Watt-seconds to Joules Conversion

Enter the energy in watt-seconds below to get the value converted to joules.

Results in Joules:
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1 Ws = 1 J

How to Convert Watt-seconds to Joules

To convert a watt-second measurement to a joule measurement, divide the energy by the conversion ratio.

Since one joule is equal to 1 watt-second, you can use this simple formula to convert:

joules = watt-seconds ÷ 1

The energy in joules is equal to the watt-seconds divided by 1.

For example, here's how to convert 5 watt-seconds to joules using the formula above.
5 Ws = (5 ÷ 1) = 5 J

Watt-seconds and joules are both units used to measure energy. Keep reading to learn more about each unit of measure.


The watt-second is a measure of electrical energy equal to one watt of power over a one second period. One watt-second is equal to 1/3,600 of a watt-hour or one joule.

Watt-seconds are usually abbreviated as Ws, although the formally adopted expression is W·s. The abbreviation W s is also sometimes used. For example, 1 watt-second can be written as 1 Ws, 1 W·s, or 1 W s.

In formal expressions, the centered dot (·) or space is used to separate units used to indicate multiplication in an expression and to avoid conflicting prefixes being misinterpreted as a unit symbol.[1]


The joule is the energy equal to the force on an object of one newton at a distance of one meter.[2] One joule is equal to the heat energy dissipated by the current of one ampere through one ohm of resistance for one second.

One joule is also equal to the energy needed to move an electric charge of one coulomb through a potential difference of one volt. In addition, one joule is also equal to the one watt-second.

The joule is the SI derived unit for energy in the metric system. Joules can be abbreviated as J; for example, 1 joule can be written as 1 J.

Watt-second to Joule Conversion Table

Watt-second measurements converted to joules
Watt-seconds Joules
1 Ws 1 J
2 Ws 2 J
3 Ws 3 J
4 Ws 4 J
5 Ws 5 J
6 Ws 6 J
7 Ws 7 J
8 Ws 8 J
9 Ws 9 J
10 Ws 10 J
11 Ws 11 J
12 Ws 12 J
13 Ws 13 J
14 Ws 14 J
15 Ws 15 J
16 Ws 16 J
17 Ws 17 J
18 Ws 18 J
19 Ws 19 J
20 Ws 20 J
21 Ws 21 J
22 Ws 22 J
23 Ws 23 J
24 Ws 24 J
25 Ws 25 J
26 Ws 26 J
27 Ws 27 J
28 Ws 28 J
29 Ws 29 J
30 Ws 30 J
31 Ws 31 J
32 Ws 32 J
33 Ws 33 J
34 Ws 34 J
35 Ws 35 J
36 Ws 36 J
37 Ws 37 J
38 Ws 38 J
39 Ws 39 J
40 Ws 40 J


  1. Bureau International des Poids et Mesures, The International System of Units (SI), 9th edition, 2019, https://www.bipm.org/documents/20126/41483022/SI-Brochure-9-EN.pdf
  2. International Bureau of Weights and Measures, The International System of Units, 9th Edition, 2019, https://www.bipm.org/documents/20126/41483022/SI-Brochure-9-EN.pdf

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