How long can I power an appliance with my electricity budget?

How it works

Understand the estimate

Divide your budget by (electricity price × appliance power in kW). A device using 0.12 kW for one hour consumes 0.12 kWh, costing about 36 cents at R3/kWh.

Make it more accurate

Power use varies between appliances. Use a measured average where possible.

The starting figures are examples. Replace them with the rates or prices that apply to you.

The difference between watts and kilowatt-hours

Watts describe the power an appliance uses at a moment in time. Kilowatt-hours describe energy consumed over time and are the units commonly used to charge for electricity. Divide watts by 1,000 to obtain kilowatts before multiplying by hours.

Example: A 2,000 W heater operating for two hours consumes 4 kWh. At R3/kWh that costs R12. A R120 budget covers ten such two-hour sessions, but less if the true tariff is higher.

Before relying on the estimate

Fridges, washing machines and devices with thermostats do not draw their labelled maximum continuously. Energy-label usage or a measured average often gives a more useful estimate.

For more detail, read our calculation and editorial standards. Use your own bill, receipt or quote for current prices. These tools do not fetch live rates.