Heating Cost Calculator (UK) – Compare Electric, Gas & Heaters
About this calculator
This calculator works out what your heating is actually costing you, using your own unit rate rather than a national average. UK energy tariffs vary significantly between suppliers and between fixed and variable deals, and the difference between a 24p and a 32p electricity rate changes the running cost of a 2kW heater by around £12 a month at typical usage. Entering your own rate from your energy bill gives you a figure that reflects your home rather than a statistical average.
The calculator covers both electric heaters and gas central heating. Electric heater costs are straightforward to calculate from wattage and unit rate. Gas central heating is more variable because the cost depends on how much gas the boiler consumes per hour, which is affected by the size of the home, how well it retains heat, the efficiency rating of the boiler, and how long the system runs before the thermostat is satisfied. The gas inputs allow you to adjust for your home’s specific characteristics rather than relying on a single typical figure.
If your actual heating bills are consistently higher than the calculator suggests, the most common explanation is that the heating runs longer than expected because the home is losing heat faster than it should. Cold rooms, draughty floors, poorly insulated walls, and an unbalanced radiator system all force the boiler to cycle more frequently to maintain the thermostat setting. The house cold diagnostic helps identify which of these factors is active in your home, and the complete guide to keeping a UK home warm for cheap covers the fixes in order of impact.
UK Heating Cost Calculator
Per hour, day, week and month
Enter your unit rate and usage. See exactly what your electric heater or gas central heating costs to run – instantly.
UK Heating Cost Calculator
Adjust any value – results update instantly
Find on your energy bill. Apr 2025 cap: ~24p electric, ~6.4p gas.
Check the label on the heater.
Typical 3-bed: 8–14 kWh/hr. Check your smart meter.
Modern condensing: 0.89–0.93. Older boiler: 0.70–0.80.
Understanding your results
Gas central heating costs vary more than electric heater costs because the boiler does not simply run at a fixed wattage. A home that holds heat well reaches the thermostat target quickly and keeps the boiler off for longer between cycles. A home with significant heat loss through uninsulated walls, draughty floors, or an unbalanced radiator system requires the boiler to run almost continuously, pushing the real hourly cost well above the theoretical figure. Why houses lose heat quickly covers the most common causes of excessive boiler runtime in UK homes.
The difference between heating one room with an electric heater and heating the whole house with gas is not as straightforward as comparing unit rates. Gas is roughly three to four times cheaper per kWh than electricity, but gas central heating heats every room whether occupied or not. For one or two people spending most of their time in a single room, a low-wattage electric heater used alongside a reduced central heating schedule can cost less overall than running the full system. The full comparison is covered in heating one room versus the whole house, and whether it makes sense to leave the heating on low or use a timer is explained in whether turning the thermostat down saves money.
Common heater costs at a glance
At 28p/kWh electric · 6.4p/kWh gas · 4 hrs/day · 7 days/week
| Heater type | Power | / hour | / month | |
|---|---|---|---|---|
| Oil-filled radiator (low) | 600W | 17p | £11.90 | Low |
| Panel heater | 1,000W | 28p | £19.84 | Low |
| Oil-filled radiator (full) | 1,500W | 42p | £29.76 | Mid |
| Fan / convector heater | 2,000W | 56p | £39.68 | Mid |
| Fan heater (max) | 3,000W | 84p | £59.52 | High |
| Gas central heating | 10kWh/hr | ~58p* | ~£40* | Whole home |
Heating cost questions answered
The questions people search most – answered directly.
How much does a 2kW electric heater cost per hour in the UK?
At the April 2025 price cap of ~24p per kWh, a 2kW heater costs 48p per hour. At a typical 28p tariff it is 56p per hour.
Run for 4 hours every day that is roughly £5.60–£7.90 per week, or £24–£34 per month.
How much does gas central heating cost per hour?
A typical 3-bedroom home uses roughly 8–14 kWh of gas per hour while the boiler is actively heating. At 6.4p/kWh with a 90% efficient boiler that is approximately 45p–80p per hour.
Modern boilers cycle on and off rather than running continuously, so real daily cost depends heavily on how well the home holds heat. If the boiler runs constantly, this guide explains the most common causes.
Is it cheaper to use one electric heater or gas central heating?
Gas is roughly 3–4 times cheaper per kWh than electricity. But gas heats the whole home while an electric heater heats one room.
One person, one room, a few hours: electric often wins. Family, several rooms, most of the day: gas wins. Full comparison: heating one room vs the whole house.
How much does a 500W panel heater cost per hour?
At 28p/kWh: 14p per hour. At the 24p cap rate: 12p per hour. Run for 6 hours a day, 7 days a week, that is around £5–£6 per month.
Why is my actual bill higher than the calculator suggests?
Most common reasons: the heating runs longer than you think, the home loses heat faster than average, or radiator distribution issues mean the boiler overcompensates. The house cold diagnostic helps identify the cause.
Does leaving heating on low all day save money vs a timer?
For most UK homes a timer is cheaper. Full breakdown: Leave Heating on Low or Use a Timer.
What is the cheapest way to heat a room in the UK?
For one person in one room for a few hours, a low-wattage electric heater (500–700W) with good draught-proofing is usually cheapest. Full strategy: How to Keep a UK Home Warm for Cheap.
Related guides and tools
Estimates only. Actual costs vary with boiler cycling, thermostat behaviour, heat loss and individual tariffs. Always check your current unit rate on your energy bill. WarmGuide is an independent, non-commercial UK home heating resource.