Energy Converter
Convert between joules, calories, kilowatt-hours, BTU, and more.
Convert Energy Units
This tool switches between eight energy units: joules, kilojoules, calories, kilocalories (food Calories), watt-hours, kilowatt-hours, BTU, and foot-pounds. Enter a value and choose your units for an accurate conversion.
Common uses include matching nutrition labels (kilocalories) to scientific measurements (joules), reading a home electricity bill in kWh, and comparing heating or cooling equipment rated in BTU.
Frequently Asked Questions
Is a food Calorie the same as a calorie?
No. A food "Calorie" (capital C) printed on nutrition labels is actually a kilocalorie, equal to 1,000 small calories. The "kilocalorie" option in this converter is the one that matches food-label Calories.
How many joules are in a kilocalorie?
One kilocalorie equals 4,184 joules. That's the figure used behind the scenes whenever you convert between kilocalories and any other energy unit here.
How many BTU are in a kilowatt-hour?
1 kilowatt-hour equals approximately 3,412.14 BTU. This is the conversion most often used to compare an appliance's electrical energy use with a heating or cooling rating given in BTU.
What's the difference between BTU and BTU/h?
BTU measures a fixed amount of energy, while BTU/h (BTU per hour) measures a rate of power over time. An air conditioner rated at 10,000 BTU/h uses 10,000 BTU for every hour it runs, not 10,000 BTU total. This converter works with BTU as an energy amount, not a rate.
What is a foot-pound?
A foot-pound is the energy needed to move a one-pound force through a distance of one foot. It's common in US mechanical and engineering contexts, such as torque and impact energy ratings.
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