What this tool does
This mortgage calculator works out your monthly payment, total interest and total cost from the loan amount, annual rate and term — and compares equal-installment with equal-principal repayment.
The two methods differ a lot in total interest: on the same loan, equal-principal usually costs less interest but demands noticeably higher payments in the early years. Work it out before signing, not after.
The calculation runs in your own browser; the amounts you enter are never uploaded.
How to use
- Enter three numbers Loan amount, annual rate (%) and term in years. A rate of 0 is allowed — subsidised or provident-fund loans really do occur.
- Pick a repayment method Equal installment: a constant monthly payment, mostly interest at first. Equal principal: payments decrease month by month, heavier early on but less total interest.
- Read the result Press Calculate to get the first and last monthly payment, the monthly decrease, total interest and total cost. Copy or download the report to keep it.
FAQ
Which method is better?
On total interest alone, equal principal is cheaper because you repay principal faster. But its early payments are higher, demanding more cash flow. Pick equal installment for stable, lighter early payments; pick equal principal if you plan to prepay or expect income to fall.
Why doesn’t this match my bank?
This uses the standard annuity formulas only. It excludes drawdown-date differences, rate resets, prepayments, insurance and fees. Your bank’s repayment schedule is authoritative.
Can it model prepayment?
Not yet. Prepayment requires recalculating the remaining balance and choosing between shortening the term or lowering the payment, and each bank has its own rules — this tool does not model that.
Does a 0% rate break it?
No. At 0% both methods reduce to splitting the principal evenly. That branch is handled explicitly, so there is no division by zero and no NaN.
Does it work for provident-fund loans?
Yes, as long as you know the annual rate. Provident-fund loans often carry low or subsidised rates — enter the actual rate; 0 works fine too.
Is anything I enter uploaded?
No. Everything is computed locally in your browser and disappears when you close the page. There is no server-side storage.
Limits
This is a theoretical calculation using the standard annuity formulas. It is not financial or legal advice and cannot replace the repayment schedule issued by your bank.
It excludes drawdown-date differences, rate resets, prepayments, insurance, fees and local policy variations.
Accepted ranges: amount 1,000–100,000,000; annual rate 0–30%; term 1–40 years. Values outside these ranges are rejected with a message.