Principal & Contributions
Initial Investment The lump sum you're starting with — this could be savings you already have.
R
Monthly Contribution The amount you add every month going forward. Even small amounts make a big difference over time.
R
Annual Interest Rate The yearly return on your money. A typical SA savings account offers 7–9%. The JSE has historically returned around 12–14% per year.
%
Time & Frequency
Investment Period How many years you leave your money to grow. The longer the better — this is where compounding gets magical.
yrs
Compound Frequency
Contribution Timing Start of period means you contribute at the beginning of each month — slightly better returns. End of period is the default for most debit orders.
Final Balance
—
Total Contributed
—
Interest Earned
—
Growth Over Time
Total Balance
Amount Contributed
Year-by-Year Breakdown
| Year | Annual Contrib | Total Contributed | Annual Interest | Total Interest | Balance |
|---|
How does compound interest work?
Compound interest means you earn interest not just on your initial deposit, but also on all the interest you've already accumulated. Over time this creates exponential growth — the longer you stay invested, the more powerful the effect.
A = P(1 + r/n)^(nt) + contributions compounded over each period
Where P is your initial principal, r is the annual interest rate, n is the number of compounding periods per year, and t is time in years.
South African savings accounts and money market funds typically offer rates between 8% and 11% per year. Fixed deposits and unit trusts may offer higher rates depending on term and risk profile.