Boneyard Tools

How to read your electricity rate and estimate a bill

Find the true price per kWh on your bill, watch for fixed and tiered charges, and turn appliance wattage into a monthly cost.

Finding your real price per kWh

The single number this calculator needs is your price per kilowatt-hour, but bills rarely make it obvious. Look for a line called the energy charge, supply rate or unit price, usually shown in cents or dollars per kWh. If your plan lists several components, add the per kWh parts together, since generation and delivery are often billed separately. The most reliable check is to take the total kWh used from the bill and divide the bill amount by it, which gives your true blended rate including any extras.

Fixed charges and tiered rates

A flat rate per kWh is only part of the story. Many providers add a fixed daily or monthly connection charge you pay no matter how little you use, so a low usage month still carries a base cost. Tiered plans raise the price once you pass a threshold, meaning the last kWh of a heavy month can cost more than the first. Time of use plans go further and change the rate by hour of day. This tool models a single flat rate, so for those plans enter the rate for the block of usage you care about and treat the result as an estimate.

From appliance watts to daily kWh

To estimate what a device costs, first turn its power into energy. Multiply the wattage by the hours it runs, then divide by 1000 to get kilowatt-hours. A 1500 watt space heater run for 4 hours uses 1500 x 4 / 1000 = 6 kWh a day. Feed that into the calculator with your rate and tick daily usage to see the monthly and yearly weight of that one appliance. Repeat for the big loads, heating, cooling, water heating and laundry, and you can rank where your money actually goes.

Cutting the cost you find

Once a number has a price tag, savings get concrete. Running the heavy loads during off peak hours on a time of use plan, swapping incandescent bulbs for LEDs, and trimming standby draw all lower the kWh total that this calculator multiplies. Even a small rate difference compounds: at $0.30 per kWh, 10 kWh a day works out to $1,095 a year, while the same use at $0.15 halves that to about $547. Because monthly and yearly figures scale straight from the daily cost, any daily saving multiplies by 365 over a year.

Frequently asked questions

Should I use the summer or winter rate?

Use the rate that matches the period you are estimating. If your price changes by season or tier, run the calculator once per rate and compare, since a single flat figure cannot capture a plan that shifts through the year.

Why does the monthly total not match my calendar month?

The monthly projection is the yearly cost divided by 12, which averages about 30.4 days. A 28 or 31 day billing cycle, plus fixed fees and taxes, will make your real statement differ from the estimate.