How we check our calculators

A calculator is only useful if you can trust the number it gives you. These are the steps every page on CalcPantry goes through before it's published, and how it's kept accurate afterwards.

1. Start from the published figure

Where a calculator depends on a rate, a limit or a constant set by someone else, it uses that organization's own figure. Examples:

• Selling fees from each marketplace's published fee schedule (eBay, Etsy, Poshmark, Mercari and others).
• Tax brackets, the Social Security wage base and mileage rates from the IRS and the Social Security Administration.
• Safe cooking temperatures and turkey roasting and thawing times from the USDA Food Safety and Inspection Service.
• Atomic weights from IUPAC and physical constants from NIST.

Those calculators list their sources at the bottom of the page. When a figure isn't published officially (for example, average music streaming payouts or the soft-pity curve in gacha games), the page says it's an estimate and explains where the estimate comes from.

2. Show the formula and a worked example

Every calculator explains the formula it uses in plain language and includes a worked example with real numbers. The example's numbers are produced by the calculator itself, so the explanation and the tool can't drift apart.

3. Test it

Before a page goes live, its default inputs are run and checked against the worked example, unusual inputs (zero, blanks, very large numbers) are tried to make sure the page handles them sensibly, and the page is checked on a phone-sized screen.

4. Keep it current

Fees and rates change, so every calculator shows the month its figures were last checked. Pages that depend on yearly figures, like tax brackets and mileage rates, are reviewed when the new figures are announced. Reports from readers are fixed as soon as possible.

What these calculators are, and aren't

The calculators give estimates for planning. They're not a substitute for professional advice on taxes, finances, health or safety. Always check product labels, official notices and your own circumstances before acting on a result.

Spotted a mistake?

Email kagegarasu@gmail.com with the page and what looks wrong. Thank you for helping keep CalcPantry accurate.