Mortgage Calculator
Calculate your monthly payments and view your complete amortization schedule.
What this calculator does
Calculating your monthly mortgage payment is the most crucial step before buying a home. Simply enter your loan principal, annual interest rate, and loan term. This tool instantly applies the standard amortization formula to calculate your fixed monthly payment, total repayment amount, and total interest paid. It also generates a complete 360-month amortization schedule, allowing you to clearly see the principal and interest breakdown over time. This offers a neutral baseline to compare quotes from different major banks.
Formula & how it works
M = P × r × (1+r)^n ÷ ((1+r)^n − 1). P is principal, r is monthly rate (annual rate ÷ 12), and n is total months. Interest decreases while principal repayment increases over time, keeping the total payment fixed.
Worked examples
- Example 1: HKD 8M ($1M USD approx) first home mortgage over 25 years at 3.5% results in a monthly payment of roughly HKD 40,051 and total interest around HKD 4.01M.
- Example 2: A TWD 12M ($380K USD approx) loan over 30 years at 2.1% means a monthly payment of TWD 44,865 and total interest of TWD 4.15M.
Frequently asked questions
- Why might a real bank quote differ slightly?
- Our calculator focuses on pure principal and interest. It excludes origination fees, home insurance, property taxes, and variable rate tiers.
- How much does a 0.5% rate increase cost?
- For an HKD 8M loan over 25 years, a rate hike from 3.5% to 4.0% adds about HKD 1,170 to your monthly payment and roughly HKD 350,000 to total interest over the term.
- What is the difference between standard amortization and fixed principal payments?
- Standard amortization offers a fixed monthly payment. Fixed principal payments start higher but decrease over time, ultimately saving on total interest.