Microjoule is 0.000001 joule units.
Microjoules to Kilocalories Converter — uJ to kcal
Convert Microjoule (uJ) to Kilocalorie (kcal) using the exact conversion factor (1 microjoule = 2.390057e-10 kilocalorie). See the formula, worked examples, and conversion table.
Microjoules to Kilocalories converter
Converter
Energy Converter
Convert joules, calories, kilowatt-hours, BTU, electronvolts, therms, and mechanical work units.
Context values
Some unit families need one extra value for a physically accurate result.
A kilocalorie is 1,000 calories.
Result = input x 1e-6 / 4184.
Energy uses the joule as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Microjoules to Kilocalories
Microjoule and Kilocalorie both measure energy, and the conversion is especially useful for comparing nutrition labels (kilocalories) against scientific energy figures (joules). Specifically: Microjoule is 0.000001 joule units, and a kilocalorie is 1,000 calories.
Formula
kilocalories = microjoules × 2.390057e-10
This factor comes from each unit's defined relationship to the category's base unit: 1 microjoule equals 0.000001 base units, and 1 kilocalorie equals 4184 base units, so dividing one by the other gives the direct microjoule-to-kilocalorie factor of 2.390057e-10.
Simple example
1 uJ × 2.390057e-10 = 2.390057e-10 kcal
1 microjoule = 2.390057e-10 kilocalories.
Real-world example
100 uJ × 2.390057e-10 = 2.390057e-8 kcal
100 microjoules = 2.390057e-8 kilocalories.
Conversion table
| Microjoule (uJ) | Kilocalorie (kcal) |
|---|---|
| 1 uJ | 2.390057e-10 kcal |
| 10 uJ | 2.390057e-9 kcal |
| 100 uJ | 2.390057e-8 kcal |
| 500 uJ | 1.195029e-7 kcal |
| 1,000 uJ | 2.390057e-7 kcal |
| 2,000 uJ | 4.780115e-7 kcal |
Reverse conversion: Kilocalorie to Microjoule
2.390057e-10 kcal × 4184000000 = 0.9999998488 uJ
2.390057e-10 kilocalories = 0.9999998488 microjoules.
microjoules = kilocalories × 4184000000
For a page dedicated to this direction, see Kilocalorie to Microjoule.
Understanding the Microjoule (uJ)
Microjoule is 0.000001 joule units.
Understanding the Kilocalorie (kcal)
A kilocalorie is 1,000 calories.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many kilocalories are in 1 microjoule?
1 microjoule equals 2.390057e-10 kilocalories, using the exact defined conversion factor rather than an estimate.
How do I convert microjoule to kilocalorie?
Multiply the microjoule value by 2.390057e-10. The converter above does this instantly to whatever precision you set.
How do I convert kilocalorie back to microjoule?
Use the reverse factor: 1 kilocalorie equals 4,184,000,000 microjoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a microjoule?
Microjoule (uJ) is a unit of energy.
What is a kilocalorie?
Kilocalorie (kcal) is a unit of energy.
Is the microjoule to kilocalorie conversion exact?
Yes. Both microjoule and kilocalorie are defined by fixed standards rather than physical artifacts, so the factor of 2.390057e-10 used above is exact to as many digits as you choose to display.