15 vs 30 Year Mortgage Cost Calculator
Compare a 15-year and a 30-year mortgage side by side: monthly payment with taxes, insurance, PMI and HOA, total interest, closing costs, balance and equity over time, paying a 30-year on a 15-year schedule, and investing the payment difference.
How it works
Payment = P·r ÷ (1 − (1+r)^−n), r = annual rate ÷ 12, n = 180 or 360 · Total interest = payment × n − principal · Monthly housing cost = payment + tax/12 + insurance/12 + HOA + PMI · Total cost = principal + interest + PMI + closing costs
A 15-year mortgage almost always carries a lower rate than a 30-year, and it repays principal in half the time. Both effects cut total interest, often by more than half. The catch is a much larger monthly payment. This comparison sets the payment gap against the interest saved so you can judge whether the higher commitment fits your budget. Under More options you can add property tax, insurance and HOA fees to see the full monthly housing cost, and add a home value and PMI rate. PMI is charged until the balance falls to 78% of the home value, which a 15-year loan reaches years sooner. Closing costs and points for each loan count in the total cost. If you expect to sell or refinance early, enter the years you will keep the loan to see the interest paid and balance left at that point. Two extra views help with the decision. One is a 30-year loan paid on a 15-year schedule: you keep the lower required payment but pay the higher rate. The other is the "invest the difference" comparison, which spends the same amount each month in both plans. The yearly table and chart show how fast each balance falls.
Worked example
On a $300,000 loan, a 15-year at 5.75% costs about $2,491 a month with roughly $148,000 total interest. A 30-year at 6.5% costs about $1,896 a month but around $383,000 in interest. The 15-year asks $595 more each month yet saves close to $235,000 over the life of the loan. After 5 years the 15-year balance is about $227,000 against $281,000 on the 30-year. Paying $2,491 a month on the 30-year loan instead would clear it in 16 years 4 months, with about $187,000 interest — $39,000 more than the true 15-year.
Sources: CFPB — Choosing a loan term · CFPB — When can I remove PMI?
Frequently asked questions
Why is the 15-year rate usually lower?
Lenders take on less risk over a shorter term and get their money back faster, so they charge less. A 15-year rate is often 0.5 to 0.75 percentage points below the 30-year rate, which compounds the interest savings.
Can I get 15-year savings with a 30-year loan?
Partly. Taking a 30-year loan and paying it off on a 15-year schedule cuts the term and interest, and keeps flexibility to drop to the lower required payment in a tight month. But you keep the higher 30-year rate, so you save less than a true 15-year loan. Turn on the 15-year-schedule option under More options to see how much less.
Is the 15-year always the better deal?
On pure interest, yes. But the larger payment leaves less for investing, emergencies or other goals. If you can earn more investing the payment difference than the mortgage rate, a 30-year plus investing can build more wealth despite the higher interest. Turn on the investing comparison to test your own return assumption, remembering that returns are not guaranteed.
What if I sell or refinance before the loan ends?
Most mortgages do not run to the end. Enter the years you expect to keep the loan and the calculator shows the interest paid and the balance left on each loan at that point. The 15-year still saves interest and builds equity faster, but the gap is smaller than the full-term figures suggest.
Does the 15-year help with PMI?
Yes. PMI usually stops once the balance reaches 78% of the home’s original value, and the 15-year loan pays principal down much faster, so it gets there years earlier. Enter the home value and PMI rate to see the difference.
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This is an educational estimate, not financial advice. Real results depend on rates, taxes, fees and market returns that no calculator can guarantee — confirm figures with your lender or a licensed advisor.