Find the energy use and running cost of an appliance — free and instant.
Electricity is billed in kilowatt-hours (kWh) — the energy a 1,000-watt appliance uses running for one hour. Enter an appliance's power rating (in watts, usually printed on the device or its label), how many hours a day it runs, and your rate per kWh, and this finds the daily energy use and cost, plus a 30-day estimate.
The formula is straightforward: energy (kWh) = watts ÷ 1,000 × hours, and cost = energy × your rate. The 30-day figure is a simple estimate (daily cost × 30), not an actual billing-cycle calculation, since real bills often have tiered rates or fixed charges this tool doesn't account for.
Check the label or nameplate on the device itself, or its manual — it’s usually listed directly in watts. If only amps and voltage are given, multiply them together to get watts (W = V × A).
Real electricity bills often include tiered pricing (the rate can change based on total usage), fixed monthly charges, taxes, and other appliances running at the same time — this tool estimates one appliance in isolation using a flat rate.
Check your most recent electricity bill for your actual per-kWh rate — it varies significantly by location and utility provider.