Free tools

What it costs to run

Two appliances that can do the same job rarely draw the same power. This calculator takes each one's rated watts and how long a session runs, a shared number of uses a week, and your own electricity price per kWh — and lands both on a cost per use, per week and per year. Every figure is yours, including the power price; no winner is ever declared.

$per kWh times a week
Option A
One way of doing it
watts

On the rating plate or label

minutes

Power cost a year
Option B
The other way of doing it
watts

On the rating plate or label

minutes

Power cost a year
Power cost a year
Option A
a year
Option B
a year
Enter your kWh price and both wattages

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.

A year of power, side by side
Option A
Option B

Both bars are electricity only — neither side's purchase price is counted here.

The breakdown
Option AOption 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.

Download on the App Store Get it on Google Play

About this calculator

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.