How we test

How we check the formulas

A spreadsheet that looks right can still be wrong. One cell pointing at the wrong row and every total below it is off. So before a template goes on this site it goes through the same three checks.

1. Built from a script, not by hand

Each template is generated by a small program. That means every row of a schedule uses exactly the same formula — no cell that was edited by mistake halfway down.

2. Every formula recalculated

The finished file is opened in a spreadsheet program and every formula is calculated. If a single cell shows an error (#REF!, #VALUE!, #NAME? and so on), the file doesn't go up.

3. A second calculation must agree

A separate program, written independently of the spreadsheet, works out the same answers from the same sample data. For the debt planner that means the payoff month and the total interest for every method, and the balance left at the end of every month. The spreadsheet and the program have to agree to the cent. We also test awkward cases: an empty row in the middle, ten debts at once, a monthly amount that's too low.

What we only promise as far as it goes

The checks prove the sheet does what it says. They don't make it a substitute for your lender's statements — banks round, charge daily interest and add fees in their own ways. Each template page lists what it assumes.

Found a mistake?

Please tell us at [email protected] with the template name and what you typed in. We fix it and note the date on the template page.