1 joule ≈ 0.0002778 watts per hour. You are currently converting energy units from joule to watt hour 1 J = 0.00027777777777778 Wh Joules to watts calculation The power P in watts (W) is equal to the energy E in joules (J), divided by the time period t in seconds (s): P(W) = E(J) / t(s) The user must fill one of the two fields and the conversion will become automatically. The power P in watts (W) is equal to the energy E in joules (J), divided by the time period t in seconds (s): P (W) = E (J) / t (s) So. How to convert watts to joules 1 joules = 0.0002778 watts per hour Formula joules in watts per hour (j in wh). Watt-hours = 10 Joules 3600 = 0.0027778 Watt-hours Watt-hours = 10 Joules 3600 = 0.0027778 Watt-hours Joules to Watt-hours Conversion Table Convert Joules to other energy units FreeConvert.com can convert Joules to these other formats: P (W) = 90J / 3s = 30W . Wh = joules*1.163/4186.8 ≈ joules*0.0002778 What is the power consumption of an electrical circuit that has energy consumption of 90 joules for time duration of 3 seconds? or. W = J / s. Example. Do a quick conversion: 1 joules = 0.000277777778 watt hours using the online calculator for metric conversions. Joules to watts calculation formula. Check the chart for more details. This tool converts joules to watts per hour (j to wh) and vice versa. watt = joule / second.