15-Year Mortgage Calculator

Last updated: August 2026 • Rates reflect Freddie Mac PMMS averages

The quick answer: At 6.5% interest, a 15-year $300,000 mortgage costs about $2,614 a month — vs $1,896 for a 30-year loan.

Use the 15-Year Mortgage Calculator below — modify the values and click Calculate to see your monthly payment.

$
Please enter a valid home price.
$
Down payment cannot exceed home price.
%
Please enter a valid interest rate (0.1–30%).
years
$
$
Total Monthly Payment
$0
Principal & Interest
$0

Loan Summary (15-Year)

Loan Amount$0
Total Interest Paid$0
Total of Payments$0
Payoff Date

30-Year Comparison

30-Yr Monthly P&I$0
30-Yr Total Interest$0
Interest Saved$0
Payment Difference$0

Amortization Schedule (Year-by-Year)

YearPrincipal PaidInterest PaidBalance Remaining

How to Use This 15-Year Mortgage Calculator

  1. Enter the Home Price — the full purchase price of the property.
  2. Set your Down Payment — enter the dollar amount you plan to put down. The loan amount is home price minus down payment.
  3. Enter the Annual Interest Rate — the current national 15-year average is about 6.1% (mid-2026). A 15-year loan usually carries a lower rate than a 30-year.
  4. Optionally add Property Tax and Home Insurance to see your total out-of-pocket monthly cost.
  5. Click "Calculate Payment" to see your monthly payment, total interest, payoff date, and a side-by-side comparison with a 30-year mortgage.

15-Year vs 30-Year Mortgage: The Real Difference

The most important number on this page is the total interest saved. Because you repay the loan in half the time, far less interest compounds along the way — and because 15-year loans carry lower rates, the savings stack even higher.

Factor15-Year Mortgage30-Year Mortgage
Monthly Payment ($300K loan)~$2,548~$1,956
Total Interest ($300K loan)~$159,000~$404,000
Interest Rate (avg. 2026)~6.1%~6.8%
Equity After 5 Years~$72,000~$27,000
Years Until Paid Off1530

Example: On a $320,000 loan at 6.1%, your 15-year payment is $2,718/month with $169,200 in total interest. On the same amount at 6.8% over 30 years, the payment is $2,086/month but total interest balloons to $431,000 — over $261,800 more. The 15-year route is cheaper overall if you can swing the higher monthly payment.

How the 15-Year Payment Is Calculated

15-year mortgages use the same standard amortization formula as any fixed-rate loan:

M = P × [ r(1 + r)^n ] / [ (1 + r)^n - 1 ]

Where:
  M = monthly P&I payment
  P = loan principal (home price - down payment)
  r = monthly interest rate = (annual rate ÷ 100) ÷ 12
  n = total payments = term in years × 12 = 180 for a 15-year loan

For a $320,000 loan at 6.1% for 15 years: r = 0.061/12 = 0.005083, n = 180. Monthly P&I = $320,000 × [0.005083 × (1.005083)^180] / [(1.005083)^180 - 1] = $2,718/month. Total paid over 15 years is $489,200, of which $169,200 is interest.

Frequently Asked Questions

Is a 15-year mortgage worth it?
A 15-year mortgage is worth it if you can comfortably afford the higher monthly payment. You pay significantly less total interest (often 60-70% less than a 30-year loan), build equity twice as fast, and typically qualify for a lower interest rate. The trade-off is a monthly payment roughly 40-50% higher than a 30-year mortgage.
How much more is a 15-year mortgage payment than a 30-year?
A 15-year mortgage payment is typically 30-50% higher than a 30-year mortgage for the same loan amount, because the same principal is repaid in half the time. For example, a $300,000 loan at 6.8% has a 30-year payment of $1,956/month versus a 15-year payment of $2,548/month at 6.1% — about 30% more per month.
How much interest do you save with a 15-year mortgage?
On a $300,000 loan, a 30-year mortgage at 6.8% costs about $404,000 in total interest, while a 15-year mortgage at 6.1% costs about $159,000 — a savings of roughly $245,000. The exact amount depends on your loan amount and the rate difference between the two terms.
Do 15-year mortgages have lower interest rates?
Yes. Lenders price shorter terms with lower rates because the lender's money is at risk for less time. Historically the 15-year fixed rate runs 0.4 to 0.8 percentage points below the 30-year rate. As of mid-2026 the national average is roughly 6.1% for 15-year versus 6.8% for 30-year (Freddie Mac PMMS).
Can you refinance a 30-year mortgage into a 15-year?
Yes, refinancing a 30-year mortgage into a 15-year term is one of the most common refinance strategies. You will need enough income to cover the higher payment, and you should compare the new rate against your current rate including closing costs. Use our refinance calculator to see your break-even point.

Data sources: Freddie Mac Primary Mortgage Market Survey (PMMS) July 2026, Consumer Financial Protection Bureau (CFPB) mortgage disclosures, HUD FHA Handbook 4000.1. Rates vary by credit score, lender, and loan size. For informational purposes only.

Free Online Calculators

Current Average Mortgage Rates (2026)

Loan TypeAvg. RateTrend
30-yr Fixed6.80%? Stable
20-yr Fixed6.50%? Stable
15-yr Fixed6.10%? Easing
5/1 ARM6.30%? Rising
10-yr Fixed6.05%? Easing

Source: Freddie Mac PMMS, July 2026. For informational purposes only.

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15-Year Mortgage Quick Facts

  • 15-year loans carry rates roughly 0.5–0.8% lower than 30-year loans.
  • You reach 50% equity in ~8 years, versus ~24 years on a 30-year.
  • If rates fall later, you can still refinance — a 15-year to an even shorter term or lower rate.
  • Homebuyers near retirement often choose 15-year terms to own free-and-clear by retirement.
  • On a $300K loan, a 15-year can save $225,000+ in interest vs a 30-year.