Keep Above
Microwave or oven
Reheating and plenty of cooking can happen in a microwave or the oven, at very different wattages for very different lengths of time. Enter each one's rated watts, the minutes the job would take each way, and your own price per kWh — the page lands both on a cost per use, per week and per year. No winner is declared; every figure is yours.
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 does a microwave's label state?
Microwaves usually carry two figures: the cooking power (what the food receives) and the rated input power (what the wall supplies), which is higher. The one that belongs here is the input power from the rating plate — the electricity being paid for — not the cooking power on the front of the door.
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.