Show the formula and working
This free heating oil litres to kWh converter turns litres of kerosene or gas oil into kilowatt hours of energy, or kWh back into litres, for homes off the gas grid in the UK, Ireland and Europe. It also works out the useful heat your boiler delivers and, from your own oil price, the cost per kWh, so you can compare oil with gas, electricity or a heat pump.
Quick answer: To convert heating oil litres to kWh, multiply the litres by about 10.27 for kerosene on a gross basis, or 9.82 on a net basis. So 1,000 litres of kerosene holds about 10,267 kWh. A boiler that is 90% efficient turns that into about 9,240 kWh of useful heat. Gas oil holds about 10.52 kWh per litre.
What Is a Heating Oil Litres to kWh Converter?
A heating oil litres to kWh converter is a tool that changes a volume of heating oil into the energy it contains, measured in kilowatt hours. The formula in plain words is: kWh = litres x kWh per litre. The kWh per litre comes from the fuel’s calorific value in megajoules per kilogram, multiplied by its density in kilograms per litre and divided by 3.6, because 1 kWh is exactly 3.6 MJ. Useful heat = kWh x boiler efficiency.
For kerosene, a gross calorific value of 46.20 MJ/kg and a density of 0.800 kg per litre give 36.96 MJ per litre, or 10.27 kWh. The density matches the 1,250 litres per tonne for burning oil used in the Digest of UK Energy Statistics. Real deliveries vary a little with the batch and temperature, so you can enter your supplier’s own figure as a custom value.
How Do You Use the Heating Oil Litres to kWh Converter?
- Choose the Direction: “Litres to kWh” or “kWh to litres”.
- Enter the amount in Litres or kWh, for example the litres on your last delivery note.
- Pick the Fuel type: “Kerosene (28 second heating oil)” for most home boilers, “Gas oil (35 second, red diesel)” for some older or larger systems, or “Custom value” and then type your figure in Custom energy content.
- Choose the Calorific value basis: “Gross (same basis as UK gas bills)” to compare with gas, or “Net (used in many EU and boiler figures)”.
- Set the Boiler efficiency from your boiler’s manual, or 100 to see the raw energy only.
- Enter your Oil price per litre from your latest quote. The default is only an example.
- Read the result, then open “Show the formula and working” to see the kWh per litre, the useful heat and the cost per kWh.
How Many kWh Are in a Litre of Heating Oil?
A litre of kerosene heating oil holds about 10.27 kWh gross or 9.82 kWh net, and a litre of gas oil holds about 10.52 kWh gross or 10.17 kWh net. The net figures come from the SEAI conversion factors, which give kerosene 35.36 MJ per litre and gas oil 36.60 MJ per litre. Gas oil is denser, so each litre carries a little more energy.
What Is the Difference Between Gross and Net Calorific Value?
The gross calorific value includes the heat released when water vapour in the flue gases condenses, and the net value leaves it out, so for kerosene the gross figure is about 4.5% higher. UK gas bills use gross values, so choose gross when comparing oil with mains gas. Many European statistics and some boiler efficiency figures use net values, so match the basis to the figure you are comparing with.
How Many Litres of Heating Oil Do I Need for a Year?
Divide the heat your home needs in a year by about 9.24 kWh per litre, which is kerosene at 10.27 kWh gross with a 90% efficient boiler. For example, a home needing 12,000 kWh of heat would use about 1,299 litres. To estimate the heat demand of your home and the boiler output it needs, use the boiler size calculator.
Is Heating Oil Cheaper Than Gas or a Heat Pump per kWh?
Compare the cost per kWh of useful heat, which is the oil price per litre divided by the kWh per litre and the boiler efficiency. At an example price of 62p per litre and 90% efficiency, kerosene heat costs about 6.71p per kWh. Put your own prices into the converter and compare the result with the heat pump running cost calculator. Oil boiler installation and servicing should be done by an OFTEC registered technician or the local equivalent.
Heating Oil Litres to kWh Conversion Table
| Litres | Kerosene, gross (kWh) | Kerosene, net (kWh) | Gas oil, gross (kWh) | Gas oil, net (kWh) |
|---|---|---|---|---|
| 1 | 10.27 | 9.82 | 10.52 | 10.17 |
| 100 | 1,026.67 | 982.22 | 1,051.56 | 1,016.67 |
| 500 | 5,133.33 | 4,911.11 | 5,257.78 | 5,083.33 |
| 1,000 | 10,266.67 | 9,822.22 | 10,515.56 | 10,166.67 |
| 1,500 | 15,400 | 14,733.33 | 15,773.33 | 15,250 |
| 2,500 | 25,666.67 | 24,555.56 | 26,288.89 | 25,416.67 |
These are typical values. The energy in a real delivery can differ slightly, so treat the last digit as an estimate.
Worked Example: An Oil Delivery
Example: 1,000 litres of kerosene has just been delivered and the quote was 62p per litre. Leave the Direction on “Litres to kWh”, enter 1,000 in Litres or kWh, keep “Kerosene (28 second heating oil)” and “Gross (same basis as UK gas bills)”, set Boiler efficiency to 90 and Oil price per litre to 0.62. The converter shows 1,000 x 10.2667 = 10,267 kWh in the oil, 10,267 x 90% = 9,240 kWh of useful heat, an oil cost of £620.00 and a cost of 6.71p per kWh of heat. You can now compare that figure with other options on the heating calculators page.
Heating Oil Litres to kWh Converter FAQs
How do I convert litres of heating oil to kWh?
Multiply the litres by the energy content of the oil. For kerosene use about 10.27 kWh per litre on a gross basis, so 500 litres is about 5,133 kWh. Multiply by your boiler efficiency to find the useful heat.
How many kWh is 1,000 litres of kerosene?
About 10,267 kWh on a gross basis, or 9,822 kWh net. With a 90% efficient boiler, 1,000 litres gives about 9,240 kWh of useful heat, which you can compare directly with the kWh on a gas or electricity bill.
What is the difference between kerosene and gas oil?
Kerosene, also called 28 second oil, is the lighter fuel used by most modern home oil boilers. Gas oil, or 35 second oil, is heavier and denser, so it holds about 2% more energy per litre on a gross basis. Use the fuel your boiler is designed for.
How do I work out the cost per kWh of heating oil?
Divide the price per litre by the kWh per litre. At 62p per litre and 10.27 kWh per litre, the oil costs about 6.04p per kWh. Divide again by your boiler efficiency, such as 0.9, for the cost per kWh of useful heat, about 6.71p.
How do I convert kWh to litres of oil?
Divide the kWh by the kWh per litre. For kerosene on a gross basis, 10,000 kWh of fuel energy is about 974 litres. Choose “kWh to litres” in the converter, and remember to allow for boiler losses if the kWh figure is heat you need.
What efficiency should I use for my oil boiler?
Use the seasonal efficiency in your boiler’s manual or product data. Modern condensing oil boilers are more efficient than older non condensing ones. The 90% default is only an example, and setting 100% shows the raw energy in the oil.
Checked October 2026. Sources: SEAI conversion factors (net calorific values and densities), Digest of UK Energy Statistics, Annex A (gov.uk), Heat of combustion (Wikipedia, gross calorific values).