Does running the AC on a higher temperature save electricity?

Yes. Each degree higher on the thermostat reduces compressor run time, which reduces electricity consumption. Moving from a set temperature of 22 to 26 degrees can reduce hourly electricity use by 15 to 25 percent, depending on the unit and outdoor conditions.

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How Much Electricity Does an AC Use? Real Examples

Q: How much does it cost to run a 1 ton AC for a month?

Running 8 hours per night for 30 days, a 5-star inverter 1 ton AC uses roughly 120 to 150 units per month, costing about 960 to 1,200 rupees at 8 rupees per unit. A 3-star 1 ton unit uses about 175 to 210 units per month, costing roughly 1,400 to 1,680 rupees.

Q: Which uses more electricity, a 1.5 ton or a 2 ton AC?

A 2 ton AC uses more electricity than a 1.5 ton unit of the same star rating, typically 30 to 40 percent more per hour at similar star ratings. However, a correctly sized 2 ton AC in a room that genuinely needs 2 ton will run more efficiently and for shorter cycles than a 1.5 ton unit struggling to keep up in the same room.

By Shahzad Arsi, Founder & Editor
Updated January 2026 · 7 min read

The question of how much electricity an AC uses is one of the most practical questions any homeowner in India can ask. The answer depends on tonnage, star rating, hours of use, and ambient conditions, but with a few reference figures you can estimate your own unit's consumption and cost with reasonable accuracy. This guide gives real numbers, not ranges so broad they are useless.

Quick answer: A 5-star inverter 1.5 ton AC uses roughly 0.8 to 1.1 units per hour in steady operation and about 7 to 9 units over an 8-hour night. A 3-star unit of the same size uses 1.3 to 1.6 units per hour and about 10 to 13 units overnight. At 8 rupees per unit, that is 56 to 72 rupees versus 80 to 104 rupees per night.

Electricity Use by Tonnage and Star Rating

The table below gives approximate average power draw figures for Indian split ACs in steady operation, once the room has reached the set temperature. The first hour runs higher because the compressor works at full load to cool the room down.

Steady-state averages. Actual figures vary with room conditions, set temperature, and outdoor temperature. First-hour draw is higher than these figures.
AC size	Rating	Avg draw (steady)	Units per hour	Units per 8 hrs	Cost per 8 hrs (at 8 rupees)
1 ton	5-star inverter	0.6 to 0.8 kW	0.6 to 0.8	5 to 7	40 to 56 rupees
1 ton	3-star	0.9 to 1.1 kW	0.9 to 1.1	7 to 9	56 to 72 rupees
1.5 ton	5-star inverter	0.8 to 1.1 kW	0.8 to 1.1	7 to 9	56 to 72 rupees
1.5 ton	3-star	1.3 to 1.6 kW	1.3 to 1.6	10 to 13	80 to 104 rupees
2 ton	5-star inverter	1.1 to 1.5 kW	1.1 to 1.5	9 to 12	72 to 96 rupees
2 ton	3-star	1.7 to 2.1 kW	1.7 to 2.1	14 to 17	112 to 136 rupees

Monthly Cost Estimates

Extending the overnight figures to a full 30-day month gives a picture of what each unit type adds to a household bill:

Based on 8 hours of use per night for 30 days. Includes the higher draw of the first hour each night. Tariff varies by state; swap in your local rate.
AC size and rating	Units per month (8 hrs/night, 30 days)	Monthly cost (at 8 rupees/unit)
1 ton, 5-star inverter	150 to 210	1,200 to 1,680 rupees
1 ton, 3-star	210 to 270	1,680 to 2,160 rupees
1.5 ton, 5-star inverter	210 to 270	1,680 to 2,160 rupees
1.5 ton, 3-star	300 to 390	2,400 to 3,120 rupees
2 ton, 5-star inverter	270 to 360	2,160 to 2,880 rupees
2 ton, 3-star	420 to 510	3,360 to 4,080 rupees

To estimate your own unit's monthly cost with your actual usage hours and tariff, use the Electricity Cost Calculator.

What the Star Rating Difference Costs Over a Season

The gap between a 3-star and 5-star 1.5 ton unit is roughly 90 to 120 units per month at the same usage. At 8 rupees per unit, that is 720 to 960 rupees per month, or roughly 2,900 to 3,800 rupees over a four-month peak season. Over three to four seasons, the electricity saving typically exceeds the extra purchase price of the 5-star unit. For a full payback analysis, see 5 star vs 3 star AC: is the extra cost worth it.

Factors That Change Actual Consumption

The figures above are for steady-state operation in a properly sized room. Several factors push consumption higher:

Higher outdoor temperature. At 44 degrees outside versus 36 degrees, the compressor works significantly harder to maintain the same indoor temperature. Summer months in hot cities will show materially higher consumption than early or late season.
Lower set temperature. Each degree lower increases compressor run time. Setting 22 instead of 26 degrees can increase hourly consumption by 15 to 25 percent.
Under-sized AC. A unit smaller than the room needs will run at full load continuously rather than cycling down to idle, pushing consumption well above these averages.
Dirty filters. Restricted airflow forces the unit to run longer for the same cooling. Clean filters monthly in heavy use.
Hot room at switch-on. Starting with a room at 36 degrees draws much more in the first hour than starting at 30 degrees.

Enter your unit's wattage, hours, and tariff for a precise monthly cost.

Electricity Cost Calculator

Key takeaways

A 5-star inverter 1.5 ton AC uses roughly 0.8 to 1.1 units per hour in steady operation and 7 to 9 units per 8-hour night.
A 3-star 1.5 ton unit uses 1.3 to 1.6 units per hour and 10 to 13 units overnight: about 40 percent more.
Monthly consumption at 8 hours per night for 30 days ranges from roughly 150 units (1 ton, 5-star) to 510 units (2 ton, 3-star).
Outdoor temperature, set temperature, and filter cleanliness all significantly affect actual consumption.
The electricity saving from a 5-star vs 3-star 1.5 ton unit is roughly 2,900 to 3,800 rupees over a four-month peak season.

Frequently Asked Questions

How many units of electricity does a 1.5 ton AC use per day?

Running 8 hours per night, a 5-star inverter 1.5 ton AC uses approximately 7 to 9 units per day. A 3-star unit uses roughly 10 to 13 units for the same hours. The first hour uses more because the compressor runs at high load to cool the room down.

How much does it cost to run a 1 ton AC for a month?

At 8 hours per night for 30 days, a 5-star inverter 1 ton AC uses roughly 150 to 210 units per month, costing about 1,200 to 1,680 rupees at 8 rupees per unit. A 3-star unit uses about 210 to 270 units, costing roughly 1,680 to 2,160 rupees.

Which uses more electricity, a 1.5 ton or a 2 ton AC?

A 2 ton AC typically uses 30 to 40 percent more electricity per hour than a 1.5 ton unit at similar star ratings. However, a correctly sized 2 ton unit in a room that genuinely needs 2 ton will be more efficient than a 1.5 ton unit struggling with an oversized load in the same room.

Does running the AC at a higher temperature save electricity?

Yes. Each degree higher on the thermostat reduces compressor run time. Moving from 22 to 26 degrees set temperature can reduce hourly electricity use by 15 to 25 percent, depending on the unit and outdoor conditions.

Sources and Further Reading

Bureau of Energy Efficiency, India, ISEER and energy labelling standards (beeindia.gov.in)
ENERGY STAR, room air conditioner energy use (energystar.gov)
U.S. Department of Energy, air conditioning electricity consumption (energy.gov)

Shahzad Arsi

Founder & Editor, CalcArcond

Shahzad builds CalcArcond's calculators and writes its guides, turning published HVAC standards and energy data into plain-language answers for homeowners and buyers. He is not a licensed HVAC engineer, and complex installations should be confirmed with a professional. More about CalcArcond.

Electricity consumption figures are estimates based on typical Indian split AC units and average usage patterns. Actual consumption varies with unit model, room conditions, set temperature, and local climate. Use the Electricity Cost Calculator for a figure specific to your unit and tariff.