Heating Cost Calculator
Estimate how much your heating costs per hour, day, month and heating season. Use it for electric heaters, gas boilers, heat pumps, oil/LPG systems or a custom heating setup.
Calculator
Choose manual runtime for a specific heater, or estimate demand from floor area and insulation.
This sets a sensible default efficiency and carbon factor. You can still edit the values.
Use your unit rate from your energy bill. Do not include the standing charge here.
Example: portable heater 2 kW, small radiator 1.5 kW, boiler heat output 18–30 kW.
Use the actual time the heating is actively running, not just switched on.
Only include the rooms/area you are heating.
This estimates useful heat demand using watts per square metre.
Higher thermostat settings increase heat demand. The estimate uses 20 °C as the baseline.
For electric heating, 100% means 1 kWh of electricity becomes about 1 kWh of heat.
Optional. Set to 0 if you only want usage cost.
Optional estimate for emissions.
Cost breakdown
Quick saving estimates
How the calculation works
The calculator first estimates the useful heat required. In manual mode, this is based on the heater or heating system output multiplied by daily runtime. In home estimate mode, it estimates heat demand using floor area, an insulation/heat-loss value and heating hours.
Paid energy = useful heat ÷ efficiency or COP
Usage cost = paid energy × tariff
Electric resistive heating is normally close to 100% efficient at the point of use. Gas and oil boilers lose some energy through flue gases and system losses, so their efficiency is usually below 100%. Heat pumps are different because they move heat rather than create it directly; a COP of 3 means 1 kWh of electricity can deliver about 3 kWh of heat.
Note: Results are estimates. Actual heating cost depends on outside temperature, thermostat settings, property fabric, draughts, room size, radiator sizing, boiler flow temperature, heat pump performance, occupancy, tariffs and control settings.
Typical heating examples
Portable electric heater
Usually 1–3 kW. It can be expensive if used for long periods because every kWh of heat normally uses about one kWh of electricity.
Gas central heating
Often cheaper per kWh than direct electric heating, but efficiency, boiler condition and whether you heat the whole home matter a lot.
Heat pump
Can be much cheaper to run when the seasonal COP is strong, especially with good insulation and low flow temperatures.
Ways to reduce heating costs
- •Heat the space you use, not the whole property. Zoning and thermostatic radiator valves can reduce unnecessary heating.
- •Lower the thermostat slightly. A small reduction can noticeably reduce heat demand over a full winter.
- •Use timers properly. Heating earlier than needed or leaving it on after the house is warm adds avoidable cost.
- •Stop draughts. Draught-proofing doors, windows and loft hatches can reduce heat loss quickly and cheaply.
- •Improve boiler or heat pump operation. Lower flow temperatures, servicing and correct controls can improve efficiency.