Electricity Calculator
Calculate electricity cost, usage, and power consumption for appliances and devices.
An electricity cost calculator estimates your energy bill based on appliance wattage, usage hours, and your local electricity rate.
Examples
100W bulb running 8 hours/day
1500W space heater, 4 hours/day
Frequently Asked Questions
How do I find my cost per kWh?
What uses the most electricity in a home?
Quick Tips
- •Check your utility bill or provider website for your exact cost per kWh, including delivery charges.
- •Unplug appliances or use smart power strips to eliminate phantom power draw when devices are off.
- •Switching to LED bulbs can reduce lighting electricity costs by up to 75%.
An electricity cost calculator estimates your energy bill based on appliance wattage, usage hours, and your local electricity rate.
How to Use This Calculator
Enter the wattage of an appliance, how many hours per day it runs, the number of days per month, and your electricity rate. The calculator shows daily, monthly, and annual energy usage and cost.
Understanding the Formula
kWh = Watts x Hours / 1000. Cost = kWh x Rate per kWh. Monthly cost = Daily kWh x Days x Rate.
Examples
100W bulb running 8 hours/day
Daily: 100 x 8 / 1000 = 0.8 kWh. Monthly (30 days): 24 kWh. At $0.12/kWh: $2.88/month or $35.04/year.
1500W space heater, 4 hours/day
Daily: 1500 x 4 / 1000 = 6 kWh. Monthly: 180 kWh. At $0.12/kWh: $21.60/month.
Frequently Asked Questions
How do I find my cost per kWh?
Check your electricity bill. Divide the total charges by the total kWh used. The US average is approximately $0.12-$0.16/kWh but varies widely by state.
What uses the most electricity in a home?
Heating/cooling (HVAC) typically accounts for 40-50% of electricity use. Water heating, clothes dryers, and electric ovens are also major consumers.
Assumptions & Limitations
- Assumes constant wattage draw; actual consumption may vary with appliance cycling and power modes.
- Electricity rates are assumed flat; tiered or time-of-use pricing structures are not modeled.
- Does not include fixed service charges or demand fees that may appear on your bill.