Watt-hours: conversions & definition
One watt-hour equals 3,600 joules. It is the energy transferred by one watt over one hour. Battery energy estimates also depend on usable capacity and losses.
Choose the unit you need
Each row converts one Wh. Open a converter to enter any value and see its formula, worked example and reference table. Results below are rounded to 10 significant digits.
| Convert to | Equivalent value | Calculator |
|---|---|---|
| Joules (J) | ≈ 3,600 | Convert Wh to J |
| Kilojoules (kJ) | ≈ 3.6 | Convert Wh to kJ |
| Megajoules (MJ) | ≈ 0.0036 | Convert Wh to MJ |
| Kilowatt-hours (kWh) | ≈ 0.001 | Convert Wh to kWh |
| Kilocalories (kcal th) | ≈ 0.8604206501 | Convert Wh to kcal th |
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Choose units that represent the same quantity and preserve the measurement conditions. A scale conversion changes the number and unit together; it does not change the physical amount or improve the accuracy of your measurement.
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