Calculate the future value of an investment with regular monthly contributions and compound interest.
A future value calculator works out what a sum of money today, plus any regular monthly contributions, will be worth at a future date, assuming it grows at a constant annual interest rate. This is a core "time value of money" concept — money available now is generally worth more than the same amount in the future, because it can be invested to grow in the meantime.
This calculator compounds your present value and contributions monthly: each month, growth is calculated on the current balance and added, then your monthly contribution is added — so future growth is calculated on a progressively larger base.
Formula: Each month: Balance = Balance × (1 + monthly rate) + Monthly Contribution, where monthly rate = Annual Rate ÷ 12 ÷ 100, starting from Balance = Present Value, repeated for Years × 12 months.
Example: A present value of £5,000, with £200 contributed monthly, at a 6% annual rate (example rate — enter a rate appropriate to your situation) over 10 years, gives a future value of roughly £41,900. Of that, about £29,000 comes from your present value plus contributions (£5,000 + £24,000 over 10 years), and about £12,900 is growth. (Note: all figures in this example are for illustration purposes only and are not guaranteed.)
The future value calculation is a building block used across financial planning — for working out how a pension pot, ISA, or general savings goal might grow toward a target date, or for comparing the future value of money kept in different types of accounts (a Cash ISA versus a Stocks & Shares ISA, for example, which would typically use different rate assumptions reflecting their different risk levels). It's the mirror image of the Present Value Calculator, which works backwards from a future amount to find out what it's worth today. The interest rate you choose matters enormously for long time horizons — even a 1-2 percentage point difference compounds into a substantial difference in future value over 10, 20, or 30 years, which is why it's worth running this calculator with a few different rate assumptions rather than relying on a single figure.
Future value answers "what will this amount be worth later, given growth?" while present value answers "what is a future amount worth today, given a discount rate?" They're mirror images of the same time-value-of-money concept — use the Present Value Calculator if you're working backwards from a future target.
No. This calculator shows nominal future value — the actual pound amount, without adjusting for inflation. To estimate purchasing power in today's terms, you could enter a "real" interest rate (your expected return minus expected inflation) instead of a nominal rate.
This is the effect of compounding — small differences in annual rate compound every month over many years, leading to a much larger gap in the final result than the percentage difference might suggest. This is why testing a range of rate assumptions is particularly important for long-term projections.
Yes, in principle — the underlying maths (a present value, regular contributions, and compound growth) is the same. However, pensions and ISAs may have specific features (such as tax relief on pension contributions, or annual ISA allowances) that this general-purpose calculator doesn't account for.
No specific rate is guaranteed — the default is an example only. Realistic rates depend heavily on how the money is held: cash savings typically offer lower, more stable rates, while investments in shares or funds may offer higher average returns but with significant volatility and risk of loss.
Enter 0 for the monthly contribution. The calculator will then show the future value of your present value amount growing on its own at the entered interest rate, with no further additions.
Disclaimer: The information and figures provided on this page are for educational and illustrative purposes only and do not constitute financial advice. The default interest rate is a sample value and does not reflect the performance of any specific investment, fund, or savings account. This calculator does not account for inflation, fees, or tax. The value of investments can go down as well as up. Always consult a qualified financial adviser before making financial decisions.