Yoctojoule is 1e-24 joule units.
Yoctojoules to Watt-hours Converter — yJ to Wh
Convert Yoctojoule (yJ) to Watt-hour (Wh) using the exact conversion factor (1 yoctojoule = 2.777778e-28 watt-hour). See the formula, worked examples, conversion table, and common uses.
Yoctojoules to Watt-hours converter
Converter
Energy Converter
Convert joules, calories, kilowatt-hours, BTU, electronvolts, therms, and mechanical work units.
Context values
Some unit families need one extra value for a physically accurate result.
A watt-hour is 3,600 joules.
Result = input x 1e-24 / 3600.
Energy uses the joule as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Yoctojoules to Watt-hours
Yoctojoule and Watt-hour both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). Specifically: Yoctojoule is 1e-24 joule units, and a watt-hour is 3,600 joules.
Formula
watt-hours = yoctojoules × 2.777778e-28
This factor comes from each unit's defined relationship to the category's base unit: 1 yoctojoule equals 1e-24 base units, and 1 watt-hour equals 3600 base units, so dividing one by the other gives the direct yoctojoule-to-watt-hour factor of 2.777778e-28.
Simple example
1 yJ × 2.777778e-28 = 2.777778e-28 Wh
1 yoctojoule = 2.777778e-28 watt-hours.
Real-world example
100 yJ × 2.777778e-28 = 2.777778e-26 Wh
100 yoctojoules = 2.777778e-26 watt-hours.
Conversion table
| Yoctojoule (yJ) | Watt-hour (Wh) |
|---|---|
| 1 yJ | 2.777778e-28 Wh |
| 10 yJ | 2.777778e-27 Wh |
| 100 yJ | 2.777778e-26 Wh |
| 500 yJ | 1.388889e-25 Wh |
| 1,000 yJ | 2.777778e-25 Wh |
| 2,000 yJ | 5.555556e-25 Wh |
Reverse conversion: Watt-hour to Yoctojoule
2.777778e-28 Wh × 3.6e+27 = 1.00000008 yJ
2.777778e-28 watt-hours = 1.00000008 yoctojoules.
yoctojoules = watt-hours × 3.6e+27
For a page dedicated to this direction, see Watt-hour to Yoctojoule.
Understanding the Yoctojoule (yJ)
Yoctojoule is 1e-24 joule units.
Understanding the Watt-hour
Watt-hour (Wh) measures energy. The energy delivered by one watt of power sustained for one hour — equal to 3,600 joules. It is classified as a metric derived energy unit.
Where it's used: Universal — standard consumer-electronics and battery energy unit worldwide
Wh vs. kWh. The same unit at different scales: 1,000 Wh equals 1 kWh. Wh suits small consumer-electronics batteries; kWh is used for household electricity billing and larger energy storage.
Uses of the Watt-hour today
- Phone, laptop, and power-bank battery capacity ratings
- Electric-vehicle battery capacity specifications
- Small-scale renewable energy (solar panel) output ratings
Watt-hour — sources
- BIPM SI Brochure — Watt-hour as a common energy unit derived from the coherent SI units watt and second (via the hour).
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many watt-hours are in 1 yoctojoule?
1 yoctojoule equals 2.777778e-28 watt-hours, using the exact defined conversion factor rather than an estimate.
How do I convert yoctojoule to watt-hour?
Multiply the yoctojoule value by 2.777778e-28. The converter above does this instantly to whatever precision you set.
How do I convert watt-hour back to yoctojoule?
Use the reverse factor: 1 watt-hour equals 3.6e+27 yoctojoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a yoctojoule?
Yoctojoule (yJ) is a unit of energy.
What is a watt-hour?
Watt-hour (Wh) measures energy. The energy delivered by one watt of power sustained for one hour — equal to 3,600 joules. It is classified as a metric derived energy unit.
Is the yoctojoule to watt-hour conversion exact?
Yes. Both yoctojoule and watt-hour are defined by fixed standards rather than physical artifacts, so the factor of 2.777778e-28 used above is exact to as many digits as you choose to display.
What is the difference between wh vs. kwh?
The same unit at different scales: 1,000 Wh equals 1 kWh. Wh suits small consumer-electronics batteries; kWh is used for household electricity billing and larger energy storage.