Editorial Policy

NumberPrism is published by The NumberPrism Editorial Team, an independent editorial desk rather than a bank, broker or clinic. The desk is accountable for the formulas, the written content and any corrections, and it does not sell the data readers type into the tools.

NumberPrism does not employ accountants, tax practitioners or medical professionals, and nothing here is personalised financial, tax, legal or medical advice. The tools are calculators: they apply a stated formula to the numbers you enter. For decisions that matter, check the result against a qualified professional.

Every calculator implements a published formula rather than an opaque model. Where a calculator page documents its method, that documentation describes exactly what the code does — the formula shown is the formula that runs.

Calculations execute entirely in your browser. Nothing you type into a calculator is transmitted to NumberPrism, stored on a server, or shared with a third party. You can verify this by loading a calculator and then disconnecting from the network — the results still compute.

Results are cross-checked against other widely used implementations of the same formula before a calculator ships. Cross-checking is a sanity check on our arithmetic; it is not an endorsement of those tools, and where the underlying rule is set by an authority — income tax slabs, small-savings interest rates, WHO weight categories — that authority governs, not another calculator.

Some calculators depend on values that change by regulation rather than by arithmetic: tax slabs, statutory contribution rates, savings rates and published health thresholds. These are updated when the governing rule changes — a budget, a rate notice, or revised guidance — rather than on a fixed schedule.

Where a result depends on a specific year or regime, the calculator states which one it is applying. If a page does not say which year it uses and the answer depends on it, treat that as a bug and tell us.

If a calculator produces a wrong answer, we would rather hear about it than not. Email hello@numberprism.com with the calculator, the inputs you used, the result you got and the result you expected. Reproducible arithmetic errors are treated as the highest priority work on the site.

When a correction changes the numbers a page produces, the fix is applied to the calculator itself rather than only to the surrounding text, so anyone who reruns the calculation gets the corrected answer.

NumberPrism is free to use. It carries a limited number of clearly labelled display ads from Google AdSense; it does not accept sponsored placements or affiliate links. There is no paywall, no account and no data sale. The site is funded by its publisher and, when enabled, by those limited ads.

Commercial pressure has no influence on what the calculators return or on how tools are described or ranked. We do not accept payment to change a calculation, to rank a tool higher in the directory, or to write a favourable comparison. Where we compare NumberPrism to another product, the comparison reflects our own assessment and says plainly that we are one of the parties being compared.

The embeddable calculator widget is free, and its credit links carry rel="nofollow", so embedding the widget cannot affect anyone's search rankings. See the widget terms.

AI tools are used during development — writing and reviewing code, drafting explanatory copy, and checking for errors. They are not used to generate calculation results, and no page is published on the strength of an AI draft alone. An editor checks the formula and the numbers before a calculator goes live, and that editor is accountable for what ships.