How Many Units Does an AC Use? Inverter vs Non-Inverter, and the 200-Unit Line
A 1.5-ton non-inverter AC uses about 432 units a month at 8 hours a day; an inverter about 264. Why the 200-unit protected line matters, and easy ways to cut units.
By the TurantTools PK team · Updated 16 October 2026 · 4 min read
When the summer electricity bill arrives, the AC is the first suspect, and usually rightly so. But how many units does it really use? And how much does an inverter AC actually save? Let's just do the maths.
How units add up
One unit is one kilowatt-hour. The formula is simple: watts × hours a day × 30 ÷ 1000. A normal 1.5-ton AC draws about 1,800 watts, while an inverter AC averages around 1,100 watts once the room is cool.
| Hours a day | Inverter AC (units a month) | Non-inverter AC (units a month) |
|---|---|---|
| 4 | 132 | 216 |
| 6 | 198 | 324 |
| 8 | 264 | 432 |
| 10 | 330 | 540 |
Units a month at 8 hours a day
Why the 200-unit line matters
If every one of your last 6 months was at 200 units or less, you're a “protected” customer, and units 101 to 200 cost only about Rs 13.01 each. Go over 200 in a single month and you become non-protected for 6 months, where the same slab costs about Rs 28.91, before taxes.
One non-inverter AC running 8 hours a day uses 432 units on its own, so the AC alone can push you over the line.
Easy ways to cut units
- Set the thermostat to 26°C; every degree lower costs more.
- Clean the filter every two weeks and keep the outdoor unit out of direct sun.
- Keep doors and windows shut, and curtains closed in the daytime.
- Use the timer at night, and run the AC a little warmer with a fan on.