HDB Loan Formula Explained, With Examples
Every hdb loan result comes from one formula. Once you understand what goes into it, you can sanity-check any figure you are given, whether by an employer, a bank, a teacher or another website.
The formula
Monthly instalment = P × r ÷ (1 − (1 + r)^−n), where r is the monthly rate and n the number of months.
What each input means
- Loan amount (S$): the value you enter in the calculator.
- Interest rate (% a year): the value you enter in the calculator.
- Loan tenure (years, max 25): the value you enter in the calculator.
Example
For example, with these inputs:
- Loan amount (S$): 400,000
- Interest rate (% a year): 2.6
- Loan tenure (years, max 25): 25
the calculator returns:
- Monthly instalment: S$1,814.68
- Total interest: S$144,403.41
- Total repaid: S$544,403.41
How the result changes
The table keeps the other inputs at their example values and changes loan amount (s$).
| Loan amount (S$) | Monthly instalment | Total interest | Total repaid |
|---|---|---|---|
| 400,000 | S$1,814.68 | S$144,403.41 | S$544,403.41 |
| 200,000 | S$907.34 | S$72,201.70 | S$272,201.70 |
| 300,000 | S$1,361.01 | S$108,302.56 | S$408,302.56 |
| 500,000 | S$2,268.35 | S$180,504.26 | S$680,504.26 |
| 600,000 | S$2,722.02 | S$216,605.11 | S$816,605.11 |
Why it matters
Property is the largest purchase most Singaporeans make, and stamp duties, loan limits and cash requirements are front-loaded. Small mistakes in these figures can mean a shortfall at completion, so it pays to run the numbers before you commit to an option to purchase.
Beyond the price, buyers should budget for legal fees, valuation, home insurance, renovation and furnishing. Running the figures in advance helps you decide how much cash to hold back and whether a smaller loan or longer tenure makes more sense.
Most Singaporeans live in HDB flats, which can be financed with an HDB concessionary loan at 0.1% above the CPF Ordinary Account rate or with a bank loan. Private property must be financed with a bank loan, and banks offer fixed, floating and SORA-pegged packages.
CPF Ordinary Account savings can pay for the downpayment, stamp duties and monthly instalments, but using CPF reduces the money compounding for retirement, and the amount withdrawn plus accrued interest must be refunded to your CPF account when you sell.
Related calculations
- Buyer's Stamp Duty (BSD) Calculator: Calculates Buyer's Stamp Duty on a Singapore residential property using the tiered rates from 1% to 6%.
- Additional Buyer's Stamp Duty (ABSD) Calculator: Calculates ABSD by buyer profile and the number of residential properties owned, using the rates in force since 27 April 2023.
- Total Property Stamp Duty Calculator: Adds BSD and ABSD together so you know the full stamp duty bill before you sign an option to purchase.
- Seller's Stamp Duty (SSD) Calculator: Calculates SSD for residential property bought on or after 4 July 2025 and sold within four years.
Use the HDB Loan Calculator to plug in your own numbers.
Run your own numbers: HDB Loan Calculator