100 therms to kWh
100 × 105.506 MJ ÷ 3.6 = 2,930.72 kWh. Older UK gas contracts and some suppliers still quote prices per therm; divide by 29.31 to get a price per kWh.
In kilowatt-hours 2,930.72 kWh Open in the calculator
Energy unit converter
Convert energy between kWh, MJ, GJ, Btu, therms, kcal and toe, or power between kW, Btu/h, tons of refrigeration and horsepower.
In tonnes of oil equivalent
21.4961toe
1 MWh = 0.0859845 toe.
Check the values to see a result.
- Kilowatt-hours
- 250,000 kWh
- Watt-hours
- 250,000,000 Wh
- Megajoules
- 900,000 MJ
- Gigajoules
- 900 GJ
- Kilojoules
- 900,000,000 kJ
- British thermal units
- 853,035,408 Btu
- Million Btu
- 853.035 MMBtu
- Therms (EC)
- 8,530.32 therm (EC)
- Therms (US)
- 8,532.39 therm (US)
- Kilocalories
- 214,961,307 kcal
How it’s calculated
- xtoe = xMWh × 0.0859845=250 × 0.0859845=21.4961 toe
xto = xfrom × (size of the from-unit ÷ size of the to-unit)
250 MWh is 21.4961 toe.
Tip: Therms differ: the EC therm is 105.506 MJ and the US therm 105.4804 MJ. For UK and Irish gas bills the difference is under 0.03%.
How to convert energy units
Every energy unit is a fixed number of joules, so converting between them is one multiplication. 1 kWh is exactly 3.6 MJ, about 3,412 Btu and 0.03412 therms. 1 tonne of oil equivalent is 11,630 kWh.
The same holds for power: 1 kW is about 3,412 Btu per hour, and one ton of refrigeration, the US unit for chiller capacity, is 3.517 kW.
Any energy unit to any other
xto = xfrom × (joules per from-unit ÷ joules per to-unit)
The calculator holds each unit’s size in joules, from NIST Special Publication 811, and divides one by the other.
kWh and MJ
1 kWh = 3.6 MJ
A kilowatt for an hour is 1,000 J/s × 3,600 s = 3,600,000 J. This is exact, which is why gas bills divide megajoules by 3.6.
Btu, therms and MMBtu
1 Btu = 1055.06 J; 1 therm = 100,000 Btu
The International Table Btu is 1055.05585262 J. The EC therm is 105.506 MJ, 29.3072 kWh; the US therm is slightly smaller, 105.4804 MJ. An MMBtu, used in gas trading, is one million Btu, 293.07 kWh.
Power: kW, Btu/h, tons and horsepower
1 TR = 12,000 Btu/h = 3.517 kW
Chiller and air-conditioning capacity is often in tons of refrigeration or Btu per hour. Mechanical horsepower is 745.7 W and metric horsepower 735.5 W.
Energy unit conversion examples
A 100-ton chiller in kW
100 × 12,000 Btu/h is 1.2 million Btu/h, which is 351.685 kW of cooling. Divide it by the electrical input to get the chiller’s COP, as the chiller COP calculator does.
In kilowatts 351.685 kW Open in the calculator
250 MWh in tonnes of oil equivalent
National energy statistics report in toe, defined as 41.868 GJ. 250 MWh is 900 GJ, or 21.4961 toe.
In tonnes of oil equivalent 21.4961 toe Open in the calculator
Energy conversion table
One of each energy unit in kWh and MJ.
| Unit | kWh | MJ |
|---|---|---|
| 1 kWh | 1 | 3.6 |
| 1 MWh | 1,000 | 3,600 |
| 1 MJ | 0.277778 | 1 |
| 1 GJ | 277.778 | 1,000 |
| 1 Btu | 0.000293071 | 0.00105506 |
| 1 MMBtu | 293.071 | 1,055.06 |
| 1 therm (EC) | 29.3072 | 105.506 |
| 1 therm (US) | 29.3001 | 105.48 |
| 1 kcal | 0.001163 | 0.0041868 |
| 1 toe | 11,630 | 41,868 |
Power conversion table
One of each power unit in kW and Btu per hour.
| Unit | kW | Btu/h |
|---|---|---|
| 1 kW | 1 | 3,412.14 |
| 1 MW | 1,000 | 3,412,142 |
| 1 Btu/h | 0.000293071 | 1 |
| 1 ton of refrigeration | 3.51685 | 12,000 |
| 1 hp | 0.7457 | 2,544.43 |
| 1 hp (metric) | 0.735499 | 2,509.63 |
Questions about energy units
How many kWh in a therm?
About 29.31 kWh. The EC therm is 29.3072 kWh and the US therm 29.3001 kWh.
How many Btu in a kWh?
About 3,412.14 Btu, using the International Table Btu.
What is the difference between kWh and kW?
kWh is energy, kW is power. This converter keeps them apart: choose Energy for kWh, MJ and therms, and Power for kW, Btu/h and tons. To go from power to energy, multiply by time with the kW to kWh calculator.
Why is a tonne of oil equivalent not exact?
It is a convention for comparing fuels, fixed at 41.868 GJ, the net calorific value of a notional crude oil. Real oils vary.
Limits of this result
- The tonne of oil equivalent is a convention (41.868 GJ, a net calorific value); other agencies have used slightly different values.
- Converting a fuel quantity to energy needs its calorific value; this converts energy units only.
- Ton of refrigeration is the US unit of 12,000 Btu per hour, not a metric tonne of anything.
Measure the energy behind the figure
Heat meters report in kWh, MWh or GJ depending on the model. A ZHM reads a wired M-Bus heat meter and passes its registers to Edge with their units.
