Electricity Cost Calculator

Work out what electricity costs per day, month, and year from appliance watts, hours of use, and your price per kWh. Running a plant instead? Continue in the industrial energy estimator.

Cost inputs

Appliance preset

Power per unit (W)

Quantity

Hours used per day

Electricity rate ($/kWh)

Days per month

About this calculator

Cost is power in kilowatts times hours times your price per kWh, shown for a day, a month, and a year. Enter your own rate — 0.17 $/kWh is a common US residential average. Continue on the power calculators hub.

Result

Planning estimate. Rates, duty cycles, and standby draw vary, so confirm against your own bill.

Assumptions: the device runs at a constant rated power for the hours entered, and the rate is flat. It ignores duty cycling, standby power, tiered or time-of-use rates, and taxes or fees on the bill.

Continue Your Calculation

Running a factory or a panel instead of an appliance? Continue in the energy estimator for demand, power factor, and industrial energy cost.

Industrial energy estimator →

Typical appliance power and monthly cost

Appliance	Typical power (W)	Hours/day	kWh/month	$/month at 0.17
Refrigerator	150	24	108	18.36
Window air conditioner	1200	8	288	48.96
Space heater (1.5 kW)	1500	8	360	61.20
Electric water heater	4000	3	360	61.20
Desktop PC	200	8	48	8.16
LED TV	100	5	15	2.55
Washing machine	500	1	15	2.55
EV charger (Level 2)	7200	3	648	110.16

Estimates at a flat 0.17 $/kWh and 30 days a month, using the rated power for the hours shown. Heaters and EV chargers dominate because they run at high power for long, not because their rate is different.

Formula

Cost = (Watts ÷ 1000) × Hours × Rate. A 1,500 W space heater at 8 hours a day is 1.5 kW × 8 h = 12 kWh a day. At 0.17 $/kWh that is 12 × 0.17 = $2.04 a day, $2.04 × 30 = $61.20 a month, and $2.04 × 365 = $744.60 a year. To go the other way, kWh ÷ hours × 1000 gives watts back.

Worked example

Energy cost of a 2,000 sq ft house: about 900 to 1,100 kWh a month, or 30 kWh a day. At 0.17 $/kWh that is roughly $153 to $187 a month. Enter the same 30 kWh a day here as 1,250 W running 24 hours, or add the big loads — heating, cooling, and water heating — one at a time.

Comparing two options: a 1,500 W heater for 8 h/day costs $61.20 a month, while a 150 W refrigerator running 24 h/day costs $18.36. Higher watts do not decide the bill on their own — hours matter just as much.

FAQ

How do you calculate the electricity cost of an appliance?

Multiply the power in kilowatts by the hours it runs, then by your price per kWh. A 1,500 W heater running 8 hours uses 12 kWh; at 0.17 dollars per kWh that is 2.04 dollars a day.

How do I convert kWh to watts?

Divide the kilowatt-hours by the hours to get kilowatts, then multiply by 1,000 for watts. 12 kWh over 8 hours is 1.5 kW, which is 1,500 W.

How many kWh does a 2,000 sq ft house use?

A typical 2,000 sq ft US home uses roughly 900 to 1,100 kWh a month, about 30 kWh a day. At 0.17 dollars per kWh that is about 153 to 187 dollars a month, and heating, cooling, and climate move this a lot.

How can I calculate the cost of electricity per month?

Take the daily kWh, multiply by the number of days you are billed for (usually 30), then multiply by your dollars per kWh rate. This calculator shows the day, month, and year at the same time.

Does this calculator use my local electricity rate?

Enter your own rate in dollars per kWh. The default is 0.17, a common US residential average, but rates vary by state, by utility, and by time of day.

What is the difference between this and the energy estimator?

This page is a household and general electricity cost calculator for appliances and devices. For factory demand, power factor, and industrial energy audits, use the industrial energy estimator.