How do I convert joules to calories?

Divide the joule value by 4.184 to get calories. For example, 100 joules is about 23.9 calories.

How do I convert calories to joules?

Multiply the calorie value by 4.184 to get joules. For example, 50 calories equals 209.2 joules.

What is the formula for kinetic energy?

Kinetic energy equals half the mass times the velocity squared, written KE = 0.5mv².

How do I convert kWh to joules?

Multiply the kilowatt-hour value by 3,600,000 to get joules, since one kWh is the energy of one kilowatt sustained for one hour.

What is the difference between a calorie and a food Calorie?

A food Calorie (capital C), also called a kilocalorie, equals 1000 small calories. Nutrition labels use the food Calorie even though they usually just write 'calories'.

How do I convert BTU to joules?

Multiply the BTU value by approximately 1055.06 to get joules, using the International Table BTU definition.

What is an electronvolt used for?

The electronvolt is used in physics and chemistry to describe extremely small energies, such as those of individual atoms, electrons and photons.

How many joules are in a kilowatt-hour?

One kilowatt-hour equals exactly 3,600,000 joules.

A watt-hour is the energy delivered by one watt of power sustained for one hour, equal to 3600 joules.

How accurate is this energy converter?

All conversions are calculated internally in joules using exact or internationally standardized constants, with results rounded to up to 10 decimal places.

How do I calculate kinetic energy from mass and speed?

Convert the mass to kilograms and the speed to meters per second, then apply KE = 0.5 × mass × speed squared.

What is the difference between energy and power?

Energy measures a total amount of work done or heat transferred, while power measures the rate at which energy is used or produced, in energy per unit time.

Can this tool handle negative or scientific notation values?

Yes, decimals and scientific notation such as 1.5e3 are supported, though energy and mass are generally treated as positive magnitudes.

Is ConvertGPT's energy converter free to use?

Yes, it is completely free, requires no registration, and runs entirely in your browser with no usage limits.

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Energy Conversions

8 energy units · calculator + converter

Energy Converter & Calculator

Work out kinetic energy from a mass and a velocity, then convert the result into Joules, Calories, kilowatt-hours, BTU, electronvolts and more — all calculated instantly in your browser.

8Energy units

10Decimal precision

0msServer round-trips

Mass

Velocity

Mass unit Velocity unit Show result in

9J

KE = 0.5 × m × v² = 0.5 × 2 × 3² = 9 J

From

J

To

cal

23.900573614cal

cal = J / 4.184

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Joule	Calorie

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