Free mortgage calculator: estimate monthly payments, total interest, and full amortization schedule. Compare 15-year vs 30-year loans, see PMI and tax impact. Make informed home buying decisions.
The mortgage calculator helps you estimate monthly payments based on home price, down payment, interest rate, and loan term. It supports Equal Payment (fixed monthly payment) and Equal Principal (declining payments). The full amortization schedule shows how each payment splits between principal and interest over time.
Key concepts: Amortization spreads a loan into fixed payments over time. Early payments are mostly interest; later payments are mostly principal. PMI (Private Mortgage Insurance) is required when your down payment is below 20%. Use the extra payment feature to see how additional payments can save interest and shorten your loan term.
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Decision Reference: Key Factors in Your Mortgage Decision
This calculator helps you understand how four main variables affect your mortgage. Adjusting any one of them changes your monthly payment, total interest, and payoff timeline.
1. Down Payment A larger down payment reduces your loan amount and may eliminate PMI (Private Mortgage Insurance). Putting 20% or more down typically removes the PMI requirement, saving hundreds per month. Even an extra 5% can meaningfully reduce your total interest cost over the life of the loan.
2. Interest Rate The interest rate is the single biggest factor in your total mortgage cost. A 1% rate reduction on a $350,000 loan can save over $60,000 in interest over 30 years. Use the amortization schedule to see how much of each payment goes to interest — especially in the early years.
3. Loan Term A 30-year term offers lower monthly payments but costs significantly more in total interest. A 15-year term roughly doubles your monthly payment but can cut total interest by more than half. Choose the shortest term you can comfortably afford, and consider making extra payments to shorten the term further.
4. Extra Payments Adding even a small extra payment each month goes almost entirely to principal, accelerating your payoff and saving substantial interest. For example, adding $100/month to a $350,000 loan at 6.5% can save tens of thousands in interest and shave years off your mortgage. The breakdown chart shows how extra payments shift the balance from interest to principal over time.
Frequently Asked Questions
What affects my monthly mortgage payment?
Your monthly payment is primarily determined by the loan amount, interest rate, and loan term. A higher down payment reduces the loan amount and thus the monthly payment.
Should I choose a 15-year or 30-year mortgage?
A 15-year mortgage has higher monthly payments but you pay significantly less interest overall. A 30-year mortgage has lower monthly payments but more total interest.
What is the difference between Equal Payment and Equal Principal?
Equal Payment (等额本息) keeps your monthly payment the same throughout the loan term, with interest decreasing and principal increasing over time. Equal Principal (等额本金) keeps the principal portion fixed, so your total payment decreases over time. Equal Principal results in less total interest but higher initial payments.
When do I need to pay PMI?
PMI (Private Mortgage Insurance) is typically required when your down payment is less than 20% of the home price. It protects the lender in case of default. PMI can usually be canceled once you reach 20% equity in your home.