How many calories are in 1 joule?

1 J equals 0.2390057361 cal. This is an exact conversion factor defined by NIST.

How do I convert joules to calories?

Multiply the value in J by the conversion factor. For example, 10 J = 2.390057361 cal. Use our calculator above for instant results.

Is the joules to calories conversion exact?

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

Can I convert joules to calories 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 joules and calories?

Joules (J) and Calories (cal) are both units of energy but belong to different measurement systems. 1 J = 0.2390057361 cal. Use the converter above to switch between them instantly.

Joules to Calories (J → cal) — Free Online Converter

J → cal Reference Table

J	cal
0.001 J	0.0002390057361 cal
0.002 J	0.0004780114723 cal
0.003 J	0.0007170172084 cal
0.004 J	0.0009560229446 cal
0.005 J	0.001195028681 cal
0.006 J	0.001434034417 cal
0.007 J	0.001673040153 cal
0.008 J	0.001912045889 cal
0.009 J	0.002151051625 cal
0.01 J	0.002390057361 cal
0.02 J	0.004780114723 cal
0.03 J	0.007170172084 cal
0.04 J	0.009560229446 cal
0.05 J	0.01195028681 cal
0.06 J	0.01434034417 cal
0.07 J	0.01673040153 cal
0.08 J	0.01912045889 cal
0.09 J	0.02151051625 cal
0.1 J	0.02390057361 cal
0.2 J	0.04780114723 cal
0.3 J	0.07170172084 cal
0.4 J	0.09560229446 cal
0.5 J	0.1195028681 cal
0.6 J	0.1434034417 cal
0.7 J	0.1673040153 cal
0.8 J	0.1912045889 cal
0.9 J	0.2151051625 cal
1 J	0.2390057361 cal
1.5 J	0.3585086042 cal
2 J	0.4780114723 cal
2.5 J	0.5975143403 cal
3 J	0.7170172084 cal
3.5 J	0.8365200765 cal
4 J	0.9560229446 cal
4.5 J	1.075525813 cal
5 J	1.195028681 cal
5.5 J	1.314531549 cal
6 J	1.434034417 cal
6.5 J	1.553537285 cal
7 J	1.673040153 cal
7.5 J	1.792543021 cal
8 J	1.912045889 cal
8.5 J	2.031548757 cal
9 J	2.151051625 cal
9.5 J	2.270554493 cal
10 J	2.390057361 cal
11 J	2.629063098 cal
12 J	2.868068834 cal
13 J	3.10707457 cal
14 J	3.346080306 cal
15 J	3.585086042 cal
16 J	3.824091778 cal
17 J	4.063097514 cal
18 J	4.30210325 cal
19 J	4.541108987 cal
20 J	4.780114723 cal
25 J	5.975143403 cal
30 J	7.170172084 cal
35 J	8.365200765 cal
40 J	9.560229446 cal
45 J	10.75525813 cal
50 J	11.95028681 cal
55 J	13.14531549 cal
60 J	14.34034417 cal
65 J	15.53537285 cal
70 J	16.73040153 cal
75 J	17.92543021 cal
80 J	19.12045889 cal
85 J	20.31548757 cal
90 J	21.51051625 cal
95 J	22.70554493 cal
100 J	23.90057361 cal
120 J	28.68068834 cal
125 J	29.87571702 cal
130 J	31.0707457 cal
140 J	33.46080306 cal
150 J	35.85086042 cal
160 J	38.24091778 cal
175 J	41.82600382 cal
180 J	43.0210325 cal
200 J	47.80114723 cal
225 J	53.77629063 cal
250 J	59.75143403 cal
275 J	65.72657744 cal
300 J	71.70172084 cal
350 J	83.65200765 cal
400 J	95.60229446 cal
450 J	107.5525813 cal
500 J	119.5028681 cal
600 J	143.4034417 cal
700 J	167.3040153 cal
750 J	179.2543021 cal
800 J	191.2045889 cal
900 J	215.1051625 cal
1000 J	239.0057361 cal
1200 J	286.8068834 cal
1250 J	298.7571702 cal
1500 J	358.5086042 cal
1750 J	418.2600382 cal
2000 J	478.0114723 cal
2500 J	597.5143403 cal
3000 J	717.0172084 cal
4000 J	956.0229446 cal
4500 J	1075.525813 cal
5000 J	1195.028681 cal
6000 J	1434.034417 cal
7000 J	1673.040153 cal
7500 J	1792.543021 cal
8000 J	1912.045889 cal
9000 J	2151.051625 cal
10000 J	2390.057361 cal
15000 J	3585.086042 cal
20000 J	4780.114723 cal
25000 J	5975.143403 cal
50000 J	11950.28681 cal
75000 J	17925.43021 cal
100000 J	23900.57361 cal

Values based on NIST SP 811 conversion factors

Why Convert Joules to Calories?

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

Energy conversions from J to cal 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 Joules to Calories

To convert joules to calories, use the following formula:

cal = J × 0.2390057361

Example: 1 J = 0.2390057361 cal

For example, 5 J = 1.195028681 cal, 10 J = 2.390057361 cal, and 100 J = 23.90057361 cal. For larger values, 1000 J = 239.0057361 cal. Conversely, 1 cal = 4.184 J. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Use Cases

Energy in one food Calorie (kilocalorie): 4184 J = 1000 cal
Lifting a 1 kg object to 10 m height: 100 J = 23.90057361 cal
Kinetic energy of a thrown baseball: 500 J = 119.5028681 cal
Energy to heat 1 mL of water by about 0.24°C: 1000 J = 239.0057361 cal

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 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.

What is a Calorie?

The calorie (cal) is a pre-SI unit of energy. Historically defined as the heat needed to raise 1 gram of water by 1°C. Food calories are actually kilocalories (kcal).

Calories (specifically kilocalories) are universally used in nutrition to measure the energy content of food and the energy expenditure of physical activity.

Joules → Calories

Joules to Calories Formula