WagePension Contribution Calculator
This calculator shows how paying into a workplace or personal pension changes your take-home pay, income tax and National Insurance. The effect depends on how the contribution is collected - net pay, relief at source or salary sacrifice - because each interacts with tax and NI differently. Enter your salary and contribution, choose the method, and the calculator shows what actually leaves your pay, how much tax relief you gain, and, for higher earners, how a contribution can pull back Personal Allowance lost in the £100,000 to £125,140 taper.
Pension contribution calculator
| Your gross contribution | £2,250 |
| Employer contribution | £1,350 |
| HMRC basic-rate top-up | £450 |
| Total into pension | £3,600 |
| Take-home without pension | £35,920 |
| Take-home with pension | £34,120 |
Auto-enrolment minimums are £6,240–£50,270 qualifying earnings, 8% total (3% employer + 5% employee). Relief-at-source shows the basic-rate top-up here; higher-rate relief, where due, is claimed via self-assessment or your tax code. Estimates, not advice.
The three contribution methods
Under a net pay arrangement, your contribution comes out of your salary before income tax is worked out. That lowers your taxable pay, so you get full relief at your highest rate automatically - but the contribution is taken after National Insurance, so it does not reduce your NI.
Under relief at source, the contribution is paid from money that has already been taxed. The pension scheme then reclaims basic-rate relief from HMRC and adds it to your pot, and higher and additional-rate taxpayers claim the rest through Self Assessment. This method also lowers your adjusted net income, which matters above £100,000.
Under salary sacrifice, you agree to give up part of your gross salary in return for an employer pension contribution. Because it comes off your pay before both income tax and National Insurance, it is the most efficient of the three - you save NI as well as tax.
The Personal Allowance taper lever
Between £100,000 and £125,140, the Personal Allowance is withdrawn by one pound for every two pounds of income - the reason this band carries an effective marginal rate well above the headline 40%. Income in this range is unusually expensive to earn.
A pension contribution reduces the adjusted net income that the taper is measured against. By bringing income back down towards £100,000, a relief-at-source or salary-sacrifice contribution can restore some or all of the withdrawn allowance, so the effective relief on that slice of pay is far larger than the basic rate alone. The calculator shows how much allowance is restored at your salary.
Frequently asked questions
Which method gives the biggest boost to take-home pay?
Salary sacrifice, because the contribution avoids both income tax and National Insurance. Net pay and relief at source save income tax but not NI on the employee side.
How does a pension contribution help above £100,000?
It lowers the adjusted net income used to taper the Personal Allowance between £100,000 and £125,140, so contributing can restore allowance you would otherwise lose and sharply raise the effective relief.
General information, not advice. Estimates assume the standard 1257L tax code and typical circumstances; your payslip may differ by a pound or two because HMRC payroll software truncates at each step. Verify with HMRC or an accountant for any decision. WageReckon stores no salary data - the calculators run in your browser.
Rates for the 2026-27 tax year, current as of 24 July 2026. Source: HMRC (gov.uk). Contains public sector information licensed under the Open Government Licence v3.0. Source: HMRC / gov.uk. See how we calculate.