Tools

Mortgage affordability calculator

See the likely monthly instalment, mortgage size, and property budget before you start speaking to banks or agents.

Simple mode

Quick repayment estimate

Enter mortgage amount, rate and tenure for a fast monthly estimate.

Mortgage amount

Enter the loan amount in full dollars (e.g. 900000 for $900,000)

Interest rate

Annual rate as a percentage (e.g. 3.20)

Tenure (years)

Max 30 yrs bank / 25 yrs HDB

Result

Summary

Estimate

Monthly instalment

$4,362

$900,000 at 3.20% over 25 yrs

Total interest

$408,633

Total repayment

$1,308,633

Simple mode does not check income eligibility, LTV limits, stamp duty, or downpayment. Switch to advanced mode for a full affordability check.

Mortgage amount$900,000

Rate used3.20% p.a.

Tenure25 years

Total repayment$1,308,633

Mortgage breakdown

How your mortgage gets paid down

The red line shows remaining principal over time. Stacked bars show how each monthly instalment splits between principal and interest.

Amortisation

Your entered rate

$900,000 over 25 years at 3.20% p.a.

Monthly

$4,362

3.20% p.a.

PrincipalLoan paidInterest paid

First payment

$4,362

Split: 45% principal / 55% interest

Half paid by

Year 15

Balance then: $447,457

Halfway through

$538,704 left

At Year 13

Total interest

$408,633

Total paid: $1,308,633

Simple reading: early payments usually contain more interest. Later payments contain more principal. In this chart, interest share moves from 55% at the start to 0% near the end.

Amortisation

2.6% fixed-rate reference

$900,000 over 25 years at 2.60% p.a.

Monthly

$4,083

2.60% p.a.

PrincipalLoan paidInterest paid

First payment

$4,083

Split: 52% principal / 48% interest

Half paid by

Year 15

Balance then: $449,791

Halfway through

$522,411 left

At Year 13

Total interest

$324,908

Total paid: $1,224,908

Simple reading: early payments usually contain more interest. Later payments contain more principal. In this chart, interest share moves from 48% at the start to 0% near the end.

Mortgage basics

Before you choose a mortgage

A calculator tells you the monthly number. The harder part is knowing what kind of mortgage risk you are taking. Start with simple mode if you already know your mortgage amount. Use advanced mode when you want to include property price, downpayment, property type, mortgage type, and the optional historical SORA backtest.

Fixed vs floating

Fixed rates are easier to plan. Floating rates need monitoring.

Simple mode assumes the rate you enter stays fixed across the mortgage schedule. That makes it good for a quick repayment check. A floating-rate package can move over time, so your future instalments may rise or fall.

Fixed rate

More predictable. Easier to budget. Usually less scary if rates rise.

Floating rate

Can benefit when rates fall, but repayment can become painful when rates rise.

SORA packages

If your package is SORA + spread, both parts matter.

SORA is commonly used as the reference rate for Singapore-dollar floating mortgage packages. For many floating packages, the practical mortgage rate is the selected SORA rate plus the bank spread. The backtest chart is not a forecast; it simply shows how a mortgage would have behaved using past SORA rates.

Simple formula: mortgage rate = SORA + bank spread

Reading the graph

Early payments feel slow because more money goes to interest.

Mortgage interest is commonly calculated on a reducing balance. In the early years, a larger share of each instalment usually goes to interest. Later, more of the same monthly payment goes toward reducing the remaining mortgage balance.

Remaining principal shows how much mortgage is still unpaid.
Principal paid is the part that reduces your mortgage.
Interest paid is the cost of borrowing for that month.

HDB vs bank mortgage

HDB mortgages are stable. Bank mortgages can be cheaper, but need more attention.

The HDB concessionary mortgage rate is currently 2.6% per annum. That makes it useful as a stable reference. Bank mortgages may offer attractive promotional rates, but you need to watch lock-in periods, repricing, refinancing, and what happens when the promotional rate ends.

Use the comparison chart as a sanity check: not just “which rate is lower today”, but “which repayment path can I live with if life gets messy?”