normally 3.6, 3.7 or 3.85 V, which is why a 20,000 mAh power bank at 3.7 V is 20,000 × 3.7 ÷ 1000 = 74 Wh. Do not use the 5 V, 9 V or 20 V USB output voltage: the mAh figure on the label is measured at the cell voltage, so multiplying by an output voltage overstates the energy. When the label prints a Wh rating, that figure is the one security staff check.
| Power bank | Wh at 3.7 V | Can it fly? |
|---|---|---|
| 10,000 mAh | 37 Wh | Yes, in cabin baggage |
| 20,000 mAh | 74 Wh | Yes, in cabin baggage |
| 26,800 mAh | 99.16 Wh | Yes — just under 100 Wh |
| 30,000 mAh | 111 Wh | Only with airline approval, often refused |
| 40,000 mAh | 148 Wh | Only with airline approval, often refused |
| 50,000 mAh | 185 Wh | No |
The rules behind the verdict (checked 24 October 2026)
The ICAO Technical Instructions for the Safe Transport of Dangerous Goods by Air (2025–2026 edition, Addendum No. 1, applicable from 27 March 2026) say power banks must be carried as carry-on baggage, must not be recharged while on board, should not be used to recharge a portable electronic device on board, are limited to two per person and must be individually protected against short circuits. The same table allows lithium-ion batteries up to 100 Wh, and over 100 Wh up to 160 Wh only with the operator’s approval. IATA’s guidance for airlines on the change (31 March 2026) goes further and lists power banks over 100 Wh as forbidden; the 68th edition of the IATA Dangerous Goods Regulations takes over from 1 January 2027.
In India, DGCA Dangerous Goods Advisory Circular 01/2025 (11 November 2025) adds that power banks and spare batteries must not be placed in overhead bins, so keep them in your seat pocket or a bag under the seat. Many airlines are stricter still — allowing only one power bank, or banning any use in flight — and the airline’s rules always win. Spare camera and laptop batteries follow similar Wh limits but are not counted as power banks.
Power Bank mAh to Wh Calculator & Flight Checker FAQ
How many Wh is a 20000 mAh power bank?
About 74 Wh at the usual 3.7 V cell voltage (20,000 × 3.7 ÷ 1000). That is under the 100 Wh limit, so it can go in your cabin bag without approval.
Can I take a 30000 mAh power bank on a plane?
At 3.7 V it is 111 Wh, over the 100 Wh limit. The ICAO rules allow batteries up to 160 Wh only with the airline’s approval, and IATA’s 2026 guidance lists power banks over 100 Wh as forbidden, so expect it to be refused. Many “30,000 mAh” banks state 108–111 Wh on the label.
What is the largest power bank allowed on a flight without approval?
Anything up to 100 Wh — about 27,000 mAh at 3.7 V. Power banks sold as 26,800 mAh (99.16 Wh) are sized for exactly this limit.
How many power banks can I carry?
No more than two per person under the ICAO rules applicable from 27 March 2026. Some airlines allow only one.
Can I charge my phone with a power bank on the plane?
No. The 2026 rules say a power bank should not be used to recharge a device on board and must not itself be recharged from seat power.
Why can’t power banks go in checked luggage?
A lithium battery fire in the hold may go unnoticed and cannot be fought by the crew. In the cabin, a smoking power bank is seen at once and can be dealt with.