Convert Calories to Kilojoules
No popups. No autoplay ads. Accurate answers with formulas shown.
Science
About Energy Conversions
One quantity, energy, shows up under a different unit in every field. The joule is the SI base; from there it ties to the food calorie in nutrition (1 Calorie = 4,184 joules), the kilowatt-hour on your power bill, the British thermal unit in HVAC, and the electron volt in particle physics. Numbers make the scale concrete: a 2,000-calorie day is about 8.4 megajoules, and a household burning 900 kWh a month runs through roughly 3.24 gigajoules. Every unit below converts on exact factors.
Quick Conversions
| Unit Name | Symbol | Per 1 Calorie |
|---|---|---|
| British Thermal Unit | BTU | 0.00396567 |
| Calorie | cal | 1 |
| Electron Volt | eV | 2.61145 × 10¹⁹ |
| Joule | J | 4.184 |
| Kilocalorie | kcal | 0.001 |
| Kilojoule | kJ | 0.004184 |
| Kilowatt-hour | kWh | 0.00000116222 |
| Megajoule | MJ | 0.000004184 |
| Watt-hour | Wh | 0.00116222 |
Frequently Asked Questions
How do I convert Calories to Kilojoules?
To convert Calories to Kilojoules, use the conversion where 1 Calorie (cal) = 0.004184 Kilojoules (kJ). For example, 1 Calorie = 0.004184 Kilojoules.
What are common Calorie to Kilojoule conversions?
Here are common conversions: 1 Calories = 0.004184 Kilojoules, 5 Calories = 0.02092 Kilojoules, 10 Calories = 0.04184 Kilojoules, 25 Calories = 0.1046 Kilojoules, 50 Calories = 0.2092 Kilojoules, 100 Calories = 0.4184 Kilojoules.
When would I need to convert Calories to Kilojoules?
Energy conversions are needed when comparing electricity bills across regions using different units, in engineering calculations involving mechanical and thermal energy, for understanding nutritional energy (calories vs joules), and in renewable energy system planning.
How precise are the conversions?
All conversions use exact factors verified against NIST and ISO standards with up to 10 significant figures of precision. Results are calculated using IEEE 754 double-precision arithmetic, which provides approximately 15-17 significant digits. For temperature and other non-linear conversions, exact formulas are used rather than approximations.