Methodology
SalarySense computes 2026/27 take-home pay with one calculation engine shared by every page on this site. This page documents each rule, its source, and the conventions — so you can check our working, not just our answer.
Calculation order
- Salary sacrifice first. Sacrificed pension comes off gross pay before anything else; the reduced figure is the base for income tax, National Insurance and student loans.
- Personal allowance. £12,570, plus £1,260 for a Marriage Allowance recipient, tapered by £1 for every £2 of income above £100,000 — nil from £125,140.
- Income tax in band slices. Taxable income (post-sacrifice pay minus allowance) is charged band by band at your region's rates. Relief-at-source pension does not reduce PAYE taxable pay — the provider adds basic-rate relief, and higher-rate relief is reclaimed from HMRC (Scottish intermediate and higher rates change that reclaim).
- Employee National Insurance, annualised. 8% between £12,570 and £50,270 and 2% above, computed on annual pay. Payroll computes NI per pay period, so a payslip can differ by pennies from an annualised figure — and by more if pay varies month to month.
- Student loans. 9% of income above your plan's threshold for each undergraduate plan; postgraduate loans take 6% above £21,000 concurrently. Scotland collects postgraduate loans within Plan 4; Northern Ireland collects them as Plan 1.
- Net pay and frequencies. What remains is take-home; monthly is annual ÷ 12, four-weekly ÷ 13, weekly ÷ 52, daily and hourly from a 5-day, 37.5-hour week unless you set otherwise.
- The marginal line. We recompute everything at +£1,000 and report the difference — that single number encodes the 60% taper trap, the NI step-down, Scottish band edges and student-loan drag.
Rounding
Each displayed figure is rounded once, independently, half-up to the penny (the monthly figure comes from the unrounded annual, not the rounded one). Annual figures display to the pound, per-period figures to the penny. In band-by-band tables, rows are rounded for display and can differ from the independently rounded total by a penny.
Sources
| Parameter | Source |
|---|---|
| Personal allowance, taper, rUK bands | gov.uk — Rates and thresholds for employers 2026–27; Commons Library CBP-10618 |
| Scottish bands | gov.scot — Scottish Income Tax 2026–27 factsheet (Budget 13 Jan 2026, rate resolution 19 Feb 2026) |
| Employee NI (Class 1, cat A) | gov.uk — Rates and thresholds for employers 2026–27 |
| Student loan thresholds | gov.uk — Student loans terms & conditions 2026–27; HMRC Employer Bulletin Dec 2025; Commons Library CBP-10654 |
| Marriage Allowance | gov.uk — Marriage Allowance |
| NHS Agenda for Change pay points | NHS Employers — Pay scales for 2026/27 (England, 3.3% uplift, effective 1 April 2026) |
All parameters last verified against the primary sources on 2 July 2026.
Testing
The engine must reproduce 33 golden test cases — covering every band boundary in England and Scotland, the £100,000–£125,140 taper edges, all five student loan plans, concurrent undergraduate and postgraduate loans, both pension arrangements and the Marriage Allowance — before any release. Two of those cases are anchored to the Scottish Government's own published £100,000 figures (income tax £27,432 rUK / £30,732.05 Scotland). The engine that renders this site and the independent reference engine both run the same suite on every change.
Known deviations & judgement calls
- Scottish Top-rate boundary. Some published calculators start the 48% Top rate at £112,570 of taxable income. The statutory boundary is £125,140 of taxable income (the personal allowance is nil at that level, so income and taxable terms coincide) — confirmed by gov.uk employer rates and gov.scot's frozen-threshold statement. SalarySense follows the statute.
- Annualised method. NI and student loans are annualised (the standard for salary calculators); payroll operates per pay period. Bonuses and variable pay change per-period results — a bonus-aware mode is planned.
- Tax codes. The calculator assumes the standard 1257L allowance (with region selected explicitly). Custom tax code support (K, BR, D0/D1, NT) is planned for v1.1.
Changelog
- 2 July 2026 — site launch: 2026/27 engine, NHS Agenda for Change 2026/27 pay points.
- 2 July 2026 — all tax parameters re-verified against gov.uk and gov.scot primary pages.
Report a discrepancy
If any figure disagrees with HMRC's calculator or your payslip's annualised equivalent, email feedback@salarysense.co.uk with the inputs you used. Confirmed discrepancies are fixed and noted in the changelog within a day.