Electricity Cost Calculator
Calculate the cost of running any electrical appliance. Find out how much electricity costs per day, month, and year based on wattage and usage.
Electricity Cost
Monthly Cost
$2.88
24.0 kWh
Yearly Cost
$34.56
288 kWh
Appliance Wattage
Quick select common appliances:
Usage Settings
Electricity Rate
US average: $0.12-0.15/kWh. Check your electric bill for your actual rate.
Cost Breakdown
Daily
$0.10
0.80 kWh
Monthly
$2.88
24.0 kWh
Yearly
$34.56
288 kWh
How It's Calculated
Daily Energy Usage:
(100 W × 8 hours) ÷ 1000 = 0.800 kWh
Monthly Energy Usage:
0.800 kWh × 30 days = 24.00 kWh
Monthly Cost:
24.00 kWh × $0.12/kWh = $2.88
Common Appliance Wattages
| Appliance | Watts | $/Month (8h/day) |
|---|---|---|
| LED Light Bulb | 10 W | $0.29 |
| Incandescent Bulb | 60 W | $1.73 |
| Laptop | 50 W | $1.44 |
| Desktop Computer | 200 W | $5.76 |
| Gaming PC | 500 W | $14.40 |
| TV (LED 55") | 80 W | $2.30 |
| Refrigerator | 150 W | $4.32 |
| Washing Machine | 500 W | $14.40 |
| Clothes Dryer | 3000 W | $86.40 |
| Dishwasher | 1800 W | $51.84 |
| Microwave | 1000 W | $28.80 |
| Air Conditioner (Window) | 1200 W | $34.56 |
| Central AC | 3500 W | $100.80 |
| Space Heater | 1500 W | $43.20 |
| Hair Dryer | 1500 W | $43.20 |
| Electric Oven | 2500 W | $72.00 |
| Ceiling Fan | 75 W | $2.16 |
| Phone Charger | 5 W | $0.14 |
| Electric Kettle | 1500 W | $43.20 |
| Coffee Maker | 900 W | $25.92 |
Environmental Impact
CO₂ Emissions (Monthly)
10.1 kg
Based on US average grid
CO₂ Emissions (Yearly)
121 kg
≈ 0.12 metric tons
The average US electricity grid produces ~0.42 kg CO₂ per kWh. This varies significantly by region and energy mix. Renewable energy sources have near-zero operational emissions.
Quick Answer
To calculate electricity cost: multiply watts by hours used, divide by 1000 for kWh, multiply by rate per kWh. Formula: (Watts x Hours / 1000) x Rate = Cost. A 100W bulb running 8 hours at $0.12/kWh: (100 x 8 / 1000) x $0.12 = $0.096 per day = $2.88 per month. Average US electricity rate is $0.12-0.15 per kWh.
Key Facts
- Formula: kWh = (Watts x Hours) / 1000
- Cost = kWh x Rate per kWh
- Average US electricity rate: $0.12-0.15 per kWh
- 1 kilowatt-hour (kWh) = 1000 watts used for 1 hour
- Average US home uses 886 kWh per month (~$106/month)
- Biggest energy users: HVAC (46%), water heating (14%), appliances (13%)
- LED bulbs use 75-80% less energy than incandescent
- Standby power ("vampire" draw) accounts for 5-10% of residential electricity
Frequently Asked Questions
Electricity cost = (Watts × Hours used ÷ 1000) × Cost per kWh. First convert watts to kilowatts by dividing by 1000, multiply by hours of use, then multiply by your electricity rate. A 1000W device used for 5 hours at $0.12/kWh costs $0.60.
A kilowatt-hour (kWh) is a unit of energy equal to 1,000 watts used for one hour. It's how electric companies measure and bill electricity. A 100W bulb running for 10 hours uses 1 kWh. Most US homes use 800-1000 kWh per month.
US average is about $0.12-0.15 per kWh, but varies widely by state ($0.08 in Louisiana to $0.30+ in Hawaii). Check your electric bill for your actual rate. Some areas have tiered pricing or time-of-use rates that change throughout the day.
Heating and cooling typically account for 40-50% of home energy use. Other major consumers: water heater (14%), washer/dryer (13%), lighting (9%), refrigerator (4%). Old appliances and inefficient usage significantly increase costs.
Switch to LED bulbs (save 75%). Use smart power strips (eliminate standby power). Set thermostat 2-3°F higher/lower. Wash clothes in cold water. Air dry dishes. Use appliances during off-peak hours if time-of-use pricing. Upgrade old appliances to Energy Star.
Electricity Cost
Monthly Cost
$2.88
24.0 kWh
Yearly Cost
$34.56
288 kWh