CalculatorMortgage payment
Estimate monthly instalment, interest and total repayment.
SGD 800,000 loan: how rate and tenure change the outcome
Each scenario uses an amortising loan and keeps the principal at SGD 800,000, changing only the factors that matter to the decision.
25 years at 3.5% p.a.
- Input
- Loan SGD 800,000; tenure 25 years; interest 3.5% p.a.
- Result
- Monthly payment about SGD 4,005; total repaid about SGD 1,201,070; interest about SGD 401,070
- What it means
- A payment near SGD 4,000 covers the loan only. Stamp duties, legal fees, insurance and ongoing housing costs still need a separate buffer.
If the rate rises to 4.5%
- Input
- The same SGD 800,000 loan; 25 years; interest 4.5% p.a.
- Result
- Monthly payment about SGD 4,447—roughly SGD 442 more than at 3.5%; total interest about SGD 533,998
- What it means
- One percentage point adds about SGD 132,928 of interest over 25 years. A household near its limit should stress-test first.
Keep 3.5%, shorten to 20 years
- Input
- Loan SGD 800,000; tenure 20 years; interest 3.5% p.a.
- Result
- Monthly payment about SGD 4,640—roughly SGD 635 more than over 25 years; total interest about SGD 313,524
- What it means
- Monthly pressure rises, but lifetime interest falls by about SGD 87,546. Compare cash flow and total cost together.
How should you use the calculated result?
The tool uses the amortising-loan formula to turn principal, annual rate and tenure into a monthly instalment and total interest. A longer tenure can reduce monthly pressure but increase lifetime interest.
Do not test only today’s rate
- If the payment is already close to the household limit, rerun at 0.5 to 1 percentage point higher and retain buffers for maintenance, insurance and living costs.
- When comparing 20 and 25 years, consider both payment and total interest: a longer tenure reduces current pressure but may raise lifetime cost.
When should you not use this result directly?
- The result is not a loan approval and does not replace TDSR, MSR, LTV, minimum cash down-payment or lender underwriting.
- Floating rates, lock-ins, repricing, prepayment, insurance, legal fees and maintenance fees are outside the instalment result.
- If CPF will fund payments, the property is under construction or income is irregular, assess cash buffers and payment timing separately.
Continue with the mortgage guide
The guide compares rates of 3%, 3.5% and 4%, as well as different tenures, so you can weigh monthly payment against long-term interest.
Open the full mortgage guide
Official source: Open authority guidance
Rules last checked: 7 Sep 2026. See the Sources page.