🔌 Electricity Bill Calculator

Estimate the running cost of an appliance from its wattage and usage.

About this tool

Estimates how much it costs to run a single appliance based on its wattage, how many hours a day it's used, how many days a month, and your electricity rate per kilowatt-hour.

Useful for comparing appliances, spotting which devices actually drive up a bill, or sanity-checking a suspiciously high electricity charge.

Worked example

A 1,500-watt space heater run 2 hours a day for 30 days at $0.15/kWh costs about $13.50 a month.

How to use it

Enter the appliance's wattage (check the label or spec sheet).
Enter how many hours a day it's typically used.
Enter days per month and your electricity rate.
Press Calculate cost.

Tips

Wattage is often printed on the appliance itself or in its manual — if only amps and volts are listed, multiply them together to estimate watts.
Standby power (devices left plugged in but off) is usually small per device but can add up across a household — this tool is best for a single, actively used appliance.
Electricity rates vary by time of day and provider in many places — check a recent bill for your actual per-kWh rate rather than guessing.

FAQ

How do I find an appliance's wattage?

Check the label, nameplate, or manual — it's often listed directly in watts, or as volts × amps, which you can multiply together to get watts.

Does this include standby power when the appliance is off?

No — this estimates active-use cost only, based on the hours you specify as "in use."

Why is my actual bill different from this estimate?

Real bills include every device in the house, tiered or time-of-use rates, taxes, and fixed service charges — this tool estimates one appliance in isolation using a flat rate.

From the blog: getting the most out of this tool

This tool started from a very ordinary question — "is my space heater actually the reason my bill went up" — and that's still the best use case: isolate one appliance, plug in realistic numbers, and get a concrete monthly figure instead of a vague guess.

High-wattage devices used for even a couple of hours a day (heaters, hair dryers, older AC units) are usually where the surprises hide — this is a fast way to check a hunch before assuming a bill is wrong.