Practical guide
Compound Interest Explained with a Simple Example
Compound growth means returns can be earned on the original money and on earlier returns. Time, regular contributions, fees and the achieved rate all influence the final value.
Fact checked and updated 13 September 2026
The four main inputs
Starting capital begins compounding immediately. Monthly contributions add new capital, the return controls the assumed growth rate and the investment period determines how long compounding can continue.
Nominal results are not guarantees
A calculator normally applies one steady rate, while real investments rise and fall and may deduct fees or tax. Inflation also reduces what a future Rand amount can buy.
Use ranges instead of one forecast
Compare conservative, middle and optimistic return assumptions. Focus on contributions you can sustain and review progress periodically instead of treating a projected value as promised.
Use the related calculators
Apply the explanation above with your own figures. Open a calculator below, check every input and review the result assumptions before making a decision.
Official source checked
This guide was checked against Financial Sector Conduct Authority consumer education. Rules, rates and institutional requirements can change, so confirm time-sensitive information at the official source.