🏠 Mortgage Interest Calculator
Calculate mortgage interest
Enter number of payments made to see interest paid so far
How to Use This Calculator
Enter Loan Details
Input the mortgage loan amount, interest rate, and loan term (typically 15 or 30 years).
Enter Months Paid (Optional)
Optionally enter how many payments you've made to see interest and principal paid so far.
Review Interest Analysis
See total interest over the loan term, first year interest, first month interest, and interest paid so far (if months paid entered).
Formula
Monthly Payment = P × [r(1 + r)ⁿ] / [(1 + r)ⁿ - 1]
Monthly Interest = Outstanding Balance × (Rate ÷ 12)
Example Calculation:
If loan $300,000, rate 6%, term 30 years:
• Monthly payment: ~$1,799
• First month interest: $300,000 × (6% ÷ 12) = $1,500
• First year interest: ~$17,900
• Total interest (30 years): ~$347,515
About Mortgage Interest Calculator
A mortgage interest calculator helps you understand how much interest you'll pay over the life of your mortgage. Mortgages are amortized loans, meaning early payments are mostly interest and later payments are mostly principal. This calculator shows you total interest over the loan term, first year interest, first month interest, and interest paid at any point in the loan. Understanding mortgage interest helps you see the true cost of homeownership and make informed decisions about extra payments and refinancing.
When to Use This Calculator
- Mortgage Planning: Understand total interest costs before taking a mortgage
- Interest Analysis: See how much interest you'll pay over time
- Refinancing: Calculate interest paid so far before refinancing
- Extra Payments: Understand interest savings from extra payments
Understanding Mortgage Interest
- Amortization: Interest front-loaded in early payments
- Early Payments: Mostly interest, little principal reduction
- Later Payments: Mostly principal, less interest
- Total Interest: Can be substantial over 30 years
Why Use Our Calculator?
- ✅ Total Interest: See total interest over loan term
- ✅ Time Analysis: See interest at different time points
- ✅ Interest Tracking: Track interest paid so far
- ✅ Cost Awareness: Understand true cost of mortgage
- ✅ 100% Free: No registration or payment required
Frequently Asked Questions
How much interest will I pay on my mortgage?
Total interest depends on loan amount, interest rate, and term. For example, a $300,000 mortgage at 6% for 30 years results in approximately $347,515 in total interest - more than the original loan amount! Use this calculator to see your specific interest costs.
Why do I pay so much interest in the early years?
Mortgages are amortized, meaning interest is calculated on the outstanding balance. Early in the loan, the balance is high, so interest is high. As you pay down principal, the balance decreases, so interest decreases. This is why early payments are mostly interest and later payments are mostly principal.
How can I reduce mortgage interest?
Reduce mortgage interest by: (1) Making extra principal payments, (2) Choosing a shorter loan term (15 vs. 30 years), (3) Refinancing to a lower rate, (4) Making bi-weekly payments, (5) Making a larger down payment to reduce loan amount.
Is mortgage interest tax deductible?
Mortgage interest may be tax deductible, subject to certain limits and conditions. The Tax Cuts and Jobs Act limits the mortgage interest deduction to loans up to $750,000 (or $1 million for loans taken before 2018). Consult a tax professional for advice on your specific situation.