Cost per kWh Calculator

This cost per kWh calculator finds what you really pay for electricity. Enter the total from your bill, the kWh you used and any fixed monthly charge. It returns your all-in price per kWh, your energy-only price and how your rate compares with the US average. Use the result in every other electricity calculator for accurate costs.

How cost per kWh is calculated

1. All-in price (¢/kWh) = total bill ÷ kWh used × 100
2. Energy-only price (¢/kWh) = (total bill − fixed charges) ÷ kWh used × 100
3. Versus US average = (all-in price − 18.2) ÷ 18.2 × 100%, using the 18.16¢ August 2026 average from EIA Table 5.6.A

A fixed charge (also called a customer, service or basic charge) is the flat monthly fee you pay regardless of how much electricity you use.

Worked example with the default inputs

Defaults: a $152 bill, 850 kWh used and a $12 fixed customer charge.

• All-in price: 152 ÷ 850 = $0.1788 → 17.88¢/kWh
• Energy-only price: (152 − 12) ÷ 850 = $0.1647 → 16.47¢/kWh
• In dollars: $0.1788 per kWh
• Versus the US average of 18.2¢: (17.88 − 18.2) ÷ 18.2 = about 2% lower

Cost per kWh examples

The same formula applied to other bills, each with a $12 fixed charge.

Bill total	kWh used	All-in price	Energy-only price	vs. US average
$100	500	20.00¢	17.60¢	+10%
$152	850	17.88¢	16.47¢	−2%
$200	1,200	16.67¢	15.67¢	−8%
$300	1,500	20.00¢	19.20¢	+10%

Notice the first and last rows share the same all-in price but have different energy rates. Fixed charges weigh more heavily on small bills.

US benchmarks from EIA

Monthly prices come from the Electric Power Monthly; annual use and bill figures from EIA Table 5A.

Measure	Value	Data period
Average residential price	18.16¢/kWh	August 2026
Average residential price	16.00¢/kWh	2023 (annual)
Average monthly use	855 kWh	2023
Average monthly bill	$136.84	2023

What affects your price per kWh

Fixed charges. The larger the customer charge, the bigger the gap between all-in and energy-only prices, especially in low-use months.

Tiered rates. Some utilities charge more per kWh above a monthly threshold. Your marginal price may be higher than the average this calculator shows.

Time-of-use plans. Prices differ by hour. Calculate peak and off-peak prices separately if your bill splits them.

Season and fuel costs. Fuel and purchased-power adjustments change month to month, so check several bills. EIA explains how generation, transmission and distribution each feed into the price (factors affecting electricity prices).

Step-by-step: reading your electric bill

1. Find the billing period dates and make sure the kWh and dollar total cover the same days.
2. Find the total amount due for electricity only. If the bill also includes gas, water or past balances, leave those out.
3. Find the kWh used, usually shown as the difference between two meter readings.
4. Find the fixed monthly charge, often called a customer charge, service charge or basic charge.
5. Enter all three numbers above and note both prices.

For the most reliable rate, repeat this for three to twelve bills and average the results. Summer and winter rates can differ, and some utilities change prices partway through the year.

All-in price vs energy charge: which to use

Use the all-in price when you want to know what your electricity costs on average, for example to compare utilities or budget for the year. Use the energy-only price when you want to know what an extra kWh, or a kWh saved, is worth. That is the right number for solar savings, EV charging costs and appliance upgrades, because the fixed charge does not change when your usage does.

History of paying per kilowatt-hour

Paying a price per kWh is younger than electric light. The earliest commercial electricity in the 1880s had predictable loads, so customers were commonly billed by the number of lamps or motors installed (electricity meter history). Edison’s Pearl Street Station, which began service on 4 September 1882 with about 85 customers, included a consumption meter in its system; Edison’s version was electrochemical, using an electrolytic cell to total the current used. True energy billing became practical once recording watt-hour meters appeared in 1889 (Bláthy at Ganz, and Elihu Thomson), followed by Shallenberger’s induction meter for Westinghouse in 1894, the design behind the spinning-disc meters still found on some homes.

Year	Milestone	Source
1882	Edison’s Pearl Street Station in New York begins supplying about 85 customers on 4 September	IEEE ETHW
1882	C. William Siemens proposes the watt as the unit of power to the British Association	Watt (unit)
1889	Bláthy (Ganz Works) and Elihu Thomson introduce recording watt-hour meters	Electricity meter
1894	Shallenberger’s induction watt-hour meter sets the modern meter design	Electricity meter
1960	The 11th CGPM adopts the watt as the SI unit of power	Watt (unit)

References

• Thompson, A. & Taylor, B. N. (2008). Guide for the Use of the International System of Units (SI). NIST Special Publication 811. doi:10.6028/NIST.SP.811e2008
• U.S. Energy Information Administration. Electric Power Monthly, Table 5.6.A. eia.gov

How to use your rate

• Enter your all-in price into the electricity cost calculator to cost any device.
• Use it with the kWh calculator or the electricity usage calculator to see what each appliance adds to your bill.
• For EV owners, plug the rate into our guide on the cost to charge an electric car.

To understand the unit on your bill, read what a kilowatt-hour is. Knowing your real rate also tells you how much rooftop solar and other renewable energy options could save you.