Energy Cost Calculator
See how much any appliance costs to run per day, month, and year.
How to Use This Energy Cost Calculator
- Find the wattage — look for a label on the appliance, check the manual, or use the preset dropdown. Wattage is printed on most appliances near the power cord or on the bottom.
- Estimate hours of use — how many hours per day does the appliance run? A refrigerator runs about 8-10 hours total (cycling on and off). A space heater might run 8 hours during the day.
- Enter your rate — find your per-kWh rate on your electric bill. The US average is about $0.12/kWh, but rates vary widely by location.
- Review your costs — see the daily, monthly, and yearly cost impact of running this appliance.
Understanding Electricity Costs
Your electric bill is determined by the total kilowatt-hours (kWh) you consume during the billing period, multiplied by your utility's per-kWh rate. Understanding how individual appliances contribute to your total consumption is the first step toward managing energy costs effectively.
The Energy Cost Formula
This calculator uses the standard formula for electricity cost:
kWh per Day = (Watts × Hours) ÷ 1,000
Cost per Day = kWh per Day × Rate ($/kWh)
Cost per Month = Cost per Day × 30
Cost per Year = Cost per Day × 365
What Is a Kilowatt-Hour?
A kilowatt-hour (kWh) is the standard unit of energy used for electric billing. One kWh equals 1,000 watts of power used for one hour. So a 100-watt light bulb running for 10 hours consumes 1 kWh. The average American household uses about 900 kWh per month, resulting in a monthly bill of roughly $100-120 at average rates. Understanding kWh helps you compare the cost of running different appliances and identify the biggest contributors to your electric bill.
Biggest Energy Consumers in Your Home
Heating and cooling systems are typically the largest electricity consumers, accounting for 40-50% of a home's energy use. Central air conditioning draws 3,000-5,000 watts while running. Electric water heaters consume 4,500 watts during heating cycles. Clothes dryers pull 3,000-5,000 watts per load. Electric ranges use 2,000-5,000 watts while cooking. Even the humble refrigerator costs $50-150 per year because it runs around the clock, cycling on and off throughout the day.
Phantom Loads and Standby Power
Phantom loads (vampire power) are the electricity devices consume while off but still plugged in. Cable boxes, game consoles, TVs, laptop chargers, and microwave clocks all draw power 24/7. A single cable box can consume 20-30 watts on standby — costing $20-30 per year just sitting idle. The average home loses $100-200 annually to phantom loads. Combat this waste with smart power strips that cut power to devices when not in use, or simply unplug electronics you rarely use.
Tips to Reduce Your Electric Bill
Switch to LED bulbs — they use 75% less energy than incandescent bulbs and last 25 times longer. Run dishwashers and laundry on cold water cycles when possible. Set your thermostat to 78 degrees F in summer and 68 degrees F in winter. Use ceiling fans to supplement air conditioning (fans cost pennies per hour to run). Seal air leaks around windows and doors. Consider a smart thermostat that learns your schedule and adjusts temperatures automatically. Even small changes add up: replacing five 60-watt bulbs with 10-watt LEDs saves about $50 per year.
How to Read Your Electric Bill
Your electric bill shows total kWh consumed during the billing period. Some utilities have tiered rates where the per-kWh price increases as you use more. Others have time-of-use rates where electricity costs more during peak hours (2-7 PM). Understanding your rate structure helps you shift energy-intensive tasks to off-peak hours and stay in lower rate tiers. Look for the "supply charges" and "delivery charges" sections — both contribute to your effective per-kWh rate.