Appliance Electricity Cost Calculator
Enter an appliance's power draw in watts, how many hours a day it runs, and your electricity rate, and this calculator shows the energy it uses and what it costs per day, per month, and per year. Use it to find the hidden running cost of space heaters, air conditioners, gaming PCs, or anything else that stays plugged in.
Appliance
Cost per month
$61.20
12.00 kWh/day × $0.17/kWh
Per day
$2.04
Per year
$744.60
Energy & cost breakdown
Cost by period
How it works
Energy use is power multiplied by time. A device's wattage divided by 1,000 gives kilowatts; multiplied by hours of use it gives kilowatt-hours (kWh), the unit your utility bills. So daily energy = watts / 1000 × hours per day. A 1,500-watt space heater running 8 hours a day uses 1.5 × 8 = 12 kWh per day. Monthly and yearly figures scale that daily number by 30 and 365 days respectively.
Cost is simply energy multiplied by your rate. At a $0.15 per kWh rate, that heater's 12 kWh per day costs $1.80 a day, $54 a month, and $657 a year. The US average residential rate is around 18.8 cents per kWh as of 2026 (EIA), but rates vary widely by state — from roughly 11 cents in parts of the South to over 40 cents in Hawaii and California — so use your own rate from a recent bill for an accurate figure.
One important caveat: the nameplate wattage printed on an appliance is its maximum draw, not necessarily its continuous draw. Devices with thermostats or compressors — refrigerators, air conditioners, heaters — cycle on and off, so their average consumption is lower than running at full watts the whole time. For those, estimate the fraction of each hour the device actually runs, or use a plug-in energy meter to measure real usage. The reference table gives rough typical figures for common appliances.
Frequently asked questions
Where do I find an appliance's wattage?+
Look for a label or nameplate on the appliance itself — usually on the back, bottom, or near the power cord — which lists watts (W) or, sometimes, volts and amps (watts = volts × amps). The manufacturer's manual or spec sheet also lists it. For devices that cycle, like refrigerators and air conditioners, the nameplate shows peak draw; their real average is lower. The most accurate method is a plug-in energy monitor (a 'Kill A Watt'-style meter), which measures actual kWh over time and removes the guesswork about duty cycles entirely.
Why is my estimate different from my actual bill?+
A few reasons. First, appliances that cycle on and off draw their rated watts only part of the time, so a continuous-run estimate overstates their cost. Second, your utility rate may include tiered pricing, time-of-use rates, delivery charges, and taxes that a single per-kWh figure does not capture — check your bill for the all-in rate. Third, this tool models one device; your total bill sums dozens. Use it to compare and prioritize individual appliances rather than to reconcile a whole bill to the penny.
What uses the most electricity in a typical home?+
Heating and cooling usually dominate — central air conditioning, electric furnaces, space heaters, and heat pumps move the most energy because they run for long stretches at high wattage. Water heating, clothes dryers, and older refrigerators are typically next. Low-wattage electronics like LED bulbs, phone chargers, and laptops cost very little even when used often. Running the biggest, longest-running loads through this calculator is the fastest way to see where your money actually goes, and where efficiency upgrades pay off.