Appliance Electricity Cost Calculator
Calculate the electricity cost of any home appliance from wattage, daily usage hours, and electricity rate.
Returns daily, monthly, and annual costs.
The kWh math, demystified
Electricity is sold by the kilowatt-hour (kWh) — running 1,000 watts for one hour. The formula:
kWh per day = (watts × hours per day) ÷ 1,000 daily cost = kWh × rate ($/kWh) annual cost = daily cost × 365
A 1500W space heater running 2 hours a day: 1,500 × 2 ÷ 1,000 = 3 kWh/day × $0.16 = $0.48/day, or $175/year. Run it 8 hours a day and that climbs to $700/year — more than the heater cost. That’s where energy bills go.
US electricity rates vary wildly by state (2024 EIA data)
| State | Avg rate ($/kWh) |
|---|---|
| Louisiana | $0.10 |
| Idaho | $0.11 |
| Washington | $0.11 |
| Texas | $0.14 |
| Florida | $0.15 |
| US national average | $0.16 |
| New York | $0.22 |
| California | $0.28 |
| Massachusetts | $0.30 |
| Hawaii | $0.40 |
Same appliance costs 4x more to run in Hawaii than Louisiana. Worth knowing before planning a smart-home project or buying an electric car.
What your appliances actually cost (typical wattages × typical usage)
| Appliance | Watts | Daily use | Annual cost (@$0.16/kWh) |
|---|---|---|---|
| Refrigerator | 150 (avg with cycling) | 24 hr | $210 |
| Central AC (3-ton) | 3,500 | 8 hr (peak summer) | $1,635 (cooling season) |
| Electric water heater | 4,000 | 3 hr | $700 |
| Heat pump dryer | 800 | 1 hr | $47 |
| Conventional dryer | 5,000 | 1 hr | $292 |
| Dishwasher | 1,800 | 1 hr (4×/wk) | $60 |
| Electric oven | 2,400 | 1 hr (4×/wk) | $80 |
| Microwave | 1,000 | 10 min | $10 |
| Coffee maker | 800 | 15 min | $12 |
| TV (LED 55-inch) | 100 | 5 hr | $29 |
| Desktop PC | 200 | 8 hr | $93 |
| Laptop | 50 | 8 hr | $23 |
| LED light bulb | 10 | 5 hr | $3 |
| Smart speaker (always on) | 3 | 24 hr | $4 |
| Game console (Xbox/PS5) | 200 | 3 hr | $35 |
| Hot tub | 1,500 | 12 hr (heating) | $1,050 |
Where the real money goes (most US households)
Order of magnitude:
- HVAC (heating + cooling) — typically 40 to 50% of total electric bill
- Water heating — 15 to 20%
- Refrigerator + freezer — 5 to 10%
- Laundry (dryer especially) — 5 to 8%
- Lighting — 3 to 6% (down hugely since LED switch)
- Electronics — 5 to 10%
- Cooking — 3 to 5%
- Everything else — 5 to 10%
The big wins on cutting electric bills come from temperature management — better insulation, smart thermostats, heat pump water heaters, lower-setting laundry — not from unplugging chargers when not in use (which saves cents a year).
The phantom load myth
“Vampire draw” from devices in standby gets a lot of press but is a small share of bills for most homes. A TV in standby draws about 1 to 3 watts ($3 to $9/year). Phone chargers plugged in but not charging draw about 0.1 watts ($0.30/year). Cable/satellite boxes are the exception at 20 to 30 watts always-on (~$30 to $50/year per box). Unplugging chargers is virtue signaling; unplugging the second cable box is real savings.
Time-of-use rates
About a third of US utilities offer time-of-use rates: cheaper at night (often $0.08 to $0.12/kWh), more expensive during peak hours (often $0.25 to $0.45/kWh, 4-9 pm in summer). If you’re on this plan:
- Run dishwasher and laundry overnight
- Pre-cool the house in the afternoon, let it drift up during peak
- Charge EVs after 11 pm
Time-shifting half your variable load can cut bills 20 to 35%.
The most-effective single change
Switching from incandescent or halogen bulbs to LED: a 60W incandescent burning 5 hours/day costs $18/year. The LED equivalent (9W) costs $2.60/year. Replace 30 bulbs: save ~$460/year. The LEDs pay for themselves in 6 to 18 months.
Why your bill might be higher than the calculator predicts
The calculator covers active appliance use only. Your real bill also includes:
- Standing draw (always-on devices: refrigerator, internet router, smart thermostat, security system)
- Heating and cooling cycles you forget about (running while you’re at work)
- Hot water tank standby losses
- Utility delivery charges and taxes (often 30 to 50% of total bill)
A typical US household pays $130 to $180/month for electricity at average rates, far higher in California, the Northeast, and Hawaii.