Total Debt Servicing Ratio (TDSR) Formula Explained, With Examples
Every total debt servicing ratio (tdsr) 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
Room for new loan = 55% × income − existing monthly debts.
What each input means
- Gross monthly income (S$): the value you enter in the calculator.
- Existing monthly debt payments (S$): the value you enter in the calculator.
Example
For example, with these inputs:
- Gross monthly income (S$): 12,000
- Existing monthly debt payments (S$): 800
the calculator returns:
- Total debt allowed (55%): S$6,600.00
- Room left for a new mortgage: S$5,800.00
- Current TDSR: 6.67%
How the result changes
The table keeps the other inputs at their example values and changes gross monthly income (s$).
| Gross monthly income (S$) | Total debt allowed (55%) | Room left for a new mortgage | Current TDSR |
|---|---|---|---|
| 12,000 | S$6,600.00 | S$5,800.00 | 6.67% |
| 6,000 | S$3,300.00 | S$2,500.00 | 13.33% |
| 9,000 | S$4,950.00 | S$4,150.00 | 8.89% |
| 15,000 | S$8,250.00 | S$7,450.00 | 5.33% |
| 18,000 | S$9,900.00 | S$9,100.00 | 4.44% |
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.
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stamp duties and monthly instalments, but using CPF reduces the money compounding for retirement, and the amount withdrawn plus accrued interest must be refunded to your CPF account when you sell.
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.
Stamp duties are paid upfront. Buyer's Stamp Duty applies to every purchase at tiered rates up to 6%, while ABSD depends on the buyer's residency status and how many residential properties they already own. Sellers who dispose of a property within the holding period pay Seller's Stamp Duty.
Related calculations
- Property Affordability Calculator: Estimates the biggest loan and property price your income supports under TDSR, using the stress-test rate banks apply.
- Rental Yield Calculator: Measures the return from rent before and after costs such as property tax, maintenance fees and agent fees.
- Home Loan Refinancing Calculator: Compares your current mortgage with a new rate to show the monthly saving and how long switching costs take to recover.
- Property Downpayment Calculator: Splits the downpayment into cash and CPF and shows the remaining loan.
Use the Total Debt Servicing Ratio (TDSR) Calculator to plug in your own numbers.
Run your own numbers: Total Debt Servicing Ratio (TDSR) Calculator