FigurePath builds free UK calculators that show the assumptions and working behind each result. Our first release focuses on renting.
How calculations are designed
Each tool begins with a defined user question. We publish a separate page only when the calculation or decision is genuinely different. Formula rules live in the FigurePath calculator plugin rather than being copied between pages.
Source hierarchy
Where a calculation depends on a rule, we prioritise current primary sources such as GOV.UK, legislation and official public bodies. Independent guidance may be used to explain a practical question, but it does not override an official source.
Rent-affordability assumptions
Income multiples are adjustable scenarios, not legal thresholds. The rent-affordability tool combines a selected gross-income multiple with a cautious budget check. Its budget check allocates 35% of take-home pay remaining after the debts and essential costs entered. That percentage is a visible FigurePath planning assumption, not an industry standard.
Deposit assumptions
The tenancy-deposit tool is explicitly for applicable tenancies in England. Monthly rent is multiplied by 12 and divided by 52 to calculate weekly rent, then the relevant five- or six-week amount is applied. High-rent and excluded arrangements receive warnings.
Testing
- Every release is checked against manual worked examples.
- Zero, missing, decimal and unusually high inputs are tested.
- Desktop and mobile layouts are checked before indexing is enabled.
- Important source links and dated assumptions are reviewed at least annually and when relevant rules change.
Privacy by design
Calculator inputs and results are processed in the visitor’s browser. FigurePath does not require an account and the calculator plugin does not submit those financial inputs to the website server.
Versions and review dates
Calculator pages show a calculation version and review date. A version change indicates that code, assumptions or important result wording changed.
Limitations
Results are estimates for education and planning. They do not replace a tenancy decision, contract review, credit check or individual financial or legal advice.
Corrections
If a formula, source or explanation appears wrong, please use our corrections page. Material errors will be investigated and corrected with the calculation version or review date updated where appropriate.
Methodology version: 1.0
Last reviewed: 18 July 2026