Future Value Calculator
Compute the future value (FV) of a present sum under compound interest.
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At a glance:The Future Value (FV) is the nominal amount a principal invested today grows into after a number of years at a given rate and compounding frequency. It is the core of the time value of money: because money earns interest and interest earns interest (compounding), the longer the principal is left and the higher the rate, the larger the future value. FV is the reverse of present value (PV) — PV discounts a future amount back to today, while FV pushes today's principal forward. Hong Kong savers and investors use it to estimate the nominal amount of time deposits, lump-sum investments or retirement savings after many years, and to appreciate the power of compounding — noting that FV is a nominal figure and does not yet subtract inflation's erosion of purchasing power.
Formula
FV = PV × (1 + annual rate ÷ m)^(m × years), where m is compounding periods per year.
Interest earned = future value − present value.
$$FV = PV \times \left(1 + \dfrac{r}{m}\right)^{m \cdot n}$$How to Use
- Enter the present value (principal invested today).
- Set the annual rate and number of years.
- Choose the compounding frequency to see the future value and interest instantly.
FAQ
Why does the compounding frequency affect the future value?
The more often interest is compounded, the earlier it is added to the principal and starts earning interest itself, so the future value ends up slightly higher over time. For example, at the same 5% annual rate, monthly compounding yields a higher future value than annual compounding.
What is the difference between future value and present value?
Future value (FV) pushes today's principal forward in time at a given rate, answering 'how much will this sum become after a number of years'. Present value (PV) pulls a future amount back to today at a discount rate, answering 'how much do I need today to receive a certain amount in the future'. They are two sides of the same formula: at 5% for 10 years, HK$100,000 today grows to about HK$162,889; conversely, a future HK$162,889 discounted back is exactly HK$100,000.
Why does the interest share grow as the term gets longer?
Because compounding is a snowball effect where interest earns interest, and it becomes more pronounced the longer the time. With HK$100,000 principal at 5% annual rate, the FV after 10 years is about HK$162,889 (interest about HK$63k), but after 20 years it jumps to about HK$265,330 (interest about HK$165k). Doubling the term from 10 to 20 years raises the interest by over 1.6 times — a clear illustration that time is compounding's best friend, which is why starting to save or invest early matters so much.
Does future value account for inflation?
No. Future value is a nominal figure — the number on paper — and does not subtract inflation's erosion of purchasing power. For instance, at 5% return over 20 years, HK$100,000 grows to about HK$265,330, but if average inflation is 3% over that period, the real purchasing power is far lower than the headline figure. To know what that future amount is worth in today's purchasing power, adjust it with an inflation or real-return tool rather than reading the nominal FV alone.
Is monthly compounding really much better than annual compounding?
Usually the difference is small. With HK$100,000 at 6% over 10 years: annual compounding gives about HK$179,085, monthly compounding about HK$181,940 — a gap of about HK$2,855, less than 3% of the principal. The gap widens only with higher frequency, higher rates and longer terms. When choosing a deposit or investment product, the effective annual rate (APY/EAR) and fees usually matter more than compounding frequency.
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References
Content review: Calculatorism Finance Team. Results are for reference only; please refer to the relevant authorities for the official figures.