Home heating cost: gas, heating oil, electricity and heat pump calculator

A Belgian household burning 17,000 kWh of gas a year now pays about 2,500 EUR to heat its home and produce hot water, or 208 EUR a month as an advance payment. The useful question comes right after: what would the same heat cost with heating oil, with electricity, or with a heat pump? The calculator starts from your bill and answers for five systems, at November 2026 prices.

Annual heating cost, five systems side by side

Start from your bill: the calculator works out how much heat your home needs, then prices that same heat with each system. Every value can be edited.

I start fromMy gas bill (kWh per year)My heating oil purchases (litres per year)My direct electric heating (kWh per year)My heat pump (kWh per year)My EPC certificate (floor area and kWh/m² per year)

Gas consumed (kWh)

Efficiency of your current system (%)

If you cook with gas, your bill includes cooking: take it out to keep only heating and hot water.

All-in unit prices

Gas (EUR/kWh)

Electricity (EUR/kWh)

Heating oil (EUR/litre)

Efficiency of the systems compared

Condensing gas boiler (%)

Recent oil boiler (%)

Energy per litre of heating oil (kWh)

Heat pump, low-temperature circuit (SCOP)

Heat pump, high-temperature radiators (SCOP)

Useful heat required

15,640kWh per year

Your estimated current cost

EUR 2,499

System

To buy

Per year

Per month (smoothed)

Per kWh of heat

Gap with today

Heat pump, low temperaturecheapest

4,469 kWh

EUR 2,172

EUR 181

EUR 0.139

EUR -327

Condensing gas boiler

17,000 kWh

EUR 2,499

EUR 208

EUR 0.160

EUR 0

Oil boiler

1,712 L

EUR 2,542

EUR 212

EUR 0.163

+EUR 43

Heat pump, high temperature

6,256 kWh

EUR 3,040

EUR 253

EUR 0.194

+EUR 541

Electric convectors

15,640 kWh

EUR 7,601

EUR 633

EUR 0.486

+EUR 5,102

Break-even point: at these prices, a heat pump costs less to run than the gas boiler as soon as its SCOP exceeds 3.04.

The low-temperature line assumes underfloor heating or low-temperature radiators. On radiators running at 55 or 65 °C, read the high-temperature line.

Assumptions, sources and dates

Gas EUR 0.147/kWh and electricity EUR 0.486/kWh: all-in annual bill of a fixed contract on 2 November 2026 according to Test-Achats (EUR 2,500 for 17,000 kWh of gas, EUR 1,700 for 3,500 kWh of electricity), divided by those volumes. These averages include fixed charges: the variable price on your own bill is more accurate.

Heating oil EUR 1.4846/litre: official maximum price incl. VAT for an order of 2,000 litres or more, valid from 4 November 2026 (FPS Economy). Below 2,000 litres: EUR 1.5277/litre.

10.15 kWh per litre of heating oil: net calorific value of 0.03655 GJ per litre, AwAC table of values, 2026 edition.

Gas boiler 92 %, expressed on the gross calorific value like your bill; the European floor has been 86 % since 26 September 2015 (Regulation 813/2013). Oil 90 %, convector 100 %.

SCOP 3.5 and 2.5: values used by this site. Since 2017, Regulation 813/2013 requires at least 125 % seasonal efficiency from a low-temperature heat pump and 110 % from the others, i.e. a SCOP of roughly 3.2 and 2.8.

Default starting point: 17,000 kWh of gas, CREG standard residential profile D3a.

Informative estimate based on the amounts you enter: not a quotation, not an energy audit, not personal advice. Not included: fixed charges, mandatory boiler servicing, oil tank inspection, investment, regional subsidies, the Flemish capacity tariff. The national default prices do not distinguish Wallonia, Brussels and Flanders. Sizing a heat pump or a boiler is a job for an approved professional. This site is neither a supplier nor an installer and earns no commission.

How much does it cost to heat a house per year in Belgium?

Around 2,500 EUR for a gas-heated household on the national average.

That figure combines two public references. The first is the standard residential profile D3a of the CREG, the federal energy regulator, set at 17,000 kWh of gas a year for a household that heats its home and its water with gas. The second is the survey of supplier price cards published by Test-Achats on 2 November 2026, the Belgian consumer association: on a new fixed contract, average gas consumption costs 2,500 EUR a year, all charges included. Divided by 17,000, that gives 0.147 EUR per kilowatt-hour.

That amount has jumped. In March 2026, the energy component of gas alone was 5.14 euro cents per kWh in Wallonia; on 2 November it reached 11.29 cents, and the association puts the difference at 1,046 EUR a year for average consumption. Wholesale prices passed 100 EUR/MWh at the end of October. A heating cost benchmark dated from the summer is therefore wrong by several hundred euros.

Your own bill is not the average. A well-insulated flat falls below 1,000 EUR, an old detached house goes above 3,000 EUR, which is why the calculator starts from your real consumption rather than from a typical home.

How does the calculator get from your bill to the cost of each system?

Through useful heat, the only quantity the five systems have in common.

A kilowatt-hour of gas, a litre of heating oil and a kilowatt-hour of electricity do not heat alike. The calculation therefore brings them all back to the heat actually delivered inside the home, in three steps:

1. Useful heat = quantity bought × energy per unit × efficiency of your current system. For 17,000 kWh of gas burnt in a boiler at 92 %, that makes 15,640 kWh of heat.
2. Energy to buy with another system = useful heat ÷ that system's efficiency, or ÷ its SCOP for a heat pump.
3. Annual cost = energy to buy × all-in unit price. The monthly cost shown is that amount divided by twelve, like an advance payment.

Every coefficient comes from a public source, and every one can be edited in the tool.

Two notes on these values. Gas boiler efficiency is expressed on the gross calorific value (GCV), like the kilowatt-hours on your bill: that is the convention of European Regulation 813/2013, restated in the note by the AwAC, the Walloon air and climate agency, and the DGO4. Since 26 September 2017 the same regulation has required a seasonal efficiency of at least 125 % from low-temperature heat pumps and 110 % from the others; divided by the 2.5 coefficient it applies to electricity, that corresponds to a SCOP of roughly 3.2 and 2.8, before small control corrections.

The electricity and gas prices are averages that include fixed charges. The variable price printed on your bill is more accurate; replace it in the tool if you have it.

What would the heat of 17,000 kWh of gas cost with another system?

Between 2,170 EUR and 7,600 EUR a year, depending on the system, at November 2026 prices.

Let us redo the calculator's default case by hand: a gas-heated house using 17,000 kWh a year, condensing boiler at 92 %. Current cost: 17,000 × 0.147 = 2,499 EUR. Useful heat: 17,000 × 0.92 = 15,640 kWh.

• Low-temperature heat pump, SCOP 3.5: 15,640 ÷ 3.5 = 4,469 kWh of electricity, × 0.486 = 2,172 EUR.
• Heating oil, boiler at 90 %: 15,640 ÷ (10.15 × 0.90) = 1,712 litres, × 1.4846 = 2,542 EUR.
• High-temperature heat pump, SCOP 2.5: 15,640 ÷ 2.5 = 6,256 kWh, × 0.486 = 3,040 EUR.
• Electric convectors: 15,640 kWh × 0.486 = 7,601 EUR.

Gas and heating oil are neck and neck, 43 EUR apart. A well-installed heat pump saves 327 EUR a year. Convectors triple the bill.

Second check case, for an oil-heated house: 2,000 litres a year in an old boiler at 80 %. Useful heat: 2,000 × 10.15 × 0.80 = 16,240 kWh. Current cost: 2,000 × 1.4846 = 2,969 EUR. A recent oil boiler at 90 % would bring the bill down to 2,639 EUR, gas to 2,595 EUR, a low-temperature heat pump to 2,255 EUR, a saving of 714 EUR a year. The old boiler costs more than any replacement except the heat pump on high-temperature radiators, at 3,157 EUR.

What does heating cost depending on heat demand?

Here is the reference table, calculated with the tool's default values. The first column is the useful heat the home needs, space heating and hot water, not the amount of fuel bought.

Per kilowatt-hour of heat, the ranking does not change with the size of the home: 0.139 EUR for the low-temperature heat pump, 0.160 EUR for gas, 0.163 EUR for heating oil, 0.194 EUR for the high-temperature heat pump, 0.486 EUR for the convector. Only the gap in euros grows with demand.

How much does it cost to heat a 100 m² house?

Often between 1,300 and 3,200 EUR a year with gas, and floor area explains only part of that gap.

Two 100 m² houses do not have the same needs. Our survey of average gas consumption gives a ratio of 1 to 3 between a flat and a detached house, and a 30 to 50 % gap at equal size between a well and a poorly insulated home. The amounts of 1,300 and 3,200 EUR correspond to 8,000 and 20,000 kWh of heat a year. Multiplying a floor area by an average cost per square metre gives a tidy figure that is wrong.

Without a bill, your EPC certificate (the PEB certificate, Belgium's energy performance certificate) is a better starting point. It shows a specific consumption in kWh per m² per year. For a home heated by gas or heating oil, floor area × specific consumption approximates the amount of fuel bought each year, heating, hot water and auxiliaries included. Brussels Environment reports that the average for certified homes in the capital fell from 317 kWh/m² per year in 2011 to 254 in 2024.

Example: 100 m² at 250 kWh/m² per year gives 25,000 kWh of fuel, so 23,000 kWh of heat with a boiler at 92 %. With gas, that comes to 3,675 EUR a year; with a low-temperature heat pump, 3,194 EUR. That is probably too high. The certificate is a standardised calculation, with typical occupancy and temperature, and it tends to overestimate the real consumption of poorly performing homes: the CREG average profile, 17,000 kWh, is clearly lower. Read the EPC result as a ceiling. Our article on the EPC certificate explains how to read it.

How much does heating cost per month?

As a smoothed advance payment, 208 EUR for the gas-heated house in the example. In reality, next to nothing in July and much more in January.

The calculator divides the annual cost by twelve because that is how you pay it: most Belgian contracts bill a fixed monthly advance, then a settlement based on the meter reading. Consumption follows winter. Gas burns mostly from October to April, only hot water runs in summer, and a cold January uses far more than a May.

Two consequences. An advance payment set on winter 2025-2026 does not cover November 2026 prices: on a variable contract, the settlement will be heavy if you do not adjust it. Our method for lowering or adjusting your advance payments starts from the same calculation. And multiplying a January monthly bill by twelve greatly overestimates the annual cost.

Why does the result change between Wallonia, Brussels and Flanders?

Because network tariffs and taxes differ, and they weigh far more on electricity than on gas.

The calculator uses national average prices. The most recent regional survey giving the all-in variable part is the one Test-Achats published on 18 September 2026, before the October surge. Levels have moved since; the ratio between electricity and gas, which decides the ranking, still tells the story.

Flanders stands out clearly. With cheaper electricity, a heat pump there overtakes gas from a SCOP of 2.71, where Wallonia needs 3.25. A Flemish household must however add the capacity tariff, which bills the monthly peak of quarter-hourly power: a heat pump starting at the same time as its backup resistance pushes that peak up. The VREG, the Flemish regulator, publishes this tariff. In Wallonia and Brussels, the high network cost of electricity keeps gas and the heat pump neck and neck, and installation quality makes the difference.

To test your region, replace the tool's two default prices with those from your latest bill.

Four mistakes that distort the calculation

The calculator gives a sound order of magnitude if it gets the right figures. Gaps almost always come from the input:

• Comparing prices per kWh without efficiency. Gas is not three times cheaper than electricity for heating, only against a convector. Our comparison of gas or electric heating covers this point.
• Leaving cooking in your gas consumption, or lighting and appliances in your electricity consumption. Only heating and hot water belong in the calculation.
• Keeping the catalogue SCOP. A heat pump measured at a 35 °C flow temperature does not hold that value on radiators at 65 °C. The tool's high-temperature line exists for that case.
• Forgetting what the tool leaves out: fixed charges, mandatory boiler servicing, oil tank inspection, investment, regional subsidies. Those items decide the payback period of a system switch, which our articles on heating oil or gas and the hybrid heat pump put figures on.

This calculator is not a quotation, not an energy audit and not personal advice. Sizing a heat pump or replacing a boiler is a job for an approved professional, and only your bill and your contract are authoritative on prices.

Once the system is settled, the next lever is the contract. On 4 November, Test-Achats recorded a gap of more than 555 EUR a year between the cheapest and the most expensive fixed gas contract in Wallonia and Flanders. The energy supplier ranking works in total annual cost, and the gas m³ to kWh converter turns your meter reading into the calculator's unit.

Sources and dates. CREG, standard residential profile D3a of 17,000 kWh of gas a year. Test-Achats, press release of 2 November 2026 on November price cards: energy component of gas at 11.29 euro cents/kWh and of electricity at 25.52 euro cents/kWh in Wallonia, 6 % VAT included; 1,700 EUR a year for average electricity consumption and 2,500 EUR for average gas consumption, fixed contracts, all charges included. Test-Achats, article of 4 November 2026: gap of more than 555 EUR a year between fixed gas contracts. Test-Achats, article of 18 September 2026 on the price of a kWh, variable parts by region. FPS Economy, maximum price of heating oil valid from 4 November 2026: 1.4846 EUR/L for 2,000 litres or more, 1.5277 EUR/L below, incl. VAT. AwAC, 2026 table of values: 0.03655 GJ net calorific value per litre of heating oil, i.e. 10.15 kWh. Regulation (EU) 813/2013 and AwAC and DGO4 note updated on 22 March 2016: minimum seasonal efficiency of 86 % on GCV for boilers up to 70 kW since 26 September 2015, 125 % and 110 % for heat pumps since 26 September 2017, conversion coefficient of 2.5. Brussels Environment, building performance: 254 kWh/m² per year on average for homes certified in 2024. Heating oil prices published by the FPS Economy. Pages consulted on 4 November 2026. Variable contracts are reindexed every month: redo the calculation with your own prices. No affiliate links, no products tested, no equipment brand recommended.