Kilocalories to Microjoules Converter
Enter the energy in kilocalories below to convert it to microjoules.
Convert Kilocalories to Microjoules
Enter a value in kilocalories (kcal) to convert to microjoules (µJ).
Kilocalorie to Microjoule Conversion Table
Table showing various kilocalorie measurements converted to microjoules. Click any preset value or arrow to load it into the converter.
| Kilocalories (kcal) | Microjoules (µJ) |
|---|---|
| 0.0000001 kcal | 418.4 µJ |
| 0.0000002 kcal | 836.8 µJ |
| 0.0000003 kcal | 1,255.2 µJ |
| 0.0000004 kcal | 1,673.6 µJ |
| 0.0000005 kcal | 2,092 µJ |
| 0.0000006 kcal | 2,510.4 µJ |
| 0.0000007 kcal | 2,928.8 µJ |
| 0.0000008 kcal | 3,347.2 µJ |
| 0.0000009 kcal | 3,765.6 µJ |
| 0.00000001 kcal | 41.84 µJ |
How to Convert Kilocalories to Microjoules
To convert kilocalories to microjoules, multiply the energy by the following conversion ratio: 4,184,000,000 microjoules/kilocalorie.
Since one kilocalorie is equal to 4,184,000,000 microjoules, you can use this simple formula to convert:
The energy in microjoules is equal to the energy in kilocalories multiplied by 4,184,000,000.
For example, here's how to convert 5 kilocalories to microjoules using the formula above.
How Many Microjoules Are in a Kilocalorie?
There are 4,184,000,000 microjoules in a kilocalorie, which is why we use this value in the formula above.
Our kilocalorie to microjoule calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Kilocalories and microjoules are both units used to measure energy. Keep reading to learn more about each unit.
What Is a Kilocalorie?
A kilocalorie is a unit of energy equal to 4,184 joules (J), the base unit for energy. Dietary Calorie equal to 1,000 small calories (4,184 Joules). [1]
The kilocalorie is classified as a standard unit of energy. Kilocalories can be abbreviated as kcal; for example, 1 kilocalorie can be written as 1 kcal.
In the metric system, "kilo" is the standard SI prefix for thousands, or 10³. This makes the kilocalorie (kcal) a convenient decimal multiple of the calorie (cal).
In practice, kilocalories (kcal) are widely used across large-scale industrial, bulk, and macro-level energy specifications within international standard workflows, engineering documentation, and technical data sheets.
What Is a Microjoule?
A microjoule is a unit of energy equal to 1/1,000,000 of a joule (0.000001 J). One-millionth of a Joule. [2]
The microjoule is classified as a metric and SI-compatible unit of energy. Microjoules can be abbreviated as µJ; for example, 1 microjoule can be written as 1 µJ.
In the metric system, "micro" is the standard SI prefix for millionths, or 10⁻⁶. This makes the microjoule (µJ) a convenient decimal multiple of the joule (J).
In practice, microjoules (µJ) are widely used across fine-tolerance laboratory, analytical, and micro-scale energy measurements within SI metric workflows, engineering documentation, and technical data sheets.
When converting energy between kilocalories (kcal) and microjoules (µJ), keep full floating-point precision (1 kcal = 4,184,000,000 µJ; 1 µJ = 2.390057e-10 kcal) during intermediate calculations and round only the final microjoule figure to match your instrument tolerance.
More Kilocalorie & Microjoule Conversions
Need to calculate in the opposite direction? Use our microjoules to kilocalories calculator to switch your starting unit immediately. You can also explore related tools such as converting microjoules to kilocalories, converting kilocalories to kilojoules, or converting joules to calories.
Convert from Kilocalories
Frequently Asked Questions
References
- [1]NIST CODATA StandardNIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — Kilocalories (kcal) to Microjoules (µJ)
- [2]NIST SP 811 SpecificationNIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Kilocalorie (Food Calorie) (kcal) & Microjoule (µJ)
- [3]BIPM ReferenceBIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (kcal to µJ)