At One Place

Joules to watt-hours

1 joule in watt-hours
1 J = 0.0002778 Wh
Wh = J × 0.000277777778

To convert joules to watt-hours, multiply by 0.000277777778. The table below gives the values people look up most often, and the converter works for any number.

Joules to watt-hours table

Common joule values converted to watt-hours.
Joules Watt-hours
1 J 0.0002778
2 J 0.0005556
3 J 0.0008333
4 J 0.0011111
5 J 0.0013889
10 J 0.0027778
15 J 0.0041667
20 J 0.0055556
25 J 0.0069444
30 J 0.0083333
40 J 0.011111
50 J 0.013889
75 J 0.020833
100 J 0.027778
250 J 0.069444
500 J 0.13889
1,000 J 0.27778

How the conversion works

The relationship is Wh = J × 0.000277777778. Both units measure energy, so the conversion is a fixed factor that never changes.

Common questions

How many watt-hours are in one joule?
One joule equals 0.0002778 watt-hours. Wh = J × 0.000277777778.
How do you convert joules to watt-hours?
Use Wh = J × 0.000277777778. So 10 J is 0.0027778 Wh.
How many joules are in one watt-hour?
One watt-hour equals 3,600 joules, which is the reverse of the conversion above.

Related pages

Sources

  1. Guide for the Use of the International System of Units (SP 811) — NIST (Public domain (US Government))
  2. The International System of Units (SI Brochure) — Bureau International des Poids et Mesures
  3. Calculated on this page — At One Place

How these figures are compiled and checked