How the calculators work

Every rate, threshold and rule behind the calculators, with the GOV.UK page each figure came from and the simplifications we make.

Every calculator on UK Pay Calculators is a form over one shared tax engine. The engine reads its rates from a single data file for each tax year, and this page is generated from that same file. If a number here changes, the calculators change with it, and the date above moves. Nothing is typed twice.

The rule we hold ourselves to: if a figure cannot be traced to a GOV.UK or Scottish Government page, it does not ship. Each table below names its source, and the full list is at the end.

The calculation, step by step

  1. Salary sacrifice comes off gross first. The sacrificed amount is not pay, so it reduces income tax, National Insurance and student loan repayments alike.
  2. Net-pay pension contributions reduce taxable pay only. National Insurance and student loan deductions are worked out on pay before them.
  3. Relief-at-source contributions are paid from net pay at 80% of the gross contribution. The provider reclaims the other 20%. Any further relief due to a higher, intermediate, advanced or top-rate taxpayer is reported separately because HMRC pays it outside payroll.
  4. Adjusted net income is pay after all three pension routes (relief-at-source contributions grossed up). It decides the personal allowance taper: £1 of allowance is withdrawn for every £2 above £100,000, rounded down to whole pounds. Pension contributions are rounded to pence first, so the taper always matches the income figure shown.
  5. Income tax is charged on taxable income (pay less the allowance) using the band table for the nation chosen or implied by the tax code prefix.
  6. Employee National Insurance is charged on pay after salary sacrifice using the annual thresholds for the category letter. Nothing is due from State Pension age.
  7. Student loan and Postgraduate Loan repayments are a fixed percentage of the same pay National Insurance uses, above each plan's threshold. A postgraduate loan is collected alongside an undergraduate plan.
  8. Take-home pay is pay after salary sacrifice, less income tax, National Insurance, loan repayments and any pension paid from pay. Monthly is a twelfth, weekly a fifty-second, daily a two-hundred-and-sixtieth, and hourly is weekly divided by hours worked.
  9. Marginal rate is measured by re-running the whole calculation with £2 more gross (with the pension contribution held fixed) and comparing the deductions. It therefore includes tax, NI and loans, and shows the effective 60% (England) or 67.5% (Scotland) tax rate in the £100,000 to £125,140 zone.

Personal allowance and other allowances, 2026/27

Item Figure Source
Standard personal allowance £12,570 (tax code 1257L) GOV.UK: income tax rates
Allowance taper £1 lost per £2 of adjusted net income over £100,000; zero at £125,140 GOV.UK: income over £100,000
Blind Person's Allowance £3,250, added to the personal allowance and not tapered GOV.UK: Blind Person's Allowance
Marriage Allowance £1,260 transferable (reference only; enter your M or N code to apply it) GOV.UK: Marriage Allowance

Income tax bands, 2026/27

HMRC publishes bands in taxable income (after the allowance). Many websites quote them as total income assuming the standard allowance; both columns are shown so you can match either. The engine applies the taxable-income column, which is what keeps it right for people with a reduced allowance.

England, Wales and Northern Ireland

Band Rate Taxable income Total income on 1257L
Basic rate 20% £1 to £37,700 £12,571 to £50,270
Higher rate 40% £37,701 to £125,140 £50,271 to £125,140
Additional rate 45% over £125,140 over £125,140

Source: Rates and thresholds for employers 2026 to 2027. Wales sets its own rates but has matched England and Northern Ireland for 2026/27, per GOV.UK: Welsh income tax.

Scotland

Band Rate Taxable income Total income on S1257L
Starter rate 19% £1 to £3,967 £12,571 to £16,537
Scottish basic rate 20% £3,968 to £16,956 £16,538 to £29,526
Intermediate rate 21% £16,957 to £31,092 £29,527 to £43,662
Scottish higher rate 42% £31,093 to £62,430 £43,663 to £75,000
Advanced rate 45% £62,431 to £125,140 £75,001 to £125,140
Top rate 48% over £125,140 over £125,140

Sources: Scottish Rate Resolution 2026-27 (taxable-income limits) and GOV.UK: income tax in Scotland (total-income table). The personal allowance and its taper are UK-wide and apply to Scottish taxpayers.

Flat-rate tax codes

BR, D0 and D1 charge one rate on all pay from that job with no allowance. In Scotland the codes are SBR, SD0, SD1, SD2 and SD3 and they map to the Scottish rates: SD0 is the 21% intermediate rate, not the 40% higher rate. A K code adds ten times its number to taxable pay, and the tax taken under it is capped at half of pay. NT charges no tax. 0T gives no allowance but uses the normal bands. Source: GOV.UK: what your tax code means.

National Insurance, 2026/27

Threshold Per year
Lower earnings limit £6,708
Primary threshold (employee NI starts) £12,570
Secondary threshold (employer NI starts) £5,000
Upper earnings limit £50,270
Upper secondary threshold (under 21s, apprentices under 25, veterans) £50,270
Category Who Employee, PT to UEL Employee, above UEL Employer
A Most employees 8% 2% 15%
B Married women and widows with a valid certificate of election (reduced rate) 1.85% 2% 15%
C Employees over State Pension age 0% 0% 15%
H Apprentices under 25 8% 2% 0% to £50,270, then 15%
J Employees deferring NI because they already pay it in another job 2% 2% 15%
M Employees under 21 8% 2% 0% to £50,270, then 15%
V Veterans in their first civilian job 8% 2% 0% to £50,270, then 15%
Z Employees under 21 who are deferring NI 2% 2% 0% to £50,270, then 15%
X No National Insurance due (for example, under 16) 0% 0% 0%

Source: Rates and thresholds for employers 2026 to 2027, cross-checked against GOV.UK: NI rates and categories. Employees who have reached State Pension age pay no Class 1 NI (GOV.UK). State Pension age is 66, rising to 67 between 2026 and 2028 for people born on or after 6 April 1960. The calculators treat age 66 as State Pension age; anyone born on or after 6 April 1960 can use the explicit option instead (timetable).

Student loan repayments, 2026/27

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

Source: HMRC: rates and thresholds for employers 2026 to 2027, matching GOV.UK: repaying your student loan. Which plan you are on is explained at GOV.UK: which repayment plan you are on.

Pension contributions

Under relief at source the provider claims 20% basic-rate relief for everyone, including Scottish starter-rate taxpayers. Higher-rate taxpayers can claim the difference between their marginal rate and 20% from HMRC; the calculators show that amount but do not add it to take-home pay. Under a net pay arrangement the contribution is taken before tax, so relief arrives automatically at your marginal rate. Under salary sacrifice your contractual pay is reduced and the employer pays the contribution, which is why NI falls as well. Sources: GOV.UK: tax relief on pensions and HMRC: adjusted net income.

Simplifications, stated plainly

How we test

The engine ships with an automated test suite of hand-worked cases for 2026/27: basic, higher and additional-rate earners in both nations, the £100,000 to £125,140 taper zone, each student loan plan alone and stacked with a Postgraduate Loan, the three pension methods at the same salary (asserting that salary sacrifice always leaves the most), an employee over State Pension age, every tax code form HMRC issues, and edge inputs from £0 to £10 million. The suite runs on every change before anything is published, and a rate cannot be changed without changing a test.

When the figures change

The UK tax year starts on 6 April. New rates are loaded as a new data file and every calculator, this page and the visible "rates last checked" date switch together. Mid-year changes announced at a Budget or Spring Statement are applied from the date they take effect. Spotted something wrong? Please tell us; corrections are published with a note.

All sources