Electricity cost calculator
Any appliance, any rate. Enter the watts and hours yourself, or start from an appliance preset and a state rate and adjust from there. Everything runs in your browser — nothing you type here is sent to our server, or anywhere else.
Work out a running cost
— per year
The formula, in the open
kWh per day = watts ÷ 1000 × hours per day × duty cycle. Cost = kWh × your rate. That is the whole method — the same one used on every page of this site, published in full in how it works. Monthly figures use the mean month length of 30.44 days rather than a flat 30, so twelve months always sum to the yearly figure.
For a per-state answer with local context — how the rate got there, when the seasonal load actually falls — every preset above also exists as its own page: pick from all 40 appliances or browse rates by state.
How do I calculate the running cost of an appliance?
Multiply the power draw in kilowatts by the hours used per day and by your electricity rate per kWh. A 1500W heater used 4 hours a day at 18.83 cents per kWh costs 1.5 x 4 x $0.1883 = about $1.13 a day. The calculator above does this, and also accounts for duty cycle.
Where do I find the wattage of my appliance?
Check the nameplate sticker or plate, usually near the power cord, the model label, or the manual. It lists watts (W) or amps (A); amps times volts (120V for most US outlets, 240V for large appliances) gives watts.
What is a duty cycle and when should I change it?
Duty cycle is the share of switched-on time an appliance actually draws power. Thermostat-controlled equipment - fridges, heaters, air conditioners - cycles on and off, so a fridge that is plugged in 24 hours a day might draw power only a third of that time. For lights, TVs and fans, leave it at 100%.
Which electricity rate should I use?
The rate printed on your own bill, in cents per kWh, is always more accurate than any average. If you do not have a bill to hand, pick your state in the preset above and we fill in the current EIA state average for June 2026.