How it works
Enter the home or condo price, down payment, annual interest rate and term. You get the monthly payment on the reducing-balance method banks use, total interest and a yearly schedule. Planning to pay extra? Enter a monthly amount to see how much sooner you finish.
Formula
Payment = loan × r ÷ (1 − (1 + r)−n), where r = annual rate ÷ 12 and n = number of months
Each month’s interest = remaining balance × r. The rest of the payment reduces the principal.
Income needed ≈ payment ÷ 40%
How is home loan interest calculated?
Thai home loans use the reducing-balance method: each month’s interest is charged on the principal still owed. The payment stays the same every month, but the mix changes. Early payments are mostly interest; later ones are mostly principal.
Real Thai mortgage rates usually come in steps, such as a promotional rate for the first 3 years, then a floating rate (MRR minus a discount). For a long-term estimate, use the bank’s 3-year average or the post-promotion rate, which is closer to reality than the first-year rate.
Monthly payment per 1 million baht borrowed
| Average rate | 20 years | 25 years | 30 years | 35 years |
|---|---|---|---|---|
| 3% | 5,546 | 4,742 | 4,216 | 3,849 |
| 4% | 6,060 | 5,278 | 4,774 | 4,428 |
| 5% | 6,600 | 5,846 | 5,368 | 5,047 |
| 6% | 7,164 | 6,443 | 5,996 | 5,702 |
| 7% | 7,753 | 7,068 | 6,653 | 6,389 |
For 2 million, multiply by 2; for 3.5 million, multiply by 3.5.
Longer terms: smaller payments, more interest
Borrowing 1 million at 5% over 20 years costs about 584,000 baht in interest. Over 35 years it costs about 1,120,000 baht, almost double, even though the monthly payment differs by only 1,550 baht.
A common approach is to take a long term to keep the minimum payment low, then pay extra when you can. You get flexibility and still save interest.
How much does paying extra help?
Borrow 2 million at 5% over 30 years: the payment is 10,736 baht and total interest about 1.87 million. Pay an extra 2,000 baht a month and the loan ends in 21 years 4 months, saving about 612,000 baht of interest.
Before a large extra payment or closing the loan, check your contract for a prepayment fee. The Bank of Thailand bans this fee on most consumer loans, but home loans may still charge it only in the first 3 years from the contract date. The rate depends on the bank: for example, Government Savings Bank charges 3% of the remaining principal if you redeem the mortgage to move to another lender within 3 years. After year 3 is when most people refinance.
How much income do you need?
Banks look at your debt service ratio (DSR). Most want all loan payments together to stay under about 40% of monthly income, so this calculator estimates the income needed as payment ÷ 0.4. Existing car loans or credit card debt reduce how much you can borrow.
Other costs to plan for
- Down payment — depends on how much the bank will lend against the property value and on the developer’s terms
- Transfer and mortgage registration fees at the Land Department
- Valuation fee and fire insurance, plus loan insurance if you choose it
- Common fees for condos and housing estates
Home loan interest is tax deductible up to 100,000 baht a year. Enter it in the income tax calculator to see the tax you save.
FAQ
What is the monthly payment on a 1 million baht loan?
At an average 6% a year over 30 years, about 5,996 baht a month. At 4%, about 4,774 baht. Lower rates or longer terms mean smaller payments, but a longer term costs more interest overall.
How much do I need to earn to get a home loan?
Most Thai banks want total debt payments under about 40% of income, so this calculator estimates the income needed as payment ÷ 0.4. The real figure depends on the bank, your job and other debts.
How much does paying extra help?
Every extra baht goes straight to principal, so next month’s interest is lower and the loan ends years earlier. Enter an amount in "Extra payment each month" to see the interest saved.
Why do early payments go mostly to interest?
Interest is charged on the remaining balance. Early on the balance is high, so most of each payment is interest. As the balance falls, more goes to principal. See the yearly schedule.
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