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Calories to Joules Converter

Enter the energy in calories below to convert it to joules.

Convert Calories to Joules

Enter a value in calories (cal) to convert to joules (J).

Result
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209.2joules
50 cal = 209.2 J
Result updates automatically
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Suggested Conversions
Reference:NIST CODATA (CODATA Energy & Thermodynamic Constants)
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Gram Calorie to Joule Conversion Table

Table showing various gram calorie measurements converted to joules. Click any preset value or arrow to load it into the converter.

Calories (cal)Joules (J)
1 cal4.184 J
2 cal8.368 J
5 cal20.92 J
10 cal41.84 J
15 cal62.76 J
20 cal83.68 J
25 cal104.6 J
30 cal125.52 J
50 cal209.2 J
75 cal313.8 J

How to Convert Calories to Joules

To convert calories to joules, multiply the energy by the following conversion ratio: 4.184 joules/gram calorie.

Since one gram calorie is equal to 4.184 joules, you can use this simple formula to convert:

joules = calories × 4.184

The energy in joules is equal to the energy in calories multiplied by 4.184.

For example, here's how to convert 50 calories to joules using the formula above.

joules = (50 cal × 4.184) = 209.2 J

How Many Joules Are in a Gram Calorie?

There are 4.184 joules in a gram calorie, which is why we use this value in the formula above.

1 cal = 4.184 J|1 J = 0.2390057 cal

Our gram calorie to joule calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.

Calories and joules are both units used to measure energy. Keep reading to learn more about each unit.

What Is a Gram Calorie?

A gram calorie is a unit of energy equal to 4.184 joules (J), the base unit for energy. Thermochemical gram calorie defined as 4.184 Joules. [1]

The gram calorie is classified as a standard unit of energy. Calories can be abbreviated as cal; for example, 1 gram calorie can be written as 1 cal.

When working with calories (cal) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.

In practice, calories (cal) are widely used across standard energy applications within international standard workflows, engineering documentation, and technical data sheets.

What Is a Joule?

Coherent SI unit of energy and work (1 W·s = 1 N·m). It serves as a primary reference unit for measuring energy across scientific and practical applications. [2]

The joule is classified as an International System of Units (SI) unit of energy. Joules can be abbreviated as J; for example, 1 joule can be written as 1 J.

As the primary coherent reference unit for energy in this category, all other energy units are mathematically anchored to the joule (J).

In practice, joules (J) are widely used across standard energy applications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.

When converting energy between calories (cal) and joules (J), keep full floating-point precision (1 cal = 4.184 J; 1 J = 0.2390057 cal) during intermediate calculations and round only the final joule figure to match your instrument tolerance.

More Gram Calorie & Joule Conversions

Need to calculate in the opposite direction? Use our joules to calories converter (J to cal) to switch your starting unit immediately. You can also explore related tools such as converting kilojoules to joules, converting kilowatt-hours to joules, or converting calories to kilocalories.

Frequently Asked Questions

There are 4.184 joules (J) in 1 gram calorie (cal). Conversely, 1 joule (J) is equal to 0.23901 calories (cal).

References

NIST · BIPM · ISO
  1. [1]
    NIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — Calories (cal) to Joules (J)
    NIST CODATA Standard
  2. [2]
    NIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Gram Calorie (cal) (cal) & Joule (J)
    NIST SP 811 Specification
  3. [3]
    BIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (cal to J)
    BIPM Reference
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