Skip to content
Convertto

Energy Converter

Convert energy between 9 units with the formula, a reverse conversion and a quick-reference table.

To convert energy, enter a value and pick the units. The result appears instantly with the exact conversion formula, the reverse conversion, a quick-reference table of common values and every one of the 9 supported units. The "calorie" on food labels is actually a kilocalorie — 4184 joules. Nutrition labels in the EU show both kcal and kJ.

Runs in your browser
Units supported
9
Base unit
J
Precision
Adjustable from 1 to 15 significant figures
Shows
Formula, reverse conversion and a common-values table
Privacy
Runs entirely in your browser — nothing is uploaded
Cost
Free, unlimited, no sign-up

Frequently asked questions

How accurate is this energy converter?

Conversions use exact SI definitions where one exists and are computed in double-precision floating point. You can raise the displayed precision to 15 significant figures, and the unrounded result is shown separately. The "calorie" on food labels is actually a kilocalorie — 4184 joules. Nutrition labels in the EU show both kcal and kJ.

Can I reverse the conversion without retyping?

Yes — the swap toggle reverses the two units in place. The reverse rate is also shown in the detail section, so you can read it either way without changing anything.

Is my data sent anywhere?

No. The conversion is plain JavaScript running in your browser. No value you type is transmitted, logged or stored.

Can I link to a specific conversion?

Yes. The URL updates as you type, so you can bookmark or share a link that reopens with exactly the same conversion.

How to use the energy converter

  1. 1Set the value.
  2. 2Choose the from.
  3. 3Choose the to.
  4. 4Turn "Swap direction" on or off as needed.
  5. 5Set the significant figures.
  6. 6The result appears immediately — copy or download it.

Embed this tool

Put the working energy converter on your own site. It runs in your visitors' browsers exactly as it does here — free, no account, nothing uploaded.

Share this tool

Related tools

Angle ConverterConvert angle between 7 units with the formula, a reverse conversion and a quick-reference table.Area ConverterConvert area between 10 units with the formula, a reverse conversion and a quick-reference table.Clothing Size ConverterConvert clothing size between 6 units with the formula, a reverse conversion and a quick-reference table.Cooking Measurement ConverterConvert cooking measurement between 10 units with the formula, a reverse conversion and a quick-reference table.Data Storage ConverterConvert data size between 11 units with the formula, a reverse conversion and a quick-reference table.Data Transfer Rate ConverterConvert transfer rate between 8 units with the formula, a reverse conversion and a quick-reference table.

Last updated

More unit converters