The price that changes once the meter passes a line

A tiered plan divides the month into bands. The first so many kilowatt-hours are billed at one price, the next at another, and the meter starts again at zero next month. The bands are published in the tariff, which is why this page can state the step in cents rather than infer it from a bill.

More ladders climb than fall: of the 104 tiered plans here, 74 rise, 21 fall and 9 move both ways depending on the season or the hour. A rising ladder prices a large household’s last kilowatt-hour highest, the opposite of most things bought in bulk; a falling ladder, a declining block, does the reverse and bills the heaviest use cheapest.

One row per utility, at the largest step it publishes. A company that files the same ladder for each region it serves publishes it many times over; listing every filing would fill the table with one company’s variants.

A tier raises the price of the next kilowatt-hour. A fixed monthly charge does the opposite to the average: it is the same whether the household buys 500 kWh or 2,000 kWh, so it spreads thinner the more the meter records. Which force wins is a question about a particular plan, and the answer here is close to even.

On 43 of the 104 tiered plans — 41% — the whole bill costs more per kilowatt-hour at 2,000 kWh a month than at 500 kWh. On the 138 plans with no bands, that is true of 0. Tiers are what make the exception; they do not guarantee it.

Potomac Electric Power Co’s Residential - Schedule R shows both at once: a step of 14.9¢ at 30 kWh, and a whole bill that moves from 19.8¢ to 19.2¢ a kilowatt-hour between the two rungs.

45 of the tiered plans here publish their threshold as a daily allowance rather than a monthly one. California writes them that way: a baseline quantity per day, multiplied by the length of the billing month, and set differently for each climate zone and season. A household in one region of a utility’s territory therefore crosses into the dearer band at a different point from a household in another, on the same schedule.

That is why the threshold column is a single number for a plan that may publish several, and why the figures on this site are attributed to the record they came from. The utility pages list every band of every plan they price.

21 plans here price an upper band below the one beneath it, the structure that was standard when electricity was sold to encourage use. The utilities whose largest step runs downward are Duke Energy Indiana Inc, Kansas City Power & Light Co (Missouri), NorthWestern Energy, Union Electric Co, Ameren Illinois Company, Entergy Texas Inc., Entergy New Orleans Inc, Cuivre River Electric Coop Inc, Westar Energy Inc, Alabama Power Co, Indianapolis Power & Light Co, Southwestern Electric Power Co (Texas), Progress Energy Carolinas Inc, Progress Energy Carolinas Inc (South Carolina), Entergy Mississippi Inc, Omaha Public Power District, Jackson Electric Member Corp, South Carolina Electric&Gas Co, City of Memphis, Tennessee (Utility Company), Ohio Power Co, Ohio Edison Co.

It does not say which plan is cheaper for a particular household. A band structure only matters alongside the consumption it is billed against, and the figures here are priced at three fixed levels rather than at yours. The rate comparator prices every plan a utility publishes at a consumption you enter.

Nor does it price an appliance. A tier means the cost of running one depends on what the rest of the household has already used that month — a dryer on a plan whose band has already been crossed is billed at the dearer price, not at the bill’s average. That is the calculation behind the cost-to-run pages, which price each appliance as the difference it makes to a real bill rather than as watts times an average rate.

Taxes are not included, and consumption is spread evenly across the month. A household that uses the same total unevenly crosses its bands sooner in the heavier months, which moves a tiered bill and leaves a flat one where it was.

• What a plan charges by the hour, and what moving a kilowatt-hour is worth
• How much electricity a home uses, state by state, and what it pays
• What uses the most electricity in a home

Every figure here is computed when the site is built, from the records named below, by the same code that fills the state, utility and cost-to-run pages this guide links to. When those records are refreshed, the figures change with them; the words around them do not, which is why no sentence here states a direction the data has not been checked for.

The methodology page sets out what the rate engine assumes and where its figures stop being reliable.