Direct conversion
Convert joule [J] to watt-hour [Wh] instantly with formula, examples, chart, and FAQs.
Quick answer
Use the calculator below for any custom value, then check the formula, examples, chart, and reverse conversion links.
1 joule [J] = 0.000278 watt-hour [Wh]
1 joule [J] = 0.000278 watt-hour [Wh]
Example: 1 joule [J] equals 0.000278 watt-hour [Wh].
Energy conversions use joule as the reference unit, including electrical, thermal, nutrition, and mechanical energy units.
Displayed results are rounded for readability. The calculator keeps enough precision for everyday use and switches to scientific notation for very large or very small values. Last reviewed: 2026-05-21.
The joule is the SI derived unit of energy, work, and heat.
HistoryThe joule is named after James Prescott Joule and became the standard SI energy unit.
Current useJoules are used in physics, engineering, nutrition science, batteries, heating, and mechanical work.
The watt-hour (Wh) is a energy unit used to express measurements in this converter.
HistoryThis unit is included because it appears in practical measurement systems, technical references, product specifications, or everyday conversion needs.
Current useUse watt-hour when comparing energy values, checking specifications, converting between systems, or preparing quick estimates.
| joule [J] | watt-hour [Wh] |
|---|---|
| 1 | 0.000278 |
| 2 | 0.000556 |
| 5 | 0.001389 |
| 10 | 0.002778 |
| 20 | 0.005556 |
| 25 | 0.006944 |
| 50 | 0.013889 |
| 100 | 0.027778 |
| 1000 | 0.277778 |
Use this formula: 1 joule [J] = 0.000278 watt-hour [Wh] Enter your value in the calculator and the result updates instantly.
1 joule [J] equals 0.000278 watt-hour [Wh].
Yes. Use the swap button in the calculator or open the related reverse conversion link when it is listed on this page.