Bond (Home Loan) Calculator ☆ Stoor

Your rate is quoted against prime

South African home loans are priced relative to the prime lending rate, currently 10.50% (the repo rate is 7.00%). A lender quotes you something like "prime less 0.5%" or "prime plus 1%", so your actual rate moves whenever the Reserve Bank moves the repo.

Two consequences worth planning for:

• Your repayment is not fixed. A rate change of one percentage point on a 20-year bond changes the instalment meaningfully — run your amount at prime, prime +1% and prime +2% in the calculator above to see your realistic range before you commit;
• The margin is negotiable. A concession of half a percentage point sounds trivial and is worth a large sum over 20 years. It is one of the highest-value negotiations most people ever have — and worth using a bond originator to shop several banks at once.

For context, the legal maximum on a mortgage under the National Credit Act is repo + 12 percentage points = 19.00% at the current repo. Ordinary home loans sit far below that; the cap matters mainly as a boundary.

What the amortisation reveals

Two things surprise almost every first-time buyer:

• Early payments are overwhelmingly interest. In the first years only a small slice of each instalment reduces the balance, which is why the total-interest figure is so much larger than people expect — often approaching or exceeding the purchase price over a full 20-year term;
• Extra payments have outsized effects, precisely because they attack the capital directly and remove interest from every remaining month. See what yours would do in the extra payment calculator — for most homeowners it is the single best-value use of spare money.

Budget the costs that arrive at transfer

The bond repayment is not the cost of buying. Budget separately, in cash:

• Transfer duty — restructured in Budget 2026, now nil below R1,210,000. Work yours out with the transfer duty calculator;
• Conveyancing fees (transferring attorney) and bond registration costs (a separate attorney, a separate bill);
• Deeds Office fees;
• Rates and levy clearance, usually several months in advance;
• Homeowner's insurance, which your lender will require, plus moving costs and immediate repairs.

Ask the conveyancer for a written pro-forma early — a transfer stalling because the buyer cannot fund the fees is common and avoidable.

Check affordability against take-home

Lenders assess on gross, but you live on net. R25,000 gross is about R21,442 after PAYE and UIF; R50,000 gross is about R38,747 — check yours with the income tax calculator, then test the instalment in the bond qualification calculator.

And stress-test it: can you still afford the instalment if rates rise two percentage points? Rates have moved substantially within the span of a normal bond term, and the household that budgeted only at today's rate is the one that struggles.

Frequently asked questions

What rate should I enter?

Start at prime (10.50%) and adjust for the margin you have been offered. If you have no quote yet, model prime and prime +1% to bracket the range.

Should I take 20 years or 30?

A longer term lowers the instalment and substantially increases total interest. If cash flow forces a longer term, take it — then overpay when you can, which recovers much of the difference.

Is a bigger deposit worth it?

Yes, on two counts: a smaller loan, and usually a better rate concession. Test the combined effect in the calculator — it is often larger than people expect.

Fixed or variable rate?

Fixed buys certainty, usually at a higher starting rate and for a limited period. Variable follows prime both ways. Ask what the fixed rate would be and for how long, then decide against your own tolerance for a rising instalment.

Can I use a bond originator?

They shop several banks at once, usually at no cost to you, and competing offers are what produce a better margin. Worth doing even if you have a bank you like.

Prime is currently 10.50% and the repo rate 7.00%; both move with SARB decisions, so re-check after any announcement. The NCA mortgage cap is repo + 12 percentage points. Transfer duty bands are the restructured 2026/27 rates. General information, not financial advice.