Find the electricity cost of running an appliance.
Power is converted from watts to kilowatts, multiplied by hours of use to get units (kWh), then multiplied by your tariff rate.
Units: (Power in watts ÷ 1000) × hours
Cost: Units × rate per unit
The electricity cost calculator estimates what an appliance adds to your power bill. You enter its wattage, how many hours a day it runs, for how many days, and your rate per unit, and it returns the units consumed and their cost. It turns the rating on a label into rupees you can plan around.
Indian households often see the bill jump in summer without knowing which appliance is responsible. Running each big load through this calculator, such as an AC, a geyser, a water pump, an iron or a room heater, shows where the money goes. It is equally useful for small shops and offices deciding whether to replace an old appliance, and for landlords working out a fair electricity share for a tenant's heater or AC.
1. Find the appliance's power in watts from its label or manual.
2. Estimate the hours it actually runs each day.
3. Units per day = Watts ÷ 1000 × Hours. One unit is one kilowatt-hour.
4. Total units = Units per day × Number of days.
5. Cost = Total units × Rate per unit.
6. For a truer bill figure, use the rate of the slab your usage falls into and remember fixed charges and duties are extra.
Watts measure power, the rate at which an appliance uses energy. Energy is power multiplied by time. The billing unit in India is the kilowatt-hour: 1000 watts for one hour. So a 2000 W geyser running for 45 minutes uses 2 kW × 0.75 h = 1.5 units. Dividing watts by 1000 converts to kilowatts, and multiplying by hours gives kWh. The calculator does this, then scales up by the number of days and multiplies by your rate.
The wattage on a label is usually the maximum. Many appliances do not draw it all the time. An AC compressor or a fridge cycles on and off with a thermostat, and an inverter AC runs at variable speed. A geyser stops heating once the water reaches the set temperature. Using the full rated wattage for all running hours therefore tends to overestimate. For a better figure, count only the hours the heating element or compressor is actually on, or use a plug-in energy meter.
Most Indian electricity boards use telescopic slabs, where the first block of units each month is billed at a low rate and later blocks at higher rates. The bill also carries fixed or demand charges and electricity duty, which vary by state and connection type. The calculator uses one flat rate, so it is most accurate if you enter the rate of the slab your extra units fall into. That marginal rate is what the appliance really costs you.
Pooja's family in Lucknow runs a 2000 W geyser for about 45 minutes every winter morning for 31 days, and their tariff for the extra units is ₹6.50 each.
Answer: Estimated cost ₹302; Units consumed 46.5 kWh
Entering minutes as hours, for example 45 instead of 0.75.
Assuming a thermostat-controlled appliance draws full power for every hour it is switched on.
Using the lowest slab rate when the extra units will be billed at a higher slab.
Forgetting fixed charges, meter rent and electricity duty when comparing with the actual bill.
Using an old appliance's label wattage without allowing for wear, which can raise real consumption.
Finding which appliances drive a high summer or winter bill.
Deciding whether replacing an old AC, fridge or pump will pay off.
Splitting electricity costs fairly between flatmates or with a tenant.
Budgeting power costs for a small shop, clinic or home office.
What does 'unit' mean on my electricity bill?
One unit means one kilowatt-hour (kWh) — the energy used by a 1000-watt appliance running for one hour.