Bond Repayment Calculator South Africa: Monthly Repayments and Savings
Work out your estimated monthly bond repayment, total interest and total repayment based on your purchase price, deposit, interest rate and loan term. See how much you could save in interest and how much sooner you could pay off your bond by adding an extra monthly payment.
Calculate My Bond Repayment ↓Bond Repayment Calculator
Enter your bond details below, then press Calculate to see your repayment breakdown.
Your Monthly Bond Repayment
R0
Over your loan term
Repayment breakdown
| Component | Basis | Amount |
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This estimate applies the reducing balance formula to your bond amount, interest rate and term.
Your bond amount is your purchase price minus your deposit, and your monthly repayment is worked out using the reducing balance method, the same approach used for any South African home loan. Interest is charged only on the outstanding balance, so adding an extra amount to your monthly repayment reduces the balance faster, which shortens your loan term and reduces the total interest you pay. Use the calculator above for your own estimate, and confirm your exact figures with your bank’s bond quotation.
How to Use the Bond Repayment Calculator
Four quick steps to an estimated repayment.
- 1 Enter the property purchase price. This is the agreed price of the home you are buying.
- 2 Enter your deposit and interest rate. A larger deposit reduces the bond amount you need to borrow.
- 3 Enter your loan term. Most South African bonds are registered over 20 years, though shorter and longer terms are available.
- 4 Add an extra monthly payment if you want to, then press Calculate. Your repayment, total interest and any savings from paying extra appear instantly.
The Bond Repayment Calculation Formula
Bond repayments use the reducing balance method, so interest is only ever charged on what you still owe.
Monthly Rate = Annual Interest Rate / 12
Monthly Repayment = Bond Amount x Monthly Rate x (1 + Monthly Rate)^n / ((1 + Monthly Rate)^n – 1)
Total Interest = (Monthly Repayment x n) – Bond Amount
With an extra payment, n falls to n’ = ln( M’ / (M’ – Monthly Rate x Bond Amount) ) / ln(1 + Monthly Rate)
M’ in the formula above is your monthly repayment plus your extra payment. A smaller n’ means your bond is settled sooner, which is why even a modest extra payment can save a large amount of interest over a long term.
Worked Examples
Real calculations using the reducing balance formula, so you can see exactly how a bond repayment is built.
Example 1: R1,200,000 purchase price, R120,000 deposit, 10.25% per year, 20 year term
| Bond amount: R1,080,000.00 | Monthly repayment: R10,601.75 |
| Total interest: R1,464,420.00 | Total repayment: R2,544,420.00 |
Example 2: R650,000 purchase price, no deposit, 11% per year, 20 year term, R1,000 extra monthly payment
| Bond amount: R650,000.00 | Monthly repayment: R6,709.24 |
| Total interest without extra: R960,217.60 | Interest saved with extra: approximately R353,611.48 |
| Time saved: approximately 77 months | |
Example 3: R2,500,000 purchase price, R500,000 deposit, 12% per year, 25 year term
| Bond amount: R2,000,000.00 | Monthly repayment: R21,064.47 |
| Total interest: R4,319,341.00 | Total repayment: R6,319,341.00 |
Bond Repayments in South Africa: The Complete Guide
A home loan bond in South Africa is repaid using the reducing balance method, meaning your monthly instalment stays fixed while the split between interest and capital shifts over time. Understanding how this works helps you budget accurately and see the real value of paying extra into your bond whenever you can.
How your monthly repayment is calculated
Your bond amount is simply your purchase price minus your deposit. Your bank then spreads this amount over your loan term at your quoted interest rate, which is usually linked to the prime lending rate. In the early years, most of your instalment goes toward interest, since the outstanding balance is at its highest, with progressively more going toward capital as the balance reduces.
Why paying extra into your bond helps
Because interest is calculated on your outstanding balance, any extra amount you pay above your required instalment reduces that balance immediately, which reduces the interest charged the following month. Over a long term, even a relatively small extra payment can shorten your bond term by several years and save a substantial amount in total interest, since the savings compound month after month.
Deposits and loan to value
A larger deposit reduces the bond amount you need to borrow, which lowers your monthly repayment and the total interest you pay. Some buyers qualify for a 100% bond with no deposit, though a deposit can improve the interest rate you are offered and reduce the risk premium your bank applies.
Other costs when buying a home
Your bond repayment is not the only cost of buying property. Transfer duty, a tax paid to SARS, applies on purchases above R1,210,000, on a sliding scale from 3% up to 13% on the portion above that threshold, with no duty payable at or below it. You will also pay conveyancing fees to a transfer attorney and, separately, bond registration fees to a bond attorney appointed by your bank, both of which are due before registration and are not usually included in your monthly bond repayment.
Methodology
This calculator subtracts your deposit from your purchase price to get your bond amount, then applies the reducing balance formula to work out your monthly repayment and total interest. If you enter an extra monthly payment, it solves for the shorter payoff period that results, and compares the total interest in both scenarios.
Assumptions used in this calculator
- This calculator assumes a fixed interest rate and a fixed monthly repayment for the full term.
- The extra payment scenario assumes the same extra amount is paid every month until the bond is settled.
- This calculator does not include transfer duty, conveyancing fees, bond registration fees, or credit life insurance.
- Loan to value restrictions and bank specific qualifying criteria are not accounted for.
Frequently Asked Questions
It estimates your monthly bond repayment, total interest and total repayment based on your purchase price, deposit, interest rate and loan term, and shows the impact of any extra monthly payment.
Your bond amount is your property purchase price minus your deposit. If you are applying for a 100% bond, your bond amount equals the purchase price.
It depends on your bond amount, interest rate and how much extra you pay, but even a modest extra payment kept up every month can shorten your bond term by several years and save a substantial amount in interest. Enter an extra monthly payment above to see your own estimate.
20 years is the most common bond term offered by South African banks, though shorter terms and, in some cases, longer terms are available depending on the lender and the applicant.
No. This calculator covers your bond repayment only. Transfer duty, conveyancing fees and bond registration fees are separate once-off costs paid before or at registration, not part of your monthly bond repayment.
No. This tool gives a planning estimate. Your bank’s actual quotation may include a different rate offer, credit life insurance, or fee structure, so always confirm your exact figures with your bank.