Compare appliance energy costs

Enter the power and daily use for both options. Keep the useful service comparable: two heaters should provide similar warmth, and two lighting options should provide similar light. Lower wattage is only a saving if the alternative still meets your needs.

Formula

Each option uses power in kW × operating hours × operating days. Annual saving = option A’s annual cost − option B’s annual cost. Percentage saving = annual saving ÷ option A’s cost × 100.

Worked example

Using an 800 W device for four hours daily consumes 1,168 kWh annually. A 500 W alternative on the same schedule consumes 730 kWh. The difference is 438 kWh, or 37.5% of option A’s consumption.

What the result means

A positive saving means B costs less to operate than A. A negative value means B costs more. Monthly totals average the annual schedule over 12 months.

Electricity price · India

₹8.00/kWh is an illustrative input, not an India-wide average or an official electricity tariff. Replace it with the applicable rate for your state, DISCOM, consumer category and consumption slab.

Last reviewed: 9 September 2026

Electricity duty, fuel or power purchase adjustments, fixed charges and subsidies depend on the applicable state and DISCOM rules. No national tax percentage or subsidy is assumed. Slab thresholds, sanctioned-load charges and time-of-day tariffs are not automatically modelled.

Assumptions and limits

The comparison covers electricity, not purchase price, repairs, service life or differences in performance. A smaller device that needs longer to finish may not save the amount suggested by wattage alone.

Questions answered

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