Six days of sums. Which five things in your home decide the bill?
Your big five
Six days of sums. Which five things in your home decide the bill?
Every appliance obeys the same rule: units a day equals watts, times hours a day, divided by a thousand. The whole week was that one sum in different clothes. The kettle is high watts for minutes. The fridge is low watts for 24 hours. The geyser is high watts for the hours it takes to replace what you drew. The standby lights are tiny watts for every hour of the year.
The knowhow
When you line up the five biggest users in your home, the shape is usually the same. Hot water is first by a distance. Cooking and heating or cooling come next, depending on the season. The fridge is steady and modest. Lighting and screens are further down than most people expect, especially after the LED swap.
And so
The value of the ranking is not the exact numbers. It is knowing where a change is worth making. Ten minutes off the shower moves the bill. Switching off a lamp does not. Three things decide what you pay: what it draws, how long it runs, and your rate per unit.
Keep this
What it draws, how long it runs, and what you pay per unit.
Now try it with your own numbers. List your five biggest users, with the wattage from each label and an honest estimate of hours a day. The geyser's hours are the time its element actually runs, usually two to three hours a day for a family. The table sorts them and totals the month.
Arithmetic: kWh per day = W × h ÷ 1000. | Eskom Distribution, Residential calculator assumptions page (water heating leads household use). | Eskom Distribution, Tariffs and Charges Booklet 2026/27.
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My tries: every time you save, your numbers, what they came to, and your note are kept here so you can compare later.