Figures are illustrative only, ignore charges and tax, and are not a forecast or personal recommendation.
This calculator projects the size of your retirement fund based on your current age, target retirement age, current savings, ongoing monthly contributions, and an assumed annual investment return — the standard building blocks of a simple retirement projection.
How the projection works
The calculator first works out your time horizon by subtracting your current age from your target retirement age, then compounds your current savings and monthly contributions over that number of years at the rate you specify, using the same monthly-compounding methodology as our other growth calculators. The result is split into the projected total, how much of that you'll have contributed yourself, and how much is investment growth.
Retirement savings isn't just about pensions
This calculator is deliberately generic — the "current savings" and "monthly contribution" fields can represent a pension, a Stocks & Shares ISA earmarked for retirement, or a combination of accounts. Many people build retirement provision across multiple wrappers: a workplace pension for its employer contribution and tax relief, a SIPP for additional tax-relieved saving, and an ISA for flexibility (since ISA withdrawals, unlike most pension withdrawals, aren't restricted by age or taxed as income). If you want a projection specifically focused on pension contributions including an employer match, our dedicated Pension Growth Calculator handles that directly, while our ISA Calculator does the equivalent for annual ISA contributions.
Worked example
Someone aged 30 today, targeting retirement at 65 (a 35-year horizon), with £20,000 currently saved and contributing £300 a month at an assumed 5% annual return, ends up with a projected fund considerably larger than the roughly £146,000 they'll have contributed in total over the period — illustrating just how much of a long-horizon retirement fund can come from growth rather than contributions alone, provided the money stays invested throughout.
Is your fund enough?
This calculator tells you what your current plan is projected to produce — it doesn't tell you whether that's enough for the retirement you want. For that comparison, use our “How much do I need to retire?” calculator, which projects your fund in the same way but also compares it against the pot needed to fund a specific desired retirement income, adjusted for inflation.
Frequently asked questions
What if I plan to increase my contributions over time?
The calculator assumes a flat monthly contribution for the whole period. If you expect contributions to rise (for example, with promotions or paying off debt), treat the current figure as a conservative baseline, or re-run the projection in stages at different contribution levels.
Does this account for the State Pension?
No — this projects only the fund built from the savings and contributions you enter. The UK State Pension is a separate, largely inflation-linked income most people become eligible for from State Pension age, on top of any private pension or savings.
What return rate should I use for a retirement projection?
This depends on how the money is invested and how many years remain — investors further from retirement can typically afford a higher-growth, higher-volatility allocation than those close to it, a topic covered in our guide to how much risk to take by age.
Should I build a core-and-satellite portfolio for retirement savings?
Many long-term investors use a simple, low-cost core holding (often a global index tracker) supplemented by smaller satellite positions — see our guide to building a core-and-satellite portfolio for how this structure works in practice.
Common mistakes when projecting a retirement fund
A frequent mistake is treating "retirement age" as fixed and unchangeable, when in reality it's one of the most powerful levers in the whole calculation. Delaying retirement by even 2-3 years adds extra years of contributions, extra years of compounding growth, and shortens the period the fund needs to support — a combination that can close a meaningful shortfall on its own. Try adjusting the retirement age in the calculator above to see how sensitive the final projection is to this single input.
A second mistake is not stress-testing the projection against a lower return assumption. Because the assumed rate compounds over potentially decades, a projection built only on an optimistic rate can create false confidence — it's worth checking the same inputs at a meaningfully lower rate (2-3 percentage points below your central estimate) to see how much the outcome changes, and planning around a figure you'd still be reasonably comfortable with under that more cautious scenario.
Should I include a spouse or partner's savings in this projection?
You can combine household figures if you plan finances jointly, though bear in mind pensions specifically are usually individually owned and have individual allowances, so it's often clearer to project each person's pension separately even if shared goals are considered together.
What if I want to retire earlier than my current plan supports?
Use our “How much do I need to retire?” calculator to see the gap between your current trajectory and a specific desired income, then adjust contributions, retirement age, or expectations to close it.
How accurate are 30+ year financial projections in general?
Not very, in absolute terms — the further out a projection reaches, the wider the realistic range of actual outcomes becomes, since small changes in the assumed rate compound into large differences over decades. The value of a long-term projection lies less in its precision and more in showing the general direction and scale of what current habits are likely to produce.
Should I use a lower return assumption the closer I get to retirement?
Many long-term investors do gradually shift toward a more cautious asset allocation approaching retirement, which would typically also lower the realistic return assumption for those final years — for a simple single-rate projection like this one, using a blended, somewhat conservative rate is a reasonable compromise.
Finally, remember that a projection like this one is a planning tool, not a target to hit precisely. Revisiting the numbers periodically as your circumstances change, rather than fixing a plan once in your 20s or 30s and never adjusting it, tends to produce far better real-world retirement outcomes than either ignoring the topic or over-engineering a single early projection.