Electricity Usage Calculator
Daily Usage (kWh)
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Monthly Usage (kWh)
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Annual Usage (kWh)
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Monthly Cost
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Annual Cost
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How to Calculate Electricity Usage
Electricity consumption is measured in kilowatt-hours (kWh): kWh = Watts × Hours / 1000. A 100-watt light bulb running for 10 hours uses 1 kWh. Your electricity bill charges per kWh consumed, typically $0.10-$0.30 depending on location and rate plan.
Common appliance wattages: LED bulb 10W, laptop 50W, TV 100-200W, refrigerator 150W (average), microwave 1000W, space heater 1500W, AC unit 1500-3500W, electric dryer 5000W. Knowing these helps identify the biggest energy consumers in your home.
To reduce costs, focus on high-wattage appliances used for many hours. Switching to LED bulbs, using a programmable thermostat, and running high-draw appliances during off-peak hours (if on time-of-use pricing) can significantly reduce your electricity bill.
Frequently Asked Questions
How do I calculate kWh?
kWh = Watts × Hours / 1000. A 1500W space heater running 6 hours = 1500 × 6 / 1000 = 9 kWh.
What is the average electricity rate?
US average is about $0.15/kWh but varies from $0.08 (Louisiana) to $0.35+ (Hawaii, California). Check your bill for your exact rate.
What uses the most electricity?
Heating/cooling (40-50%), water heating (14%), washer/dryer (13%), lighting (10%). Exact breakdown depends on climate and habits.
How can I reduce my electricity bill?
Switch to LED bulbs, seal air leaks, use programmable thermostats, wash clothes in cold water, and unplug devices not in use (phantom loads).