How the numbers work

Last updated: 19 July 2026

This page describes the assumptions and 2026/27 figures behind the calculators. Every rate and threshold is taken from official published data — GOV.UK, HMRC, The Pensions Regulator and the ONS — and each figure below links to the page it comes from. The models are intentionally simplified and maintained by hand, so they may lag changes in legislation — see the disclaimer.

Take-home pay

Gross pay is reduced by any pension contribution, then income tax, National Insurance and student-loan repayments are worked out. What is left is your take-home pay. How the pension interacts with each tax depends on the arrangement you choose — salary sacrifice, net pay or relief at source — so the three can give different results for the same contribution. Monthly and weekly figures divide the annual amount by 12 and 52 respectively.

Personal allowance

The standard tax-free personal allowance is £12,570 (GOV.UK). For income above £100,000 it is reduced by £1 for every £2of income, so it is fully withdrawn at £125,140. A pension contribution reduces the income the taper is measured against, so it can restore some or all of a withdrawn allowance.

Income tax bands (2026/27)

England, Wales & Northern Ireland — rates on income above the allowance (GOV.UK):

  • Basic rate: 20%
  • Higher rate: 40%
  • Additional rate: 45%

Scotland — non-savings, non-dividend income above the allowance (GOV.UK):

  • Starter rate: 19%
  • Basic rate: 20%
  • Intermediate rate: 21%
  • Higher rate: 42%
  • Advanced rate: 45%
  • Top rate: 48%

National Insurance (Class 1, employee)

  • 8% on earnings between £12,570 and£50,270.
  • 2% on earnings above £50,270.
  • No employee National Insurance is due once you are over State Pension age.

NI is calculated on an annual basis (GOV.UK). Real payroll assesses it per pay period, so for irregular pay this is an approximation; for steady monthly salary it matches.

Student & postgraduate loans

Repayments are a percentage of income above each plan's annual threshold. Undergraduate and postgraduate loans are repaid at the same time, each against its own threshold.

  • Plan 1: 9% above £26,900
  • Plan 2: 9% above £29,385
  • Plan 4 (Scotland): 9% above £33,795
  • Plan 5: 9% above £25,000
  • Postgraduate Loan: 6% above £21,000

Pension

Contributions can be entered as a percentage of gross pay, a percentage of qualifying earnings (£6,240–£50,270 — The Pensions Regulator), or a fixed amount. Paying in more than the annual allowance of £60,000 (GOV.UK)in a year — tapered for high earners — can trigger a tax charge.

Bonuses and one-off pay

A bonus is added on top of your salary and taxed at your marginal rate, so what you keep of it can be far less than the headline — inside the £100,000 taper band an extra £1 is effectively taxed at 62%. You can divert any share of a bonus into your pension, which avoids that tax and lowers your adjusted net income. By default your regular pension percentage is charged on your base salary only, not the bonus — most schemes define pensionable pay that way; a toggle includes the bonus if yours does. The bonus-period figure is smoothed: it shows a normal period's take-home plus the whole net bonus. Real PAYE spreads and corrects a bonus over the year, so a single payslip differs from this estimate.

One-off pension contributions

A lump-sum pension contribution is added to your regular one and, like it, reduces your adjusted net income — which can restore a personal allowance withdrawn above £100,000.

Comparing offers

The comparison places up to three scenarios side by side. Each can set its own salary, employer pension match and bonus; region, student loan, your own pension and arrangement are shared. Each column's take-home includes its bonus, so it reflects an offer's total value.

Statutory Sick Pay

Statutory Sick Pay is a flat weekly amount paid by your employer for up to 28 weeks. It is usually below the tax and National Insurance thresholds, so it is treated as paid in full here. Many employers pay more under their own sick-pay scheme; this is only the legal minimum.

How your pay compares

The median comparison uses ONS Annual Survey of Hours and Earnings data for full-time employees. It compares against the annual median and does not annualise weekly pay. The National Living Wage comparison uses the hourly rate (GOV.UK) multiplied by the hours you enter; it applies to ages 21 and over.

What is not modelled

  • Non-standard tax codes, benefits-in-kind, and most allowances and reliefs.
  • Other income (self-employment, dividends, savings, rental).
  • Marriage allowance, blind person's allowance and similar adjustments.
  • The exact tapered annual allowance and per-pay-period payroll rounding.

Sources

Every figure above is taken from these official publications for the 2026/27 tax year:

  • GOV.UK — “The standard Personal Allowance is £12,570”
  • GOV.UK — “your adjusted net income is above £100,000”
  • GOV.UK — “Up to £37,700 … From £37,701 to £125,140 … Above £125,140”
  • GOV.UK — “Scottish starter, basic, intermediate, higher, advanced and top rates”
  • GOV.UK — “21 and over £12.71”
  • GOV.UK — “up to £123.25 per week Statutory Sick Pay”
  • GOV.UK — “This table shows the rates from 6 April 2026”
  • GOV.UK — “For the 2026 to 2027 tax year the allowance is £3,000”
  • The Pensions Regulator — “Lower level of qualifying earnings £6,240 … Upper level £50,270”
  • GOV.UK — “Annual allowance … £60,000”
  • GOV.UK — “your pension provider claims tax relief at 20%”