Regular investing calculator
See what consistent monthly investing could realistically add up to. Nobody feels wealthy putting a few hundred away each month. The number at the end is the argument for carrying on.
Updated for the 2026/27 tax year · reviewed
Your investing plan
Your investment could grow to
£155,163
after 20 years - nominal, not adjusted for inflation
Total contributed
£77,000
Growth (nominal)
£78,163
Nominal final value
£155,163
Real vs nominal difference
£60,472
what inflation quietly takes
Nominal vs real value over time
The headline growth versus what it's actually worth once 2.5% inflation is factored in.
Investing monthly is the easy half. Sustaining it is the other.
See this contribution alongside your mortgage, pension and cash buffer, so you can find the level you can genuinely keep up for twenty years rather than two.
Create your free accountHow this calculator works
We grow your starting lump sum and monthly investment at the expected return you enter, compounded monthly - the same maths as the compound interest calculator, applied to an investment growth assumption rather than a savings rate. That headline figure is the nominal value: the raw pounds on the screen, not adjusted for anything.
Switching to "today's money" divides that nominal figure by an assumed 2.5% a year of inflation, showing what the pot would actually buy at today's prices rather than the bigger, less meaningful number inflation alone would produce. The gap between the two grows every year - it's the real vs nominal difference tile above.
The expected return is a labelled assumption, not a forecast - markets don't grow in a smooth, constant line, and no return is guaranteed. Try a more cautious rate alongside your main estimate, and remember this isn't investment advice.
Questions people ask
Nominal or real returns - what's the difference?
A nominal return is the headline growth rate before inflation; a real return subtracts inflation to show growth in today's spending power. This calculator can show either, and the real figure is usually the more honest one for long-term planning.
What growth rate should I assume?
There's no guaranteed answer - global equity markets have historically returned around 5-7% a year above inflation over long periods, but that's a backward-looking average, not a promise. Try a range of rates, including a cautious one, rather than anchoring on a single number, and remember this isn't investment advice.
Is it better to invest a lump sum or drip-feed monthly?
A lump sum invested immediately has historically outperformed drip-feeding on average, simply because money spends more time in the market, but drip-feeding smooths out the risk of investing everything right before a downturn. Many people do both - investing a lump sum and then continuing with regular monthly contributions.
Do fees really make a difference?
Yes, more than most people expect - a 1% annual fee difference compounded over 20-30 years can reduce your final pot by a noticeable double-digit percentage. It's worth checking the ongoing charges figure on any fund or platform alongside its returns.
Last reviewed against 2026/27 UK rules. Projections are estimates for education, not financial advice. Understanding your projections.
A calculator answers one question at a time.
The planner keeps all of them next to each other, so an overpayment you model today still shows up in the pension picture in twenty years.
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- Your figures carry over