Keep Above
Electric heater or heat pump
A plug-in heater and a heat pump can both warm a room, drawing very different power to do it. Enter each unit's rated input watts — the electricity it draws from the wall — how long a session runs, and your own price per kWh, and the page lands both on a cost per use, per week and per year. The purchase prices are not counted here, and no winner is declared.
On the rating plate or label
On the rating plate or label
Put in your price per kWh from your power bill, then each side's rated power and how long one use runs. Nothing here is read from your accounts, and nothing is saved.
| Option A | Option B | |
|---|---|---|
| Rated power | — | — |
| Energy one use takes | — | — |
| Cost of one use | — | — |
| Cost a week | — | — |
| Energy a year | — | — |
| Cost a month | — | — |
| Cost a year | — | — |
This is one of the tools built into Keep Above
Keep Above is a budgeting app where you enter your bills and income and it works out the balance you need to keep — so you can see what's safe to spend. No bank connection, no ads on your data.
About this calculator
Which wattage counts for a heat pump?
The rated input power — the electricity the unit draws — not the heating output on the brochure, which is a different and larger number. This page compares electricity only: what each unit would take from the wall for the hours you run it. Whether the two would deliver the same warmth in your room is a question about the units and the room, not one this arithmetic can settle.
Why is the rated power a ceiling, not an average?
A rating plate states the most an appliance draws, not what it averages. Anything with a thermostat — an oven, a heater, an iron — cycles on and off, so its real draw over a session can sit well under the rating. The figures here are what each side would cost at full rated power for the whole time: the honest upper end, not a meter reading.
Where do I find the wattage and the kWh price?
The wattage is on the appliance's rating plate or sticker — usually near the plug, the door frame or the base — as watts (W) or kilowatts (kW; 1 kW is 1 000 W). Manuals and product pages list it too. The price per kWh is on your own electricity bill, and this page never assumes one for you.
Why do both sides share one uses-a-week figure?
Because the two sides are two ways of doing the same job, so the job happens the same number of times either way. What can differ is how long one session runs — that is why each side has its own minutes.