Pension contribution calculator
Under HMRC's pension tax relief rules, a relief-at-source pension adds 20% basic-rate relief to the contribution taken from pay, and gov.uk's workplace pensions rules set the minimum employer contribution for automatic enrolment at 3% of qualifying earnings. This calculator converts employee and employer percentages of salary into the estimated monthly and annual amount reaching the pension.
How is the amount into my pension worked out?
Three parts build a relief-at-source pension contribution. First, the employee part, taken as a percentage of salary from pay that has already been taxed. Second, the basic-rate tax relief that the provider claims from HMRC and adds to that part, worth 20% under gov.uk's pension tax relief rules. That relief means the net contribution is grossed up by dividing it by 0.80. Third, the employer part, paid on top as a separate percentage, with a statutory minimum set by gov.uk's workplace pensions automatic enrolment rules.
The relief exists to hand back the income tax already paid on money set aside for a pension. A higher or additional-rate taxpayer still only receives the automatic 20% from the provider, under the same HMRC rule. The rest must be claimed separately through Self Assessment. This calculator shows only the automatic basic-rate figure, which is the amount most savers see land in their pot without any extra claim.
What would this look like on my salary?
On a £35,000 salary with a 5% employee contribution and 3% from the employer, £1,750 a year is taken from pay. The provider adds £438 of basic-rate relief, lifting the employee part to £2,188. The employer adds £1,050 on top. Altogether an estimated £3,238 is projected to reach the pension across the year, about £270 a month, worth 9.3% of salary.
Common questions
How is the amount into my pension worked out?
Your employee percentage is taken from your pay, your employer adds their percentage on top, and for a relief-at-source pension the provider adds 20% basic-rate tax relief to your part. Adding the three together gives the total that lands in your pension.
What is relief at source?
It is how most workplace and personal pensions add tax relief. You pay your contribution from taxed pay, then the provider claims 20% back from HMRC and adds it to your pot. So a £1750 contribution becomes £2188 once the relief is added.
What if I pay higher-rate tax?
Under relief at source, only the 20% basic-rate relief is added automatically. A higher or additional-rate taxpayer claims the extra relief separately through Self Assessment or by contacting HMRC. This tool shows the automatic basic-rate top-up only.
Is this the same as salary sacrifice?
No. Salary sacrifice lowers your gross pay instead, so it saves National Insurance as well as income tax and no relief is added afterwards. If your scheme uses salary sacrifice, the figures work differently.
What would this look like on my salary?
On a £35,000 salary with a 5% employee contribution and 3% from the employer, £1,750 a year comes out of pay. The provider adds £438 of basic-rate relief, taking the employee part to £2,188. The employer adds £1,050 on top. In total an estimated £3,238 a year, around £270 a month, is projected to reach the pension.
Sources & Rate Verification
Rates verified against official statutory guidance on 6 September 2026.