Bond calculator South Africa
Once-off Costs
Gross Monthly Income Required
How are home loans calculated?
We use monthly-compounded amortisation. Capacity is the lower of 30% of gross or net − expenses. Banks may price differently based on credit profile and prime.
Including additional payments
Without additional payments
Bond registration cost breakdown
Property transfer cost breakdown
South African Bond Calculator:
How It Works, What Each Section Means, and How to Use It to Your Advantage
South African Bond (Home Loan) Calculator – Repayments, Affordability, Extra Payments & Transfer Costs
Learn exactly how our South African bond calculator works. See your monthly home-loan repayments, affordability, the impact of extra payments, and a breakdown of bond & transfer costs. Updated for ZAR with clear explanations and tips.
Why this calculator is different
Buying a home in South Africa means juggling four moving parts: your monthly repayment, what you can afford to borrow, the impact of extra payments, and the once-off bond & transfer costs. Our calculator puts all four in one place with clean, readable outputs in Rands (ZAR)—so you can make smart decisions in minutes.
What each section does (and how to use it)
1) Bond Repayment
Purpose: Estimate your monthly home-loan repayment based on the purchase price, deposit, interest rate and term.
Inputs you’ll see on the left
Purchase Price (R): The agreed price of the property.
Deposit (R): Cash paid upfront to reduce your loan amount.
Interest Rate (% p.a.): Your expected home-loan rate (fixed or linked to prime).
Loan Term (years): Typical options are 20–30 years.
What we calculate on the right
Monthly Bond Repayment: Your estimated instalment (excludes monthly extras like rates/levies/insurance unless you add them elsewhere).
Once-off Costs (snapshot): A quick view of likely bond registration and property transfer fees (with a link to the full breakdown).
Gross Monthly Income Required: A guideline showing the income needed if banks cap repayments at ~30% of gross income (a common affordability rule-of-thumb in SA).
Behind the scenes (the formula)
We use standard amortisation with monthly compounding:
Repayment=P×r(1+r)n(1+r)n−1\text{Repayment} = P \times \frac{r(1+r)^{n}}{(1+r)^{n}-1}
Where P = loan amount (price – deposit), r = monthly interest rate (annual/12), n = total months (years × 12).
Tip: A bigger deposit or lower interest rate moves the needle fastest on your monthly repayment.
2) Affordability
Purpose: Estimate the maximum loan amount you’re likely to qualify for based on your income and expenses.
Inputs
Gross Monthly Income (R): Total income before deductions.
Net Monthly Income (R): Take-home pay after tax and deductions.
Monthly Expenses (R): Your recurring expenses (credit, transport, childcare, etc.).
Interest Rate & Term: So we can convert a monthly capacity into a realistic loan size.
What we calculate
Amount You Qualify For: Conservative loan size based on the lower of:
~30% of gross income; and
Net income – expenses.
Monthly Bond Repayment at that Amount: So you can see the expected instalment for the qualified loan.
Good to know: Banks run their own affordability models (credit score, existing debts, property type, deposit size). Our estimate is a guide, not a promise.
3) Additional Payment
Purpose: See how extra payments—either monthly or once-off—reduce total interest and loan term.
Inputs
Current Bond Debt (R) and Current Monthly Repayment (R).
Additional Monthly Payment (R): An extra amount you can add to each instalment.
Once-off Extra Payment (R): A lump-sum you can put in now or soon.
Interest Rate (% p.a.).
What we calculate
You would save (R): Estimated interest saved over the life of the loan.
You would reduce your loan term by: Years and months shaved off.
Breakdown including vs. excluding additional payments: Side-by-side totals for monthly repayment, total interest, total payment, and remaining term.
Pro tip: Even small monthly extras (e.g., R300–R800) can save years and hundreds of thousands of rands in interest.
4) Bond & Transfer Costs
Purpose: A transparent estimate of the once-off costs to budget for on transfer.
Inputs
Purchase Price (R) and Loan Amount (R).
What we show
Total Bond & Transfer Costs: Big number at a glance.
Bond registration cost breakdown: Attorney fees for registering the bond, bank initiation fee, deeds office levy, and admin/postage.
Property transfer cost breakdown: Transfer attorney fees, deeds office levy, transfer duty (if applicable), and admin/postage.
About transfer duty: South Africa has thresholds/bands that change over time (there’s often a 0% band up to a certain price). The calculator uses a current table for convenience, but your conveyancer will confirm the official amount on your deal date.
Example: How deposit and rate change your repayment
No deposit vs 10% deposit (R1,000,000 purchase @ 10.5%, 20 years)
0% deposit: Higher loan, higher instalment.
10% deposit (R100,000): Smaller loan → lower monthly repayment → less total interest.
Rate sensitivity: A 1% change in rate can add or remove hundreds of rands per month and tens of thousands in lifetime interest. Shop around or work with a bond originator to negotiate.
What affects your bank approval (beyond the calculator)
Credit score & track record (on-time payments).
Loan-to-value (LTV): Bigger deposits reduce bank risk.
Income stability & debt-to-income ratio.
Property type & valuation vs. purchase price.
Rate type: Variable (linked to prime) vs. fixed (for a set period).
Assumptions, accuracy, and updates
Calculations use monthly compounding and standard amortisation.
Affordability uses conservative rules and is not a final bank decision.
Bond & transfer costs are estimates; actual quotes depend on your attorneys, bank, and the transfer duty table in effect at the time of purchase.
For the most accurate numbers, request a formal quote or speak to us.
Glossary (plain-English)
Bond / Home Loan: Money borrowed from the bank to buy property.
Deposit: Cash you put down upfront. Reduces your loan and risk.
Amortisation: How each payment is split between interest and principal over time.
Transfer Duty: Tax payable to SARS when buying property (based on price bands).
Bond Registration Fees: Legal fees to register your bond at the Deeds Office.
Initiation Fee: Bank’s once-off fee for opening the bond account.
Deeds Office Levy: Statutory fees for deeds processing.
LTV (Loan-to-Value): Loan amount ÷ Purchase price. Lower is safer for banks.
How to get the most from this tool (checklist)
Test scenarios: Try different deposits, rates and terms to see the impact.
Run the Affordability tab: Confirm your income-based limit.
Plan your once-off costs: Use Bond & Transfer to budget accurately.
Make a savings plan: Use Additional Payment to set a monthly extra—even a small one.
Speak to us: We’ll help verify the numbers with banks and negotiate a rate.
Frequently Asked Questions (FAQ)
Q1: Is this the same as what the bank will approve?
A: Not exactly. Banks use their own credit models. This calculator gives a solid estimate so you can plan. We can help you get pre-qualification and apply across multiple banks.
Q2: Why does my repayment change when the rate changes?
A: Most South African bonds have variable rates linked to prime. When prime moves, your instalment follows. A fixed rate (if offered) can lock the rate for a period.
Q3: How big should my deposit be?
A: Even 5–10% can meaningfully lower repayments and total interest. Bigger deposits may improve your rate and approval odds.
Q4: Are bond & transfer costs negotiable?
A: Some components (like attorney professional fees) can vary by firm; statutory fees (e.g., transfer duty and deeds levies) are not negotiable.
Q5: Do extra payments really help?
A: Yes. Extra payments reduce your principal sooner, cutting interest and term. The Additional Payment tab shows your exact savings.
Q6: What if I plan to fix my rate?
A: You can still use the calculator—just enter the fixed rate offered for the fixed period. After the fixed period ends, your rate will likely revert to a variable rate.
Q7: Does the calculator include insurance, levies, or municipal rates?
A: No—those are separate monthly costs. Add them to your budget to get your all-in monthly cost of owning the property.
Ready to take the next step?
Use the calculator above to fine-tune your numbers, then reach out to Real Estate Assist. We’ll help you:
Validate affordability with a proper pre-qualification.
Compare multiple bank offers to secure the best rate.
Get a clear attorney fee and transfer duty quote for your property.