Pay extra into your bond
See the interest and the years you save by adding a little more each month, or a lump sum today.
Updated for the 2026/27 tax year. Free, no sign-up needed.
How the calculation works
We work out your current instalment from the balance, rate and years left, the same way your bank does. Then we run the bond month by month twice: once as it stands, and once with your lump sum taken off the balance today and the extra amount added to every instalment.
Each month, interest is charged on the balance still owed. Extra payments shrink that balance sooner, so every later month costs less interest and more of each instalment goes to capital. Interest saved is the difference in total interest between the two runs.
This assumes the rate stays where it is for the rest of the term and leaves out bank fees. If prime moves, run it again: the interest saved moves with it.
Questions people ask
How much do I save by paying extra into my bond?
Every extra rand reduces the balance that interest is charged on, so the saving compounds over the remaining term. Early in a 20-year bond most of each instalment is interest, which is why a small monthly top-up can cut years off the loan.
What interest rate should I use?
Use the rate on your latest bond statement. Most South African home loans are priced at prime plus or minus a margin, and prime has been 10.75% since 25 September 2026.
Is a lump sum or a monthly extra payment better?
Money paid in earlier saves more interest, so a lump sum today beats the same total spread over later months. A monthly top-up is easier to sustain. The calculator lets you model both together.
Can I get extra bond payments back out?
Most South African banks offer an access bond, which lets you withdraw money you paid in ahead of schedule. Terms, fees and limits differ by bank, so confirm with yours before relying on it as an emergency fund.
Should I pay off my bond or invest the money?
Paying down the bond earns a return equal to its interest rate, with no risk and no tax. Investing can earn more over long periods but with risk and possible tax. Many people first use their TFSA and retirement tax breaks, then compare.
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Estimates use the SARS tables for the 2026/27 tax year and the assumptions shown. They are for planning only and are not tax or financial advice. For a submission, use your actual figures or speak to a registered tax practitioner.