How to Read Your Electric Bill: kWh, Supply vs. Delivery, Fixed Charges and Riders

Your electric bill is mostly the number of kilowatt-hours (kWh) you used multiplied by your rates, plus a fixed monthly customer charge and a set of smaller adjustments called riders, surcharges and taxes. Most bills split the per-kWh costs into supply (the electricity itself) and delivery (getting it to your home). Once you know where each of those appears, you can check your usage, spot rate changes and compare offers.

Bill layouts differ from utility to utility, but the building blocks are similar across the country. This guide walks through each section in the order you will usually see it, using explanations published by state regulators and the U.S. Department of Energy.

The basic formula behind every electric bill

The Massachusetts Department of Public Utilities sums it up simply: your bill is the price per kWh times the kWh you used, "plus a monthly customer charge that is a fixed charge" (Mass.gov). The Minnesota Public Utilities Commission describes the same three groups in slightly different words: a fixed charge billed to each meter each month, an energy charge that changes with how much you use, and surcharges such as "taxes, fuel adjustments, riders, etc." (Minnesota PUC).

In practice, your bill looks something like this:

1. Account summary – amount due, due date, previous balance and payments.
2. Usage details – meter readings, billing period dates and total kWh used.
3. Supply (generation) charges – the cost of the electricity itself.
4. Delivery (distribution and transmission) charges – the cost of moving power to your home.
5. Fixed customer charge – a flat monthly amount.
6. Riders, adjustments and taxes – smaller line items that can change during the year.

Step 1: Find your kWh usage and billing period

Electricity on a bill is measured in kilowatt-hours. The U.S. Energy Information Administration (EIA) notes that utilities "generally measure electricity in kilowatthours (kWh)" and use meters, usually mounted where the power line connects to your home, to measure how much you use. Many utilities now use smart meters that send usage data wirelessly (EIA: Measuring electricity). If you are new to the unit itself, our explainer What is a kilowatt-hour? covers it in detail.

Your usage is calculated by "subtracting the previous billing cycle's meter reading from the current billing cycle's meter reading," and a billing period is approximately 30 days, according to the North Carolina Public Staff (NC Public Staff). Check three things in this section:

• The dates. A 34-day billing period will usually cost more than a 28-day one, even if your habits did not change.
• Actual vs. estimated reading. If the bill says "estimated," the next bill may correct up or down once the meter is actually read.
• The usage history graph. Most bills show the past 12 or 13 months, which is the fastest way to see whether this month is unusual.

For context, EIA reports that the average U.S. residential customer bought about 10,791 kWh in 2022, or about 899 kWh per month, with large differences by state (EIA FAQ). More recently, the average US home used 1,152 kWh in August 2026.

Step 2: Understand supply vs. delivery charges

Many bills, especially in states with retail electricity choice, split per-kWh costs into two groups.

Supply (generation) charges

Mass.gov describes supply charges as "the actual electricity you used for that month." In Massachusetts, supply comes either from your utility (called basic service) or from a licensed competitive supplier (Mass.gov). Other states use names like "generation," "default service" or "standard offer." If you can choose a supplier, this is the part of the bill that changes when you switch. Delivery stays with your local utility.

Delivery charges

Delivery covers the poles, wires and equipment that move electricity to your home. On Mass.gov's breakdown, delivery includes:

• Transmission – charges "used to build, maintain, and operate the transmission system," which is regulated by the Federal Energy Regulatory Commission.
• Distribution – the cost of delivering power over the local system, billed as a fixed monthly customer charge plus a per-kWh rate.
• Transition – a charge that "recovers the company's stranded investments" (not every utility has one).
• Program charges – for example, energy efficiency and renewable energy charges set by state policy.

EIA explains why delivery matters so much for households: residential and commercial customers pay more per kWh than industrial customers largely because distributing electricity to them costs more (EIA: Prices and factors affecting prices).

Bundled vs. unbundled bills

If your bill does not show separate supply and delivery sections, you probably have a bundled rate, where one provider supplies the electricity and delivers it. The Department of Energy notes that bundled and unbundled rates differ in exactly this way, and that in some deregulated states customers can buy supply from a provider other than their utility (DOE: Evaluating Your Utility Rate Options).

Step 3: Read the fixed charges

The customer charge (also called a basic customer charge, service charge or fixed charge) is the same every month no matter how much electricity you use. North Carolina's Public Staff says it covers costs such as the meter, meter reading and billing, and connection facilities (NC Public Staff).

The Department of Energy groups bill items into energy charges, demand charges and fixed charges, and says lowering fixed charges is "usually not possible" because they are set by the rate schedule rather than by consumption (DOE). That matters when you compare months: in a very low-usage month, the fixed charge can make your effective cost per kWh look much higher.

Step 4: Decode riders, adjustments and surcharges

Riders are the line items that most often confuse people. Duke Energy explains that riders "allow for the recovery of variable costs like fuel needed for the generation of power," can also apply credits, and are "reviewed annually or over a specific span of time by the utilities commission" (Duke Energy).

Common examples include:

Line item	What it usually covers	Example source
Fuel or fuel-related adjustment	Changes in the variable cost of fuel compared with what is built into the base energy charge	NC Public Staff
Energy efficiency / DSM rider	Funding for utility energy efficiency and demand-side management programs	NC Public Staff, Mass.gov
Renewable or clean energy charge	State-mandated clean energy costs or programs	Mass.gov, NC Public Staff
Transition charge	Recovery of a utility's stranded investments	Mass.gov
Taxes	State or local taxes applied to the bill (amounts vary by state)	NC Public Staff

Because riders are adjusted on their own schedules, your total can change even when the base rate does not. In North Carolina, for example, the Public Staff lists different dates on which the fuel, efficiency and clean energy riders change for each Duke Energy utility (NC Public Staff).

Step 5: Check for demand charges or time-of-use pricing

Most residential customers do not have a demand charge, according to North Carolina's Public Staff. Where one applies, it is based on "the maximum amount of electricity you used at a specific point in time" rather than total kWh (NC Public Staff).

If you are on a time-of-use plan, your kWh will be split into peak and off-peak (and sometimes shoulder) periods, each with its own price. EIA notes that demand and wholesale costs are usually highest in the afternoon and early evening, and that some utilities offer time-of-day pricing, while most consumers pay seasonal average rates (EIA). The DOE also suggests not assuming your current rate fits how you use power today, since "the current rate may be based on usage dating back a decade or longer" (DOE).

Step 6: Work out your real cost per kWh

Advertised or base rates rarely tell the whole story. To see what you actually pay, use this simple check:

1. Take the total electric charges for the month (exclude past-due balances and non-electric items).
2. Divide by the total kWh used.
3. The result is your all-in cost per kWh, including fixed charges, riders and taxes.

For example, a bill of $120 for 800 kWh works out to $0.15, or 15¢, per kWh. Compare that with the US average residential price of 18.16¢ per kWh and with the figures for your area on our electricity rates by state page. You can also compare your total with typical bills on our average electric bill by state page.

What to do if something on your bill looks wrong

• Compare meter readings on the bill with the reading on your meter.
• Check the rate code or rate schedule printed on the bill and look it up on your utility's website.
• Call the utility first and ask for an explanation of any line item you do not understand.
• If you cannot resolve it, utility complaints can go to your state's public utility commission, as the federal LIHEAP consumer FAQ notes (HHS LIHEAP FAQ).

If the issue is simply that the bill is higher than you expected, our guide Why is my electric bill so high? walks through the most common causes.

Next steps

Pull up your latest bill and note your kWh, billing days and total charges. Then plug them into our electric bill calculator to see how changes in usage or rate would affect your monthly cost, and check your state's current average on the electricity rates hub.