Formula: 10,000 × 3.7 ÷ 1000 = 37 watt-hours.
mAh to Wh Converter
Convert battery capacity between milliamp-hours, amp-hours, and watt-hours. Use it for power banks, rechargeable cells, RC batteries, solar packs, tools, and small electronics.
Convert battery capacity
Enter a capacity and voltage. The converter shows watt-hours, amp-hours, milliamp-hours, and a practical battery note.
Estimated runtime at 10 W3.7 hours
Air travel referenceUnder 100 Wh
Energy in joules133,200 J
A 10,000 mAh power bank rated at 3.7 V stores about 37 Wh. Labels can also show USB output capacity, so check which voltage the label uses.
How to use this converter
- Choose whether you are starting with mAh, Wh, or Ah.
- Enter the capacity number from the battery label or product listing.
- Select the voltage printed on the battery. Use custom voltage if needed.
- Read the equivalent Wh, Ah, and mAh values.
mAh, Ah, and Wh formulas
mAh to Wh: Wh = mAh × V ÷ 1000.
Wh to mAh: mAh = Wh ÷ V × 1000.
Ah to Wh: Wh = Ah × V.
Common battery capacity examples
These examples use typical nominal voltages. Always use the voltage shown on your own battery label for final checks.
| Battery example | Voltage | Capacity | Watt-hours |
|---|
mAh to Wh FAQ
How many Wh is a 10,000 mAh power bank?
At a common 3.7 V cell rating, 10,000 mAh is 37 Wh. At 5 V USB output, the same 10,000 mAh number would equal 50 Wh, before conversion losses.
How many mAh is 100 Wh?
At 3.7 V, 100 Wh is about 27,027 mAh. At 5 V, 100 Wh is 20,000 mAh. Voltage changes the mAh equivalent.
Is Wh better than mAh for comparing batteries?
Wh is usually better for comparing total stored energy because it includes voltage. mAh is useful when comparing batteries with the same voltage.