How is a mortgage instalment split between principal and interest?

Each month, interest is charged on the remaining balance; the rest of your level instalment repays principal. Early on the balance is large, so more of the payment is interest — on a $500,000 loan at 2% over 25 years (instalment ~$2,119), roughly $830 of the first payment is interest. As the balance falls the split shifts, and the final years are nearly all principal.

How much total interest will I pay on my home loan?

It depends on rate and tenure: $500,000 at 2% over 25 years costs about $135,800 in interest — total repayment around $635,800. A longer tenure lowers the monthly instalment but increases total interest; the table shows both effects exactly.

Does this match how Singapore banks calculate repayments?

Yes — banks use the same reducing-balance method with monthly rests shown here. The one caveat is the rate: most packages are fixed for 2–3 years and then reprice, so treat the schedule beyond your lock-in as indicative at the current rate.

Why does my outstanding loan fall so slowly in the first years?

Because interest is front-loaded by the maths of a level instalment, not by bank trickery: a bigger balance accrues more interest, leaving less of each fixed payment for principal. This is also why partial prepayments early in the tenure save disproportionately more interest than the same prepayment made late.

Amortisation Table

Where every instalment actually goes

Principal versus interest, month by month and year by year — the schedule behind your mortgage statement.

The loan

Loan amount

Interest rate

Your package rate. Bank loans reprice — rerun this when yours does.Loan tenure

yrs

Up to 35 years.

Not sure what loan you qualify for?

The Affordability Assessment runs your income against the TDSR and MSR caps.

Check my loan capacity

Enter your loan amount to build the schedule.

How the schedule is computed

Singapore home loans amortise on a reducing balance with monthly rests: every month, interest accrues on the outstanding balance at the package rate ÷ 12, and the level instalment covers that interest plus a principal repayment. The instalment is set so the balance reaches exactly zero at the end of the tenure.

The practical readings: early payments are mostly interest, so your balance barely moves in the first years; prepaying early saves far more than prepaying late; and stretching tenure trades a lower monthly for materially more total interest. For what loan size your income supports in the first place, run the Affordability Assessment (TDSR/MSR); for current rate context, see our mortgage rates analysis.

Buying a new launch instead? Progressive-payment loans draw down by construction stage and amortise differently — use the New Launch Amortisation Table, which models the ramping instalment stage by stage.

Frequently asked questions

How is a mortgage instalment split between principal and interest?: Each month, interest is charged on the remaining balance; the rest of your level instalment repays principal. Early on the balance is large, so more of the payment is interest — on a $500,000 loan at 2% over 25 years (instalment ~$2,119), roughly $830 of the first payment is interest. As the balance falls the split shifts, and the final years are nearly all principal.
How much total interest will I pay on my home loan?: It depends on rate and tenure: $500,000 at 2% over 25 years costs about $135,800 in interest — total repayment around $635,800. A longer tenure lowers the monthly instalment but increases total interest; the table shows both effects exactly.
Does this match how Singapore banks calculate repayments?: Yes — banks use the same reducing-balance method with monthly rests shown here. The one caveat is the rate: most packages are fixed for 2–3 years and then reprice, so treat the schedule beyond your lock-in as indicative at the current rate.
Why does my outstanding loan fall so slowly in the first years?: Because interest is front-loaded by the maths of a level instalment, not by bank trickery: a bigger balance accrues more interest, leaving less of each fixed payment for principal. This is also why partial prepayments early in the tenure save disproportionately more interest than the same prepayment made late.

Want a second pair of eyes on these numbers?

Estimates are a starting point. Send us your numbers and we’ll sanity-check them before you commit.

WhatsApp us your numbers

Disclaimer

The tools on this page provide estimates for general reference only and do not constitute financial, legal, tax, or investment advice. Calculations are based on prevailing MAS, IRAS, HDB, and CPF rules and rates at the time of publication, which may change without notice. Actual figures — including loan eligibility, interest rates, stamp duties, and CPF usage — depend on your specific circumstances and the final assessment of banks, IRAS, and other relevant authorities. TRIBE makes no warranty as to the accuracy or completeness of any output and accepts no liability for decisions made in reliance on these tools. Please verify all figures with the relevant institutions or a qualified professional before committing to any transaction.