Electricity Bill Calculator

The rate printed on a tariff sheet is not what a kilowatt-hour costs you. Add the customer charge, whatever riders your utility bolts on and the tax, spread it back over the kWh you used, and the real number is usually two to five cents higher.

kWh
The billed usage for the period, not the meter reading itself
Used only when the selector above is set to meter readings
Almost always 1 on a residential meter. Some meters print a multiplier of 10 or more on the faceplate.
days
Read-to-read periods run roughly 28 to 34 days, which is one reason two bills are hard to compare directly
¢/kWh
Leave this to the rate on your own bill. US residential rates span a very wide band by state, utility and season, and they move.
kWh
Optional. Only if your utility charges a higher rate above a monthly threshold.
¢/kWh
Optional. Used only when a threshold is entered above.
$
Optional. The customer or service charge, plus any flat monthly riders. It is on the bill whether you use a kilowatt-hour or not.
%
Optional. Varies by state and city, and some places exempt residential electricity entirely.
$
Optional. Enter it and the calculator backs out your true all-in rate and shows how far the estimate is off.
Electricity Bill Calculator — Estimate a Monthly Bill from kWh and Your Own RateBuildFigure

Nobody can tell you your rate

US residential electricity prices are set utility by utility, approved state by state, and revised on their own schedules. Between the cheapest and most expensive states the gap is more than threefold, and within a single state an investor-owned utility, a municipal system and a rural cooperative serving adjacent territory can all charge differently. Published ranges usually put residential rates somewhere in the low teens to the low thirties of cents per kilowatt-hour, but that is a range that moves with fuel costs and seasonal schedules, not a figure to plan against. This calculator ships with the rate field blank on purpose.

The honest way to get your own number takes ten seconds. Find the total dollars on the bill and the total kilowatt-hours, and divide. That single figure includes the energy charge, the delivery or distribution charge, every rider with a name you have never heard of, the customer charge and the tax. It is what a kilowatt-hour costs at your address. It is also, almost always, higher than the rate printed next to the words "energy charge", which is the number people quote when they say what they pay.

What the pieces do

LineWhat it isDoes using less change it?
Customer or service chargeFlat monthly amount for being connectedNo
Energy chargeCents per kWh for the electricity itselfYes, directly
Delivery / distributionCents per kWh for moving it to you, sometimes flatUsually yes
Fuel or purchased-power adjustmentRider that tracks generation cost, revised periodicallyYes, and the rate itself moves
TaxState or local sales or utility tax on the subtotalProportionally

In this calculator everything charged per kilowatt-hour goes in the rate field and everything charged flat goes in the fixed field. If your bill separates energy from delivery, add the two per-kWh figures together and enter the sum. The split matters for understanding a tariff and not at all for what you owe.

Tiers, and the reason the second field is optional

Some utilities charge a higher rate above a monthly threshold, sometimes called an inclining block or baseline structure. Where it exists it is usually two or three steps and the step applies only to the kilowatt-hours above the line, not retroactively to all of them. Enter the threshold and the higher rate and the calculator splits the usage. Where it does not exist, leaving both blank gives a flat calculation, which is what most bills are.

Time-of-use is the structure this calculator cannot represent, and it is spreading. Under time-of-use the price depends on when the kilowatt-hour was used rather than how many came before it, so a monthly total cannot be reconstructed from a monthly usage figure at all. If you are on a time-of-use plan, this page will still tell you what the month cost on average, which is useful for comparison across months. It will not tell you what the peak window is doing to you, and that is usually the thing worth knowing.

Meter readings and period length

Reading the meter yourself is the only way to see usage between bills. Subtract the previous reading from the current one; the difference is kilowatt-hours, unless the faceplate carries a multiplier, which is rare on residential service and never silent when it applies. Read at the same time of day and the arithmetic is clean.

Billing periods are read-to-read, which means they are not months. A 34-day period against a 28-day period is a 21 percent difference in exposure before anything about the weather or the household changed. Both this calculator and any sane comparison between two bills should be done on kilowatt-hours per day rather than kilowatt-hours per bill.

Where an estimate goes wrong

Enter what the bill actually came to and the calculator will tell you your true all-in rate and how far the reconstruction is off. If the gap is more than a few percent, the usual causes are a seasonal rate schedule that changed mid-period, a fuel adjustment that moved, a demand charge on a non-standard residential tariff, or a credit or arrears balance carried forward. Chasing the last dollar is rarely worth it. Take the all-in rate, use it everywhere else on this site where a rate in cents per kWh is asked for, and revisit it once a season.

Questions people ask

What is the average electricity rate in the US?

There is a national average published by the federal energy statistics agency, and quoting it here as a fact would be misleading for almost every reader. Rates vary by more than threefold across states, differ between neighbouring utilities in the same state, change between summer and winter schedules on many tariffs, and are revised on the utility's own timetable. Published figures generally put residential prices somewhere in a band from the low teens to the low thirties of cents per kilowatt-hour, and that band drifts. Your own bill answers the question exactly: total dollars divided by total kilowatt-hours. That takes less time than looking up an average that would not apply to you anyway.

Why is my all-in rate higher than the rate on my tariff?

Because the tariff rate is one line and the bill has several. The customer charge is a flat monthly amount that does not scale with usage, so when you divide the total by kilowatt-hours it shows up as extra cents on every unit. Delivery charges, fuel adjustment riders and taxes add more. The lower your usage, the more the fixed portion inflates the all-in figure — a very light month can land at double the headline energy rate. That is not an error on the bill; it is what a fixed charge does when you express it per unit.

My bill went up but I did not change anything. Why?

Check three things in order. First, the number of days in the period — read-to-read cycles vary by several days and a longer period is simply more of everything. Second, kilowatt-hours per day rather than per bill, which removes the period-length effect and shows whether usage actually moved. Third, the rate itself: fuel adjustment riders are revised periodically and seasonal schedules switch on a calendar date, so the same usage can cost more without anyone in the house doing anything differently. If usage per day is flat and the all-in rate went up, the answer is on the utility's side.

Does the calculator handle time-of-use plans?

No, and it cannot in this form. A time-of-use bill depends on when each kilowatt-hour was used, which a single monthly usage number does not record. You can still use this page to work out your average all-in rate for a month by entering the bill total, which is genuinely useful for comparing months and for any calculation that only needs an average. For anything about shifting load, you need the interval data your utility publishes to your online account, plus the peak and off-peak rates and the hours they apply.

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