Electricity Cost Calculator
Pick an appliance or enter its wattage, the hours it actually runs each day, and your rate from the bill. You get the cost per day, month and year, the kWh behind it, and a table of what common household loads cost.
From the label or plate. Amps × volts if only amps are given.
US residential average about $0.17; check your bill.
Cost per 30 days
$45.90
270.0 kWh
Per day
$1.53
9.00 kWh
Per year
$558.45
3285 kWh
Per hour running
$0.26
1.50 kW
kWh = watts × hours ÷ 1,000; cost = kWh × rate. Thermostat-controlled appliances (fridges, heaters, AC) cycle, so use the hours the compressor or element actually runs, not the hours it is switched on.
Monthly cost of common appliances at $0.17/kWh
Typical wattage and realistic running hours. Multiply by your rate ÷ 0.17 for your bill.
| Appliance | Watts | Hours/day | kWh/month | $/month | $/year |
|---|---|---|---|---|---|
| Refrigerator (modern, 20 cu ft) | 150 | 8 | 36 | $6.12 | $74.46 |
| Central AC, 3 ton (SEER2 15) | 2,400 | 8 | 576 | $97.92 | $1191.36 |
| Window AC, 8,000 BTU | 700 | 8 | 168 | $28.56 | $347.48 |
| Space heater | 1,500 | 6 | 270 | $45.90 | $558.45 |
| Electric water heater | 4,500 | 3 | 405 | $68.85 | $837.68 |
| Electric dryer (per load ≈ 1 h) | 5,000 | 1 | 150 | $25.50 | $310.25 |
| EV charging, level 2 | 7,200 | 2 | 432 | $73.44 | $893.52 |
| 65-inch TV | 100 | 5 | 15 | $2.55 | $31.03 |
| Gaming PC | 400 | 4 | 48 | $8.16 | $99.28 |
| LED bulb | 9 | 5 | 1 | $0.23 | $2.79 |
| Incandescent bulb | 60 | 5 | 9 | $1.53 | $18.62 |
| Hot tub (heater + pump, averaged) | 1,500 | 5 | 225 | $38.25 | $465.38 |
| Pool pump, 1.5 hp | 1,500 | 8 | 360 | $61.20 | $744.60 |
| Dehumidifier, 50 pint | 500 | 10 | 150 | $25.50 | $310.25 |
1,000 W for an hour a day, by electricity rate
One kWh a day. Scale linearly: a 500 W load is half, a 2 kW load double.
| Rate ($/kWh) | Where | Per day | Per month | Per year |
|---|---|---|---|---|
| $0.10 | Washington, Idaho, Louisiana | $0.10 | $3.00 | $36.50 |
| $0.13 | Texas, Georgia, Missouri | $0.13 | $3.90 | $47.45 |
| $0.17 | US average | $0.17 | $5.10 | $62.05 |
| $0.22 | Michigan, Vermont, Maryland | $0.22 | $6.60 | $80.30 |
| $0.30 | California, New York City, Massachusetts | $0.30 | $9.00 | $109.50 |
| $0.40 | Hawaii | $0.40 | $12.00 | $146.00 |
Finding the wattage
- The nameplate lists watts, or amps and volts (multiply them). Nameplate is maximum draw; many appliances average well below it.
- A plug-in meter ($15-25) measures what a 120 V appliance actually uses over a day, cycling included. It is the only honest number for a fridge or a gaming PC.
- 240 V loads (dryer, range, AC, EV) need a clamp meter or the utility's hourly usage data, which most smart-meter accounts expose online.
- Standby power adds up: a house full of chargers, set-top boxes and smart speakers idles at 50-100 W around the clock, which is $111.69 a year at the average rate.
Frequently Asked Questions
How do I calculate the cost to run an appliance?
Watts × hours ÷ 1,000 = kilowatt-hours; kWh × your rate = cost. A 1,500 W space heater for 6 hours is 9 kWh, which at the US average of $0.17/kWh is $1.53 a day and about $45.90 a month.
How much does it cost to run a space heater? An AC? A hot tub?
At $0.17/kWh: a 1,500 W space heater 6 h/day is $45.90/month; a 3-ton central AC compressor running 8 h/day is $97.92/month; a hot tub averaging 1,500 W over 5 h/day is $38.25/month; a level-2 EV charger 2 h/day is $73.44/month. The table below has more.
Where do I find my electricity rate?
On your bill, but not on one line: divide the total amount due by the kWh used for the month. That all-in rate includes delivery charges, taxes and fees that the headline supply rate leaves out, and it is typically 30-60% higher. The US residential average all-in is about $0.17/kWh; Hawaii is over $0.40, the Pacific Northwest and parts of the South under $0.13.
Why is my fridge's number lower than its wattage suggests?
Because the compressor cycles. A fridge plate might say 150 W, but the compressor runs perhaps a third of the time, so the honest 'hours per day' is 8, not 24. The same applies to anything thermostat-controlled: AC, heaters, water heaters, hot tubs. Use the running time, not the plugged-in time.
What does a kWh cost with time-of-use pricing?
It varies by hour: peak periods (often 4-9 p.m.) can be two to three times the off-peak rate. If you are on a time-of-use plan, run the calculator twice with each rate and the hours in each window, and shift what you can -- dishwashers, EV charging, laundry -- to off-peak.
These calculators use National Electrical Code tables and industry sizing charts and are for planning. They are not a substitute for a licensed electrician, an HVAC contractor's Manual J load calculation, or your local code, which governs. Electrical work can kill you and may require a permit; when in doubt, hire it out.