Energy Converter

Convert between energy units: joules, calories, watt-hours, BTU, and more.

Value

From

4184

1 kilocalorie = 4184 joule

Common energy conversions

Quick reference values for the energy units people compare most often in physics, HVAC, and nutrition.

1 kWh: 3,600,000 J
1 kcal: 4,184 J
1 BTU: 1,055.06 J
1 Wh: 3,600 J

Energy unit notes

Food Calories are kilocalories

Nutrition labels usually use "Calories" to mean kilocalories (kcal). A 200 Cal snack contains 200 kcal, which equals 836,800 joules.

BTU and kWh describe the same kind of quantity

BTU is common for heating and cooling, while kWh is common for electrical usage. Converting between them helps compare HVAC output with power consumption.

How to Use Energy Converter

Select energy units

Choose the source and target energy units from the dropdown menus. All common energy and heat units are available.

Enter the energy value

Type the energy amount you want to convert. The result updates instantly in real time as you type.

Copy or swap the result

Copy the converted energy value to your clipboard, or click swap to reverse the conversion direction.

About Energy Converter

Energy converter online — convert joules to calories, BTU to kilowatt-hours, and between all energy measurement units instantly for free. Supports joules, kilojoules, calories, kilocalories (food calories), BTU, kilowatt-hours, watt-hours, electron volts, and foot-pounds with high precision. Use it for physics homework, chemistry calculations, nutrition label conversions, HVAC planning, appliance energy comparisons, and electricity bill analysis. The page also explains calorie vs kilocalorie differences and highlights reference values like 1 kWh = 3.6 MJ and 1 BTU = 1055.06 J. No signup, no ads — runs entirely in your browser.

Key Features

Convert between all common energy units including joules, kilojoules, calories, kilocalories, BTU, kWh, and electron volts
Real-time bidirectional conversion updates results instantly as you type any energy value
Differentiates between food calories (kcal) and scientific calories (cal) to avoid confusion
High precision calculations with multiple decimal places for physics, nutrition, and engineering
Common energy references for kWh, BTU, food Calories, and joules directly on the page
One-click unit swap to quickly reverse energy conversion direction between any two units
100% free and private — all energy calculations happen in your browser with no data collection

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Frequently Asked Questions

How to convert joules to calories online?▾

Enter the joules value and select calories as target. 1 joule equals approximately 0.2390 calories. For food calories (kcal), divide by 4,184.

How to convert BTU to kilowatt-hours?▾

Select BTU as source and kWh as target. 1 BTU equals approximately 0.000293 kWh. Common for HVAC and heating system calculations.

How to convert calories to joules?▾

Enter the calorie value and select joules. 1 calorie equals exactly 4.184 joules. Used in physics and chemistry calculations.

How to convert kilocalories to calories?▾

1 kilocalorie (kcal) equals exactly 1,000 calories. Food nutrition labels list energy in kcal, often misleadingly labeled as "calories."

How to convert kWh to joules?▾

Select kWh as source and joules as target. 1 kWh equals 3,600,000 joules. Useful for understanding electricity consumption in scientific terms.

How to convert BTU to calories?▾

Enter the BTU value and select calories. 1 BTU equals approximately 252 calories. Common for comparing heating and cooling energy ratings.

How to convert electron volts to joules?▾

Select eV as source and joules as target. 1 eV equals approximately 1.602 × 10⁻¹⁹ joules. Used in particle physics and quantum mechanics.

How to understand food calories vs scientific calories?▾

Food "calories" are actually kilocalories (kcal). 1 food calorie = 1 kcal = 1,000 scientific calories = 4,184 joules. Our converter handles both correctly.

What is the difference between calories and Calories on food labels?▾

In nutrition, a capital-C Calorie means one kilocalorie (kcal). That means 200 Calories on a label equals 200 kcal, or 836,800 joules.