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Energy Converters

Convert between joules, kilojoules, megajoules, calories, kilocalories, watt-hours, kilowatt-hours, BTU, foot-pounds, and therms.

20converters
Overview

About this energy converter

UtilityEra’s Energy Converter helps you switch between standard scientific, electrical, thermal, and imperial energy units in one place. Use it for physics homework, engineering calculations, appliance energy comparisons, nutrition-related conversions, and HVAC or fuel-energy references.

The converter supports common energy units including joules (J), kilojoules (kJ), megajoules (MJ), calories (cal), kilocalories (kcal), watt-hours (Wh), kilowatt-hours (kWh), British thermal units (BTU), foot-pounds (ft·lb), and therms.

Quick Converter
Results update instantly as you type
From
To
3.6
Try:
Conversion Result
1 kWh = 3.6 MJ
× 3.6
Reference Conversion Table 1 unit → other units
Unit → Joules → Kilojoules → Kilocalories → Watt-hours → BTU → Kilowatt-hours
Guide

How to use the energy converter

  • Choose the unit you want to convert from.
  • Enter the energy value in the input field.
  • Select the target unit you want to convert to.
  • Read the converted result instantly along with the conversion factor.
  • Use the preset examples or browse dedicated converter pages for common conversions.
Reference

Common energy units explained

Joules (J) are the SI base unit of energy used in science and engineering.

Kilojoules (kJ) and megajoules (MJ) are useful for larger energy values.

Watt-hours (Wh) and kilowatt-hours (kWh) are common in electricity use.

Calories (cal) and kilocalories (kcal) are used in chemistry and nutrition contexts.

BTU, foot-pounds, and therms appear in heating, gas, and imperial systems.

Formulas

Useful energy conversion formulas

These are some of the most common energy conversions used in practice:

  • 1 kWh = 3.6 MJ = 3,600,000 J
  • 1 Wh = 3600 J
  • 1 kcal = 4.184 kJ
  • 1 BTU ≈ 1055.0559 J
  • 1 ft·lb ≈ 1.35581795 J
  • 1 therm ≈ 105,505,585.262 J
FAQ

Frequently asked questions

What does an energy converter measure?

An energy converter translates a value from one energy unit into another, such as joules, kilojoules, kilocalories, watt-hours, kilowatt-hours, BTU, foot-pounds, and therms.

What is the SI unit of energy?

The joule is the SI unit of energy and is widely used in science and engineering.

What is the difference between calories and kilocalories?

One kilocalorie equals 1000 small calories. In food labeling, the term Calories often refers to kilocalories.

How is electrical energy measured?

Electrical energy is commonly measured in watt-hours and kilowatt-hours, which are often used for appliances and utility billing.

When should I use BTU or therms?

BTU and therms are commonly used in heating, HVAC, and natural gas contexts, especially in imperial or US energy measurements.