Electricity Cost Calculator
What does a device cost in electricity? Calculate yearly, monthly and daily cost plus consumption from power, usage and price — in dollars, with the US electricity price.
Key facts
- Watts into cost: power ÷ 1000 × hours = kWh, × price = cost. Example: 100 W × 5 h = 0.5 kWh/day, at 16.5¢/kWh about $0.08 a day (≈ $30/year).
- 2026 price guide: US household average around 16.5¢/kWh (EIA). The range is wide — from ~11¢ in the cheapest states to over 40¢ in Hawaii. Best enter the unit price from your last bill.
- Always-on devices add up: 10 W on standby around the clock costs 10 ÷ 1000 × 24 × 365 × $0.165 ≈ $14 a year — just for doing nothing.
FAQ
- How do I convert watts into electricity cost?
- Power (watts) divided by 1000 gives kilowatts. Times usage hours gives consumption in kilowatt-hours (kWh). Times the price (in ¢/kWh, divided by 100) gives the cost in dollars. Example: 100 W × 5 h = 0.5 kWh/day, at 16.5¢/kWh about $0.08 per day.
- Which electricity price should I enter?
- Best use the unit price from your last bill (in ¢/kWh). The default is 16.5¢/kWh — the 2026 US residential average (EIA). Depending on your state the range runs from ~11¢ to over 40¢ (Hawaii).
- Is standby consumption included?
- No. The calculator uses the given power for the given usage time. For standby, run a second calculation with a low wattage (e.g. 1–5 W) over 24 hours and add both results.