Prepaid electricity calculator

See how many units your money buys and what each appliance really costs to run.

Check the rate on your last token slip – municipal tariffs vary.

Appliance running cost

Units you'll get
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Appliance use per day
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Cost per day
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Cost per month
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Cost per year
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How prepaid electricity units are calculated

One prepaid unit is one kilowatt-hour (kWh). Divide the rand amount you spend by your price per kWh to get your units. At R2.71 per kWh, R500 buys about 184 units.

To work out what an appliance costs, multiply its wattage by the hours you use it and divide by 1 000 to get kWh, then multiply by your rate. A 3 000 W geyser running for two hours uses 6 kWh a day.

Preset rates are approximate 2026/27 figures including VAT. Eskom direct tariffs change every April and municipal tariffs every July. Many municipalities use block tariffs, where the price per unit rises once you've bought a certain amount in a month, and some add a fixed monthly charge. The calculator doesn't include either.

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Frequently asked questions

How many units do I get for R100 of electricity?

At about R2.71 per kWh (Eskom Homelight 20A), R100 buys around 37 units. On a municipal tariff near R3.40 per kWh you'd get around 29 units.

Why do I get fewer units later in the month?

Many municipalities use inclining block tariffs. Once your monthly purchases pass a set number of kWh, the price per unit goes up for the rest of the month.

What uses the most electricity at home?

Anything that heats: geysers, heaters, kettles, ovens and tumble dryers. A geyser is often the single biggest cost in a household.

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