Rigour behind the numbers. Clarity in the answer.

Useful tools. Better decisions.

A calculation is only useful if you can understand it and act on it. Ratio-One brings together clear inputs, transparent methods and practical results, without adding complexity for its own sake.

We’re a UK-based business building tools for individuals, professionals and ambitious businesses. Our focus is analytical rigour, usability and the questions people actually need to answer.

Built simply. Designed to grow.

We’re starting with a library of free calculators. Over time, we intend to add advanced Pro tools and premium decision support, alongside bespoke analytical solutions for SMEs.

The first working calculator is available now. Other tools and Pro functionality are clearly marked as planned: they are not available products or active subscriptions.

Transparency is part of the tool.

We show the methodology and assumptions behind each calculation. We don’t claim independent validation, and we’re clear where a result is an illustration rather than professional advice.