How it is calculated
Daily energy (kWh) = power (W) × number of heaters × hours on × share of time at full power ÷ 1,000.
Monthly cost = daily energy × days of use × price per kWh. Season cost multiplies the monthly figure by the number of heating months.
Worked example
Using the calculator’s example values:
- Heater power: 2,000 W
- Number of identical heaters: 1
- Hours of use per day: 6 h/day
- Time heating at full power: 60%
- Days of use per month: 30 days/month
- Heating months per year: 4 months/year
- Electricity price: $0.15/kWh
Result: Estimated monthly cost — $32.40 (monthly consumption: 216 kWh; cost per day: $1.08; cost per heating season: $129.60).
Money-saving tips
- Heat only the rooms you use and keep doors closed.
- A programmable thermostat avoids unnecessary heating hours.
- If your tariff has cheaper hours, storage heaters can charge during them.
Frequently asked questions
Does an oil-filled radiator use less than a fan heater?
At the same wattage and on-time they use the same energy. The difference is in how they spread heat and how long they retain it after switching off.
What should I enter for “time at full power”?
Without a thermostat, 100%. With one it depends on insulation and outdoor temperature; a plug-in energy meter over a few days will give you the real figure.
Is a heat pump cheaper?
A heat pump delivers several units of heat per unit of electricity (its COP), so it usually uses much less for the same heat. You can compare using the air conditioner calculator with its electrical power.
How we calculate and the limits of the results: Methodology.