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Joules to Calories Converter

Convert joules to calories instantly. 1 J = 0.239005736138 cal. Enter any value and get an accurate result with a reference table for common conversions.

How to convert joules to calories

To convert a measurement in joules to calories, multiply the value by 0.239005736138. The conversion factor comes from the relationship between both units and the joule.

For example, to convert 5 J to calories: 5 × 0.239005736138 = 1.195029 cal.

What is a joule?

A joule is the SI derived unit of energy, equal to the work done when a force of one newton moves an object one meter (1 N·m). Named after the English physicist James Prescott Joule, who established the mechanical equivalent of heat in the 1840s. The joule became the SI standard for all forms of energy, work, and heat.

Common uses of joules include: Scientific and engineering energy calculations; Nutrition labeling in metric countries; Mechanical work and kinetic energy; Electrical energy in physics (watt-seconds).

What is a calorie?

A calorie (small calorie) is the energy needed to raise the temperature of one gram of water by one degree Celsius, defined as exactly 4.184 joules. The calorie originated in early-19th-century thermodynamics. The thermochemical calorie, fixed at exactly 4.184 J, is the modern standard, though it is often confused with the larger food Calorie (kilocalorie).

Common uses of calories include: Chemistry and thermodynamics; Heat-of-reaction measurements; Physics heat-transfer problems; Historical energy references.

Joules to calories worked examples

Here are some common values converted:

1 J = 0.239005736138 cal 5 J = 1.195029 cal 10 J = 2.390057 cal 50 J = 11.950287 cal 100 J = 23.900574 cal

Frequently asked questions

How many calories are in one joule?

One joule (J) equals 0.239005736138 calories (cal). Multiply any value in joules by 0.239005736138 to convert to calories.

How do I convert joules to calories?

Multiply the value in joules by 0.239005736138. For example, 5 J × 0.239005736138 = 1.195029 cal.

How do I convert calories to joules?

Multiply the value in calories by 4.184, or divide by 0.239005736138. Use the swap button on the converter above to reverse the direction.

Is the joule to calorie conversion exact?

The thermochemical calorie is defined as exactly 4.184 J and the BTU as 1055.056 J. Conversions between SI energy units are exact.

What is the formula for joules to calories?

The formula is: cal = J × 0.239005736138. This comes from the definition of both units relative to the joule.

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