How the mortgage calculator works
Loan principal is house price minus down payment. Then we use annual rate and term to estimate the monthly installment.
Reducing balance assumes interest is charged on the remaining balance each month, similar to typical amortizing home loans.
Flat rate is a simplified marketing-style estimate: total interest for the term is spread evenly across months and may not match true reducing-balance math.
Example calculation
House THB 3,500,000 with THB 700,000 down → THB 2,800,000 financed. At 5.5% per year over 30 years, compare reducing vs flat to see payment and total interest differences.
Frequently asked questions
- Is mortgage interest usually reducing balance or flat rate?
- Most real home loans use reducing balance interest, which charges interest on the remaining loan balance. Flat rate is more of a simplified comparison style and is less common for actual mortgage repayment.
- Does this home loan calculator include MRTA, transfer fees, or bank fees?
- No. This calculator focuses on house price, down payment, interest rate, and loan term only. Costs such as MRTA, appraisal fees, transfer fees, and bank charges need to be added separately.
- Why is my bank’s mortgage quote different from this estimate?
- Banks may use promotional rates, floating rates after a fixed period, different fee structures, or more detailed repayment assumptions. This tool is best used as a simple monthly mortgage estimate.
- How much down payment should I prepare for a home loan?
- That depends on the property price, lender policy, and your approved loan-to-value ratio. In practice, you should plan for both the down payment and other upfront housing costs, not the down payment alone.
- Can I use this with my monthly salary to check affordability?
- Yes. Start with your estimated net monthly income, then compare it with the monthly home payment here. It is a practical way to see whether the mortgage may fit your budget before you talk to a bank.