Inverter AC electricity consumption: units per hour for 1, 1.5 and 2 ton, and the bill

Inverter AC electricity consumption depends on size and star rating. By the formula on Pakistan’s energy label, a 5-star 1.5-ton inverter AC uses about 0.70 units an hour on average over the cooling season, and one at the legal minimum about 1.06 units. A 1-ton uses 0.44 to 0.66 units and a 2-ton 0.94 to 1.41. Run 8 hours a day, a 5-star 1.5-ton adds about 168 units a month to your bill.

A unit on your bill is one kilowatt-hour (kWh). An inverter AC slows its compressor down instead of switching it on and off, so its use changes from hour to hour. The figures above are averages; the arithmetic is below so you can redo it for your own AC.

Inverter AC electricity consumption: how many units per hour?

Every wall-mounted split AC up to 10.5 kW sold in Pakistan must carry a Pakistan Energy Label from NEECA (the National Energy Efficiency and Conservation Authority), under S.R.O. 413(I)/2024, notified in March 2024. The label shows the AC’s yearly use in kWh, worked out with this formula from the regulation:

Units per year = cooling capacity in watts × 1.37 ÷ CSPF

CSPF (cooling seasonal performance factor) is the efficiency number on the label: how much cooling you get for each unit of electricity over a season. Higher is better. The regulation defines 1 ton as 3,516.85 W of cooling, so a 1-ton AC is about 3,517 W, a 1.5-ton about 5,275 W and a 2-ton about 7,034 W.

NEECA’s test season has 2,283 hours of outdoor temperatures from 21°C to 44°C. Dividing the yearly units by those hours gives an average per hour:

The 1.37 in the formula works out to 1,370 hours of cooling at full capacity a year. Your own AC’s use depends on how many hours you run it and how hot it is outside.

How many watts does an inverter AC draw?

The hourly average hides a wide range. Haier’s Pakistan spec pages give the cooling power input of three of its DC inverter models, from the lowest compressor speed to full power:

So a 1.5-ton Haier uses about 0.52 units an hour at its lowest compressor speed and up to 1.85 units an hour at full power. Note that Haier’s “1 ton” and “1.5 ton” are bigger than the regulation’s definition (1 ton is 12,000 BTU), which is one reason we use the label formula for the averages.

What does an inverter AC add to the monthly bill?

Multiply the hourly units by your hours of use. At 8 hours a day for 30 days (240 hours):

The cost depends on your slab. As of October 2026, NEPRA’s residential rates for unprotected homes run from Rs 22.44 a unit (up to 100 units) to Rs 47.20 (above 700), plus a monthly fixed charge, from the schedule IESCO publishes under S.R.O. 279(I)/2026. Unprotected homes are charged every unit at the rate of the slab their total falls in.

Here is an unprotected home that uses 150 units a month without the AC, before fuel adjustments and taxes:

The 1.5-ton 5-star adds about Rs 7,357 a month here, more than its 168 units alone would cost at the old slab, because it pushes all 318 units into the Rs 36.46 slab. Fuel cost adjustments add more: the August 2026 adjustment of Rs 1.1086 a unit, charged in October 2026 bills, adds about Rs 186 on 168 units.

Check every slab and the fixed charges in our guide to the electricity unit price.

Can an AC make you lose protected status?

Yes. Protected homes pay only Rs 10.54 (up to 100 units) or Rs 13.01 (101 to 200 units) a unit, but protected status needs six continuous months under 100 or 200 units, Dawn reported in February 2026. A 5-star 1.5-ton AC run 8 hours a day adds about 168 units a month, so any home using more than 32 units without it goes over 200 units, and onto the unprotected rates.

How do you cut an inverter AC’s consumption?

• Buy more stars. At 1.5 ton, a 5-star AC’s label use is 1,606 units a year against 2,409 for one at the minimum, about a third less.
• Watch your slab. If your usual use sits just under a slab line, a few extra hours can move every unit to the next rate.
• Run it on solar. If you are sizing a rooftop system around an AC, see what size solar system you need and try our solar calculator.

More guides: is solar worth it in Pakistan, net metering, solar geyser vs gas and electric, all solar cost guides.