· Built around the Appliance running cost calculator
Photo: Karl Rayson on Pexels (free licence)
Most South African homes spend the bulk of their electricity money on three things: hot water, warming or cooling a room, and, if there is one, the pool. The kettle, the TV and the phone chargers that people feel guilty about barely register. This post puts a rand figure on twenty common appliances at the 2026/27 tariffs, shows how the bill moves between summer and winter and between suppliers, and ends with the fixes that actually pay. Every number comes from one rule - watts / 1 000 x hours = kWh, and kWh x your price = rand - which is exactly what the appliance running cost calculator does. Type in your own appliance as you read.
Work out any appliance in ten seconds
Find the watts on the label (or in the manual), estimate how many hours a day it actually draws power, and put in the price per kWh from your token slip or municipal bill. The calculator below starts on a 3 000 W geyser element running 3 hours a day at R3.83 a kWh, City Power's middle block in Johannesburg.
- Use the hours it draws power, not the hours it is switched on. A geyser, fridge, freezer, oven, heater on a thermostat or an aircon cycles on and off. A fridge can be plugged in for 24 hours and run its compressor for 8.
- The price per kWh is the one you pay for extra units. If your supplier has blocks, an extra appliance lands on top of what the house already uses, so use the block you usually end the month in.
- Labels show the maximum. A 2 000 W heater on its low setting may draw 1 000 W; a microwave rated 1 000 W of cooking power can draw more from the wall. Treat label figures as a ceiling.
What 20 appliances cost to run a month
The wattages and most of the hours below are the typical figures that ourpower.co.za lists for South African homes. Where we think their hours do not match how the appliance really runs - mostly thermostat appliances - we used our own estimate and marked it with an asterisk. Every row is 30 days at R3.83 a kWh.
| Appliance | Watts | Hours a day | kWh a month | Rand a month |
|---|
| Geyser (150 litres, 3 kW element) | 3 000 | 3* | 270.0 | R1 034.10 |
| Fan or oil heater (winter) | 2 000 | 4 | 240.0 | R919.20 |
| Pool pump | 1 100 | 6 | 198.0 | R758.34 |
| Air conditioner, 1.5 kW (summer) | 1 500 | 4* | 180.0 | R689.40 |
| 10 old 60 W bulbs | 600 | 5 | 90.0 | R344.70 |
| Stove, one plate | 1 500 | 1.5 | 67.5 | R258.52 |
| Chest freezer | 200 | 10* | 60.0 | R229.80 |
| Dishwasher | 1 800 | 1* | 54.0 | R206.82 |
| Oven | 2 000 | 0.75* | 45.0 | R172.35 |
| Tumble dryer | 2 500 | 0.5* | 37.5 | R143.63 |
| Fridge | 150 | 8* | 36.0 | R137.88 |
| Kettle | 2 000 | 0.5* | 30.0 | R114.90 |
| Laptop | 65 | 8 | 15.6 | R59.75 |
| Microwave | 1 000 | 0.5 | 15.0 | R57.45 |
| Washing machine | 500 | 1 | 15.0 | R57.45 |
| 10 LED bulbs (10 W each) | 100 | 5 | 15.0 | R57.45 |
| LED TV | 100 | 5 | 15.0 | R57.45 |
| Electric blanket | 200 | 2* | 12.0 | R45.96 |
| DStv decoder | 30 | 12 | 10.8 | R41.36 |
| Wi-Fi router | 12 | 24 | 8.6 | R33.09 |
* Hours are CalcSA estimates, not measured figures: the geyser element at 3 hours a day (enough for roughly 150 litres of hot water plus standing losses, see below), the aircon and freezer compressors cycling, and short daily averages for the oven, dishwasher, dryer, kettle and blanket. ourpower.co.za uses 5 hours for a geyser, 6 for an aircon and 24 for a fridge - which gives a much higher figure. Your own hours matter more than anyone's table.
Rand a month at R3.83 a kWh, 30 days, using the watts and hours in the table above. Hover a bar for the kWh. Hours marked * in the table are CalcSA estimates.
Three things stand out. First, the top four rows are all heating or cooling: the geyser, a heater, an aircon and the pool pump (which does not heat, but runs for hours). Second, lighting only matters if it is old: ten incandescent bulbs cost R344.70 a month, ten LEDs R57.45. Third, the gadgets people worry about - the router, the decoder, the laptop - cost between R33 and R60 a month each. They are worth switching off, but they will not fix a big bill.
Checked against a published example
- Geyser, 3 000 W for 5 hours a day at R2.71: ourpower.co.za shows 450 kWh and R1 219.50 a month - our calculator gives the same R1 219.50. 3 kW x 5 hours x 30 days = 450 kWh, x R2.71.
- Pool pump, 1 100 W for 6 hours at R2.71: both show 198 kWh and R536.58.
- Their default price is Eskom Homelight 20A, R2.71 a kWh from 1 April 2026 - the cheapest residential rate there is. At R3.83 the same geyser costs R1 723.50, which is why your supplier matters as much as your habits.
Which tariff to use - and why your supplier changes the answer
About half of South African homes buy electricity from their municipality and the rest directly from Eskom. Each sets its own price. These are the 2026/27 residential rates incl. VAT that CalcSA checked for its prepaid electricity post; Eskom's apply from 1 April 2026 and the municipal ones from 1 July 2026.
- Eskom Homelight 60A: R3.4361 a kWh, no fixed charge. Homelight 20A is R2.7030 but is meant for low-use homes, and 20 amps will not run a geyser and a heater at the same time.
- City Power (Johannesburg): R3.3403 up to 350 kWh, R3.8316 for 351-500 and R4.3659 above, plus a R241.50 monthly fixed charge.
- eThekwini (Durban): R4.1109 a kWh flat, with the service charge built in.
- Cape Town Domestic: R4.1379 up to 600 kWh and R4.9390 above, plus R2.46 a day.
The table shows what the big appliances cost on each. The units are identical; only the price changes. Check yours with the Eskom prepaid, Johannesburg prepaid, Cape Town or Durban electricity calculator.
| Supplier and block | Per kWh | Geyser | Heater | Pool pump | Aircon |
|---|
| Eskom Homelight 60A | R3.4361 | R927.75 | R824.66 | R680.35 | R618.50 |
| City Power, 351-500 kWh | R3.8316 | R1 034.53 | R919.58 | R758.66 | R689.69 |
| eThekwini (Durban) | R4.1109 | R1 109.94 | R986.62 | R813.96 | R739.96 |
| Cape Town, up to 600 kWh | R4.1379 | R1 117.23 | R993.10 | R819.30 | R744.82 |
| Cape Town, above 600 kWh | R4.9390 | R1 333.53 | R1 185.36 | R977.92 | R889.02 |
- Geyser, 270.0 kWh
- Heater, 240.0 kWh
- Pool pump, 198.0 kWh
Same units, different supplier. Dashed lines mark the 2026/27 residential prices in the table below; hover a dot for the rand figure.
Cape Town's second block is the trap. A house with a geyser and a pool pump is already near 470 kWh before anyone cooks, washes or turns on a heater, so in winter many homes cross 600 kWh - and every unit after that costs R4.9390, 19% more. A pool pump that runs into that block costs R977.92 a month instead of R819.30.
A whole-house bill, with the blocks and fixed charges
Adding every row of the first table except the old bulbs gives an example house with a pool: 1 145.0 kWh in a winter month (with the heater and electric blanket, no aircon) and 1 073.0 kWh in a summer month (aircon instead of heater). That is a big, all-electric house - not an average one - but it shows how the tariff structures play out.
| Supplier | Winter month, 1 145.0 kWh | Summer month, 1 073.0 kWh |
|---|
| Eskom Homelight 60A (no blocks, no fixed charge) | R3 934.47 | R3 687.07 |
| City Power: 3 blocks + R241.50 fixed | R4 801.35 | R4 487.01 |
| eThekwini: one rate, service charge built in | R4 707.14 | R4 411.16 |
| Cape Town Domestic: 2 blocks + R2.46 a day | R5 248.30 | R4 892.69 |
On the same usage, Cape Town costs R1 314 a month more than Eskom Homelight 60A in winter, and Joburg's three blocks push it to R4 801. Whichever supplier you have, the first table tells you where the units go.
The big three
1. The geyser: usually a third or more of the bill
A geyser heats water, and heating water takes a fixed amount of energy: 4.186 kJ to warm one litre by 1°C, and 3 600 kJ is one kWh. So 150 litres a day from 15°C to 60°C needs 7.85 kWh - the geyser electricity cost calculator works it out from the water rather than the element.
- Standing losses come on top - heat leaking through the tank and pipes while nobody uses water. We assumed 2 kWh a day; that figure is a CalcSA estimate. An old, unlagged geyser in a cold roof can lose more, a new one with a blanket less. The label on many newer geysers states the standing loss.
- Cold water gets colder in winter, so the geyser works harder. Eskom's own residential calculator assumes 20°C water coming in. We used 22°C in midsummer and 11°C in July - monthly inlet temperatures here are CalcSA estimates, and highveld and coastal homes differ.
- July costs R1 252.18 for the geyser alone, January R1 024.38 - same family, same showers, 59.5 kWh more just because the water starts colder.
2. Heating and aircon: the seasonal swing
A 2 000 W fan or oil heater running 4 hours every evening uses 240 kWh a month - about as much as the geyser. It only runs for part of the year, but those months are the ones where the geyser is also at its worst. In summer, an aircon takes over.
- Geyser
- 2 kW heater
- 1.5 kW aircon
CalcSA estimate: 150 litres of hot water a day at 60°C plus 2 kWh a day of standing loss, a 2 kW heater from May to September and a 1.5 kW aircon from November to March, at R3.83 a kWh. Hover a month for the split.
| Month | Cold water in* | Geyser kWh | Heater kWh | Aircon kWh | Big three, rand |
|---|
| Jan | 22°C | 267.5 | 0.0 | 186.0 | R1 736.76 |
| Feb | 22°C | 241.6 | 0.0 | 168.0 | R1 568.69 |
| Mar | 20°C | 278.3 | 0.0 | 93.0 | R1 421.99 |
| Apr | 18°C | 279.8 | 0.0 | 0.0 | R1 071.50 |
| May | 15°C | 305.3 | 124.0 | 0.0 | R1 644.26 |
| Jun | 12°C | 311.2 | 240.0 | 0.0 | R2 110.94 |
| Jul | 11°C | 326.9 | 248.0 | 0.0 | R2 202.02 |
| Aug | 12°C | 321.5 | 186.0 | 0.0 | R1 943.85 |
| Sep | 15°C | 295.5 | 60.0 | 0.0 | R1 361.42 |
| Oct | 18°C | 289.1 | 0.0 | 0.0 | R1 107.22 |
| Nov | 20°C | 269.3 | 0.0 | 90.0 | R1 376.12 |
| Dec | 22°C | 267.5 | 0.0 | 186.0 | R1 736.76 |
| Year | | 3 453.3 | 858.0 | 723.0 | R19 281.53 |
- July is the dearest month at R2 202.02 for the big three, against R1 071.50 in April, on our assumptions.
- An aircon heats for about a third of the cost of a heater. A split unit in heating mode is a heat pump: it moves heat in from outside, and typical units deliver around 3 kWh of heat for every 1 kWh of electricity. On that rough ratio the R919.20 heater month would cost about R306.40. The ratio of 3 is a CalcSA estimate - check the COP on your unit's label, and expect less on very cold mornings.
- Heat the person, not the room. An electric blanket on for 2 hours costs R45.96 a month; the heater costs R919.20.
3. The pool pump: hours you can simply cut
A 1 100 W pump running 6 hours a day costs R758.34 a month at R3.83. Unlike the geyser, nothing has to be heated - it is pure running time, so every hour you cut saves R126.39 a month. Eskom's calculator assumes a pool filter moves about 10 000 litres an hour, so a 50 000 litre pool turns over once in 5 hours. Work out your volume with the pool volume calculator.
- Running 4 hours instead of 6 in winter saves R252.78 a month, when the water is cold, nobody swims and algae grows slowly.
- A variable-speed pump uses far less at low speed because power falls faster than flow. Manufacturers quote big savings; we have not verified a figure, so run your own pump's watts at each speed in the calculator.
- Run it in daylight if you have solar panels - see the solar savings calculator.
Cheap wins: timers, standby and LEDs
Geyser thermostat and timer
- Turning the thermostat from 60°C to 55°C saves R100.20 a month on 150 litres a day, because each litre is heated 5°C less. The World Health Organization advises storing hot water at 60°C or more to control legionella, so weigh that saving against the risk - especially with elderly or ill people in the house.
- A geyser timer saves less than people think on a flat prepaid rate. The water you use still has to be heated. What a timer cuts is standing loss during the hours it is off, which we estimate at R57 to R115 a month (0.5 to 1 kWh a day at R3.83) - worthwhile for a R500 to R1 500 timer, but not a miracle.
- A timer matters more on a time-of-use tariff such as Eskom Homeflex, where peak winter units cost far more than off-peak ones. There, moving heating out of the evening peak is the saving.
- Solar water heating or a heat pump cuts about 60% of the water heating bill on average, according to Eskom's calculator notes. On our R1 034.10 geyser that is about R620.46 a month - compare that with the installed price before you buy.
Standby power
- 30 W of things on standby, all day, costs R82.73 a month at R3.83 - 21.6 kWh. The 30 W is a CalcSA estimate for a decoder, TV, microwave clock, sound system and chargers together; homes vary widely.
- Measure, do not guess. A plug-in energy meter (a few hundred rand) shows each device's standby draw, and the watts to amps converter helps if the label only gives amps.
- The router and alarm need to stay on. The second TV, the gaming console and the old sound system usually do not.
LED bulbs
- Ten 60 W incandescent bulbs for 5 hours a day: R344.70 a month. Ten 10 W LEDs giving similar light: R57.45. The saving is R287.25 a month.
- At roughly R30 to R50 an LED bulb (a CalcSA estimate of retail prices), ten bulbs pay for themselves in the first two months.
- Halogen downlights are 35 to 50 W each - a kitchen with eight of them is worth converting first.
The rest of the kitchen
- Boil only the water you need. The kettle in our table costs R114.90 a month at half an hour a day; Eskom's calculator assumes every boil heats a full 1.5 litres, and halving that halves the cost.
- Use the microwave or air fryer for small portions - R57.45 a month for half an hour a day, against R172.35 for the oven.
- Keep the freezer full and the fridge seals clean - the compressor hours fall, which is the number that sets the cost.
- Comparing gas? The gas vs electricity calculator does the hob and heater sums; for backup power, see the inverter calculator.
Where to start
- Write down your three biggest appliances and their real hours, then run each one in the appliance running cost calculator at your own price per kWh.
- Fix the geyser first - thermostat, blanket, lagged pipes, then a timer if you are on a time-of-use tariff.
- Cut pool pump hours in winter, and heat people rather than rooms.
- Then the cheap wins: LEDs and standby. Together they are worth a few hundred rand a month in a house that still has old bulbs.
What these figures leave out. Fixed and daily charges are left out of the per-appliance rows (they are included in the whole-house table), as are free basic electricity, Homepower and Homeflex daily charges and time-of-use rates. Tshwane, Ekurhuleni and other municipalities charge differently. City Power's rates were not checked against City Power's own PDF - they come from the schedule as published by energybee.co.za and ourpower.co.za. Wattages are typical figures from a secondary source; your appliance's label wins.
Sources
- Appliance wattages and typical hours a day (geyser 3 000 W, pool pump 1 100 W, fridge 150 W, kettle 2 000 W, etc.) and the worked example of R1 219.50 and R536.58 at R2.71 a kWh: ourpower.co.za, electricity cost calculator, read 17 October 2026. Secondary source.
- Eskom residential calculator assumptions (20°C inlet water, 1.5 litre kettle boil, pool filter 10 000 litres an hour, solar or heat pump water heating saves about 60%): residentialcalculator.eskom.co.za, read 17 October 2026.
- Eskom Tariffs and Charges Booklet 2026/2027, effective 1 April 2026 (Homelight 20A 270.30c, 60A 343.61c incl. VAT): eskom.co.za PDF, read 16 October 2026.
- City of Cape Town, The cost of electricity, 2026/27 tariffs from 1 July 2026 (Domestic R2.46 a day + 413.79c / 493.90c incl. VAT): capetown.gov.za, read 16 October 2026.
- eThekwini Municipality electricity tariffs 2026/2027 (411.09c incl. VAT): durban.gov.za, read 16 October 2026.
- City Power (Johannesburg) residential prepaid 2026/27 (290.46c / 333.18c / 379.64c excl. VAT, R241.50 fixed): as published by energybee.co.za and ourpower.co.za. Not verified from a primary source.
- Specific heat of water, 4.186 kJ per kg per °C: NIST Special Publication 811, Guide for the Use of the International System of Units.
- Hot water storage at 60°C or above against legionella: World Health Organization, Legionella and the prevention of legionellosis (2007).
Calculators used in this post
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