Compound Interest & Investment Growth Visualiser
Calculate compound interest returns, monthly recurring deposits, compounding frequencies, and visualise future wealth growth with multi-currency support.
Investment Inputs
Projected Portfolio Value
Year-by-Year Growth Table
| Year | Starting Balance | Annual Contributions | Interest Earned | Total Interest | Ending Balance |
|---|
About this tool
How to use it
- Input your initial starting principal deposit and select your desired currency symbol.
- Specify your regular monthly or annual recurring contribution amount.
- Set your expected annual interest return rate (e.g. 7.5%) and total investment horizon in years (e.g. 10 to 40 years).
- Choose your compounding frequency (Monthly, Quarterly, Semi-Annually, or Annually).
- Click Calculate Growth to render the year-by-year balance trajectory and detailed breakdown table.
Why it matters
Compound interest creates exponential wealth accumulation by reinvesting earned interest into the capital base. Modeling these trajectories locally helps you optimize contribution frequencies and savings timelines with total privacy.
When to use it
Use this visualizer when planning retirement accounts (401k, Roth IRA, SIPP), setting long-term index fund investment goals, or comparing savings accounts with different compounding frequencies.
Good to know
Calculations assume fixed compounding rates without accounting for capital gains taxes or market volatility. Inflation adjustments and regular recurring contributions significantly influence real-world purchasing power.
Common questions
What is the mathematical difference between simple interest and compound interest?
Simple interest calculates returns exclusively on the original principal balance (linear growth). Compound interest calculates returns on both the original principal and all previously accumulated interest, producing exponential capital growth over time.
How does compounding frequency impact total investment returns?
Higher compounding frequencies (such as monthly or daily compounding versus annual compounding) credit interest into your balance sooner, allowing subsequent interest cycles to earn returns on a larger base and increasing your effective annual yield (APY).
What formula calculates compound interest with regular monthly deposits?
The future value is calculated as: FV = P * (1 + r/n)^(nt) + PMT * [((1 + r/n)^(nt) - 1) / (r/n)], where P is principal, r is annual rate, n is compounding periods per year, t is years, and PMT is periodic deposit.
What is the Rule of 72 in compound interest?
The Rule of 72 is a practical rule of thumb estimating how many years it takes to double your money at a fixed annual rate: divide 72 by your annual interest rate (e.g. at 8% annual return, your capital doubles in roughly 72 / 8 = 9 years).
Are investment growth projections guaranteed?
No. Investment projections demonstrate theoretical mathematical compounding at a constant rate. Real-world equity, stock market, and mutual fund returns fluctuate annually based on macroeconomic conditions.