Useful next calculations
When to use this calculator
- Before comparing mortgage products, brokers or repayment types.
- When you want to test how a different deposit, rate or term changes the payment.
- When you need a quick estimate before using a formal illustration or agreement in principle.
- When you are stress-testing your budget against a higher rate.
A worked example
These are the example figures the calculator opens with.
| Input | Value |
|---|---|
| Loan Amount (R) | R200 000 |
| Property Value (R) | R250 000 |
| Interest Rate (%) | 5,5% |
| Term (Years) | 25 years |
For those figures the calculator returns:
- Monthly payment: R1 228,17
- Total interest: R168 452,50
- LTV: 80.00%
How to read your results
Monthly Payment
Estimated monthly mortgage repayment under the rate, term and balance you entered. Compare it with a lender illustration before you apply.
Total Interest
Additional amount paid above the original principal during the term, using the rate you entered. Fees and early-repayment charges are not included unless you added them.
LTV
Loan-to-value is the mortgage as a percentage of the property value. Crossing common LTV bands can change product eligibility and pricing.
Method & assumptions
This calculator works on a standard capital and interest repayment basis, spreading your loan across the chosen term so that each monthly payment reduces the outstanding balance while also covering interest. The calculation uses compound interest applied monthly, which is how most mortgage lenders price their products. The result shows an illustrative monthly payment based on the rate and term you enter — it does not account for mortgage fees added to the loan, payment holidays, or rate changes at the end of a fixed period. Real-world repayments may differ slightly depending on how your lender calculates daily interest. Always request a full Key Facts Illustration (KFI) or European Standardised Information Sheet (ESIS) from any lender before committing.
Common mistakes
- Mixing up loan amount and property value, which distorts affordability and LTV.
- Using a headline rate but forgetting fees, insurance or repayment type.
- Testing only one term length instead of comparing payment and total cost together.
- Treating the result as a lender decision rather than a planning estimate.
What to do next
- Run a second scenario with a cautious assumption so you can see the downside clearly.
- Compare the result with the related calculators below before making a decision.
- Check current local rules, eligibility and provider terms before applying or committing money.
- Keep a record of the assumptions so you can update the estimate when a quote, bill or pay figure changes.