TDSR and MSR Explained in Singapore

Before a Singapore lender decides what you can borrow for a home, two ceilings decide it first. The Total Debt Servicing Ratio and the Mortgage Servicing Ratio cap how much of your income may go to debt — one across everything you owe, one specifically for HDB flats and executive condominiums. They are the reason two buyers with the same income are approved for very different loans. This guide explains how each ratio works, what counts inside them, and how to read your own numbers before a lender does.

TDSR: 55% of gross monthly income, across all debts

The Total Debt Servicing Ratio caps property loans granted by financial institutions at 55% of gross monthly income across all debt obligations — the framework set by MAS and applied since 16 December 2021. "All" means all: the housing instalment you are applying for, existing mortgages, car loans, personal instalment loans, and the minimum payments on revolving balances such as credit cards. A borrower earning S$6,000 gross a month has a TDSR budget of S$3,300 a month for every debt payment combined. If a car loan (S$800) and card minimums (S$200) already claim S$1,000, the most a new housing instalment can add under TDSR is S$2,300. Lenders apply their own credit assessments on top — TDSR is a regulatory ceiling, not an entitlement.

Gross monthly income is the figure before deductions, and lenders will apply their own evidentiary rules for variable income such as bonuses or commissions. The loan affordability calculator reproduces the arithmetic: enter income and existing obligations, and it shows the servicing headroom left under the 55% ceiling.

MSR: 30% of gross monthly income for HDB flats and ECs

The Mortgage Servicing Ratio caps housing loans for HDB flats and executive condominiums at 30% of gross monthly income — a property-specific ceiling that sits alongside TDSR, not instead of it. For those properties the binding constraint is the stricter of the two, and 30% is stricter than 55% for every borrower whose housing instalment is the dominant debt. The same S$6,000 earner shopping for an HDB flat has an MSR budget of S$1,800 a month for the housing instalment itself — well below the S$2,300 the TDSR arithmetic left. At an illustrative 3% annual rate over 25 years, S$1,800 a month services roughly S$380,000 of loan; S$2,300 services roughly S$485,000. Same income, same rate, different property class, materially different borrowing power — that is the MSR at work, and the home affordability calculator shows both ceilings side by side.

What the ratios mean for loan size

A servicing ceiling translates into a loan amount through three variables: the rate, the tenure, and the repayment structure. The mortgage calculator inverts the arithmetic — enter the instalment your ratios permit and it shows the loan that instalment supports at your rate and term. Tenure interacts with regulation too: a first housing loan from a financial institution is generally capped at 75% loan-to-value, and tighter LTV limits apply where the tenure exceeds 30 years (25 years for an HDB flat) or the loan extends beyond the relevant borrower age threshold. Stretching the term to enlarge the instalment you can service can therefore shrink the share of the price you may borrow — a trade-off the calculators make visible.

The ratios also explain why small existing debts cost more than their instalments suggest. A S$200 card minimum does not just consume S$200 of your 55% budget — it consumes it at the worst possible moment, when you are applying for the largest loan of your life. Clearing or shrinking revolving balances before a mortgage application can genuinely raise the loan your ratios permit, and the debt consolidation calculator shows what restructuring would do to the monthly obligation.

How to read your own numbers

Start with your gross monthly income and every debt payment you make today — including card minimums, which borrowers routinely forget. Total them as a percentage of income: that is your current TDSR position. Anything above the mid-40s leaves little housing headroom below the 55% ceiling. Then apply 30% to your income if an HDB flat or EC is the target, and ask what instalment that permits. Feed that figure into the mortgage calculator at a realistic-for-you rate and tenure, and you have the loan size the framework will bear before any lender runs the numbers. Two cautions to finish: the thresholds are regulatory ceilings, and individual financial institutions apply their own regulatory, affordability and credit assessments — approval is never guaranteed by passing the arithmetic; and the 12-times-monthly-income unsecured threshold is a separate framework relevant to debt consolidation, not a housing rule — see the guide to the Debt Consolidation Plan for that regime.