Watt-hour to Kilowatt-hour Converter
One Watt-hour equals 0.001 Kilowatt-hour (1 Wh = 0.001 kWh). Multiply a Watt-hour value by 0.001 to get the equivalent in Kilowatt-hour. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
kWh = Wh × 0.001
Multiply the Watt-hour value by 0.001 to get the equivalent value in Kilowatt-hour.
Example Conversions
1 Watt-hour (Wh)
0.001 Kilowatt-hour (kWh)
5 Watt-hour (Wh)
0.005 Kilowatt-hour (kWh)
10 Watt-hour (Wh)
0.01 Kilowatt-hour (kWh)
25 Watt-hour (Wh)
0.025 Kilowatt-hour (kWh)
100 Watt-hour (Wh)
0.1 Kilowatt-hour (kWh)
Conversion Table
| Watt-hour (Wh) | Kilowatt-hour (kWh) |
|---|---|
| 0.1 | 0.0001 |
| 0.5 | 0.0005 |
| 1 | 0.001 |
| 2 | 0.002 |
| 5 | 0.005 |
| 10 | 0.01 |
| 25 | 0.025 |
| 50 | 0.05 |
| 100 | 0.1 |
| 250 | 0.25 |
| 500 | 0.5 |
| 1000 | 1 |
How to Convert Manually
Use these steps to convert Watt-hour values to Kilowatt-hour without the calculator.
- Write down the value in Watt-hour (Wh) that you want to convert.
- Multiply that value by 0.001.
- For example, 10 Watt-hour × 0.001 = 0.01 Kilowatt-hour.
- Label the result as Kilowatt-hour (kWh).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Watt-hour and one Kilowatt-hour.
About Watt-hour and Kilowatt-hour
The watt-hour is exactly 3,600 joules — one watt sustained for one hour. Battery capacities for phones, laptops, and e-bikes are rated in watt-hours. The kilowatt-hour is exactly 3.6 megajoules — the unit on your electricity bill. Household consumption and electric vehicle battery sizes are stated in kilowatt-hours. One Watt-hour equals 0.001 Kilowatt-hour (1 Wh = 0.001 kWh). Watt-hour to Kilowatt-hour conversion comes up most often in battery capacity ratings and in small device power consumption, typically when figures need restating for electricity billing.
Precision and Rounding: Energy factors mix exact definitions (1 kWh = 3,600,000 J; 1 cal = 4.184 J thermochemical) with measured conventions (1 BTU ≈ 1,055.056 J). Nutrition and utility bills round to whole units; engineering heat calculations should keep the full factor until the final step.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15 Watt-hour equals 0.015 Kilowatt-hour.
15 Wh × 0.001 = 0.015 kWh
FAQ
How do I convert Watt-hour to Kilowatt-hour?
Multiply the Watt-hour value by 0.001 to get the equivalent value in Kilowatt-hour.
What is the formula for Watt-hour to Kilowatt-hour?
The formula is kWh = Wh × 0.001.
How many Kilowatt-hour are in 1 Watt-hour?
1 Watt-hour equals 0.001 Kilowatt-hour.
Can I convert Kilowatt-hour back to Watt-hour?
Yes. 1 Kilowatt-hour equals 1000 Watt-hour, and the related converter can reverse the calculation.
What are common names for Watt-hour and Kilowatt-hour?
Watt-hour is shown as Wh and may also be searched as watt hour, watt-hour. Kilowatt-hour is shown as kWh and may also be searched as kilowatt hour, kilowatt-hour, kwh.
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