Electric heater vs gas central heating cost
Compare the entered running costs using your own usage and current fuel prices.
After you calculate
Compare electric and gas heating costs
Add your heater power, gas heat demand, hours and prices, then calculate to see your results.
Electric heater cost
Shown after calculationGas heating cost
Shown after calculationEnergy needed
Weekly comparison
Full calculation
Costs reflect the areas and heating demand you choose to compare.
Understand your estimate
How it works
Compare the entered energy costs of an electric room heater and gas central heating. The result shows hourly, daily and weekly costs for the hours you choose. Use heat demand for the area you want to compare, rather than assuming one portable heater replaces the whole home’s heating.
Find the electric heater’s input power in watts. Enter how much of the chosen time it draws power. For gas, enter useful heat output in kilowatts and boiler efficiency. Useful heat is heat delivered to the home; fuel input is the energy bought to produce it. The tool does not guess the room’s heat demand.
A few good questions
Before youget started.
Understand this calculator, the figures to enter and the limits of your estimate.
Sources
- Energy price cap unit rates and standing chargesChecked on 9 October 2026
- Changes to energy price cap between 1 October and 31 December 2026Checked on 9 October 2026
- Australian Government: calculate appliance energy costsChecked on 13 October 2026
- London Fire Brigade: portable heater safetyChecked on 13 October 2026
- Essex Fire: use electric heaters safelyChecked on 13 October 2026
- Last checked
- 13 October 2026
- Rates as of
- 1 October 2026
EnergySums
Electric heater vs gas central heating cost
United Kingdom · How it works
- Guide updated
- 13 October 2026
- Rates as of
- 1 October 2026
| Item | Value |
|---|---|
| Guide updated | 13 October 2026 |
| Rates as of | 1 October 2026 |
How it works
Compare the entered energy costs of an electric room heater and gas central heating. The result shows hourly, daily and weekly costs for the hours you choose. Use heat demand for the area you want to compare, rather than assuming one portable heater replaces the whole home’s heating.
Find the electric heater’s input power in watts. Enter how much of the chosen time it draws power. For gas, enter useful heat output in kilowatts and boiler efficiency. Useful heat is heat delivered to the home; fuel input is the energy bought to produce it. The tool does not guess the room’s heat demand.
Formula
Electricity input per hour = heater watts ÷ 1000 × heating-on share. Gas input per hour = entered useful heat ÷ boiler efficiency. Multiply each by its tax-inclusive fuel price and the same daily hours. A week is seven days. Enter useful heat for the area you want to compare; no heat demand is assumed.
Use a percentage as a fraction once: for example, 50% means 50 ÷ 100 = 0.5. Use 0.5 in the energy formula; do not divide it by 100 again.
Use boiler efficiency as a fraction in the gas formula. A heat output figure must be divided by efficiency to find purchased gas energy. Do not multiply it by efficiency again. Convert prices in pence per kWh to pounds by dividing by 100.
Heating-on share describes the electric heater’s switching pattern. It is not the boiler efficiency and does not show how much heat the room needs. Both daily costs use the same entered hours, and the weekly figures repeat that pattern on seven days. The prices and schedules stay constant for this comparison.
Worked example
These illustrative inputs are separate from your saved answers. Prices, use and performance are held constant for this worked scenario; they are not personal defaults.
Inputs used in this worked example.
- Electricity price
- My bill rate
- Electricity unit price
- 26.32 p / kWh
- Gas price
- My bill rate
- Gas unit price
- 7.97 p / kWh
- Heater input power
- 2000 W
- Time the heater draws power
- 50 %
- Heating time each day
- 3 hours / day
- Useful heat from gas heating
- 1 kW
- Boiler efficiency
- 90 %
- Price conversion
- 100 pence or cents per currency unit
| Item | Value |
|---|---|
| Electricity price | My bill rate |
| Electricity unit price | 26.32 p / kWh |
| Gas price | My bill rate |
| Gas unit price | 7.97 p / kWh |
| Heater input power | 2000 W |
| Time the heater draws power | 50 % |
| Heating time each day | 3 hours / day |
| Useful heat from gas heating | 1 kW |
| Boiler efficiency | 90 % |
| Price conversion | 100 pence or cents per currency unit |
- Electric heater / week
- £5.53
- Gas heating / week
- £1.86
- Difference / week
- £3.67
| Item | Value |
|---|---|
| Electric heater / week | £5.53 |
| Gas heating / week | £1.86 |
| Difference / week | £3.67 |
- Electricity / hour
- (2,000 W ÷ 1,000 W/kW) × (50 ÷ 100) × 1 h= 1 kWh
- Gas / hour
- 1 kW useful heat × 1 h ÷ (90 ÷ 100)= 1.111 kWh
- Electric heater cost / week
- 1 kWh/h × 3 h/day × 7 days × (26.32 p/kWh ÷ 100 p/GBP)= £5.53
- Gas heating cost / week
- 1.111 kWh/h × 3 h/day × 7 days × (7.97 p/kWh ÷ 100 p/GBP)= £1.86
| Calculation | Formula with saved values | Result |
|---|---|---|
| Electricity / hour | (2,000 W ÷ 1,000 W/kW) × (50 ÷ 100) × 1 h | 1 kWh |
| Gas / hour | 1 kW useful heat × 1 h ÷ (90 ÷ 100) | 1.111 kWh |
| Electric heater cost / week | 1 kWh/h × 3 h/day × 7 days × (26.32 p/kWh ÷ 100 p/GBP) | £5.53 |
| Gas heating cost / week | 1.111 kWh/h × 3 h/day × 7 days × (7.97 p/kWh ÷ 100 p/GBP) | £1.86 |
Assumptions and limits
Compare a similar area and level of warmth if you want the cost difference to guide a heating choice. Whole-home gas heating and one room heater can provide different services. A cheaper entered scenario does not prove that all other rooms can safely go without heat.
A rated maximum power is different from a measured average. Use a heating-on share that matches your power figure. Applying an extra cycling reduction to a figure that is already averaged can understate consumption. No default power, boiler efficiency or weather factor is used for an empty personal field.
The result covers fuel energy costs, rather than installation, repairs or equipment capacity. Existing standing charges are not added to this extra-use comparison. Money is rounded only for display. The calculator cannot measure comfort, assess a building or confirm that the entered heat output will keep it warm.
Country rules
Published UK electricity prices use the selected Ofgem region and payment method. Published gas uses the Great Britain Direct Debit average. Stored prices include the tax treatment recorded for their period. Use tax-inclusive prices from your own bills when the published figures do not match your tariff.
Check the price units and source dates before comparing costs. A daily standing charge already paid for a connected account does not disappear just because you use the other heater. This page compares added energy use; it does not calculate savings from closing a gas account or switching a whole tariff.
When to ask a professional
Keep portable heaters away from curtains, bedding and furniture. Plug into a suitable wall socket, follow the maker instructions and never use a heater to dry clothes.
Ask a qualified heating professional to check room heat demand and boiler performance if those figures are uncertain. Use the appropriate qualified installer for electrical or gas work. Bring your bills and equipment details. This cost comparison does not confirm a safe installation or suitable heating capacity.
Questions and answers
| Question | Answer |
|---|---|
| Is it cheaper to run an oil-filled radiator than central heating? | Compare heater electricity with the gas required to supply your entered useful heat. A room heater may use less energy than heating an entire house, but the comparison does not establish equivalent warmth or coverage. |
| Are oil filled radiators cheap to run? | An oil-filled electric radiator uses its input power while it heats. Its oil stores heat; it does not supply a cheaper fuel. Actual cost depends on heating-on time and your electricity price. |
| How much does an oil filled radiator cost to run? | For an illustrative 2000 W heater at 50% heating-on share, input energy is 1 kWh per elapsed hour. At the stored UK 26.32 p/kWh price that is GBP 0.263 per hour, or GBP 0.79 for three hours. Your own power, schedule and price may differ. |
| What is the cheapest way to heat your house? | Fuel prices, system efficiency and the useful heat needed for the rooms in use determine running cost. Compare the same heating task and ask an installer before changing a system. |
| What are the downsides of an oil-filled radiator? | A portable radiator mainly heats the space around it, so it may not replace whole-house heating. Follow the maker instructions and the linked fire-safety guidance; keep it clear of bedding, curtains and furniture. |
Sources
| Source | Checked | Reference URL |
|---|---|---|
| Energy price cap unit rates and standing charges | 9 October 2026 | https://www.ofgem.gov.uk/information-consumers/energy-advice-households/get-energy-price-cap-standing-charges-and-unit-rates-region |
| Changes to energy price cap between 1 October and 31 December 2026 | 9 October 2026 | https://www.ofgem.gov.uk/news/changes-energy-price-cap-between-1-october-and-31-december-2026 |
| Australian Government: calculate appliance energy costs | 13 October 2026 | https://www.energy.gov.au/households/energy-rating |
| London Fire Brigade: portable heater safety | 13 October 2026 | https://www.london-fire.gov.uk/safety/the-home/portable-heaters-gas-fires-and-open-fires/ |
| Essex Fire: use electric heaters safely | 13 October 2026 | https://www.essex-fire.gov.uk/save-safely |