1.5 ton AC electricity cost for 8 hours
Estimate the electricity units and energy charge for a 1.5 ton AC used for eight hours, using its actual input power and the rate on your own bill.
Start with input power, not tonnage
A 1.5 ton label describes cooling capacity, not the exact electricity drawn from the meter. Find rated input power in watts or kilowatts on the appliance label, BEE label or product sheet. Inverter AC draw can vary as the room load changes.
Use the eight-hour calculation
Energy for one day = input power in kW × operating hours × average load factor. For a labelled 1,500 W input, eight hours, a 0.60 example load factor and 30 days: 1.5 × 8 × 0.60 × 30 = 216 kWh per month. At an example ₹8 per unit, the energy-charge scenario is 216 × ₹8 = ₹1,728. Replace both the input power, factor and rate with evidence for your AC and bill.
Compare input scenarios, not star labels alone
The table holds hours, days, load factor and the example ₹8 rate constant so you can see how model input changes the estimate. These are calculation scenarios, not claims about a particular star rating.
| Labelled input | Daily energy at 0.60 factor | Monthly units (30 days) | Energy charge at ₹8/unit |
|---|---|---|---|
| 1,300 W | 6.24 kWh | 187.20 kWh | ₹1,497.60 |
| 1,000 W | 4.80 kWh | 144.00 kWh | ₹1,152.00 |
| 840 W | 4.03 kWh | 120.96 kWh | ₹967.68 |
Estimate only the energy charge
Energy charge = estimated units × your own per-unit rate. Slabs, fixed charges, duties, fuel adjustments, taxes or subsidies can change the final bill, so an energy-charge estimate is not a promised bill amount.
Check it against the meter
Compare the estimate with a normal week of readings under similar weather and use. Adjust the operating factor from evidence instead of assuming a published example matches every room.
Where the operating factor enters
Eight clock hours does not necessarily mean eight hours at full labelled input. A compressor may cycle or modulate after the room approaches the set temperature. GharGanit keeps this behaviour in a separate average operating factor, so a 0.60 example means an average of 60% of the entered full input over the eight-hour window. It is a scenario, not a promised duty cycle for every AC or room.
Inputs that can move the result
Outdoor temperature, solar heat, room size, insulation, air leakage, occupancy, thermostat setting, maintenance and equipment condition can change average power. The model’s rated input is still the correct starting evidence, but it should not be described as an exact meter reading. When comparing two models, keep the room, hours, days, set point, rate and calculation method the same.
Turn a daily estimate into a test
Take meter or smart-plug readings only with equipment and safety arrangements suitable for the AC circuit. Record the starting and ending kWh for several similar days, note weather and use, and divide the measured energy by entered full-input kW × hours to infer an observed operating factor. Do not use a domestic plug meter on a circuit or load it is not rated to measure.
Questions the estimate does not answer
The calculation does not determine the correct AC tonnage for the room, installation quality, electrical protection, wiring capacity or the final tariff bill. Cooling-load selection and electrical work require appropriate product guidance and qualified assessment. The calculator is useful for comparing transparent energy scenarios after those requirements are known.