Watt-hour per kilogram (Wh/kg)
Exactly 3600 J/kg. The usual unit for battery specific energy.
What is a watt-hour per kilogram?
- Symbol
- Wh/kg
- Quantity
- Fuel Energy per Mass
- Unit system
- SI-accepted
- Definition
- Exactly 3600 J/kg. The usual unit for battery specific energy.
- Exact
- Yes, the value is exact by definition
- Source
- SI Brochure, 9th edition (BIPM, 2019)
Common applications
Used for the specific energy of batteries and battery cells in phones, laptops and electric vehicles.
Watt-hour per kilogram in other fuel energy per mass units
- 1 Wh/kg = 3600 J/kgJoule per kilogram
- 1 Wh/kg = 3.6 kJ/kgKilojoule per kilogram
- 1 Wh/kg = 0.0036 MJ/kgMegajoule per kilogram
- 1 Wh/kg = 0.001 kWh/kgKilowatt-hour per kilogram
- 1 Wh/kg ≈ 1.54772141 BTU/lbBTU per pound
- 1 Wh/kg ≈ 0.8598452279 kcal/kgKilocalorie (IT) per kilogram
Watt-hour per kilogram quick reference
| Watt-hour per kilogram | Megajoule per kilogram | BTU per pound | Joule per kilogram |
|---|---|---|---|
| 1 Wh/kg | = 0.0036 MJ/kg | ≈ 1.54772141 BTU/lb | = 3600 J/kg |
| 10 Wh/kg | = 0.036 MJ/kg | ≈ 15.4772141 BTU/lb | = 36000 J/kg |
| 100 Wh/kg | = 0.36 MJ/kg | ≈ 154.772141 BTU/lb | = 360000 J/kg |
| 1000 Wh/kg | = 3.6 MJ/kg | ≈ 1547.72141 BTU/lb | = 3600000 J/kg |
Where the watt-hour per kilogram fits
The next smaller fuel energy per mass unit is the BTU per pound (BTU/lb). 1 Wh/kg ≈ 1.54772141 BTU/lb, and 1 BTU/lb ≈ 0.6461111111 Wh/kg.
The next larger fuel energy per mass unit is the kilocalorie (IT) per kilogram (kcal/kg). 1 Wh/kg ≈ 0.8598452279 kcal/kg, and 1 kcal/kg = 1.163 Wh/kg.
Frequently asked questions
- How many megajoules per kilogram are in one watt-hour per kilogram?
- One watt-hour per kilogram = 0.0036 MJ/kg (megajoules per kilogram).
- How many BTUs per pound are in one watt-hour per kilogram?
- One watt-hour per kilogram ≈ 1.54772141 BTU/lb (BTUs per pound).
- How many joules per kilogram are in one watt-hour per kilogram?
- One watt-hour per kilogram = 3600 J/kg (joules per kilogram).