Energy Converter
Convert energy between physics units (joules, kJ), food energy (calories and kilocalories), electricity (Wh, kWh) and heating (BTU).
Your numbers
Result
| Unit | Value |
|---|---|
| J | 418,400 |
| kJ | 418.4 |
| cal | 100,000 |
| kcal (Cal) | 100 |
| Wh | 116.22 |
| kWh | 0.12 |
| BTU | 396.57 |
The key conversions
One kilocalorie — the "Calorie" on food labels — is 4.184 kJ, so a 100 kcal snack holds about 418 kJ. One kWh is 3.6 million joules (3,600 kJ). One BTU is about 1.055 kJ, the heat to warm a pound of water by 1 °F.
Calorie vs Calorie
A food Calorie (capital C) is actually a kilocalorie — 1,000 small calories. This converter lists both cal and kcal so you can match nutrition labels (kcal) or physics problems (cal) without confusion.
Frequently asked questions
Sources
- International System of Units — energy (joule)
Embed this calculator
Copy the code and paste it into your site or blog. Credit with a link back to Contania is included, and the height adjusts itself.
<iframe src="https://contania.app/embed/conversions/energy-converter" title="Energy Converter (joules, calories, kWh, BTU)" width="100%" height="720" loading="lazy" style="border:1px solid #e5e0d8;border-radius:12px;max-width:640px"></iframe>
<script>window.addEventListener("message",function(e){if(e.data&&e.data.type==="contania:embed-height"){var f=document.querySelector('iframe[src="https://contania.app/embed/conversions/energy-converter"]');if(f){f.style.height=e.data.height+"px"}}});</script>Related calculators
Unit Converter
Convert length between mm, cm, m, km, inches, feet, yards and miles — all at once. A complete metric-to-imperial length converter.
CalculateConversionsPressure
Convert pressure between psi, bar, pascals (Pa), kilopascals (kPa), atmospheres (atm) and mmHg. Handy for tires, weather and engineering.
CalculateHealth & FitnessMacros
Split your daily calories into carbs, protein and fat. Enter your calories and the ratio you want to see how many grams of each macro to eat per day.
CalculateConversionsg → oz
Convert grams to ounces and back. One ounce is about 28.35 grams. Essential for cooking and baking with recipes written in the other system.
CalculateConversionsInches → cm
Convert inches to centimeters instantly. Multiply by 2.54 — the relation is exact. Works both ways, with a quick reference table for common inch sizes.
CalculateConversionskg → lb
Convert kilograms to pounds and back. One kilogram is about 2.2046 pounds. Handy for body weight, luggage, gym plates and recipes in US units.
Calculate