About SalaryGrid.uk

Our core mission

SalaryGrid.uk was built to solve a specific problem: the lack of transparency, speed and accuracy in mainstream UK salary calculators. Most consumer-grade payroll tools rely on outdated third-party script integrations or oversimplified code bases that fail to capture complex marginal-rate variations, regional tax codes and specialised public sector pension structures.

Working professionals deserve a high-performance, zero-dependency utility that models their income honestly. Every line of code inside the calculation library is built from scratch against statutory guidance published directly by HMRC, the Department for Education, the Scottish Public Pensions Agency, the Senedd and the Scottish Government — never wrapped around a black-box third-party API.

Engineering standards behind the engine

Every monetary value flowing through the calculator is parsed to integer pence at the input boundary, processed exclusively in pence, and converted back to display pounds only at the render boundary. That single discipline eliminates the floating-point drift that plagues most other UK calculators when summing pension contributions, holiday accruals and prorated annual figures.

The 2026/27 ruleset — Personal Allowance, basic-rate band width, NI thresholds, employer NI 15%, the six-band Scottish stack, six-tier TPS and SPPA tables — is stored as locked constants alongside the source code. No remote configuration, no runtime fetch. The number on screen today is the same number reproduced from an offline reload tomorrow, which is what makes the engine auditable in the first place.

Our platform commitments

• Continuous uprating: Autumn Budgets, Spring Statements and statutory CPI adjustments are tracked live. Any change to National Insurance thresholds, tax bands or public-sector pension tiers is fed straight into the test suite before the figures go live on the calculator.
• Zero-tracking assurance: your financial parameters belong to you. Calculations run entirely inside your browser tab against locally-bundled constants — your income data is never transmitted to an origin server, persisted to a remote database or shared with third-party marketing surfaces.
• Complete methodological transparency: the mathematical formulae for every calculator are documented in the public methodology, and editorial guides demystify second-order effects such as fiscal drag, marginal tax traps and Net Pay Arrangement pension relief.
• Devolved-first regional accuracy: Scottish, Welsh, and rest-of-UK rules are modelled by independent engines rather than shared shortcuts, ensuring SRIT bands, WRIT treatment and the C/S tax-code prefixes resolve correctly without generic English-defaults silently leaking in.