TDSR Explained: How Singapore’s 55% Rule Affects Your Home Loan

In my years helping Singapore homeowners and buyers make sense of mortgage rules, I’ve found that the Total Debt Servicing Ratio, or TDSR, is one of the biggest reasons a home loan gets approved, adjusted, or rejected. Many buyers focus only on the advertised interest rate or the property price, but the real question banks ask is simpler: can you comfortably service all your debts while still staying within Singapore’s 55% borrowing limit?

That is what TDSR does. It caps your total monthly debt obligations at 55% of your gross monthly income, and that single rule can shape everything from your maximum loan amount to whether you can buy that dream condo, upgrade from an HDB flat, or refinance for better cash flow. If you want to quickly see how this affects your own budget, I often suggest starting with the home affordability calculator and then checking your expected repayments with the monthly installment calculator.

What is TDSR and why does it matter?

TDSR stands for Total Debt Servicing Ratio. In Singapore, it means your total monthly debt repayments cannot exceed 55% of your gross monthly income when you take out a home loan covered by the TDSR framework.

In practice, banks look at more than just your property loan. They include:

• Your new home loan instalment
• Car loans
• Credit card minimum payments
• Personal loans
• Renovation loans
• Study loans and other recurring debt obligations

This is why someone earning a strong income can still find their loan amount limited. I’ve met many buyers who were surprised to learn that a car loan or multiple credit card balances can materially reduce how much they can borrow for property.

The purpose of TDSR is to prevent overleveraging. From a lender’s perspective, it protects both the borrower and the financial system by ensuring monthly commitments remain manageable even if interest rates rise. If you want to understand how your repayment changes across different loan sizes and tenures, the amortization table is a very useful way to visualise the long-term cash flow.

How the 55% TDSR limit is calculated

The calculation starts with your gross monthly income, which usually includes salary, bonuses, and some variable income depending on bank treatment and documentation. Then all monthly debt obligations are added together. The total must stay at or below 55% of your gross income.

Simple formula

TDSR = Total monthly debt obligations ÷ Gross monthly income

If your gross monthly income is S$10,000, the maximum total debt obligations allowed under TDSR would be S$5,500 per month.

If you already have:

• Car loan: S$800
• Credit card minimum payments: S$200
• Renovation loan: S$300

Your existing debt totals S$1,300. That means the remaining amount available for your home loan instalment is only S$4,200, not the full S$5,500.

That distinction matters. In many cases, buyers assume the 55% rule means they can simply allocate 55% to housing. But in reality, TDSR covers all monthly debt commitments, not just the mortgage.

TDSR, MSR, and LTV: how the rules work together

A lot of Singapore buyers think TDSR is the only rule that matters, but loan approval is really shaped by several frameworks working together.

Mortgage Servicing Ratio (MSR)

For HDB flats and Executive Condominiums, the Mortgage Servicing Ratio (MSR) also applies. MSR limits your monthly mortgage instalment to 30% of your gross monthly income for these housing types. That means even if you are under TDSR, MSR can still cap your loan size.

Loan-to-Value (LTV) limits

LTV determines how much of the property value or purchase price can be financed by a loan. In Singapore, the current maximum LTV for a bank housing loan is generally 75% for eligible borrowers, subject to the usual conditions, while HDB loans have their own financing rules. In addition, if you already have an outstanding housing loan, the LTV can be lower. The exact limit depends on factors such as the number of housing loans you already have and your loan tenure.

CPF Ordinary Account usage

CPF OA savings can usually be used for property, but usage is not unlimited. In my experience, this is where many buyers misjudge their affordability. CPF can help pay the down payment, monthly instalments, and certain upfront costs, but only within the permitted rules and subject to property type, financing method, and withdrawal limits. It is also important to remember that if you use CPF for housing, you may need to refund the amount used, together with accrued interest, when you sell the property.

For official CPF housing rules, I always recommend checking the CPF Board.

Practical worked example: how TDSR affects your loan amount

Let me walk you through a realistic example I often use when speaking with clients.

Suppose:

• Gross monthly income: S$12,000
• Existing car loan: S$900
• Existing credit card minimum payments: S$300
• No other debts

Step 1: Calculate your TDSR ceiling

55% of S$12,000 = S$6,600

That is the maximum total amount you can commit to monthly debt repayments.

Step 2: Deduct existing debts

S$900 + S$300 = S$1,200

Remaining amount for home loan repayment:

S$6,600 - S$1,200 = S$5,400

Step 3: Translate the instalment into a loan amount

The actual loan amount depends on interest rate and tenure. If we assume a 25-year tenure and a home loan rate around 3.0% p.a. for illustration, a monthly instalment of about S$5,400 could support a loan in the region of roughly S$1.25 million to S$1.35 million.

But that is not the final answer. You still need to check:

• Whether LTV allows that loan size
• Whether you have enough cash and CPF for the down payment
• Whether MSR applies if it is an HDB or EC purchase
• Whether the bank uses haircuts for variable income
• Whether your age and tenure reduce the available loan term

This is exactly why I encourage buyers to test different scenarios on the monthly installment calculator before they commit to a purchase price.

What lowers your borrowing power under TDSR?

In my work, I see a few common patterns that reduce borrowing power more than buyers expect.

1. Existing debts

Even small monthly obligations can matter. A car loan, several credit card balances, or a renovation loan can reduce the mortgage amount you qualify for.

2. Variable income treatment

Commission, bonus, and freelance income may not always be counted at full value. Banks often average income over a period and apply conservative rules.

3. Loan tenure and age

A shorter tenure means higher monthly instalments, which increases TDSR pressure. Older borrowers may also face lower loan tenure limits depending on bank policy and retirement-related considerations.

4. Interest rate assumptions

Banks assess affordability based on stressed interest rate assumptions, not just today’s promotional rate. This is one reason the same salary can qualify for different loan sizes at different times.

5. Property type

An HDB or EC purchase brings MSR into the picture, while a private property purchase is judged mainly under TDSR, LTV, and the borrower’s overall profile.

How to improve your TDSR position before applying

The good news is that TDSR is not fixed forever. If you are planning to buy, there are practical steps you can take to improve your position.

Reduce unsecured debt first

Pay down credit card balances and avoid carrying unnecessary instalment loans. These are often the easiest debts to reduce before a home purchase.

Consider clearing or restructuring a car loan

A car loan can have a surprisingly large effect on your home loan capacity. For some buyers, delaying a car purchase until after the mortgage is secured makes a meaningful difference.

Increase your joint income profile

If you are buying with a spouse or family member, joint income can improve borrowing power, provided both incomes are recognised by the bank.

Stretch your down payment wisely

A larger down payment reduces the loan principal and the monthly instalment, which helps keep you within TDSR. If you want to compare what happens when you change your down payment, I also recommend checking the home page calculator to quickly test affordability scenarios.

Review refinancing opportunities

If you already own a property, a refinance may help reduce monthly repayments and improve cash flow, especially when interest rates fall or your current package becomes less competitive. You can estimate possible savings using the refinancing savings calculator.

CPF usage, cash flow, and the hidden part many buyers miss

One misconception I often correct is that CPF usage makes affordability irrelevant. CPF is helpful, but TDSR still governs whether the loan is approved in the first place.

If your monthly instalment is too high, the bank will not approve the loan just because you intend to use CPF OA funds. CPF can support repayment, but it does not bypass the TDSR rule.

Another important point is cash flow planning. Even if your CPF OA can cover instalments, I always advise buyers to think ahead about:

• Maintenance fees
• Property tax
• Home insurance
• Repairs and renovations
• Emergency savings

For official guidance on property taxes and stamp duties, I refer clients to the IRAS website when they want to check the latest duty rules and payment obligations.

Final thoughts: borrow within the rule, not just within the price tag

TDSR is one of the most important safeguards in Singapore’s property market, but it is also one of the most misunderstood. The 55% cap is not just a technical banking rule; it is the framework that determines how much home you can truly afford without putting pressure on your monthly finances.

In my experience, the smartest buyers do not start with the maximum loan they can get. They start with the monthly instalment they can live with comfortably, then work backwards to the right property price, loan tenure, and down payment.

If you are planning to buy, upgrade, or refinance, I recommend starting with the tools on mortgageagent.sg so you can see your numbers clearly before speaking with a bank. Use the home affordability calculator, try the monthly installment calculator, and if you already own a property, compare refinancing options with the refinancing savings calculator.

If you want tailored guidance, I’m Maeve Tan, and I help Singapore buyers make sense of TDSR, MSR, LTV, and CPF rules so they can borrow with confidence and buy with clarity.