Clear Calculators
Start here: use the UK Pay Calculator for a full take-home estimate. Use Student Loan Repayment for loan plans, Salary Sacrifice for reduced cash pay, Pension Contribution for pension method checks, and Payslip Checker when you already have a payslip in front of you.
The deductions worth separating
Income Tax
Tax is based on taxable income, allowances, bands, region and tax code. It is separate from National Insurance.
National Insurance
Employee NI is usually based on pay and NI category. It does not always move in the same way as tax.
Pension
Salary sacrifice, net pay and relief at source all show up differently on a payslip. The same 5% contribution can have a different take-home effect.
Choose the right calculator
- UK Pay Calculator: for a full take-home estimate with tax, NI, pension and student loans together.
- Student Loan Repayment Calculator: for Plan 1, Plan 2, Plan 4, Plan 5 or postgraduate loan deductions.
- Salary Sacrifice Calculator: for pension or benefit arrangements that reduce cash pay before tax and NI.
- Pension Contribution Calculator: for salary sacrifice, net pay and relief at source pension methods.
- Payslip Checker: for comparing actual payslip lines with broad tax, NI, pension and net pay estimates.
- Bonus Tax Calculator: for a one-off bonus or commission month where deductions look higher than usual.
Worked check: reconcile gross pay to the bank payment
Suppose a payslip lists £2,500 gross pay, £250 Income Tax, £110 employee National Insurance, £100 employee pension and £40 student loan repayment. These are invented payslip amounts for an arithmetic check, not calculated tax rates.
The listed deductions total £500, so expected net pay is £2,000. If the bank receives £2,025, look for a separate £25 expense reimbursement before assuming a deduction is wrong. Do not subtract an employer pension contribution: it is not an employee deduction. If gross cash pay already reflects salary sacrifice, do not subtract that sacrifice a second time.
This check answers whether the lines add up. It does not establish whether the £250 tax or £110 NI is correct. For that second check, match the tax year, pay period and relevant settings in the Payslip Checker. Keep current-period figures separate from year-to-date totals.
GOV.UK explains what a payslip should show, including earnings before and after deductions and variable deductions. If a line is unclear, ask payroll what it covers and which pay period it belongs to.
Why one number is not always enough
A pay change can hit several deductions at the same time. Pension salary sacrifice can reduce cash pay before estimated tax and NI. Student loan repayments depend on plan thresholds and the pay period. A bonus can push one month above a threshold even if your yearly pay does not look unusual.
Payslips can also include tax code changes, previous pay in the tax year, rounding, statutory payments, benefits or employer pension rules. That is why the tools are split up. Start with the calculator that matches the question, then check the related one if another deduction is involved.
Useful payroll tools
This guide is for checking and planning. Real payroll can depend on tax year, region, tax code, NI category, employer scheme rules, student loan notices and payroll timing. Check your payslip, employer documents, HMRC or Student Loans Company records before treating a result as final.