Reviewed September 7, 2026. Rate reference: EIA table 5.6.A, June 2026 (opens in a new tab). The 100 kWh above is a chosen comparison quantity, not a typical household load.
Find the rate, billing period and units
Open a recent electricity statement and locate the service dates, usage in kWh and rate-plan name. Keep a copy of the tariff beside it. A payment total can include a previous balance, a credit or another service, so it is a poor starting point for appliance cost.
Read each charge's unit. A line priced per kWh changes with consumption. A daily or monthly service charge usually depends on time connected. A price per kW describes a demand charge and needs a different calculation from energy. Ask the utility to explain any line whose basis is unclear before treating it as a per-kWh price.
Record the energy price in dollars per kWh rather than cents. EIA's June 2026 national residential reference is 18.34 cents, which becomes $0.1834 after dividing by 100. Entering 18.34 into a dollar-rate field would make the answer 100 times too large. Check the decimal point first.
Separate variable charges from fixed charges
A bill can split generation and delivery into separate lines. PG&E's rate explanation (opens in a new tab) shows that electricity rates cover several services, and also describes minimum-bill and time-of-use arrangements. That is one utility's structure, not a template for every US bill.
For a flat-rate appliance estimate, add the applicable per-kWh components once. If the bill already gives a bundled price, do not add its component breakdown again. Leave a separate monthly service fee outside the appliance calculation unless you are deliberately allocating overhead rather than estimating additional usage.
Variable energy cost = kWh used × applicable variable price per kWh
A whole-bill estimate then adds applicable fixed charges and adjustments, following the actual tariff. Minimum bills, taxes and credits may alter the order of operations. The calculator does not reproduce those rules. If your bill has a minimum charge, reducing a small load may not change the amount payable.
A worked comparison using the same energy quantity
Suppose you want to price a chosen 100 kWh of additional monthly use. At the EIA national reference, the arithmetic is 100 × $0.1834 = $18.34. The table repeats that calculation using residential averages from the same EIA release. These are geographic benchmarks, not utility offers or predictions for your home.
| Reference | USD/kWh | 100 kWh cost |
|---|---|---|
| Texas | $0.1594 | $15.94 |
| United States | $0.1834 | $18.34 |
| New York | $0.2949 | $29.49 |
This comparison holds energy constant so you can see the effect of the rate alone. It ignores the household's plan, taxes charged separately and fixed fees. Replacing the reference with your own applicable variable price makes the calculation more relevant, but the consumption estimate still needs checking.
Handle time-of-use and tiered prices separately
With time-of-use billing, the same appliance can be priced differently depending on when it runs. Match its schedule to your plan's current time bands, including weekends and seasonal changes. Use the tariff for your account rather than copying a neighbor's peak hours.
Time-of-use cost = peak kWh × peak price + off-peak kWh × off-peak price
Add other time bands if your plan uses them. Calculate each band independently in the Electricity Cost Calculator and add the results. The calculator has one rate field, so a single run cannot model several bands. A simple average of the prices only works when the energy split gives that average the correct weighting.
Tiered plans depend on the household's total usage in the billing period. Additional energy may fall within the current tier or cross into another. Price each portion at its applicable tier, then add those amounts. The appliance's nameplate cannot tell you which tier applies.
Keep a calculation record you can revisit
- Write down the statement dates and the tariff version used.
- Keep the per-kWh components separate from fixed fees and credits.
- Record whether usage is measured or estimated, and whether you split it into time bands.
- Save the result with its assumptions before comparing another scenario.
If the estimate and bill differ, compare the same dates and scope first. A calculator covering one room will not match a whole-home statement. For the consumption side, use the appliance measurement guide. For buying comparisons, read how EnergyGuide labels work. The home energy audit checklist helps organize questions that individual appliance estimates leave unanswered.
Sources and assumptions
EIA table 5.6.A (opens in a new tab) supplies the dated national and state benchmarks. EIA's explanation of electricity prices (opens in a new tab) covers regional and time variation. PG&E's explanation of rate structure (opens in a new tab) provides a utility example of variable, minimum-bill and time-based charges. No current PG&E price is assumed here.
All arithmetic examples are planning comparisons. They do not promise savings, forecast future rates or replace your tariff. The calculators apply the values you enter; your utility determines how those values relate to the final bill.