How to read your electric bill

Every utility lays out its bill differently, but the same pieces are always there:

• Usage in kWh. Usually shown as a meter reading at the start and end of the period, the difference between them, and often a bar chart of the last 13 months. A kilowatt-hour is 1,000 watts for one hour: a 1,500 W space heater running for 40 minutes.
• Billing period. The dates and the number of days. Periods run from about 28 to 33 days, so a "high" bill can simply be a long month. Divide kWh by days to compare months fairly.
• The fixed charge. Called a customer charge, basic service charge or meter charge. You pay it even at zero kWh.
• The total. Everything, including taxes and fees.

Also check whether the meter reading says "actual" or "estimated". An estimated reading is corrected on a later bill, which can make one month look low and the next one high.

Most bills split the per-kWh price into two parts:

• Supply (also called generation or energy): the cost of the electricity itself.
• Delivery (also called distribution and transmission): the cost of the poles, wires, substations and meters that bring it to you.

Your local utility always charges for delivery. In states with retail choice, such as Texas, Pennsylvania, Ohio and Illinois, the supply part can come from a different company, and it may be printed on a separate section or a separate page. If you shop for a supplier, compare the supply price only, since delivery stays the same whoever you buy from.

On top of these you may see riders and adjustments: fuel or purchased-power adjustments, energy efficiency program charges, storm or wildfire recovery charges, and taxes. Most are charged per kWh or as a percentage, so they rise and fall with your usage. Add them to the rate.

Not every kWh costs the same.

Tiered rates charge a price for the first block of kWh each month and a different price above it. Most tiered rates step up, so the last kWh you use costs more than the first. Some step down. Some utilities change the tiers between summer and winter.

Time-of-use (TOU) rates charge by the hour. A peak window, often late afternoon and early evening, costs more; nights and weekends cost less. Your bill shows kWh in each period, each with its own price.

Both matter for the same reason: when you add an appliance, it is priced at the rate it actually runs at. A space heater pushed into the top tier, or a dryer run during the peak window, costs more than the average on your bill suggests. An EV charged overnight on a TOU plan costs less. The EV charging cost calculator has a field for an off-peak rate for that reason.

Here is a sample bill (made-up numbers, typical layout) for a 30-day period:

Line	Amount
Customer charge	$12.00
Delivery, 900 kWh × 6.50¢	$58.50
Supply, 900 kWh × 11.20¢	$100.80
Taxes and fees, 5%	$8.57
Total	$179.87

There are two rates you can get out of it:

1. All-in average: total ÷ kWh = $179.87 ÷ 900 = 20.0¢ per kWh. This is what you paid, on average, for each kWh this month.
2. Marginal rate: the per-kWh charges plus the percentage taxes, without the fixed charge = (6.50¢ + 11.20¢) × 1.05 = 18.6¢ per kWh. This is what one more kWh adds to the bill.

For a calculator, use the marginal rate. Adding a dehumidifier doesn't change the customer charge, so the fixed fee shouldn't be spread over its kWh. In this example the difference is 1.4¢ per kWh; on a small bill with a large fixed charge it can be several cents.

If you are on a tiered plan, use the price of the tier your usage normally ends in. On a TOU plan, use the price of the period when the appliance runs, or an average weighted by how much it runs in each.

For comparison, the average residential rate across the US is 18.2¢/kWh (EIA, August 2026). That figure is total residential revenue divided by kWh sold, so it includes fixed charges spread over usage, like the all-in average above. It is a fair default when you don't have a bill at hand, and every calculator lets you replace it with your own.

When your appliance list doesn't add up to the bill, the gap is usually one of these:

• The fixed charge and taxes. A $12 customer charge plus taxes is in every bill, whatever you use.
• Rate structure. Tiered and TOU pricing put some kWh at a higher price than the average.
• Seasonal loads. Heating and cooling can double a month's kWh or more. Compare the same month a year earlier rather than the month before.
• A long period or an estimated reading. Check the days and the reading type.
• Loads you haven't counted. An electric water heater, a well pump, a second fridge, standby power.

To compare your own month with an average home, divide your kWh by the days and multiply by 30. If the sample's 900 kWh had covered 32 days instead of 30, it would be about 844 kWh for a 30-day month. The national average bill is $140.00 a month; the electric bill estimator puts your state's figure next to your own list.

Using the state average rate, the same 900 kWh costs $163.44 at the US average, $274.32 in Massachusetts, $174.42 in Ohio and $119.79 in Utah. That spread is why the same appliance can be a minor line in one state and a major one in another. The electricity cost by state guide ranks all 50 states and DC.

If your bill's rate is far from your state's average, that is normal: utilities within one state charge different prices, and the average mixes all of them. Trust your bill over the average.

• Electric bill estimator: add your appliances, type in your marginal rate and compare with your actual bill.
• Any appliance calculator: price a single device at your rate.
• EV charging cost: with a separate off-peak rate for time-of-use plans.
• Net metering calculator: what solar exports are worth under your state's rules.