FullCalculator

Power Consumption Calculator

Single Device Consumption

Calculate energy use for one device

Compare Two Devices

Compare energy consumption and cost between two devices

Formula

kWh = Watts × Hours / 1000 | Cost = kWh × Rate | Monthly = Daily × 30 | Yearly = Daily × 365

Frequently Asked Questions

How do I calculate power consumption in kWh?
kWh = (Watts × Hours) / 1000. For example, a 100W light bulb running 10 hours uses 1 kWh. Monthly consumption = daily kWh × days per month. Your electric bill is based on total kWh consumed multiplied by the rate per kWh.
What uses the most electricity in a home?
The largest consumers are typically: HVAC (heating/cooling) at 40-50%, water heating at 14-18%, washer/dryer at 5-10%, lighting at 5-10%, refrigerator at 4-6%, and electronics at 3-5%. Actual percentages vary by climate and household size.
How can I reduce power consumption?
Switch to LED lights (85% less than incandescent), use Energy Star appliances, unplug devices when not in use (standby power is 5-10% of home energy), use smart power strips, improve insulation, and set thermostats wisely (each degree saves ~3% on HVAC).

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