Unit conversion
Energy Converter
Converts energy, where energy and power are different quantities.
Result
Conversions use exact internationally defined factors where one exists, so results are precise to the digits shown.
Get a Free Business AuditHow the calculation works
Each energy unit multiplied by its factor relative to the joule. A kilowatt hour is about 3,412 British thermal units, which is the conversion most used in heating and cooling work, where equipment is rated in one unit and energy is billed in the other.
What moves the number
- The factor for the unit pair.
- Whether the figure is energy or power.
- Whether the heat content is higher or lower heating value.
- Therms and the gas volume they represent.
Where this one goes wrong
Energy and power are distinct quantities and a kilowatt is not a kilowatt hour, so converting a power rating as though it were an energy amount is a category error rather than a factor mistake. Check the unit has a time dimension or does not. Fuel heat content is the other subtlety, since higher and lower heating values differ depending on whether the water vapour's latent heat is counted, and efficiency figures quoted against one are not comparable with the other.
Before you quote
- Check whether the quantity is energy or power.
- Note whether a heat content is a higher or lower heating value.
- Use the fuel's actual heat content where it varies.
Questions
About this calculator
How many BTU in a kilowatt hour?
About 3,412. It is the conversion most used in heating and cooling, where equipment is rated in British thermal units and electricity is billed in kilowatt hours, which makes comparing running costs a conversion exercise.
Is a kilowatt the same as a kilowatt hour?
No. A kilowatt is a rate of energy use and a kilowatt hour is an amount of energy. Converting one as though it were the other is a category error rather than a factor mistake, and it is the most common confusion here.
What are higher and lower heating values?
Two measures of a fuel's energy content, differing in whether the latent heat of the water vapour in the exhaust is counted. Efficiency figures quoted against one are not comparable with the other, which matters when comparing equipment.
Common energy conversions
| From | Equals |
|---|---|
| 1 Kilowatt-hours | 1 Kilowatt-hours |
| 1 Kilowatt-hours | 1,000 Watt-hours |
| 1 Kilowatt-hours | 3,600,000 Joules |
| 1 Kilowatt-hours | 3,600 Kilojoules |
| 1 Kilowatt-hours | 3,412.141633 BTU |
| 1 Kilowatt-hours | 0.034121 Therms |
| 1 Kilowatt-hours | 860,420.650096 Calories |
| 1 Kilowatt-hours | 860.42065 Kilocalories |
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How to use this calculator
- Value. Enter your own figure; the page starts at 1.
- From. Enter your own figure; the page starts at Kilowatt-hours.
- To. Enter your own figure; the page starts at BTU.
The result updates as you type, so you can try a figure, see what it does to converted value, and change it back. Nothing you enter is sent anywhere or saved.
A worked example
These are the figures the calculator opens with. Every number in the results column below is produced by the same calculation the page runs, so you can follow it through before putting your own figures in.
What goes in
| Input | Value |
|---|---|
| Value | 1 |
| From | Kilowatt-hours |
| To | BTU |
What comes out
| Result | Value |
|---|---|
| Converted value main result | 3,412.14 |
| Conversion factor | 3,412.14 |
1 Kilowatt-hours equals 3,412.14 BTU.
How sensitive the answer is
Holding everything else steady and changing only value, this is what happens to converted value. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Value | Converted value |
|---|---|
| 0.5 | 1,706.07 |
| 0.75 | 2,559.11 |
| 1 example above | 3,412.14 |
| 1.5 | 5,118.21 |
| 2 | 6,824.28 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Value
- A number, starting at 1.
- From
- Choose from Kilowatt-hours, Watt-hours, Joules, Kilojoules, BTU, Therms, Calories, Kilocalories, Foot-pounds.
- To
- Choose from Kilowatt-hours, Watt-hours, Joules, Kilojoules, BTU, Therms, Calories, Kilocalories, Foot-pounds.
What the results tell you
| Result | What it is |
|---|---|
| Converted value | The headline result. A number. |
| Conversion factor | A number. |
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