Bond maths: what your home loan really costs
The instalment is only the beginning of a property purchase. Here's the full arithmetic banks hope you'll skip.
How a bond instalment is built
Bonds price off prime plus or minus a risk margin. On a R1.5 million bond at prime-linked rates, each 0.25% rate change moves the instalment by roughly R250 to R300. which is why banks negotiate margins and why competing quotes matter. This calculator applies the standard annuity formula on your amount, term and rate, over terms up to 30 years.
The 5 to 8% nobody budgets for
Transfer duty (scaled by price, with exemptions at the lower end), bond registration, conveyancing and initiation fees add 5 to 8% on top of the purchase price. On R1.5 million that's R70,000 to R120,000 due before you move in. cash or short-term credit. Buyers who budget only the deposit get caught here; price it into your planning from day one.
Deposit strategy
Banks offer 100% bonds to strong applicants, but every extra 5% of deposit buys a better margin and shrinks the interest paid over the term. On a 20-year bond, moving from 90% to 85% loan-to-value saves well into six figures over the life of the bond. the best risk-free return available to most buyers.
Small margins, enormous totals
Over 240 months, the difference between 11% and 11.5% on R1.5m is more than R50,000. That's why one habit pays for itself: get pre-approved by at least two institutions and let them compete. This calculator gives you the arithmetic to judge their offers in seconds.