Editorial Policy

Every calculator is based on widely published, standard formulas. Each page shows the formula it uses so you can check the working.

Calculator math is tested against worked examples before it goes live, and re-tested whenever it changes.

Explanations are written to be understood without specialist knowledge. Where a result depends on assumptions (rates, rounding, units), we say so.

The problem helper uses AI only to choose a calculator and read the numbers from your question. The answer itself always comes from the calculator's own formula, never from the AI.

If you find a mistake, please contact us. We review every report and update the calculator and its explanation when needed.