Power Consumption Calculator
Estimate the electricity an appliance uses and what it costs. Free online power consumption calculator with appliance quick-picks.
Quick Pick Appliance
(Watts × Quantity × Hours) / 1000 = kWh per day
(1500 × 1 × 6) / 1000 = 9.00 kWh/day
Energy Used Per Day
9.00 kWh
Estimated Cost (270.0 kWh): ₹1,755
kWh Per Billing Period
270.00 kWh
Cost (₹)
₹1,755
Cost ($)
$21.14
Annual Cost (₹)
₹21,352.5
How Does the Power Consumption Calculator Work?
Enter the appliance power in watts, the quantity of identical appliances, and the hours they run per day. The calculator converts watts into kilowatt-hours (kWh) using the formula: (Watts × Quantity × Hours) / 1000 = kWh per day. Multiplying the daily consumption by your billing days and per-unit rate (₹ per kWh) gives the estimated electricity cost for the period.
Example
A 1500 W AC used for 6 hours a day consumes (1500 × 1 × 6) / 1000 = 9 kWh per day. At ₹6.5 per kWh over a 30-day billing period, the cost is 270 kWh × ₹6.5 = ₹1,755.
Common Use Cases
- Estimating the monthly electricity bill of a household appliance.
- Comparing energy usage of different appliances before buying one.
- Budgeting for electricity costs of offices, shops, or work-from-home setups.
- Calculating annual energy costs to evaluate energy-efficient alternatives.
FAQs
How do I convert watts to kilowatt-hours?
Multiply the watts by the hours of use and divide by 1000. For example, a 100 W bulb running 10 hours uses (100 × 10) / 1000 = 1 kWh.
Why does my actual bill differ from the estimate?
Real bills include fixed charges, taxes, slab-based tariffs, and appliances that do not always run at their rated power. This calculator gives a close estimate of the energy charge only.
Is a higher watt rating always worse?
Not necessarily — a higher-watt appliance used fewer hours can cost less than a lower-watt appliance left running all day. The calculator accounts for both watts and usage hours.