Figures are illustrative only, ignore charges and tax, and are not a forecast or personal recommendation.
This calculator projects the future value of a pension by combining your current pension value, your own monthly contributions, your employer's monthly contributions, an assumed annual growth rate, and the number of years until your chosen retirement age (calculated automatically from your current age).
Why employer contributions matter so much
Unlike an ISA, most UK pensions — especially workplace pensions under auto-enrolment — include an employer contribution on top of your own, which is effectively free money added to your retirement pot every month. This calculator combines both into a single monthly contribution figure for the projection, but it's worth entering them separately in your own budgeting so you can see how much of your eventual pot is employer-funded versus self-funded, particularly if you're weighing whether to reduce personal contributions.
Tax relief isn't shown separately here
If you contribute to a SIPP or a workplace pension via relief-at-source, basic-rate tax relief is typically added automatically (so a £80 net contribution becomes £100 gross in the pension), and higher and additional-rate taxpayers can claim further relief via self-assessment. This calculator doesn't add relief automatically — if you want the projection to reflect it, enter your gross (after-relief) contribution amount in the "your monthly contribution" field rather than the amount that actually leaves your take-home pay. Our detailed guide to SIPP contribution limits and the annual allowance explains how much tax-relieved contribution you're actually allowed to make each year.
Worked example
Someone aged 35 with a £40,000 pension, contributing £300 a month themselves plus £150 a month from their employer, assuming 5% annual growth until age 65 (a 30-year horizon), ends up with a projected pot considerably larger than the roughly £202,000 in combined contributions and starting balance — most of the extra growth accumulating disproportionately in the final decade before retirement, which is the compounding effect at its most powerful.
What happens after the pot is built?
This calculator stops at the projected pot size — it doesn't model what happens when you start drawing from it. For that, see our Pension Income Calculator, which converts a pot size into an illustrative annual or monthly income using a chosen withdrawal rate, and our guide to drawdown versus buying an annuity, which covers the main options for turning a pot into retirement income.
Frequently asked questions
Should I include my workplace pension and a separate SIPP together?
You can combine both into the "current pension value" and monthly contribution fields if you want a single combined projection, though be aware this loses the detail of each scheme's specific charges and investment choices — see our guide on SIPP versus workplace pension consolidation if you're considering combining pots for real.
What growth rate is realistic for a pension?
This depends on how the pension is invested — many workplace pension default funds are diversified and moderate-risk, while a self-invested SIPP could be invested more aggressively or cautiously depending on your choices, so match the assumption to your actual fund mix.
Does this calculator account for pension charges?
No — workplace pension and SIPP platform and fund charges will reduce the real-world outcome below the figure shown, in the same way described in our guide to ongoing charges.
What if my employer's contribution changes with my salary?
The calculator assumes a flat monthly figure for simplicity; if your contributions are salary-linked and you expect pay rises, treat the current monthly figure as a conservative estimate.
Common mistakes when projecting pension growth
A frequent mistake is forgetting to check whether an employer offers to match contributions above the auto-enrolment minimum — many workplace schemes will increase their own contribution if you increase yours, up to a cap, which is effectively a guaranteed extra return unavailable anywhere else. Before assuming your current contribution level is optimal, it's worth checking your scheme's specific matching structure, since leaving employer matching on the table is one of the most common and avoidable pension planning mistakes.
A second mistake is projecting pension growth without checking the underlying fund's charges, which can vary significantly between a workplace default fund, a self-selected fund, and a SIPP. A default fund is often perfectly reasonable, but it's worth confirming this rather than assuming it, since higher charges compound negatively over a multi-decade pension timeline in exactly the way growth compounds positively.
Should I increase my pension contributions or pay off debt first?
This depends on the interest rate on the debt versus your pension's tax relief and any employer match — high-interest debt (credit cards, for example) is usually worth prioritising, but contributing at least enough to get a full employer match is often still worthwhile even alongside moderate-interest debt, since the match itself is close to an immediate guaranteed return.
What happens to my pension if I change jobs?
You typically keep your existing pot (it stays invested) and are auto-enrolled into a new employer's scheme — many people accumulate several small pots this way over a career, which is one reason consolidation is worth considering periodically.
What's a reasonable default growth rate to use if I'm unsure how my pension is invested?
Many default workplace pension funds are diversified, moderate-risk portfolios; a long-run assumption in the region of 4-6% a year is a reasonably cautious starting point for this kind of fund, though it's worth checking your specific scheme's fund factsheet for a more tailored figure.
Does this calculator handle salary sacrifice pension contributions?
You can still use it — enter the actual amount going into the pension each month (which, under salary sacrifice, may be higher than an equivalent net contribution would have been, since National Insurance savings are typically also redirected into the pension by many employers).
It is also worth periodically checking your pension's projected value against the government's free State Pension forecast service (available via gov.uk) so you can see your full expected retirement income picture — private pension plus State Pension together — rather than judging overall adequacy from a workplace or SIPP projection in isolation, since the two are meant to work alongside each other.