How We Evaluate Tools and Calculators

Our tools make their arithmetic visible so you can decide whether the model fits your question. They are simplified decision aids, not forecasts or substitutes for the underlying records.

Calculators

Every calculator states its inputs, units, formula and main limitations. Examples use invented numbers to explain the calculation. Empty inputs are not silently treated as zero. Zero denominators and impossible combinations produce an unavailable result or an error. Editing an input clears an old result until it is recalculated.

Currency selection changes labels, not exchange rates. Calculations use the precision available in JavaScript numbers and round displayed results for readability. The runway tool uses constant monthly cash flows; CAC payback uses constant gross profit; the break-even tool assumes one product. Their limits are explained on the relevant pages.

Tool and vendor comparisons

We begin with the task, required inputs, evaluation criteria, workflow fit and material data-handling considerations. Product descriptions should be checked against official documentation. A comparison must distinguish documented features from tested performance. No numerical score should be presented as objective evidence without an explained method.

Templates and prioritization

Templates organize assumptions, evidence and decisions. The RICE tool ranks the inputs you provide; it does not predict product success. Obligations, safety issues and dependencies should not be ignored because their calculated score is low.

Privacy in the tools

Financial calculator inputs remain in the current page's memory. Checklists and templates offer optional local saving, with a clear-data control. Downloaded files contain the entries you choose to export. See the privacy notice.