Find out exactly what any appliance costs to run — per hour, day, month, and year. Pick from common appliances or enter your own wattage.
The formula is: Cost = (Watts ÷ 1000) × Hours × kWh Rate. For example, a 1,500W electric heater running for 8 hours at $0.13/kWh costs (1500 ÷ 1000) × 8 × 0.13 = $1.56 for that session.
A kilowatt-hour (kWh) is the standard unit of electricity measurement on your bill. It equals 1,000 watts used for one hour. A 100W light bulb running for 10 hours uses 1 kWh. Your electricity rate is expressed as a price per kWh — typically between $0.10 and $0.35 depending on your country and provider.
Check the appliance label (usually on the back or bottom), the power plug, the original packaging, or the manufacturer's website. For devices that vary in power use (like laptops or TVs), use the maximum wattage as a conservative estimate. "Standby" power consumption is much lower — typically 1–5W — but adds up across many always-on devices.
The biggest consumers are typically electric water heaters (2,000–4,500W), electric clothes dryers (4,000–6,000W), electric ovens (2,000–5,000W), air conditioners (1,000–5,000W), and electric space heaters (750–1,500W). In contrast, LED bulbs use just 8–15W and laptops typically 25–75W.
Check your most recent electricity bill — the rate (price per kWh) is usually listed in the usage breakdown section. US average is around $0.13/kWh, UK around $0.28/kWh, and Australia around $0.25/kWh, though rates vary significantly by state/region and time of use.
Yes — "vampire power" from devices left on standby can account for 5–10% of a typical household electricity bill. A TV on standby at 2W costs about $2.28/year, but if you have 20 such devices, that's over $45/year for doing nothing.