How this projection is built
This calculator projects your pension pot forward from today's value, adding your own and your employer's monthly contributions every month between now and your planned retirement age, and compounding the whole balance at an assumed annual growth rate. It's designed to mirror how a defined contribution pension — the type most UK employees and the self-employed now build, whether workplace or personal — actually accumulates over a working life.
Why the employer contribution matters so much
Under automatic enrolment, most UK employees are enrolled into a workplace pension with minimum contribution levels split between employee and employer, and many employers offer more than the legal minimum, sometimes matching a higher percentage if you contribute more yourself. An employer contribution is, in effect, additional pay that arrives only if you're paying into the pension — turning it down by opting out or contributing less than the amount needed to trigger the full employer match is one of the most commonly cited missed opportunities in UK personal finance.
Tax relief on top of what this calculator shows
This projection uses the contribution amounts you enter directly, but in most cases your own contribution benefits from pension tax relief, meaning the actual amount invested on your behalf is higher than what left your take-home pay, particularly if you pay tax at the higher or additional rate. Basic-rate relief is usually added automatically by your scheme; higher and additional-rate taxpayers often need to claim the rest via Self Assessment. See our pension tax relief and annual allowance guide for exactly how this works and the current annual allowance limit.
Why charges matter over a multi-decade projection
Pension charges are usually expressed as a small annual percentage of your fund, but because they're deducted every year for what could be several decades, they compound against your growth in the same way contributions compound in your favour. A pension with meaningfully higher charges than a comparable alternative can leave you with a noticeably smaller final pot, even with identical contributions and identical gross investment performance. It's worth checking your scheme's charges, particularly for any older pensions from previous employers that you haven't reviewed in a while.
What to do with the projection once you have it
Once you have an estimated pot, the next natural question is what income that might actually provide once you retire, which our pension income calculator addresses directly, and whether it's likely to be enough for the retirement you want, which our "how much do I need to retire?" calculator compares against a target income. If you have several old pensions from previous jobs, it's also worth checking whether consolidating them into one place would make them easier to track and manage.
A worked example
Using the calculator's defaults — a 35-year-old with a £35,000 pension pot today, contributing £250 a month themselves with a £150 monthly employer contribution, assuming 5% annual growth until age 67 — the projected pot comes to roughly £441,000 at retirement. Total contributions (your own plus your employer's, on top of the starting pot) add up to about £163,000, meaning growth accounts for around £278,000 of the final figure, well over half the total.
Now suppose the same saver negotiated their employer up from a £150 to a £250 monthly contribution, matching their own, with everything else unchanged: the projected pot rises to approximately £493,000 — an extra £52,000 at retirement, entirely from an additional £100 a month that never came out of their own take-home pay.
Reviewing where your pension is actually invested
Many workplace pensions default new members into a standard fund choice without asking, and it's worth checking what that default is actually invested in rather than assuming it automatically suits your own time horizon and comfort with risk. Someone in their thirties or forties defaulted into an unusually cautious fund may be leaving meaningful growth on the table over a multi-decade horizon, while someone close to retirement in an aggressive, high-equity default may be carrying more short-term risk than they'd choose if they thought about it directly. A five-minute check of your fund choice is one of the highest-value things you can do alongside this projection.
Frequently asked questions
Does this include my State Pension?
No — this projects a defined contribution pot only. Your State Pension is a separate, government-provided income based on your National Insurance record, and is added on top of whatever a private or workplace pension provides.
What if I have several pensions from different jobs?
Add together the current values and monthly contributions across all of them for a combined projection, or run this calculator separately for each if their assumed growth rates or charges differ significantly.
What growth rate should I assume for a pension?
This depends on how the pension is invested — many workplace pensions default to a lifestyle strategy that gradually shifts from higher-growth, higher-risk assets towards more cautious ones as you approach retirement, so a single flat rate across your whole projection is always a simplification.
Should I contribute more than my employer will match?
Often yes, once you've captured the full employer match — additional contributions still benefit from tax relief and continue compounding for retirement, even without an extra employer contribution attached to them.
What if I change jobs before retirement?
Your pension pot with a previous employer's scheme typically stays invested and keeps growing even after you leave, though contributions stop unless you keep it as a personal pension — it's worth entering the combined value of all your pensions here for the most complete projection.
Does this calculator apply to a self-employed personal pension too?
Yes — simply leave the employer contribution field at zero and enter your own contribution, since a self-employed personal pension follows the same underlying compounding maths, just without an employer paying in alongside you. It's worth remembering that self-employed pension saving is entirely voluntary, so building the contribution habit deliberately matters even more without automatic enrolment prompting it.