Cost Per kWh Calculator
Your true all-in electricity rate — divide a bill total by the kWh used.
Updated
The full amount you paid.
From the same bill.
You need
$0.2000/kWh
$180.00 over 900 kWh
- True all-in rate
- $0.2000/kWh
- In cents
- 20.00¢/kWh
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In short
What is my real cost per kWh?
Your true rate is the total bill divided by the kilowatt-hours that bill covered. A $180 bill over 900 kWh is exactly $0.20 per kWh. That one division folds in the energy charge, the fixed monthly fee, taxes, and any delivery charges, which is why it lands above the rate a provider advertises.
Use the amount due before any credit, discount, or arrears adjustment, because a one-off line item on the bill will distort the rate it implies.
How to use the cost per kWh calculator
This tool runs the energy-bill arithmetic in reverse. Instead of building a bill up from a rate you would have to guess at, you start from a bill you have already received, enter two numbers off it, and get back the only rate that actually matters: your true all-in cost per kilowatt-hour.
Both fields arrive pre-filled with a representative example of $180 over 900 kWh so you can see the tool work before you swap in your own figures. The result is worth more than any published average, because published averages describe a country or a state and your bill describes your meter, your tariff, your fixed charges, and your local taxes.
$180
Bill total entered
every line item included
900 kWh
Usage it covered
summed across tiers and periods
$0.20
True all-in rate
the only figure worth comparing
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The total bill amount is the bottom-line figure, the amount due with every line item already included. Do not strip out taxes, fixed fees, or delivery charges, because capturing them is the entire point of the exercise. If you paid $180 this month, enter $180.
The division then spreads whatever the utility folded into that bill across every kilowatt-hour it charged you for, which is exactly what you want when the question is what a unit of electricity genuinely costs you. The one thing to watch for is a one-off item, such as an arrears adjustment, a credit, a reconnection fee, or a catch-up charge after an estimated reading, since any of those will distort the rate the division implies.
Do
- Enter the full amount due with every line item included.
- Sum tiered or peak and off-peak usage into one total before entering it.
- Prefer a month with an actual meter reading and no unusual line items.
- Run the calculation once per provider, month, or home before comparing.
- Compare plans at usage levels that resemble your own months.
Don't
- Strip out taxes, fixed fees, or delivery charges from the bill total.
- Use a bill carrying a credit, an arrears adjustment, or a reconnection fee.
- Read a winter rate as describing a summer month on a tiered tariff.
- Substitute a published state or national average for your own statement.
Why a published average is a poor substitute for your own bill: the US residential price has moved a long way in a decade, and it moves within a single year too. The last column is what 900 kWh of energy alone would have cost at each price, before any fixed charge or tax is added on top.
| Period | US average residential price, cents per kWh | Cost of 900 kWh of energy at that price | Change since 2017 |
|---|---|---|---|
| 2017 average | 12.89 | $116.01 | baseline |
| 2018 average | 12.87 | $115.83 | minus 0.2 percent |
| 2019 average | 13.01 | $117.09 | plus 0.9 percent |
| 2020 average | 13.15 | $118.35 | plus 2.0 percent |
| 2021 average | 13.66 | $122.94 | plus 6.0 percent |
| 2022 average | 15.04 | $135.36 | plus 16.7 percent |
| 2023 average | 16.00 | $144.00 | plus 24.1 percent |
| 2024 average | 16.48 | $148.32 | plus 27.9 percent |
| 2025 average | 17.30 | $155.70 | plus 34.2 percent |
| January 2026 | 17.45 | $157.05 | plus 35.4 percent |
| February 2026 | 17.65 | $158.85 | plus 36.9 percent |
| March 2026 | 18.56 | $167.04 | plus 44.0 percent |
| April 2026 | 18.83 | $169.47 | plus 46.1 percent |
| May 2026 | 18.44 | $165.96 | plus 43.1 percent |
What do I actually do with the all-in rate?
Read the output as your real price per unit, shown to several decimals because the gap between $0.20 and $0.2013 compounds across hundreds of kilowatt-hours. It is almost always higher than the per-kilowatt-hour rate a provider advertises, and that gap is the part of the bill the advertised rate quietly leaves out.
To compare fairly, run the calculation once for each thing you are weighing, whether that is two providers, two months, or two homes, and line the all-in rates up next to each other.
Working in the other direction instead?
If you would rather work in the other direction, projecting a future bill from a known rate and breaking out the fixed charge and tax explicitly, the energy bill estimator is this tool forward-running sibling.
Open the energy bill estimator →Advertisement
The formula, worked line by line
There is no rate to enter here, because the rate is what you are solving for. Take the complete bill and divide it by the energy that bill was charging you for, and the result is the genuine price of one kilowatt-hour at your address, with every charge included and nothing quietly excluded.
The reason this beats any quoted rate is structural rather than arithmetic. A tariff can distribute its cost across a per-unit energy charge, a fixed daily or monthly standing charge, a separate delivery charge, a demand component, and tax, and the advertised headline usually names only the first of those.
Dividing the total by the usage collapses all of it into one comparable number, which is the only form in which two different tariffs can honestly be set side by side.
cost per kWh = total bill / kWh used
example: $180 / 900 kWh = $0.20 per kWh
headline premium = (all-in rate / advertised rate) - 1- Bill total
- $180.00
- kWh the bill covered
- 900
- Divide
- 180 ÷ 900
- True all-in rate
- $0.20 per kWh
That is the whole calculation; all the work is in reading the two correct numbers off the statement, and the division does the rest. Build the same bill forward from a $0.175 supply rate with a $15 fixed charge and 5 percent tax and it comes to $181.13, an all-in rate of $0.2013, which is about 15 percent above that headline.
Read it: A light user pays far more per unit than the rate card suggests, nearly double the advertised price at 100 kWh, and any comparison that ignores this will favour whichever plan hides more of its cost in fixed charges.
Assumes a $0.175 supply rate, a $15 fixed charge, and 5 percent tax; the premium over the headline is not a fixed markup, because the fixed charge is spread across whatever usage you had.
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Questions people ask
What is my real cost per kWh?
It is your total bill divided by the kilowatt-hours that bill covered. On the tool defaults that is $180 divided by 900, which is $0.20 per kWh. Because the total already contains the energy charge, the fixed monthly fee, taxes, and any delivery charges, that single number is the honest price of a kilowatt-hour at your address. It is the figure to use whenever you compare months, homes, or providers, and the one to enter into any other calculator that asks what your electricity costs.
Why is it higher than my advertised rate?
Because the advertised rate is only the energy or supply portion. Your bill also carries a fixed monthly charge, taxes on the subtotal, and frequently a delivery or distribution charge billed separately from supply. Dividing the whole bill by your usage spreads all of those across every kilowatt-hour, so the all-in rate lands above the headline, and that gap is precisely what the quoted price leaves out. The effect is strongest at low usage: a $15 fixed charge alone adds 5 cents per kWh across a 300 kWh month and 15 cents across a 100 kWh month.
How much does a kWh cost where I live?
The only reliable answer comes from your own bill, because the all-in cost depends on your provider fixed charges, local taxes, and delivery fees on top of the supply rate. Published averages give you scale rather than an answer: the Energy Information Administration put the US residential average at 18.44 cents per kWh in May 2026, with state averages that month running from 12.35 cents in Idaho to 52.00 cents in Hawaii. Your true all-in figure is usually higher than whichever average applies to you, so enter your bill total and usage and see.
How do I compare two providers or two months fairly?
Run the calculation once for each. Take provider A total and the kilowatt-hours it covered to get A all-in rate, then do the same with provider B. Comparing those two figures is fair because each already contains that provider fixed fees, taxes, and delivery charges. The same method works for two months in one home or for two different homes. One caution: a plan with a low unit rate and a high standing charge looks cheap on the rate card and expensive on a light month, so compare at usage levels that resemble yours.
Where do I find the total kWh used on my bill?
It is printed on the bill, usually in the usage summary or beside the meter readings, labelled something like kWh used or total usage. It equals this period meter reading minus the previous period reading, so you can check it against your own meter if a number looks wrong. If the bill breaks usage into tiers, or into peak and off-peak periods, add those pieces together into one total before entering it, so the rate you derive reflects every kilowatt-hour the bill charged you for.
Sources
Where the constants and formulas on this page come from. Each line names the figure it backs.
The 18.44 cents per kWh US residential average for May 2026 and the 18.11 cents year-to-date figure.
Electric Power Monthly, Table 5.3 — Average price of electricity to ultimate customers by end-use sector — US Energy Information Administration, Data through May 2026, released 23 July 2026
The state spread quoted for that month: 12.35 cents in Idaho against 52.00 cents in Hawaii.
Electric Power Monthly, Table 5.6.A — Average price of electricity by state — US Energy Information Administration, May 2026
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