UK Tax Calculator Guide for 2026/27

A PAYE calculator can estimate deductions from employment pay. It cannot know every fact held by HMRC or reproduce every employer's payroll from annual salary alone.

This guide explains what PayeTax models for the tax year from 6 April 2026 to 5 April 2027, which inputs matter, and where a result needs qualification.

Quick Summary

• Use gross pay, the complete tax code and the correct pay period.
• Income Tax and National Insurance are separate calculations.
• Student Loan thresholds changed for 2026/27.
• PayeTax's pension input models salary sacrifice, not net pay or relief at source.
• Benefits, cumulative pay, emergency codes and unsupported deductions can make a payslip differ.
• A PAYE estimate does not determine whether Self Assessment is required.

What the Calculator Covers

PayeTax estimates:

• PAYE Income Tax for England, Wales, Northern Ireland and Scotland
• employee Class 1 National Insurance
• Student Loan Plans 1, 2, 4 and 5
• Postgraduate Loan deductions
• a pension contribution using salary-sacrifice treatment
• annual, monthly and weekly views of estimated take-home pay

The calculator is designed for employment income. It does not calculate a complete Self Assessment liability, self-employed profits, Capital Gains Tax, foreign tax, benefits in kind or every employer-specific deduction.

Current 2026/27 Rates

For England, Wales and Northern Ireland, the main Income Tax rates are:

The standard Personal Allowance is reduced by £1 for every £2 of adjusted net income above £100,000. It is nil at £125,140. Scotland has separate rates and bands for earnings and pension income.

For most category A employees, employee National Insurance is:

These annual figures help explain the result. Payroll uses HMRC's published thresholds for each pay period.

How to Use the PAYE Calculator

Step 1: Choose the pay period and enter gross pay

Use pay before tax, National Insurance, pension and other payroll deductions. If you are testing a bonus, include it in the relevant period or compare annual scenarios.

Step 2: Enter the complete tax code

Use the code on your payslip or HMRC account. 1257L is common but not universal. C marks a Welsh code, S a Scottish code, and W1, M1 or X an emergency code. For Marriage Allowance, M means the person receives a transfer and N means the person transfers it.

Step 3: Select the correct Student Loan plan

Do not infer the plan only from the year you graduated. Use the official plan guidance or check your Student Loan account.

Step 4: Add a pension only if the method matches

The pension control models salary sacrifice. Leave it at zero if your scheme uses net pay or relief at source and you are trying to reproduce a payslip.

Step 5: Review deductions separately

Compare gross pay, Income Tax, National Insurance, Student Loan and pension. This is more useful than comparing only the final net figure.

Student Loan Thresholds from April 2026

HMRC publishes the following annual thresholds and rates:

Deductions use the threshold for the pay period, and each loan-type deduction is rounded down to the nearest whole pound. Payroll operates one undergraduate plan at a time, plus a Postgraduate Loan where applicable. If an employee cannot identify their plan, payroll uses Plan 5 until HMRC issues an SL1 notice; that default is available for Plan 1, 2 or 4 loans. If the employee has more than one undergraduate plan, payroll instead uses the plan with the lowest recovery threshold until the SL1 arrives.

Pension Methods and Why They Matter

Salary sacrifice

A salary sacrifice is a contractual reduction in cash pay in exchange for an employer pension contribution. Under 2026/27 rules, the sacrificed amount is normally outside employee Income Tax and National Insurance. It can affect statutory payments and contribution-based benefits.

Net pay

Under a net pay arrangement, the employer deducts the employee contribution before Income Tax. This gives eligible tax relief through payroll, but National Insurance is calculated on gross earnings before the contribution.

Relief at source

Under relief at source, the contribution is taken after tax and National Insurance. The provider claims basic-rate relief and adds it to the pension. Taxpayers above the basic rate may need to claim additional relief.

A percentage can also apply to qualifying earnings, pensionable pay or total pay. Auto-enrolment minimums are not proof that 5% of the whole salary is deducted.

Why a Payslip Can Differ

Common reasons include:

• a different or updated tax code
• cumulative pay from earlier in the tax year
• an emergency or non-cumulative code
• a pension method the calculator does not model
• benefits in kind or an adjustment included in the tax code
• irregular pay, arrears or a bonus
• National Insurance category other than A
• deductions such as payroll giving, court orders or workplace benefits
• payroll-period rounding

A difference is not automatically an error by the employer or the calculator. Compare the assumptions first, then check with payroll or HMRC if a deduction still appears wrong.

Employment Expenses Are Not Calculator Inputs

Do not reduce salary in the calculator for an expense unless it changes contractual pay through a supported mechanism.

For 2026/27, the approved amount for business mileage in an employee's own car or van is 55p per mile for the first 10,000 business miles and 25p after that. An employee may be able to claim tax relief if an employer pays less than the approved amount.

Employees cannot claim homeworking tax relief for 2026/27. Under separate employer homeworking-expense rules, a qualifying reimbursement can still be tax-free; an employer can pay up to £6 a week without evidence when the conditions are met.

PAYE and Self Assessment

A PAYE calculator does not decide filing obligations. Some employees need Self Assessment because of untaxed income, gains or another circumstance; others do not. Salary alone is not a universal filing rule.

HMRC's Self Assessment checker currently covers 2025/26. For 2026/27, use HMRC's current who must send a tax return guidance until the checker advances. A notice from HMRC requiring a return must be dealt with even if PAYE appears to have collected the tax.

Privacy and Saved Results

PayeTax calculations run in your browser. You do not need an account. The calculator does not store salary inputs on a PayeTax server.

If you use the optional email-results feature, the information you choose to send is processed for that delivery. See the privacy policy for the current details.

Official Sources

• Income Tax rates and Personal Allowances
• National Insurance rates and categories
• Student Loan repayment guidance
• 2026/27 Student Loan deduction tables
• Tax-code letters
• Workplace pension deduction methods
• Salary sacrifice and PAYE
• Tax-free employer homeworking reimbursements

Tools & Calculators

• Estimate your take-home pay
• Explore all tax tools

Frequently Asked Questions

Is the result exactly what my employer will pay me?

No. It is an estimate based on the inputs and supported rules. Cumulative pay, payroll timing, tax-code basis, benefits and employer-specific deductions can change the payslip.

Does the calculator handle every pension method?

No. Its pension input models salary sacrifice. Net pay and relief at source change take-home differently and should not be represented as salary sacrifice.

Can I use the calculator for self-employment?

No. It models PAYE employment deductions, not taxable business profit, allowable expenses, Class 4 National Insurance or a full Self Assessment calculation.

Why might Student Loan deductions vary from an annual estimate?

Payroll compares pay with the threshold for each pay period. Irregular earnings can therefore produce deductions that do not match a simple annual-salary calculation.

Do I need an account?

No. The calculator can be used without registration, and salary calculations run in the browser.