Heating costs compared: what a kilowatt hour of heat costs
Gas, heating oil and electricity are sold in different units. They only become comparable once you work out what one kilowatt hour of heat in the radiator costs.
Worked through by Radif Partners · Editorial policy · How we calculate
Heating costs compared
Cheapest: Ground heat pump
€943
| Air heat pump | €1,193 |
| Oil | €2,016 |
| Gas | €2,189 |
| Storage heaters | €4,208 |
Cost a year, Lower Saxony climate, 2026 prices.
To compare heating costs you have to compare the price of heat, not the price of fuel. At the official average prices for 2026, one kilowatt hour of heat from a gas boiler costs 14.81 ct, from an oil boiler 13.64 ct at the twelve-month average and 19.52 ct at the mid-October 2026 price. An air-source heat pump with the seasonal performance factor of 3.4 measured in older German houses delivers it for 8.07 ct on a heat pump tariff, a ground-source unit for 6.38 ct, storage heaters for 28.47 ct. An unrenovated 180 m² house in efficiency class G in Bavaria needs 35,793 kWh of heat a year: €5,300 with gas, €4,883 with oil or €6,986 at today’s price, €2,889 with an air heat pump. The heat pump stays cheaper than gas as long as its performance factor is above 1.9. Renovated to class D, the same house costs €2,709 a year with gas.
One yardstick: cents per kWh of heat
Gas appears on a German bill in kilowatt hours, heating oil in litres, heat pump electricity in kilowatt hours again but with a completely different meaning. Lining up the unit prices therefore compares apples with pears. This page converts every price into what actually arrives in the house: one kilowatt hour of heat. For a boiler that includes the efficiency that Fraunhofer ISE assumes for typical systems, 87 %; for a heat pump it includes the seasonal performance factor from the same field study.
| System | Energy price | Cents per kWh of heat |
|---|---|---|
| Ground-source heat pump, heat pump tariff | 27.44 ct/kWh power, SPF 4.3 | 6.38 |
| Air-source heat pump, heat pump tariff | 27.44 ct/kWh power, SPF 3.4 | 8.07 |
| Air-source heat pump, household power | 37.97 ct/kWh power | 11.17 |
| Heating oil, twelve-month average | €119 per 100 litres | 13.64 |
| Gas, household average | 11.58 ct/kWh gas | 14.81 |
| Storage heaters | 28.47 ct/kWh power | 28.47 |
| Heating oil, price of 12 October 2026 | €170 per 100 litres | 19.52 |
The prices come from the Federal Statistical Office (Destatis) survey for the first half of 2026, the European Commission’s Weekly Oil Bulletin and the Federal Network Agency monitoring report. Standing and meter charges are spread into them. District heating has no official average, so it is not in the table; how to judge your own price is explained under district heating prices.
Why oil is sometimes ahead and sometimes behind
The heating oil price jumped in 2026 more sharply than it had for years. Over the last twelve months oil was just below gas per kWh of heat; at the mid-October price it is well above. Both figures are correct, they answer different questions. If you filled your tank cheaply in spring, you heat for less than with gas this winter. If you have to buy now, you pay more. Neither value alone is a sound basis for a twenty-year decision, which is why the comparison shows both. Expats buying a house with an oil tank should ask the seller how full it is and at what price it was filled.
Two houses, two results
The price per kWh of heat says which system is cheaper. How much money that means each year depends on the amount of heat, which is driven mainly by floor area, the state of the building and the climate. The calculator derives it from the efficiency class under Annex 10 of the Building Modernisation Act and the degree days published by the German Weather Service. Two cases show the range.
| System | Terraced house 100 m², class D, NRW | Old house 180 m², class G, Bavaria |
|---|---|---|
| Ground-source heat pump | €587 | €2,284 |
| Air-source heat pump | €742 | €2,889 |
| Heating oil (twelve-month average) | €1,254 | €4,883 |
| Gas | €1,361 | €5,300 |
| Storage heaters | €2,617 | €10,190 |
| Heat demand a year | 9,194 kWh | 35,793 kWh |
In the terraced house the gap between gas and an air heat pump is €619 a year. In the old house it is €2,412, because the same price difference applies to a much larger amount of heat. That is why switching pays back faster in a poorly insulated house, even if the heat pump runs a little less efficiently there. How degree days shift the bill between Hesse and Thuringia is shown under heating costs by state.
Gas or heat pump, per year
Heat pump saves a year
€1,054
| Gas boiler | €2,316 |
| Heat pump | €1,262 |
| Heat pump electricity | 4,600 kWh |
Gas 12 ct, heat pump power 27 ct, SPF 3.
The performance factor sets the gap
A heat pump does not win by default. Its cost per kWh of heat is the electricity price divided by the seasonal performance factor. On a heat pump tariff a factor of 1.9 is enough to match gas; on household electricity it takes 2.6. In existing houses, air-source units were measured between 2.6 and 4.9, ground-source units between 3.6 and 5.4. Low flow temperatures, large enough radiators and hydraulic balancing push the figure up. Which electricity price applies to your system, and what a separate meter changes, is covered under heat pump electricity price.
Renovate or replace: which does more
In the old house above, renovating from class G to class D cuts heat demand from 35,793 to 18,294 kWh. Gas then costs €2,709 instead of €5,300, the air heat pump €1,476 instead of €2,889. The two steps complement each other: insulation shrinks the amount of heat, the heat pump lowers the price of each kWh. The class values are mid-points of the legal bands and so an assumption. If you know your measured consumption, enter it directly in the heating cost calculator; the previous owner’s bills, if you are buying, are the best starting point.
What the comparison leaves out
The comparison shows running energy costs only. It does not include purchase, servicing, the chimney sweep (Schornsteinfeger), meter rental or the standing charge of a second electricity meter, because there are no official averages for them. The future CO₂ price can only be shown as a scenario. At €100 per tonne instead of the roughly €65 contained in 2026 prices, gas in the old house would cost €5,646 and oil €5,341. That is arithmetic, not a forecast. How the gas price is made up and how much of it is CO₂ is explained under gas price. Whether switching pays off once purchase and grant are included is worked out under heat pump or gas boiler.