Energy Converter
Energy Converter. Free, instant, no signup. Results update as you type.
Kilojoules
0.001
- Joules 1
- Calories 0.23900574
- Kilocalories 0.00023901
- Watt-hours 0.00027778
- Kilowatt-hours 0.00000028
- British thermal units 0.00094782
Conversions use internationally defined factors.
How to use this calculator
- Enter value — The calculator loads with a worked example already filled in, so you can see what a realistic set of figures looks like before replacing them with your own.
- Fill in the remaining fields — Every field has a sensible default. Change the ones that apply to you and leave the rest.
- Read the result — The answer updates as you type — there is nothing to submit. The rows beneath the headline show how it breaks down.
- Expand the schedule — Where a year-by-year table is offered, open it. The breakdown over time usually shows something the single headline figure does not.
- Share or print — Use the share button to copy a link with your figures already filled in, or print the result — the print stylesheet strips the navigation and adverts.
What this calculator works out
To use the Energy Converter, enter your value, from and to. The result — kilojoules — updates as you type, with no button to press and nothing to submit. The calculation runs entirely in your browser, so the figures you enter are never sent anywhere.
How this is calculated
Each dimension is defined as a table of factors relative to one base unit, so a conversion is two multiplications rather than a lookup of every possible pair. Temperature is handled separately because it has an offset as well as a scale, and fuel economy separately again because miles per gallon and litres per 100km are reciprocals of each other rather than a simple scaling.
A worked example
Take the values this page loads with:
- Value: 1
- From: Joules
- To: Kilojoules
On those figures the kilojoules is 0.001. Broken down:
- Joules: 1
- Calories: 0.23900574
- Kilocalories: 0.00023901
- Watt-hours: 0.00027778
- Kilowatt-hours: 0.00000028
Change any field above and every figure here recalculates — these numbers are produced by the same formula the calculator runs, so they cannot drift apart from it.
What the figures mean
The headline figure is the answer most people come for. The rows beneath it break that down so you can see which component is driving it — which is usually the more useful information when you are trying to change the outcome rather than just measure it.
What this calculator assumes
Conversions use internationally defined factors.
Why it runs in your browser
Every calculation on this page is arithmetic, and arithmetic does not need a server. Running it locally means the result is instant, it keeps working if your connection drops, and — the part that matters — your salary, your debts and your medical measurements are never transmitted to us. There is no figure on our side to store, log or lose.
Where this calculator stops
A calculator applies the rules it is given to the figures you enter. It cannot see the rest of your circumstances, and real financial decisions are rarely decided by a single number.
Treat the result as a starting point for a conversation — with a lender, an accountant or an adviser — rather than as an answer. Where an institution will quote you a real figure, that figure is the one that counts: it will include fees, your credit profile and terms this page knows nothing about.
Keeping the figures current
The formula behind this page does not change, but the assumptions you should bring to it do — interest rates, inflation and market returns all move. Revisit the inputs rather than trusting a figure you calculated a year ago.