Skip to content

Joules to Watt Hours Converter

Convert joules to watt hours and Wh to joules instantly. Bidirectional energy converter with formula and common values.

J

Watt Hours

2

Wh

7200 J = 2 Wh

Wh = J × 0.000277778

Joules to Watt Hours: 1 J equals 0.000278 Wh. To convert joules to watt hours, multiply by 0.000278 (Wh = J × 0.000277778). For example, 10 J = 0.002778 Wh.

How to Convert Joules to Watt Hours

To convert from joules to watt hours, multiply the value by 0.000278. The conversion is linear, meaning doubling the input doubles the output.

Conversion Formula

  • Joules to Watt Hours: Wh = J × 0.000277778
  • Watt Hours to Joules: J = Wh ÷ 0.000277778

Joules to Watt Hours Conversion Chart

Joules (J)Watt Hours (Wh)
0.12.77778e-5
0.256.94445e-5
0.50.000139
10.000278
20.000556
30.000833
50.001389
100.002778
200.005556
250.006944
500.013889
1000.027778
2500.069445
10000.277778

Understanding the Units

What is a Joule?

The joule is the SI derived unit of energy, equal to the work done by a force of one newton acting through a distance of one meter (1 J = 1 N·m = 1 W·s).

Named after James Prescott Joule (1818–1889), the English physicist who demonstrated the mechanical equivalent of heat.

Common contexts: physics, chemistry, engineering.

What is a Watt Hour?

A watt-hour equals exactly 3,600 joules.

Common contexts: phone batteries, small device energy.

Real-World Reference Points

Item Joules (J) Watt Hours (Wh)
Energy to lift an apple 1 m10.0003
Heart beat (resting)10.0003
AA battery (alkaline)90002.5

Related

Joules to Calories Converter

Convert joules to calories and calories to joules instantly with formula and common values.

Calories to Joules Converter

Convert calories to joules and joules to calories with precise conversion factor.

BTU to Joules Converter

Convert British Thermal Units to joules and joules to BTU for heating and energy calculations.

Kilowatt Hours to Joules Converter

Convert kilowatt hours to joules and joules to kWh for electricity and energy calculations.

Calories to Kilocalories Converter

Convert calories to kilocalories and kilocalories to calories for nutrition and science.

Joules to Kilojoules Converter

Convert joules to kilojoules and kilojoules to joules with simple metric prefix conversion.

FAQ

How many watt hours are in one joule?

One joule equals approximately 0.000277778 watt hours. Since 1 Wh = 3,600 J, a joule is a very small fraction of a watt hour.

How do I convert joules to watt hours?

Divide the joule value by 3,600 (or multiply by 0.000277778). For example, 7,200 J ÷ 3,600 = 2 Wh.

What is a watt hour?

A watt hour is the energy delivered by one watt of power sustained for one hour. It equals 3,600 joules. Battery capacities for small electronics are often rated in Wh or mWh.

When should I use watt hours vs kilowatt hours?

Watt hours are convenient for small-scale energy: batteries, portable devices, and solar panels. Kilowatt hours are used for household and industrial electricity consumption.

How many watt hours are in 1 joul?

1 J equals 0.000278 Wh.

How do you convert joules to watt hours?

Multiply the joul value by 0.000278. Formula: Wh = J × 0.000277778.

How many watt hours are in 5 joules?

5 J = 0.001389 Wh.

How do you convert watt hours back to joules?

Use the inverse formula: J = Wh ÷ 0.000277778. For example, 1 Wh = 3599.99712 J.

What is the difference between Joul and Watt Hour?

The joule is the SI derived unit of energy, equal to the work done by a force of one newton acting through a distance of one meter (1 J = 1 N·m = 1 W·s). A watt-hour equals exactly 3,600 joules.