kWh × rate is the first line of the calculation, not the whole thing.
Almost every "how to calculate your electricity bill" guide on the internet stops at the same place: multiply your kWh by your supply rate and you are done. Take 886 kWh times 9.85¢ and the page tells you to pay $87.27.
The actual US-average residential bill at that usage is around $179. The naive formula misses more than half the bill.
That gap is not noise. It is structural. It is the fixed customer charge ($10–30/month), the delivery rate per kWh (5–10¢, set by your utility), the state taxes and approved riders, and the PUC-approved adjustments. None of them appear in marketing copy. All of them show up on the bill.
The real formula has four pieces, not one.
Every US residential electricity bill, in every state, is the sum of these four components. Calculate each separately, add them together, and you will land within a few dollars of the real total.
Component 1 — Supply
kWh × supply rate
The naive part. Your kilowatt-hours times your supply rate in cents per kWh, divided by 100 to get dollars.
Roughly 45–60% of your bill. The only piece you can shop in deregulated states.
Component 2 — Delivery
kWh × delivery rate
A second per-kWh rate, set by your local utility for wires, poles and meter reading. Typically 5–10¢ per kWh.
Set by your state's PUC. You pay it no matter who supplies your power.
Component 3 — Fixed
Customer charge $/month
A flat monthly fee you pay just for being connected, even at zero usage. Usually $10–30 per month, sometimes higher in rural utilities.
Independent of usage. Approved by your state PUC in each utility's rate case.
Component 4 — Tax & riders
Subtotal × tax %
State sales or gross-receipts tax applied to the subtotal, plus approved riders for efficiency programs and renewables.
Set by the state legislature and PUC. Zero in some states, up to 8% in others.
The real formula
At US averages and 886 kWh: $87.27 + $71.41 + $12.00 + $8.55 = $179.23/month. Multiply by 12 for the annual figure.
The shortcut undershoots by $30 to $50 a month.
Take the US-average household: 886 kWh, 9.85¢ supply rate. The naive formula gives you $87.27. The real bill is $179.23. That is a $91.96 gap on a single month — over $1,100 per year the naive math never accounted for.
Most of that gap is not negotiable. The delivery rate, fixed charge and tax are locked by your state. Even if you switched to a free supply rate (impossible, but humour the math), you would still owe about $92/month just to stay connected.
The takeaway: your true all-in rate is your monthly total divided by your kWh, not the rate on a marketing flyer. At 886 kWh and $179 total, that is 20.2¢/kWh effective, not 9.85¢.
Calculate your real cost in four steps.
Use a recent bill and these four steps to land on a number you can trust. The whole thing takes about five minutes.
Find your usage
Pull the kWh number from the "meter readings" or "usage" section. This is your monthly consumption. If you want an annual estimate, multiply by 12, or pull 12 months from your utility's online portal to capture seasonal swings.
Multiply by both rates, not just one
Find the supply rate AND the delivery rate, both in cents per kWh. Multiply your kWh by each, then divide by 100 to convert cents to dollars. Add the two results together. That is your variable cost.
Add the customer charge and riders
Look for "customer charge", "basic service", or "service fee". That is your fixed monthly cost. Add any "rider" line items (efficiency, renewables, storm recovery). This is your bill floor, paid even at zero kWh.
Apply tax to the subtotal
Multiply the running total by your state's electricity tax rate (0–8% depending on state). Add that to the subtotal. The final number should match the "amount due" on your bill within a few cents.
The number you just computed, divided by your kWh, is your true all-in rate in dollars per kWh. That is the only number worth comparing against another offer.
Same 886 kWh, very different bills.
Geography is the single biggest factor in your bill. Same household, same usage, three different addresses produces three radically different costs.
| State | Avg ¢/kWh | Monthly @ 886 kWh | Annual | Retail choice? |
|---|---|---|---|---|
| Hawaii | 41.53¢ | $393 | $4,714 | No |
| California | 32.08¢ | $306 | $3,673 | Partial |
| Massachusetts | 30.63¢ | $284 | $3,403 | Yes |
| New York | 28.99¢ | $278 | $3,338 | Yes |
| US average | 17.91¢ | $179 | $2,151 | 18 states + DC |
| Pennsylvania | 19.32¢ | $182 | $2,185 | Yes |
| Texas | 14.92¢ | $142 | $1,700 | Yes |
| North Dakota | 11.45¢ | $135 | $1,616 | No |
Source: EIA Electric Power Monthly, March 2026 YTD. Monthly totals are state-typical all-in (supply + delivery + fixed + tax) at 886 kWh. The same household paying $135 in Bismarck would pay $393 in Honolulu, a 191% premium for the same kilowatt-hours.
Where the math quietly goes wrong.
Five patterns we see repeatedly in customer cost estimates. Each turns a "shouldn't be more than $100" guess into a real bill that's twice that.
Compare on your true all-in rate, not the supply rate.
If you take one habit away from this page, make it this one. The only honest way to compare two bills, plans or states is the total dollars divided by the total kWh.
Pull last year's total
From your utility portal, export 12 months of bills. Sum the dollar amounts. That single number is the only honest measure of what your power costs you.
Pull last year's kWh
From the same portal, sum the kWh used over the same 12 months. This is your real annual consumption, already adjusted for seasonal swings.
Divide one by the other
Total dollars ÷ total kWh = your true all-in rate in $/kWh. Multiply by 100 to see it in cents. This is the number to compare against any new offer.
Use the projector above
Plug your state and kWh into the calculator at the top of this page. Compare its all-in figure to your real annual rate. Variances tell you whether you are above or below typical.
Shop on total dollars
When comparing supplier offers, compute the projected annual dollars on each, not just the headline supply rate. The cheap-looking rate with a $9.95 monthly fee can lose to a higher rate with no fee.
Track it monthly
Note your monthly total ÷ monthly kWh each cycle. A creeping all-in rate is a fast signal that a fixed contract rolled to variable or your utility's PUC approved a delivery increase.
Common questions about calculating electricity costs.
The complete formula is: (kWh × supply ¢/kWh ÷ 100) + (kWh × delivery ¢/kWh ÷ 100) + fixed customer charge + (subtotal × tax %). The shortcut version most people see, just kWh times rate, is only the first term. At US averages (886 kWh, 9.85¢ supply, 8.06¢ delivery, $12 fixed, 5% tax) the full formula gives $179.23/month, while the shortcut gives $87.27. The shortcut misses about $92.
Three reasons stacked on top of each other: (1) a separate delivery rate per kWh (5–10¢) for the wires that carry the power to your house, (2) a flat customer charge ($10–30/month) you pay even at zero usage, and (3) state tax and riders (0–8%) added to the subtotal. Together they typically add $30–50/month at average usage, sometimes more in high-fixed-charge states like North Dakota.
Take your monthly total in dollars and divide by your monthly kWh. That ratio, in dollars per kWh, or multiplied by 100 for cents, is your true all-in rate. At the US average it is roughly 20.2¢/kWh, not the 9.85¢ supply rate marketing copy usually quotes. The all-in rate is the only number worth comparing to another offer or another month.
It depends on your usage shape. A TOU plan rewards customers who shift load to off-peak (overnight EV charging, midday laundry on a solar grid) and punishes those who do not. Tiered plans charge progressively higher rates above thresholds. California's top tier can be 2× the bottom tier. If you can model your load, you can pick the cheaper structure; if you cannot, a flat rate is the safer bet.
Yes. The customer charge, sometimes called "service charge", "basic service" or "facilities charge", pays for the meter, the line to your house, billing and customer service. It is approved by your state PUC and applies every month, whether you use 0 kWh or 5,000 kWh. The only way to avoid it is to disconnect service entirely.
The state averages come from the EIA Electric Power Monthly (March 2026 YTD) and are accurate to the cent. The supply/delivery split and fixed-charge values are state-typical estimates calibrated against published residential tariffs. Your real utility may differ by ±2¢/kWh on delivery or ±$10 on the fixed charge. For an exact answer, plug your actual rates into the advanced fields. The projector also assumes a flat usage profile across 12 months; if your usage is seasonally peaky, expect ±20% monthly variation around the figure shown.