How the financial independence calculator works
Last updated 10 November 2026
The idea is simple. If you can live on a fixed share of your investments each year, you need a pot big enough that this share covers your spending. This calculator works out that pot and how long your saving takes to build it.
How it works
- Target pot = yearly spending ÷ withdrawal rate.
- The pot grows each month by the growth rate above inflation (a twelfth of the yearly rate) and you add your monthly investment at the end of the month.
- The time is the number of months until the pot reaches the target.
Worked example
With the starting figures:
- Spending of the amount shown each month needs a pot of R 7 500 000 at a 4% withdrawal rate.
- You are 5% of the way there.
- Investing the monthly amount shown, you reach it in about 30 years 11 months.
The idea in plain words
Financial independence means your investments could pay for your spending without a salary. The sum behind it is simple. If you plan to draw a fixed share of the pot each year, the pot has to be big enough that this share covers a year of spending. This calculator works out that pot and how long it takes you to build it.
What you enter
- Monthly spending you would need in the future, in today's money
- Savings so far and what you add each month
- Growth above inflation, so the sum stays in today's money
- Withdrawal rate, the share of the pot you plan to draw each year
Reading the result
You see the target pot, the share you have reached and the time to reach it at your monthly saving. The target equals yearly spending divided by the withdrawal rate, so a lower withdrawal rate needs a bigger pot. A chart shows how the pot could grow towards the target.
Why the numbers are only a guide
The sum uses one steady growth rate. Real markets rise and fall, and a bad run early on can change the outcome a lot. The calculator ignores tax, fees and changes in your spending. It also ignores retirement fund rules, which limit when and how you can take money out of some products. Treat the answer as a way to compare scenarios and not as a forecast.
Related tools
Try the savings goal calculator and the compound interest calculator for simpler questions. The retirement annuity tax calculator shows how contributions to a retirement annuity change your tax.
Things to watch
- Returns are not guaranteed and can be negative in some years. The estimate uses one steady rate.
- Tax, fees and changes in your spending are not included.
- A lower withdrawal rate needs a bigger pot but is more cautious. Try several.
- South African retirement funds have rules on when and how you can take money out.
This is an illustration, not advice. See the disclaimer. Related: compound interest calculator and tax-free savings calculator.