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Energy • NIST Exact

Joules → Calories

J → cal

1 J = 0.2390057361 cal• NIST Exact

J → cal Reference Table

J cal
0.01 J 0.002390057361 cal
0.1 J 0.02390057361 cal
0.5 J 0.1195028681 cal
1 J 0.2390057361 cal
2 J 0.4780114723 cal
5 J 1.195028681 cal
10 J 2.390057361 cal
20 J 4.780114723 cal
50 J 11.95028681 cal
100 J 23.90057361 cal
500 J 119.5028681 cal
1000 J 239.0057361 cal

Values based on NIST SP 811 conversion factors

🌍 Real-World Examples

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

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 between J and cal are important for nutrition, electricity costs, and engineering. Food labels in different countries use different energy units — China and the EU use kilojoules (kJ), while the US and Australia use Calories (kcal). Understanding kWh-to-joule conversions helps calculate electricity costs and compare energy efficiency of appliances. In HVAC, BTU ratings are standard in North America while watts or kilowatts are used elsewhere.

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. 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 vs kilocalorie: Food labels in the US show "Calories" (capital C) which are actually kilocalories (kcal). 1 food Calorie = 1 kcal = 4.184 kJ.
  • kWh is not kW: Kilowatt-hours (kWh) measure energy consumed over time, while kilowatts (kW) measure instantaneous power. Don't confuse them.
  • Regional food labels: China/EU labels use kilojoules (kJ), US/Australia use Calories (kcal). Check which system before comparing.

Pro Tips

  • Memorize the factor: 1 J = 0.2390057361 cal. For quick mental math, remember this base conversion.
  • Quick reference: 5 J = 1.195028681 cal · 10 J = 2.390057361 cal · 25 J = 5.975143403 cal · 50 J = 11.95028681 cal · 100 J = 23.90057361 cal
  • Bookmark this page: Save this converter for instant access. It works offline once loaded — no internet needed.

Joules to Calories Conversion Table

Jcal
0.01 J0.002390057361 cal
0.1 J0.02390057361 cal
0.5 J0.1195028681 cal
1 J0.2390057361 cal
2 J0.4780114723 cal
5 J1.195028681 cal
10 J2.390057361 cal
20 J4.780114723 cal
50 J11.95028681 cal
100 J23.90057361 cal
500 J119.5028681 cal
1000 J239.0057361 cal

All values in this table are mathematically exact per NIST SP 811.

Frequently Asked Questions

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).

Energy More Conversions

kJ → kcal kcal → kJ cal → J kWh → J BTU → J