What your aircon costs to run - from its BTU size, inverter or not, and the hours it runs in summer and winter.
Questions
How many watts does a 12 000 BTU aircon use?
About 1 100 W. 12 000 BTU/h is 3.5 kW of cooling (12 000 / 3 412); divide by a typical inverter COP of 3.2 and it draws about 1.1 kW from the wall - about 1.26 kW for a non-inverter at COP 2.8.
What does a 12 000 BTU aircon cost to run a month?
About R758 a month at 6 hours a day for 30 days, for an inverter unit at R3.83 a kWh (City Power's 2026/27 middle prepaid block): 1.1 kW x 180 hours = 198 kWh. Your own hours and price change it - type them in above.
Is BTU the same as power consumption?
No. BTU/h (or kW of cooling) is the heat the aircon moves out of the room. The electricity it uses is that figure divided by its efficiency (COP or EER), which is usually around 3 - so it draws roughly a third of its cooling rating.
Does an inverter aircon save money?
On efficiency alone, at COP 3.2 against 2.8, an inverter uses about 12.5% less power for the same hours - R877 a year for a 12 000 BTU unit on our default hours. It also slows down instead of switching off and on, which usually saves more than that.