Bill-credit break-even calculator

A bill credit is a fixed dollar amount a retailer subtracts from your bill in any month your usage lands inside a stated window. It is not a discount on the price of electricity and it does not scale with how much you use: cross the line by one kilowatt-hour and you get the whole thing, miss it by one and you get none of it.

That all-or-nothing shape is what makes these plans hard to compare. Almost every other charge on an electricity plan is proportional — use twice as much, pay roughly twice as much — so a single average price describes it well. A credit is a step, and no single average price describes a step.

Bill-credit plans are usually fixed-rate plans as well. The energy charge is locked for the term exactly as it would be on any other fixed plan. What differs is that part of what you end up paying depends on a usage target rather than on the contract price alone.

Texas retailers advertise an average price per kilowatt-hour, and that figure has to be calculated at a specific usage level. On a bill-credit plan, the level chosen is one where the credit applies — so the advertised number quietly includes a lump sum you only receive if your month looks like the assumed month.

At that exact usage the advertised figure is accurate. Slightly below it, the credit vanishes and the true cost per kilowatt-hour jumps, sometimes by a third or more. The advertised price was never wrong; it was answering a narrower question than the one you were asking.

This is why two plans advertised at the same cents-per-kilowatt-hour are not necessarily comparable. One number is a description of your whole year. The other is a description of one hypothetical month.

The threshold is a line, not a slope. A plan offering a credit at 1,000 kWh pays nothing at 999 kWh — there is no partial credit, no proration, and no grace. The calculator above shows the two rows side by side for exactly this reason.

Some plans stop there: a minimum to clear, and nothing above it. Others add an upper limit as well, so the credit is withdrawn again once usage passes some higher figure — a plan crediting between 1,000 and 2,000 kWh pays nothing at 2,001 kWh, which catches large all-electric homes in a Texas August precisely when their bills are highest. The example loaded above is the first kind and has no upper cutoff; type a figure into the upper usage limit box and the calculator prices that second cliff too.

Household usage moves far more than these thresholds allow for. The same home can use 1,900 kWh in August and 700 in October — one of those months earns the credit and the other does not, so a single plan produces two completely different prices per kilowatt-hour in the same year.

A price per kilowatt-hour is only comparable between two plans if it was calculated the same way for both, at your usage rather than at a benchmark. Total monthly cost has no such problem: it is what you would owe, and it can be compared plan against plan without any further translation.

That is why the calculator leads with two monthly totals and treats the effective price per kilowatt-hour as a consequence rather than as the headline. It is also why the annual figure is shown as an illustration only — twelve times one month is a fair way to feel the size of a difference and a poor way to predict a year, because no household uses the same amount twelve times.

If you want a genuinely useful answer, run the calculator at two or three usage levels you actually recognise from past bills: a mild month, an average one, and your worst August.

Every retail electricity plan sold in Texas comes with an Electricity Facts Label, and it is the only document that states the plan's terms in a standard form. The credit amount, the usage window that earns it, the base charge, any minimum-usage fee, and the average price at 500, 1,000 and 2,000 kWh are all on it.

Read the price table on the label before anything else. If the average price at 500 kWh is far higher than at 1,000 kWh, something is being added at the low end or subtracted at the high end, and the advertised headline is describing the middle column rather than your home.

Advertising, comparison sites and this calculator are all secondary to that document. Where a label and anything else disagree, the label and the retailer's terms of service are what you signed.

Open both Electricity Facts Labels. Put the plan with no bill credit into the Fixed-Rate Plan card on the left and the one with a credit into the Bill-Credit Plan card on the right, taking the energy charge and any monthly base charge from each. Enter the credit, the usage that earns it, and the upper limit if the label states one — leave that last box blank if it does not, as the loaded example does.

Then fill in the two delivery charges from a recent bill. They are not on either plan's label, because they are not the retailer's charges — they belong to the utility that owns the wires at your address and are the same whichever plan you pick. Leaving them at zero still gives you the right answer about which plan is cheaper; filling them in gives you monthly totals close to what you would actually be billed, before tax.

Then set the usage figure to a month you recognise from a past bill rather than to 1,000 kWh out of habit. The break-even line tells you where the cheaper plan changes; the table tells you what happens either side of every threshold.

Nothing you type here is sent anywhere. The arithmetic runs in your browser, the page stores nothing, and there is no account, no sign-up, and no result saved when you close the tab.