Watt-hours to Joules (Wh → J) — Free Online Converter

Wh → J Reference Table

Wh	J
0.001 Wh	3.6 J
0.002 Wh	7.2 J
0.003 Wh	10.8 J
0.004 Wh	14.4 J
0.005 Wh	18 J
0.006 Wh	21.6 J
0.007 Wh	25.2 J
0.008 Wh	28.8 J
0.009 Wh	32.4 J
0.01 Wh	36 J
0.02 Wh	72 J
0.03 Wh	108 J
0.04 Wh	144 J
0.05 Wh	180 J
0.06 Wh	216 J
0.07 Wh	252 J
0.08 Wh	288 J
0.09 Wh	324 J
0.1 Wh	360 J
0.2 Wh	720 J
0.3 Wh	1080 J
0.4 Wh	1440 J
0.5 Wh	1800 J
0.6 Wh	2160 J
0.7 Wh	2520 J
0.8 Wh	2880 J
0.9 Wh	3240 J
1 Wh	3600 J
1.5 Wh	5400 J
2 Wh	7200 J
2.5 Wh	9000 J
3 Wh	10800 J
3.5 Wh	12600 J
4 Wh	14400 J
4.5 Wh	16200 J
5 Wh	18000 J
5.5 Wh	19800 J
6 Wh	21600 J
6.5 Wh	23400 J
7 Wh	25200 J
7.5 Wh	27000 J
8 Wh	28800 J
8.5 Wh	30600 J
9 Wh	32400 J
9.5 Wh	34200 J
10 Wh	36000 J
11 Wh	39600 J
12 Wh	43200 J
13 Wh	46800 J
14 Wh	50400 J
15 Wh	54000 J
16 Wh	57600 J
17 Wh	61200 J
18 Wh	64800 J
19 Wh	68400 J
20 Wh	72000 J
25 Wh	90000 J
30 Wh	108000 J
35 Wh	126000 J
40 Wh	144000 J
45 Wh	162000 J
50 Wh	180000 J
55 Wh	198000 J
60 Wh	216000 J
65 Wh	234000 J
70 Wh	252000 J
75 Wh	270000 J
80 Wh	288000 J
85 Wh	306000 J
90 Wh	324000 J
95 Wh	342000 J
100 Wh	360000 J
120 Wh	432000 J
125 Wh	450000 J
130 Wh	468000 J
140 Wh	504000 J
150 Wh	540000 J
160 Wh	576000 J
175 Wh	630000 J
180 Wh	648000 J
200 Wh	720000 J
225 Wh	810000 J
250 Wh	900000 J
275 Wh	990000 J
300 Wh	1080000 J
350 Wh	1260000 J
400 Wh	1440000 J
450 Wh	1620000 J
500 Wh	1800000 J
600 Wh	2160000 J
700 Wh	2520000 J
750 Wh	2700000 J
800 Wh	2880000 J
900 Wh	3240000 J
1000 Wh	3600000 J
1200 Wh	4320000 J
1250 Wh	4500000 J
1500 Wh	5400000 J
1750 Wh	6300000 J
2000 Wh	7200000 J
2500 Wh	9000000 J
3000 Wh	10800000 J
4000 Wh	14400000 J
4500 Wh	16200000 J
5000 Wh	18000000 J
6000 Wh	21600000 J
7000 Wh	25200000 J
7500 Wh	27000000 J
8000 Wh	28800000 J
9000 Wh	32400000 J
10000 Wh	36000000 J
15000 Wh	54000000 J
20000 Wh	72000000 J
25000 Wh	90000000 J
50000 Wh	180000000 J
75000 Wh	270000000 J
100000 Wh	360000000 J

Values based on NIST SP 811 conversion factors

Why Convert Watt-hours to Joules?

Converting between watt-hours (Wh) and joules (J) is one of the most common energy conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert Wh to J saves time and prevents errors.

Energy conversions from Wh to J are crucial for dietitians, physicists, and engineers. In nutrition, understanding the link between calories and joules helps individuals manage their diet and energy intake effectively. In the power sector, converting between kilowatt-hours and British Thermal Units (BTU) is necessary for sizing heating and cooling systems for homes and offices. Physicists rely on precise energy unit conversions to calculate work, heat, and thermodynamic processes. Whether tracking fitness goals or analyzing home energy bills, accurate conversion empowers users to make better health and financial decisions.

How to Convert Watt-hours to Joules

To convert watt-hours to joules, use the following formula:

J = Wh × 3600

Example: 1 Wh = 3600 J

For example, 5 Wh = 18000 J, 10 Wh = 36000 J, and 100 Wh = 360000 J. For larger values, 1000 Wh = 3600000 J. Conversely, 1 J = 0.0002777777778 Wh. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Mistakes to Avoid

Calorie confusion: Food 'Calories' are actually kilocalories (kcal).
Joule scale: 1 kWh is 3.6 million Joules (orders of magnitude difference).
Power vs Energy: mixing up Watts (power) and Watt-hours (energy).

Pro Tips

Food labels: Learn to read kcal; average adult needs ~2000 kcal/day.
Battery capacity: Wh = V * Ah. Useful for comparing different voltage batteries.
Efficiency: Energy cannot be created/destroyed, only converted (with some loss as heat).

What is a Watt-hour?

A unit of energy equivalent to one watt of power expended for one hour.

Used for battery capacity.

What is a Joule?

The joule (J) is the SI derived unit of energy. Defined as the work done by a force of one newton displacing an object by one meter.

Joules are used in science and engineering to measure work, energy, and heat. In nutrition, kilojoules (kJ) are used in many countries instead of calories.

Frequently Asked Questions

How many joules are in 1 watt-hour?

1 Wh equals 3600 J. This is an exact conversion factor defined by NIST.

How do I convert watt-hours to joules?

Multiply the value in Wh by the conversion factor. For example, 10 Wh = 36000 J. Use our calculator above for instant results.

Is the watt-hours to joules conversion exact?

Yes, this conversion is mathematically exact based on the international definition of these units (NIST SP 811).

Can I convert watt-hours to joules offline?

Yes! OmniConvert runs entirely in your browser — no internet connection needed after the page loads. Your data never leaves your device, ensuring complete privacy.

What is the difference between watt-hours and joules?

Watt-hours (Wh) and Joules (J) are both units of energy but belong to different measurement systems. 1 Wh = 3600 J. Use the converter above to switch between them instantly.

Watt-hours → Joules