Electricity Cost Calculator
Electricity cost is calculated by multiplying power (watts) by usage hours by rate per kWh: Cost = (Watts × Hours × Days) / 1000 × Rate. For example, a 100W bulb running 8 hours/day at $0.12/kWh costs $2.88/month (100 × 8 × 30 / 1000 × 0.12). A 1500W space heater running 8 hours/day costs $43.20/month. Compare appliances to find energy hogs. US average rate: $0.12-0.15/kWh.
Calculate how much electricity your appliances use and what they cost. Enter wattage, hours of use, and your electricity rate to see daily, weekly, monthly, and yearly costs. Compare multiple appliances side by side.
Appliance Presets
Wattage (W)
Hours Per Day
Electricity Rate ($/kWh)
$/kWh
Monthly Electricity Cost
$2.88
24 kWh/month
Daily
$0.10
0.8 kWh
Weekly
$0.67
5.6 kWh
Monthly
$2.88
24 kWh
Yearly
$35.04
292 kWh
Cost Breakdown
Daily
$0.10
Weekly
$0.67
Monthly
$2.88
Yearly
$35.04
Electricity Cost Formula
- kWh per day = (Wattage × Hours per day) / 1,000
- Daily cost = kWh per day × Rate per kWh
- Monthly cost = Daily cost × 30 days
- Yearly cost = Daily cost × 365 days
How to Use
- Enter your value in the input field
- Click the Calculate/Convert button
- Copy the result to your clipboard
Frequently Asked Questions
- How do I calculate electricity cost for an appliance?
- Multiply the wattage by hours of use per day, then divide by 1,000 to get kWh. Multiply kWh by your electricity rate. For example, a 100W TV used 8 hours/day at $0.12/kWh: (100 × 8) / 1,000 × $0.12 = $0.096/day or about $2.88/month.
- What is a kilowatt-hour (kWh)?
- A kilowatt-hour (kWh) is a unit of energy equal to using 1,000 watts for one hour. Your electricity bill is measured in kWh. A 100W light bulb running for 10 hours uses 1 kWh. A 1,500W space heater running for 1 hour uses 1.5 kWh.
- What is the average electricity rate in the US?
- The US national average electricity rate is approximately $0.16 per kWh as of 2024. Rates vary widely by state: New England averages $0.27/kWh, while the Mountain region averages $0.13/kWh. Check your utility bill for your exact rate.
- Which household appliances use the most electricity?
- The biggest electricity consumers are typically: central AC (3,000-5,000W), EV chargers (7,200W), clothes dryers (3,000W), water heaters (4,500W), space heaters (1,500W), and dishwashers (1,800W). Reducing usage of these appliances has the greatest impact on your bill.
- How can I reduce my electricity bill?
- Key strategies include: switching to LED bulbs (saves 75% per bulb), using smart power strips to eliminate phantom loads (5-10% of your bill), adjusting thermostat by 1°F (saves ~3%), running full loads in washer/dryer, air-drying clothes, and unplugging chargers when not in use.
- How do I find my electricity rate?
- Check your monthly electricity bill — the rate is listed as cost per kWh (kilowatt-hour). You can also find it on your utility company's website. If your bill shows tiered rates, use the average rate: divide total electricity charges by total kWh used.