Power converter

Joules to Watts Calculator

Convert an energy amount in joules into power in watts over a time period.

How Joules to Watts works

Power is the rate of energy transfer, so watts equal joules divided by the number of seconds over which the energy is delivered. One watt is exactly one joule per second.

This is the inverse of the watts-to-joules calculation. If a device uses a known amount of energy in joules over a measured time, dividing energy by time gives its average power draw in watts.

Formula

1P(W) = E(J) ÷ t(s)

1 watt = 1 joule per second.

Joules to Watts conversion table

Reference Table6 rows

Energy in joules delivered over a time period, converted to watts.
Energy↕	Over 1 s↕	Over 60 s↕
100 J	100 W	1.67 W
500 J	500 W	8.33 W
1,000 J	1,000 W	16.7 W
3,600 J	3,600 W	60 W
10,000 J	10,000 W	167 W
60,000 J	60,000 W	1,000 W

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FAQ: Joules to Watts

How do you convert joules to watts?

Divide the energy in joules by the time in seconds. Watts = Joules ÷ Seconds. For example, 3,600 J delivered over 60 s equals 60 W.

Can you convert joules to watts without time?

No. Joules measure total energy and watts measure the rate of energy use, so you must know the time period over which the energy is delivered.

How many watts is 1000 joules?

It depends on the time. 1,000 J used in one second is 1,000 W, but the same 1,000 J spread over 10 seconds is only 100 W.

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