Mortgage Calculator

How to Use

Calculate Mortgage Amount and Monthly Payment

Enter the loan amount, loan term, and interest rate, then click the calculate button to get the monthly payment and total repayment amount. For combined loans, you can enter different interest rates and terms separately, then click calculate to get the monthly payment and total repayment amount.

Calculate Repayment Plan After Interest Rate Change

Check your current remaining balance and remaining term at the bank, then enter the new interest rate and click calculate to get the new monthly payment and total repayment amount. The term provided by the bank is usually in months, so make sure to set the loan term unit to "months". You can paste the results into Excel for comparison and recalculation.

Calculate Early Repayment Plan

Check your current remaining balance and remaining term at the bank, subtract the intended repayment amount from the principal to calculate the monthly payment situation after early repayment. You can paste the results into Excel for comparison and recalculation.

Mortgage Knowledge

The monthly interest on a mortgage is the interest generated on all principal for that month. The amount beyond interest payment goes toward principal repayment. Therefore, the monthly payment must be greater than the interest generated on all principal for that month, otherwise it would be impossible to repay. Thus, mortgage interest is simple interest, not compound interest. With equal principal payments, the monthly principal repayment is fixed, so the monthly interest payment decreases. With equal installment payments, the monthly payment remains the same, with interest taking up a larger portion in the early stages and principal taking up a larger portion in the later stages, resulting in relatively higher total interest.

Differences Between Equal Payment and Equal Principal

Equal Payment

• Same monthly payment amount
• Higher interest portion in early stages
• Higher principal portion in later stages
• Relatively higher total interest

Equal Principal

• Fixed monthly principal repayment
• Decreasing monthly total payment
• Higher payment burden in early stages
• Relatively lower total interest

Mortgage Calculation Formulas

Equal Payment Monthly Payment Formula

Monthly Payment = Loan Amount × Monthly Rate × (1 + Monthly Rate)^Number of Months ÷ [(1 + Monthly Rate)^Number of Months - 1]

Equal Principal Monthly Payment Formula

Monthly Payment = (Loan Amount ÷ Number of Months) + (Remaining Balance × Monthly Rate)

Selection Advice

1. If you prioritize stable monthly payments, equal payment is recommended
2. If you want to pay less interest and can handle higher payments in the early stages, equal principal is recommended
3. For early repayment plans, equal principal method saves more interest