Joule (J)
The joule is the SI unit of energy — the work done when one newton moves an object one meter.
Joules quantify electricity bills (as kWh), food energy (as kcal), and scientific energy transfers.
Joule to Watt-Hour
Convert joule to watt-hour instantly. Type in either field — results update live.
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Energy Joule Watt-Hour
1 joule = 0.0002777778 watt-hours
Unit
Unit
Conversion table
Selected J values converted to W·h using the exact factor from this tool.
| J | W·h |
|---|---|
| 0.01 | 0.0000027778 |
| 0.1 | 0.0000277778 |
| 1 | 0.0002777778 |
| 2 | 0.0005555556 |
| 3 | 0.0008333333 |
| 5 | 0.0013888889 |
| 10 | 0.0027777778 |
| 20 | 0.0055555556 |
| 50 | 0.0138888889 |
| 100 | 0.0277777778 |
| 1,000 | 0.2777777778 |
How to convert
Exact conversion factors in both directions, plus a worked example.
1 J = 0.0002777778 W·h
1 W·h = 3600 J
To convert joule to watt-hour, multiply by 0.0002777778.
To convert watt-hour to joule, multiply by 3600.
Example: convert 10 J to W·h
10 × 0.0002777778 = 0.0027777778 W·h
About these units
Short background on the units used in this conversion.
Watt-Hour (W·h)
A watt-hour is the energy from one watt of power sustained for one hour — 3,600 joules.
Watt-hours size phone batteries, power banks, and small rechargeable devices.
Frequently asked questions
How many watt-hours are in one joule?
One joule equals 0.0002777778 watt-hours. Multiply your joules value by 0.0002777778 to convert to watt-hours.
What is the conversion formula?
W·h = J × 0.0002777778The reverse is
J = W·h × 3,600, using the same exact factors as this converter.Is this Joule to Watt-Hour converter private?
Yes. All calculations run locally in your browser. Nothing you type is sent to a server.
All joule conversions
Jump to any energy conversion starting from joule — including the reverse direction and every other unit in our dataset.
watt-hour (W·h) → joule (J)
joule (J) → kilojoule (kJ)joule (J) → megajoule (MJ)joule (J) → gigajoule (GJ)joule (J) → kilowatt-hour (kW·h)joule (J) → calorie (nutritional / food calorie) (Cal)joule (J) → kilocalorie (it) (kcal (IT))joule (J) → kilocalorie (thermochemical) (kcal (th))joule (J) → calorie (it) (cal (IT))joule (J) → calorie (thermochemical) (cal (th))joule (J) → british thermal unit (it) (Btu (IT))joule (J) → british thermal unit (thermochemical) (Btu (th))joule (J) → foot-pound (ft·lbf)joule (J) → newton meter (N·m)joule (J) → horsepower hour (mechanical) (hp·h)joule (J) → horsepower (metric) hour (metric hp·h)joule (J) → millijoule (mJ)joule (J) → microjoule (µJ)joule (J) → nanojoule (nJ)joule (J) → attojoule (aJ)joule (J) → megaelectron-volt (MeV)joule (J) → kiloelectron-volt (keV)joule (J) → electron-volt (eV)joule (J) → ergjoule (J) → gigawatt-hour (GW·h)joule (J) → megawatt-hour (MW·h)joule (J) → kilowatt-second (kW·s)joule (J) → watt-second (W·s)joule (J) → mega british thermal unit (it) (MBtu (IT))joule (J) → ton-hour (refrigeration) (ton·h)joule (J) → fuel oil equivalent @ kiloliter (kL oil eq)joule (J) → fuel oil equivalent @ barrel (us) (bbl oil eq)joule (J) → gigaton (tnt) (Gton)joule (J) → megaton (tnt) (Mton)joule (J) → kiloton (tnt) (kton)joule (J) → ton (explosives / tnt) (ton TNT)joule (J) → dyne centimeter (dyn·cm)joule (J) → gram-force meter (gf·m)joule (J) → gram-force centimeter (gf·cm)joule (J) → kilogram-force centimeter (kgf·cm)joule (J) → kilogram-force meter (kgf·m)joule (J) → kilopond meter (kp·m)joule (J) → pound-force foot (lbf·ft)joule (J) → pound-force inch (lbf·in)joule (J) → ounce-force inch (ozf·in)joule (J) → inch-pound (in·lbf)joule (J) → inch-ounce (in·ozf)joule (J) → poundal foot (pdl·ft)joule (J) → thermjoule (J) → therm (ec)joule (J) → therm (us)joule (J) → hartree energy (Eh)joule (J) → rydberg constant (Ry)