Estimate kWh usage and electricity cost for appliances over time.
This tool provides estimates for informational purposes only and is not a substitute for professional advice. Individual results vary based on personal circumstances and assumptions.
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Your electricity bill is one of the most controllable household expenses — but only if you understand what is driving it. Most people have no idea how much individual appliances cost to run, which ones are the biggest culprits, or how to estimate a monthly bill before it arrives. This electricity cost calculator lets you enter any appliance's wattage, usage hours, and your energy tariff rate to see its daily, monthly, and annual electricity cost instantly. This guide explains how electricity is measured and billed, what the average rates are in the USA and UK, which appliances use the most energy, and practical strategies for reducing your bill.
Electricity is sold in kilowatt-hours (kWh). One kilowatt-hour is the energy consumed by a 1,000-watt appliance running for one hour. Understanding the relationship between these units is key to calculating costs:
The formula: kWh = (watts × hours) ÷ 1,000
Cost: total cost = kWh × electricity rate per kWh
Example: A 1,500W electric kettle used for 10 minutes (1/6 of an hour) per day: 1,500 × (10/60) ÷ 1,000 = 0.25 kWh per day. At $0.16/kWh (US average): 0.25 × $0.16 = $0.04/day, $1.20/month, $14.60/year.
US electricity rates vary significantly by state and by the season. The national average residential rate is approximately 15–17 cents per kWh (as of recent data), but individual states range widely:
Your rate also depends on your plan type: fixed-rate plans lock in a rate for 12–24 months; variable-rate plans fluctuate with the market. Time-of-use (TOU) plans charge different rates at different times of day — peak hours (typically 4–9 PM on weekdays) are more expensive.
UK electricity pricing is centrally regulated with an Ofgem price cap. From October 2024, the standard unit rate was approximately 24.50p per kWh (with a standing charge of about 61p/day), but rates have been volatile since the 2022 energy crisis. Key facts:
To find your exact rate, check your electricity bill or your supplier's tariff page. Enter it into the calculator above for precise cost estimates.
Here is a reference guide for typical appliance power consumption:
Many appliances continue to draw power even when "switched off" at the appliance level but left plugged in. This "vampire power" or "standby power" adds up across a household:
The US Department of Energy estimates standby power accounts for 5–10% of residential electricity use — potentially $100–$200/year for an average American household. Smart power strips, programmable outlets, and simply unplugging devices can meaningfully reduce this.
Use this calculator to estimate the annual cost of your heating, cooling, and water heating — these typically account for 50–70% of a household's electricity use. Small savings here have far bigger impact than turning off phone chargers.
If you still have any incandescent or halogen bulbs, replacing them with LEDs is the single easiest energy-saving upgrade. An LED uses 75–80% less energy than an equivalent incandescent and lasts 15–25 times longer.
Running dishwashers, washing machines, and EV chargers overnight on off-peak rates can save 30–50% on those specific loads if you are on a time-of-use electricity plan.
Add up the kWh used by all your appliances: (watts × daily hours) ÷ 1,000 = daily kWh. Multiply by 30 for monthly kWh. Multiply by your per-kWh rate. Add any standing charges or fixed fees from your tariff.
According to the US Energy Information Administration (EIA), the average American household uses about 886 kWh per month and pays approximately $125–$140/month. This varies greatly by climate, home size, and state rates.
As of 2024–2025 with the Ofgem price cap, a typical UK household (using around 2,700 kWh/year) pays approximately £700–£900 per year for electricity, or £60–£75/month. Larger homes or those with electric heating pay significantly more.
US average: roughly 29 kWh per day (886 kWh/month ÷ 30). UK average: approximately 7.4 kWh per day (2,700 kWh/year ÷ 365). The difference reflects the larger average US home size, more air conditioning, electric dryers, and less energy-efficient building stock.
Disclaimer: Energy costs shown are estimates based on inputs provided. Actual bills include standing charges, taxes, and other fees not reflected in simple kWh calculations. Rates change frequently — use your actual tariff for precise budgeting.