How many kilojoules are in 1 kilocalorie?

1 kcal equals 4.184 kJ. This is an exact conversion factor defined by NIST.

How do I convert kilocalories to kilojoules?

Multiply the value in kcal by the conversion factor. For example, 10 kcal = 41.84 kJ. Use our calculator above for instant results.

Is the kilocalories to kilojoules conversion exact?

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

Can I convert kilocalories to kilojoules 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 kilocalories and kilojoules?

Kilocalories (kcal) and Kilojoules (kJ) are both units of energy but belong to different measurement systems. 1 kcal = 4.184 kJ. Use the converter above to switch between them instantly.

Kilocalories to Kilojoules (kcal → kJ) — Free Online Converter

kcal → kJ Reference Table

kcal	kJ
0.001 kcal	0.004184 kJ
0.002 kcal	0.008368 kJ
0.003 kcal	0.012552 kJ
0.004 kcal	0.016736 kJ
0.005 kcal	0.02092 kJ
0.006 kcal	0.025104 kJ
0.007 kcal	0.029288 kJ
0.008 kcal	0.033472 kJ
0.009 kcal	0.037656 kJ
0.01 kcal	0.04184 kJ
0.02 kcal	0.08368 kJ
0.03 kcal	0.12552 kJ
0.04 kcal	0.16736 kJ
0.05 kcal	0.2092 kJ
0.06 kcal	0.25104 kJ
0.07 kcal	0.29288 kJ
0.08 kcal	0.33472 kJ
0.09 kcal	0.37656 kJ
0.1 kcal	0.4184 kJ
0.2 kcal	0.8368 kJ
0.3 kcal	1.2552 kJ
0.4 kcal	1.6736 kJ
0.5 kcal	2.092 kJ
0.6 kcal	2.5104 kJ
0.7 kcal	2.9288 kJ
0.8 kcal	3.3472 kJ
0.9 kcal	3.7656 kJ
1 kcal	4.184 kJ
1.5 kcal	6.276 kJ
2 kcal	8.368 kJ
2.5 kcal	10.46 kJ
3 kcal	12.552 kJ
3.5 kcal	14.644 kJ
4 kcal	16.736 kJ
4.5 kcal	18.828 kJ
5 kcal	20.92 kJ
5.5 kcal	23.012 kJ
6 kcal	25.104 kJ
6.5 kcal	27.196 kJ
7 kcal	29.288 kJ
7.5 kcal	31.38 kJ
8 kcal	33.472 kJ
8.5 kcal	35.564 kJ
9 kcal	37.656 kJ
9.5 kcal	39.748 kJ
10 kcal	41.84 kJ
11 kcal	46.024 kJ
12 kcal	50.208 kJ
13 kcal	54.392 kJ
14 kcal	58.576 kJ
15 kcal	62.76 kJ
16 kcal	66.944 kJ
17 kcal	71.128 kJ
18 kcal	75.312 kJ
19 kcal	79.496 kJ
20 kcal	83.68 kJ
25 kcal	104.6 kJ
30 kcal	125.52 kJ
35 kcal	146.44 kJ
40 kcal	167.36 kJ
45 kcal	188.28 kJ
50 kcal	209.2 kJ
55 kcal	230.12 kJ
60 kcal	251.04 kJ
65 kcal	271.96 kJ
70 kcal	292.88 kJ
75 kcal	313.8 kJ
80 kcal	334.72 kJ
85 kcal	355.64 kJ
90 kcal	376.56 kJ
95 kcal	397.48 kJ
100 kcal	418.4 kJ
120 kcal	502.08 kJ
125 kcal	523 kJ
130 kcal	543.92 kJ
140 kcal	585.76 kJ
150 kcal	627.6 kJ
160 kcal	669.44 kJ
175 kcal	732.2 kJ
180 kcal	753.12 kJ
200 kcal	836.8 kJ
225 kcal	941.4 kJ
250 kcal	1046 kJ
275 kcal	1150.6 kJ
300 kcal	1255.2 kJ
350 kcal	1464.4 kJ
400 kcal	1673.6 kJ
450 kcal	1882.8 kJ
500 kcal	2092 kJ
600 kcal	2510.4 kJ
700 kcal	2928.8 kJ
750 kcal	3138 kJ
800 kcal	3347.2 kJ
900 kcal	3765.6 kJ
1000 kcal	4184 kJ
1200 kcal	5020.8 kJ
1250 kcal	5230 kJ
1500 kcal	6276 kJ
1750 kcal	7322 kJ
2000 kcal	8368 kJ
2500 kcal	10460 kJ
3000 kcal	12552 kJ
4000 kcal	16736 kJ
4500 kcal	18828 kJ
5000 kcal	20920 kJ
6000 kcal	25104 kJ
7000 kcal	29288 kJ
7500 kcal	31380 kJ
8000 kcal	33472 kJ
9000 kcal	37656 kJ
10000 kcal	41840 kJ
15000 kcal	62760 kJ
20000 kcal	83680 kJ
25000 kcal	104600 kJ
50000 kcal	209200 kJ
75000 kcal	313800 kJ
100000 kcal	418400 kJ

Values based on NIST SP 811 conversion factors

Why Convert Kilocalories to Kilojoules?

Converting between kilocalories (kcal) and kilojoules (kJ) is one of the most common energy conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert kcal to kJ saves time and prevents errors.

Energy conversions from kcal to kJ 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 Kilocalories to Kilojoules

To convert kilocalories to kilojoules, use the following formula:

kJ = kcal × 4.184

Example: 1 kcal = 4.184 kJ

For example, 5 kcal = 20.92 kJ, 10 kcal = 41.84 kJ, and 100 kcal = 418.4 kJ. For larger values, 1000 kcal = 4184 kJ. Conversely, 1 kJ = 0.2390057361 kcal. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Use Cases

Daily calorie intake for an average adult: 2000 kcal = 8368 kJ
A bowl of cooked white rice: 200 kcal = 836.8 kJ
Energy burned in 30 minutes of running: 300 kcal = 1255.2 kJ
A Big Mac hamburger: 550 kcal = 2301.2 kJ
A medium-sized banana: 100 kcal = 418.4 kJ

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 Kilocalorie?

A unit of energy equal to 1,000 calories ("Calorie").

Widely used for measuring food energy content.

What is a Kilojoule?

A unit of energy equal to 1,000 Joules.

Standard unit for food energy labeling in most of the world.

Kilocalories → Kilojoules

Kilocalories to Kilojoules Formula