Mortgage Calculator Singapore: Monthly Repayment, Total Interest & Real Affordability
You pull up the listing. S$850,000. The monthly repayment estimate looks manageable — S$2,800, give or take. You can probably make that work. You’ve seen the salary, you know roughly what CPF covers, it seems fine on paper.
But here’s what the listing does not show: how much of that S$2,800 comes from your actual bank account every month. Whether your CPF OA contribution is even enough to cover it. What happens if interest rates rise by 1%. How much you will pay in total over 25 years — not just per month.
Most people check the monthly repayment. Almost nobody checks what it does to their financial life. That’s the gap this calculator fills.
Enter your numbers below. See the full picture — not just the headline.
A mortgage calculator that only shows monthly repayment is telling you about 20% of what you need to know. The full picture includes total interest paid over the loan (often S$150,000–S$300,000+ on a standard HDB loan), how much of your repayment comes from CPF versus cash you actually see, and what happens to your finances if rates rise. For a S$500,000 loan at 2.6% over 25 years: monthly repayment is approximately S$2,268, total interest paid is S$180,400, and at a 1% rate increase, repayment rises to S$2,530/month. Use the calculator above with your actual numbers for your real result.
Use the Calculator ↑What This Calculator Actually Shows You
This is not a one-number mortgage calculator. It shows the full financial impact of the loan you are considering.
- Monthly repayment — the standard amortising payment for your loan amount, rate, and tenure
- Total interest paid — how much extra you pay over the full loan on top of what you borrowed
- Total amount repaid — loan principal plus all interest, which is the real cost of the property
- CPF OA vs cash split — how much of the monthly repayment your CPF OA covers, and how much is a real cash outflow from your bank account
- Cash top-up shortfall — whether your stated cash budget can handle what CPF does not cover
- MSR usage — your repayment as a percentage of gross income against the 30% guide
- Debt ratio — mortgage plus existing debts as a percentage of income against the 55% TDSR guide
- Stress test at +1% and +2% — what your repayment becomes if interest rates rise
- Amortisation summary (optional) — your outstanding loan balance at years 5, 10, 15, and end
- Reality verdict — Safe, Manageable, Stretched, or Risky, with a plain-English explanation
On a S$600,000 HDB loan at 2.6% over 25 years, the monthly repayment is approximately S$2,722. Over 25 years, you will repay approximately S$816,600 — meaning you pay S$216,600 in interest alone. That is over a third of the original loan. Most buyers never calculate this number before signing.
How to Use the Calculator — Step by Step
Step 1 — Property price and loan amount. Enter the flat price you are considering. The loan amount is typically 75% of the purchase price (the remaining 25% is your downpayment). You can enter the loan amount directly or let the calculator derive it from 75% of the property price.
Step 2 — Loan type. Toggle between HDB loan and bank loan. This changes the default interest rate and tenure limits. HDB defaults to 2.6% p.a. with a 25-year cap. Bank loan defaults to 3.5% p.a. with a 30-year cap — adjust to match your actual package offer.
Step 3 — Interest rate and tenure. Use the default HDB rate of 2.6% unless you are on a different arrangement. For bank loans, enter the rate from your current package or an offer you are comparing. For tenure, longer means lower monthly payments but significantly more total interest paid.
Step 4 — Income and debts. Enter your combined gross monthly household income. Then add any existing monthly debt repayments — car loan, personal loan, credit card instalments. These affect your debt ratio and the calculator’s verdict.
Step 5 — CPF OA and cash budget. Enter how much CPF OA you can direct toward the monthly repayment. A rough estimate is 23% of your gross ordinary wages for employees aged 55 and below — but your actual amount depends on your CPF OA contribution rate, balance, and whether any of it already services other commitments. Then enter your monthly cash budget — the additional cash you can comfortably set aside for the mortgage.
Step 6 — Optional: other expenses and amortisation. Open the advanced section to enter other monthly expenses for a deeper reality check, and to see your outstanding loan balance at key milestones over the loan tenure.
HDB Loan vs Bank Loan — Which Is Right for You?
This is one of the most consequential financial decisions in a Singapore home purchase. The right answer depends entirely on your priorities and risk tolerance.
| Feature | HDB Loan | Bank Loan |
|---|---|---|
| Interest rate | 2.6% p.a. (pegged to CPF OA rate + 0.1%) | Variable — typically 2.8%–4.5%+ depending on package and market |
| Rate stability | Relatively stable — changes with CPF OA rate, which is policy-set | Fluctuates with market rates — can move significantly |
| LTV | Up to 75% of flat price | Up to 75% for HDB flats (first property, no outstanding property loan) |
| Minimum cash downpayment | None — full 25% downpayment can come from CPF OA | 5% in cash; remaining 20% from CPF OA or cash |
| Max tenure | 25 years | 30 years |
| TDSR application | Not formally applied the same way as bank loans | 55% TDSR applies alongside MSR |
| Prepayment penalty | None | Lock-in period applies — penalties for early repayment during lock-in |
| Eligibility | Singapore Citizens only; income ceiling applies; no outstanding HDB loan | Citizens and PRs; broader eligibility; no income ceiling |
| Best for | Stability, no cash downpayment pressure, predictable repayments | Potentially lower initial rate; longer tenure; more flexibility on property type |
If you qualify for the HDB loan and stability matters more than chasing a lower rate, the HDB loan’s predictability and no-cash-downpayment requirement make it the lower-risk choice for most first-time buyers. Bank loans can offer lower initial rates but introduce refinancing decisions, rate volatility, and lock-in risk. Always compare your actual bank package rate against 2.6% — the gap may be smaller than you expect once fees and lock-in terms are factored in.
The CPF vs Cash Reality
This is the section most mortgage guides skip entirely. And it is where most buyers get a financial shock three months after moving in.
CPF OA contributions can service eligible HDB housing repayments — up to the amount in your OA, subject to CPF Board rules. For employees aged 55 and below, approximately 23% of your gross ordinary wages flows into CPF OA each month. That sounds like a lot. Here is the problem.
Your mortgage repayment at the 30% MSR ceiling is — by definition — 30% of gross income. Your CPF OA contribution is 23% of gross income. That leaves a 7% monthly gap between what CPF covers and what the full repayment requires.
On a S$10,000 household income, that gap is S$700/month in cash. Every month. For 25 years.
CPF contributions are invisible — they never touch your bank account. This makes buyers feel the mortgage is “mostly covered.” The cash top-up, however, comes directly from your take-home pay after CPF. On a near-ceiling mortgage, this can be S$400–S$1,000/month in real cash you need to find, every single month, before any other expense.
How the Split Works in Practice
Imagine a household earning S$8,000 gross monthly on a HDB mortgage:
- Monthly CPF OA contribution: approximately S$1,840 (23% of S$8,000)
- Maximum mortgage at 30% MSR: S$2,400/month
- Cash top-up required: approximately S$560/month — every month, from take-home pay
- Take-home pay after CPF: approximately S$6,400
- That S$560 represents about 8.75% of take-home pay before any other expense
Now add food, transport, insurance, parents’ allowance — and the S$560 cash top-up is not a rounding error. It is a real, recurring commitment that most people do not model before buying.
Use the CPF Take-Home Pay Calculator to find your exact take-home pay first, then model the mortgage cash top-up against it.
What Most Mortgage Calculators Don’t Tell You
Standard mortgage calculators give you one number: the monthly repayment. That number is accurate. It is also dangerously incomplete.
The Total Interest Cost Is Often Larger Than Expected
On a S$500,000 loan at 2.6% over 25 years, you pay back S$680,400 in total. You borrowed S$500,000. The difference — S$180,400 — is interest. That is more than a quarter of the original loan, paid quietly in small amounts every month for 25 years until most people stop noticing it.
On a bank loan at 3.5% over 30 years, a S$500,000 loan costs approximately S$808,000 total. You pay S$308,000 in interest — 62% more interest than the principal.
Lifestyle Does Not Pause When You Buy a Flat
The mortgage repayment does not exist in isolation. It exists alongside everything else: food, transport, insurance, parents’ allowance, childcare, the car loan that felt manageable before the flat, the renovation loan that did not exist in the original plan. The mortgage calculator gives you one line item. You need to model the full budget.
The Longer the Tenure, the More You Pay — Always
A 30-year loan has a lower monthly payment than a 25-year loan on the same amount. What it does not have is a lower total cost. Every additional year of tenure adds years of interest. Extending from 25 to 30 years on a S$500,000 bank loan at 3.5% adds approximately S$57,000 in total interest. That is the price of the lower monthly payment.
The monthly repayment is what the mortgage costs you each month. The total interest is what the mortgage costs you in your lifetime. Both numbers matter. Most people only see one.
MSR and TDSR Explained Simply
Two ratios govern how much you can borrow in Singapore. The calculator uses both.
MSR — Mortgage Servicing Ratio
For HDB flat purchases, your monthly property loan repayment cannot exceed 30% of your gross monthly household income. This applies to both HDB loans and bank loans taken for HDB flats.
If your combined household gross income is S$9,000, the MSR cap means your maximum monthly mortgage repayment is S$2,700. The bank or HDB will not approve a loan that produces a higher repayment — regardless of how much you request.
TDSR — Total Debt Servicing Ratio
For bank loans, a broader cap applies. Your total monthly debt obligations — mortgage, car loan, personal loan, credit card instalments, student loan, everything — cannot exceed 55% of gross monthly income.
If you have a S$1,200/month car loan and apply for a bank loan for an HDB flat on a S$10,000 household income, the TDSR cap allows a maximum of S$5,500/month in total debt repayments. Your car loan has already used S$1,200, leaving S$4,300 for the mortgage — even though the MSR cap by itself would allow S$3,000.
The MSR and TDSR figures in the calculator are planning guides. Whether your actual loan is approved depends on HDB or your bank’s credit assessment, your income type and stability, CPF balances, property details, remaining lease, and many other factors. Use these ratios to understand your position — not as a substitute for an actual HDB Flat Eligibility (HFE) letter or bank pre-approval.
Real Singapore Mortgage Scenarios
The same loan amount feels completely different depending on income, existing debts, and CPF contribution. These three scenarios show the range.
HDB concessionary loan at 2.6% p.a., 25-year tenure. CPF OA estimated at 23% of gross ordinary wages for employees aged 55 and below. Figures are estimates — use the calculator above with your exact numbers.
Scenario 1: Single Professional, S$5,000 Gross Income
S$330,000 (near MSR ceiling)
Monthly repayment. MSR: 29.9% of gross income — at the ceiling.
~S$1,150/month
Remaining cash top-up required from take-home pay every month.
Over 25 years
Total interest paid on a S$330k loan over the full tenure.
On S$5,000 gross, take-home pay after CPF is approximately S$4,000. After the S$347/month cash top-up, S$3,653 remains for all other expenses. This is workable — but leaves limited room for a car, children, or large irregular expenses. The safer loan at 25% MSR (approximately S$275,000) reduces the cash top-up to just S$98/month and adds meaningful breathing room.
Scenario 2: Couple, S$10,000 Combined Gross Income
S$650,000
Monthly repayment. MSR: 29.5% — near the ceiling.
~S$2,300/month
Cash top-up from combined take-home pay each month.
Over 25 years
Total interest paid over the full loan tenure.
Combined take-home after CPF is approximately S$8,000. After the S$649/month cash top-up, S$7,351 remains. That sounds comfortable — until you add parents’ allowance for both sets of parents (potentially S$600–S$1,200/month combined), insurance, and the fact that children often arrive a few years after the flat purchase. The S$649/month cash top-up is manageable now, but should be stress-tested against what the budget looks like with a child and childcare costs.
Scenario 3: Family, S$12,000 Combined, S$700k Flat, Car Loan
S$700,000 loan
26.5% MSR — within the 30% ceiling with some room.
S$1,600/month
Combined mortgage + car = 39.8% of gross income.
Mortgage only
After CPF OA covers ~S$2,760. Car loan is 100% cash.
This is the combination that catches many families off guard. The mortgage alone looks fine at 26.5% MSR. Add the car loan, and combined debt obligations are 39.8% of gross income — still below the 55% TDSR ceiling, but leaving less margin than it looks. The car loan S$1,600 is entirely from cash take-home. Combined with the S$416 mortgage cash top-up, the family is committing S$2,016/month in cash to housing and transport before food, insurance, childcare, or parents’ allowance.
See how your full budget looks after these commitments using the Cost of Living Calculator.
Interest Rate Risk and the Stress Test
This matters more than most buyers realise at the time of purchase.
The HDB concessionary rate of 2.6% is pegged to the CPF OA rate (currently 2.5%) plus 0.1%. This rate has been stable for years — but it is a policy rate, not a market rate. It can and does change. Bank loan rates move with market conditions and have shown significant volatility in recent years.
The calculator shows your repayment at current rate, +1%, and +2%. Here is what that looks like on common loan amounts at 2.6% base rate over 25 years:
| Loan Amount | 2.6% (current) | 3.6% (+1%) | 4.6% (+2%) | Monthly increase at +1% |
|---|---|---|---|---|
| S$300,000 | S$1,361 | S$1,518 | S$1,685 | +S$157/mo |
| S$500,000 | S$2,268 | S$2,530 | S$2,808 | +S$262/mo |
| S$700,000 | S$3,176 | S$3,542 | S$3,931 | +S$366/mo |
| S$900,000 | S$4,083 | S$4,554 | S$5,053 | +S$471/mo |
Based on standard amortising mortgage formula. HDB rate at 2.6% p.a. as of 2026. Bank loan rates vary by package and lender. These are estimates — always verify with your lender.
A S$366/month increase on a S$700,000 loan at +1% is not abstract. That is a meaningful deterioration in monthly cash flow that happens without any change in your income, lifestyle, or other expenses. If your current budget only works at 2.6%, a rate rise creates immediate financial pressure.
Bank loan borrowers typically start with a lower rate than the HDB concessionary rate — sometimes significantly lower. But variable or floating rate packages can reprice upward when market rates move, and fixed-rate lock-in periods typically last only 2–3 years. If you take a bank loan at 2.8% because it is cheaper than 2.6%, ensure your budget can handle 3.8% or 4.8% before your next refinancing. The calculator’s stress test exists for exactly this reason.
The Biggest Mistakes Singapore Buyers Make
1. Buying at the Maximum Loan the Bank Will Approve
Approval does not equal affordability. The bank approves your loan based on the regulatory limits — MSR and TDSR. It does not know your parents’ allowance, your insurance premiums, or whether you are planning children. The maximum approved loan amount is a ceiling, not a recommendation. Most financial planners suggest targeting 25% MSR rather than 30%.
2. Ignoring the Cash Top-Up
Every buyer knows CPF can service the mortgage. Far fewer model exactly how much CPF covers — and how much cash they need to top up monthly. The gap between CPF OA contribution (approximately 23% of gross) and a near-ceiling repayment (30% of gross) is approximately 7% of gross income in cash, every month, for the loan tenure. Calculate this before you commit.
3. Not Accounting for the Renovation Loan
BTO flats need renovation. Resale flats often need extensive renovation. Typical renovation costs in Singapore range from S$30,000 for a basic 4-room to S$80,000+ for a premium fit-out. Many buyers finance this through a renovation loan — which adds another S$500–S$1,200/month in repayments on top of the mortgage, often for three to five years immediately after purchase.
4. Over-Relying on CPF OA Growth
Some buyers underestimate how quickly CPF OA gets depleted when both monthly contributions and the mortgage draw on the same account. If monthly contributions are insufficient to cover the full repayment, the OA balance decreases over time, eventually requiring full cash top-up well before loan maturity.
5. Not Running the Stress Test
Rates are not static. A mortgage that works comfortably at 2.6% may create real financial pressure at 3.6%. The stress test result in the calculator is not a worst-case warning — it is the baseline question you should be able to answer comfortably before signing.
Before you commit — check what the flat does to your full monthly budget.
Use the Cost of Living Calculator to model the mortgage cash top-up alongside all your other monthly expenses and see your real savings rate.
Cost of Living Calculator →Frequently Asked Questions
The regulatory guide is the Mortgage Servicing Ratio (MSR) of 30% of gross monthly income for HDB flat purchases. If your household earns S$8,000/month, your maximum monthly repayment is approximately S$2,400 under this guide. At 2.6% p.a. over 25 years, that supports a loan of approximately S$529,000. For comfortable affordability, most financial planners suggest targeting 25% MSR rather than the 30% ceiling — that gives approximately S$441,000 on an S$8,000 income. Use the HDB Affordability Calculator to find your specific number based on CPF, cash, and existing debts.
Partially — and often not fully, especially if your mortgage is near the MSR ceiling. For employees aged 55 and below, approximately 23% of gross ordinary wages goes to CPF OA each month. If your mortgage repayment is set at 30% of gross income, CPF OA covers roughly 23/30 of the repayment — the remainder is a cash top-up from your take-home pay. Only if your repayment is at or below your CPF OA contribution (approximately 23% of gross income) can CPF potentially cover it fully. Enter your actual CPF OA amount in the calculator to see your specific split.
It depends on your priority. The HDB loan offers rate stability (pegged to CPF OA rate + 0.1%, currently 2.6%), no minimum cash downpayment, no lock-in period, and no TDSR application. Bank loans may offer lower initial rates but introduce variable rate risk, minimum cash downpayment of 5%, lock-in periods with prepayment penalties, and full TDSR application. For first-time buyers who value predictability and want to avoid a cash downpayment requirement, the HDB loan is often the lower-risk choice. For buyers with strong cash reserves and the ability to manage refinancing, a bank loan may be worth exploring — but always compare the full-tenure cost, not just the initial rate.
At 75% LTV, a S$1 million property requires a S$750,000 loan. At 2.6% p.a. over 25 years, the monthly repayment is approximately S$3,403. At 30% MSR, the household income needed is approximately S$11,343/month gross. At the safer 25% MSR threshold, the income needed is approximately S$13,612/month gross. Note that for new HDB flats, a household income ceiling applies — households earning above S$14,000/month combined are generally not eligible for new HDB flats. Resale HDB flats have no income ceiling. The S$1M range is typically relevant for resale flats in mature estates or executive flats.
On a standard HDB loan at 2.6% over 25 years: a S$300,000 loan accumulates approximately S$108,000 in total interest; a S$500,000 loan accumulates approximately S$180,400; a S$700,000 loan accumulates approximately S$252,700. At a bank loan rate of 3.5% over 30 years, the same S$500,000 loan accumulates approximately S$308,000 in interest — nearly 62% of the principal, paid in addition to repaying the loan itself. Total interest is one of the most important numbers in any mortgage decision, and it scales significantly with both rate and tenure.
If your CPF OA contributions are insufficient to cover the full monthly repayment, the shortfall must come from cash. If you cannot cover it consistently, your CPF OA balance will deplete over time, eventually requiring full cash top-up before the loan ends. Sustained inability to service the mortgage can lead to arrears, and in severe cases, HDB may take action including compulsory sale of the flat. This is why modelling the cash top-up before purchasing — not after — is critical. If your current CPF OA and cash budget together cannot comfortably cover the monthly repayment, the loan is too large for your current financial position.
A longer tenure reduces the monthly repayment but increases total interest paid — always. On a S$500,000 loan at 2.6%: a 20-year tenure costs approximately S$2,703/month but S$148,700 in total interest. A 25-year tenure costs approximately S$2,268/month but S$180,400 in total interest. A 30-year tenure (bank loan) costs approximately S$1,981/month but S$213,200 in total interest. The 30-year loan saves you S$722/month versus the 20-year loan but costs you S$64,500 more in total interest. Whether that trade-off is worth it depends entirely on your cash flow situation — there is no universally right answer.
Your Next Steps
The mortgage calculator tells you the cost of a specific loan. Three other calculators complete the picture.
HDB Affordability Calculator
If you haven’t found a flat yet — this tells you the maximum price and safer range based on your income, CPF, and cash.
CPF Take-Home Calculator
Find your exact take-home pay after CPF. This is the cash baseline your mortgage top-up and all other expenses draw from.
Cost of Living Calculator
Enter all monthly expenses including the mortgage cash top-up. See your real savings rate and whether the flat fits your life.
Stop guessing. Start knowing.
Eight calculators built around how Singapore actually works — CPF, HDB, cars, cost of living, savings. Your real numbers, in under five minutes.