⚡ Energy

Convert between Joules, Calories, BTU, and Watt-hours.

About Energy tools

This Energy category lets you convert between 58 units using verified ratios. Conversions run locally in your browser and display up to 8 decimals for quick verification.

Many converters are anchored to a base unit (here: Joule), then derived through stable multipliers. Each converter page includes the formula and reference tables for transparency.

Professional verification
Validate results with clear formulas, reference tables, and consistent unit symbols.
Fast exploration
Search tools instantly, open a dedicated page, and share deep-links.
Repeatable workflow
Keep results consistent across projects by using the same definitions and rounding.

Featured tools

joule → kilowatt hourkilojoule → kilocaloriebtu → joulecalorie → joule

Top conversions people use

People often convert joule → kilowatt hour, kilojoule → kilocalorie, calorie → joule.

joule → kilowatt hourkilojoule → kilocaloriecalorie → joulebtu → joulejoule → kilojoulejoule → caloriejoule → kilocaloriejoule → food caloriejoule → watt hourjoule → btu

FAQ

What is Energy used for?
Energy tools help you convert and verify values when unit systems differ. They are commonly used in engineering calculations, academic work, product specs, and data normalization.
Why can results differ between websites?
Different standards, rounding rules, and unit definitions can change results. Use the formula and reference tables on each tool page to confirm what definition is being applied.
Are the results accurate?
Yes. Calculations run locally in your browser using verified ratios and display up to 8 decimals. For professional work, keep unit symbols and round at the end.

Available Tools

All Energy Tools

Joule
Symbol: J
Kilojoule
Symbol: kJ
Calorie
Symbol: cal
Kilocalorie
Symbol: kcal
Food Calorie
Symbol: Cal
Watt-hour
Symbol: Wh
Kilowatt-hour
Symbol: kWh
BTU
Symbol: BTU
Electronvolt
Symbol: eV
Erg
Symbol: erg
Gigajoule
Symbol: GJ
Megajoule
Symbol: MJ
Millijoule
Symbol: mJ
Microjoule
Symbol: µJ
Nanojoule
Symbol: nJ
Attojoule
Symbol: aJ
Kiloelectron-volt
Symbol: keV
Megaelectron-volt
Symbol: MeV
Gigawatt-hour
Symbol: GWh
Megawatt-hour
Symbol: MWh
Kilowatt-second
Symbol: kW·s
Watt-second
Symbol: W·s
Newton-meter
Symbol: N·m
Horsepower hour
Symbol: hp·h
Horsepower (Metric) hour
Symbol: PS·h
Calorie (nutritional, IT)
Symbol: Cal
Kilocalorie (IT)
Symbol: kcal (IT)
Kilocalorie (th)
Symbol: kcal (th)
Calorie (IT)
Symbol: cal (IT)
Calorie (th)
Symbol: cal (th)
View All Energy Tools

Joule to Kilojoule

Professional J to kJ conversion.

Kilojoule to Joule

Professional kJ to J conversion.

Joule to Calorie

Professional J to cal conversion.

Calorie to Joule

Professional cal to J conversion.

Joule to Kilocalorie

Professional J to kcal conversion.

Kilocalorie to Joule

Professional kcal to J conversion.

Joule to Food Calorie

Professional J to Cal conversion.

Food Calorie to Joule

Professional Cal to J conversion.

Joule to Watt-hour

Professional J to Wh conversion.

Watt-hour to Joule

Professional Wh to J conversion.

Joule to Kilowatt-hour

Professional J to kWh conversion.

Kilowatt-hour to Joule

Professional kWh to J conversion.

Joule to BTU

Professional J to BTU conversion.

BTU to Joule

Professional BTU to J conversion.

Joule to Electronvolt

Professional J to eV conversion.

Electronvolt to Joule

Professional eV to J conversion.

Joule to Erg

Professional J to erg conversion.

Erg to Joule

Professional erg to J conversion.

Joule to Gigajoule

Professional J to GJ conversion.

Gigajoule to Joule

Professional GJ to J conversion.

Joule to Megajoule

Professional J to MJ conversion.

Megajoule to Joule

Professional MJ to J conversion.

Joule to Millijoule

Professional J to mJ conversion.

Millijoule to Joule

Professional mJ to J conversion.

Joule to Microjoule

Professional J to µJ conversion.

Microjoule to Joule

Professional µJ to J conversion.

Joule to Nanojoule

Professional J to nJ conversion.

Nanojoule to Joule

Professional nJ to J conversion.

Joule to Attojoule

Professional J to aJ conversion.

Attojoule to Joule

Professional aJ to J conversion.

Joule to Kiloelectron-volt

Professional J to keV conversion.

Kiloelectron-volt to Joule

Professional keV to J conversion.

Joule to Megaelectron-volt

Professional J to MeV conversion.

Megaelectron-volt to Joule

Professional MeV to J conversion.

Joule to Gigawatt-hour

Professional J to GWh conversion.

Gigawatt-hour to Joule

Professional GWh to J conversion.

Joule to Megawatt-hour

Professional J to MWh conversion.

Megawatt-hour to Joule

Professional MWh to J conversion.

Joule to Kilowatt-second

Professional J to kW·s conversion.

Kilowatt-second to Joule

Professional kW·s to J conversion.

Joule to Watt-second

Professional J to W·s conversion.

Watt-second to Joule

Professional W·s to J conversion.

Joule to Newton-meter

Professional J to N·m conversion.

Newton-meter to Joule

Professional N·m to J conversion.

Joule to Horsepower hour

Professional J to hp·h conversion.

Horsepower hour to Joule

Professional hp·h to J conversion.

Joule to Horsepower (Metric) hour

Professional J to PS·h conversion.

Horsepower (Metric) hour to Joule

Professional PS·h to J conversion.

Joule to Calorie (nutritional, IT)

Professional J to Cal conversion.

Calorie (nutritional, IT) to Joule

Professional Cal to J conversion.

Joule to Kilocalorie (IT)

Professional J to kcal (IT) conversion.

Kilocalorie (IT) to Joule

Professional kcal (IT) to J conversion.

Joule to Kilocalorie (th)

Professional J to kcal (th) conversion.

Kilocalorie (th) to Joule

Professional kcal (th) to J conversion.

Joule to Calorie (IT)

Professional J to cal (IT) conversion.

Calorie (IT) to Joule

Professional cal (IT) to J conversion.

Joule to Calorie (th)

Professional J to cal (th) conversion.

Calorie (th) to Joule

Professional cal (th) to J conversion.

Joule to BTU (IT)

Professional J to Btu (IT) conversion.

BTU (IT) to Joule

Professional Btu (IT) to J conversion.

Joule to BTU (th)

Professional J to Btu (th) conversion.

BTU (th) to Joule

Professional Btu (th) to J conversion.

Joule to Mega BTU (IT)

Professional J to MBtu (IT) conversion.

Mega BTU (IT) to Joule

Professional MBtu (IT) to J conversion.

Joule to Ton-hour (refrigeration)

Professional J to TR·h conversion.

Ton-hour (refrigeration) to Joule

Professional TR·h to J conversion.

Joule to Therm

Professional J to therm conversion.

Therm to Joule

Professional therm to J conversion.

Joule to Therm (EC)

Professional J to therm (EC) conversion.

Therm (EC) to Joule

Professional therm (EC) to J conversion.

Joule to Therm (US)

Professional J to therm (US) conversion.

Therm (US) to Joule

Professional therm (US) to J conversion.

Joule to Fuel oil equivalent (kiloliter)

Professional J to FOE/kL conversion.

Fuel oil equivalent (kiloliter) to Joule

Professional FOE/kL to J conversion.

Joule to Fuel oil equivalent (barrel US)

Professional J to FOE/bbl conversion.

Fuel oil equivalent (barrel US) to Joule

Professional FOE/bbl to J conversion.

Joule to Gigaton (TNT)

Professional J to Gton conversion.

Gigaton (TNT) to Joule

Professional Gton to J conversion.

Joule to Megaton (TNT)

Professional J to Mton conversion.

Megaton (TNT) to Joule

Professional Mton to J conversion.

Joule to Kiloton (TNT)

Professional J to kton conversion.

Kiloton (TNT) to Joule

Professional kton to J conversion.

Joule to Ton (TNT)

Professional J to ton TNT conversion.

Ton (TNT) to Joule

Professional ton TNT to J conversion.

Joule to Dyne-centimeter

Professional J to dyn·cm conversion.

Dyne-centimeter to Joule

Professional dyn·cm to J conversion.

Joule to Gram-force meter

Professional J to gf·m conversion.

Gram-force meter to Joule

Professional gf·m to J conversion.

Joule to Gram-force centimeter

Professional J to gf·cm conversion.

Gram-force centimeter to Joule

Professional gf·cm to J conversion.

Joule to Kilogram-force centimeter

Professional J to kgf·cm conversion.

Kilogram-force centimeter to Joule

Professional kgf·cm to J conversion.

Joule to Kilogram-force meter

Professional J to kgf·m conversion.

Kilogram-force meter to Joule

Professional kgf·m to J conversion.

Joule to Kilopond meter

Professional J to kp·m conversion.

Kilopond meter to Joule

Professional kp·m to J conversion.

Joule to Pound-force foot

Professional J to lbf·ft conversion.

Pound-force foot to Joule

Professional lbf·ft to J conversion.

Joule to Pound-force inch

Professional J to lbf·in conversion.

Pound-force inch to Joule

Professional lbf·in to J conversion.

Joule to Ounce-force inch

Professional J to ozf·in conversion.

Ounce-force inch to Joule

Professional ozf·in to J conversion.

Joule to Foot-pound

Professional J to ft·lbf conversion.

Foot-pound to Joule

Professional ft·lbf to J conversion.

Joule to Inch-pound

Professional J to in·lbf conversion.

Inch-pound to Joule

Professional in·lbf to J conversion.

Joule to Inch-ounce

Professional J to in·ozf conversion.

Inch-ounce to Joule

Professional in·ozf to J conversion.

Joule to Poundal foot

Professional J to pdl·ft conversion.

Poundal foot to Joule

Professional pdl·ft to J conversion.

Joule to Hartree energy

Professional J to Eh conversion.

Hartree energy to Joule

Professional Eh to J conversion.

Joule to Rydberg energy

Professional J to Ry conversion.

Rydberg energy to Joule

Professional Ry to J conversion.