Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 kcal | 4.184e-06 MJ | |
| 0.01 kcal | 4.184e-05 MJ | |
| 0.1 kcal | 0.0004184 MJ | |
| 1 kcal | 0.004184 MJ | |
| 5 kcal | 0.02092 MJ | |
| 10 kcal | 0.04184 MJ | |
| 50 kcal | 0.2092 MJ | |
| 100 kcal | 0.4184 MJ | |
| 1000 kcal | 4.184 MJ |
Formula: Megajoule = Kilocalorie × 0.004184
Multiply any kilocalorie value by 0.004184 to get megajoule.
Reverse: Kilocalorie = Megajoule × 239
Common kilocalorie values — factor: 1 kcal = 0.004184 MJ
| Kilocalorie (kcal) | Megajoule (MJ) | Context |
|---|---|---|
| 1 kcal | 0.004184 MJ | 1 kcal snack |
| 10 kcal | 0.04184 MJ | Small fruit |
| 50 kcal | 0.2092 MJ | Cookie |
| 100 kcal | 0.4184 MJ | Small snack |
| 200 kcal | 0.8368 MJ | Light meal |
| 500 kcal | 2.092 MJ | Workout burn |
| 1,000 kcal | 4.184 MJ | Large meal |
| 2,000 kcal | 8.368 MJ | Daily intake |
| 2,500 kcal | 10.46 MJ | Active adult day |
| 5,000 kcal | 20.92 MJ | Marathon burn |
| 1e+04 kcal | 41.84 MJ | Ultra marathon |
| 5e+04 kcal | 209.2 MJ | Week intake |
| 1e+05 kcal | 418.4 MJ | Month intake |
| 1e+06 kcal | 4,184 MJ | Year intake |
| 1.000e+09 kcal | 4.184e+06 MJ | Decade |
1 kcal = 0.004184 MJ. Memorize for instant estimates.
Use 0.0042 as a quick mental multiplier.
Multiply result by 239 to recover the original kcal value.
Prescribes daily energy intake and food portion sizes in kcal.
Calculates calorie burn during workouts and links to dietary targets.
Measures energy content of food products for nutritional labeling.
Creates weight management plans based on daily kcal targets.
Optimizes pre/during/post workout nutrition using kcal calculations.
Calculates nutritional information per serving in kcal for labels.
The kilocalorie (kcal) equals 1,000 calories or 4,184 joules, and is the unit used on food labels worldwide (often written as 'Cal' with a capital C in the US). It was standardized by the International Table calorie in 1956.
Nutritionists, dietitians, and food scientists use kcal for daily energy intake recommendations. Most adults need 2,000–2,500 kcal/day. Exercise apps, fitness trackers, and dietary plans all operate on kcal.
Interesting fact: One gram of fat yields about 9 kcal, one gram of carbohydrate or protein yields about 4 kcal. A single sugar cube (4g) contains about 16 kcal.
The megajoule (MJ) equals 1,000,000 joules and is used for large-scale energy measurements in engineering, transportation, and industrial processes.
One liter of petrol contains about 34 MJ of chemical energy. A bolt of lightning releases about 1-5 MJ. An adult's daily food intake is roughly 8-10 MJ. Electric vehicle batteries are typically rated at 40-100 MJ (11-28 kWh).
Interesting fact: The kinetic energy of a 1,000 kg car traveling at 100 km/h is about 0.385 MJ. TNT explosive releases about 4.6 MJ per kilogram when detonated.
Converting kilocalorie to megajoule is common across energy, nutrition, engineering, and science. Different sectors use different energy units — joules in physics, kcal in nutrition, kWh in electricity, and BTU in HVAC — making accurate conversion essential for cross-disciplinary work and international comparisons.
Quick reference: 5 kcal = 0.02092 MJ and 10 kcal = 0.04184 MJ. Reverse: 1 MJ = 239 kcal. Exact factor: 1 kcal = 0.004184 MJ.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.