Compound Growth Visualiser
See how your money grows over time with compound interest. Enter your initial investment, monthly contributions, timeframe, and expected annual return rate. The chart and table show your year-by-year breakdown.
About Compound Growth Calculator
Compound interest is famously described as the eighth wonder of the world — and for good reason. It is the mathematical principle that makes long-term investing so powerful: you earn returns not just on your initial investment, but on all the accumulated returns from previous years. Over decades, this creates exponential growth that feels almost magical.
Consider this example: investing 200 pounds per month from age 25 to 65 at a 7% average annual return (roughly the long-term stock market average after inflation) grows to approximately 480,000 pounds — despite only contributing 96,000 of your own money. The other 384,000 is pure compound growth. Start at 35 instead and you get roughly 226,000. That ten-year delay costs you over 250,000 pounds.
The Rule of 72 provides a quick mental shortcut: divide 72 by your annual return rate to estimate how many years it takes to double your money. At 7% returns, your money doubles roughly every 10.3 years. At 10%, every 7.2 years. This simple rule helps you intuitively understand the power of different return rates without needing a calculator.
Our compound growth calculator lets you model different scenarios: varying contribution amounts, time horizons, return rates, and starting balances. This helps you understand exactly how much you need to save each month to reach your retirement target, emergency fund goal, or house deposit.
How to Use
- Enter your starting balance (initial lump sum, can be zero)
- Set your monthly or annual contribution amount
- Enter the expected annual growth rate (7-10% is typical for long-term equity investing)
- Set the time period and view the projected final value with a breakdown of contributions versus growth
Why This Matters
Understanding compound growth is the single most important concept in personal finance. It explains why starting to invest early matters more than investing large amounts later, why high-fee funds destroy long-term returns, and why even small regular contributions grow into life-changing sums over decades. This calculator makes the abstract concept concrete by showing you exact numbers for your specific situation.