§ 01 / TOOL
$350,000 at 6.5% for 15y.
STATUS ACTIVETYPE FIXEDLATENCY <1MS
> INPUT
MODE FIXED RATE
// LOAN AMOUNT
$
// RATE
%
// TERM
yrs
// EXTRA / MO (OPTIONAL)
$
MONTHLY PAYMENT.
P & I
// RESULT
$3,048.88
// TOTAL PAID
$548,798
// INTEREST
$198,798
// PAYOFF
15y
// LOAN
$350,000 @ 6.5% for 15 years
A $350,000 loan at 6.5% for 15 years costs $3,048.88/month. Total interest paid: $198,798.
§ 02 / ABOUT
How a fixed-rate mortgage works.
A fixed-rate mortgage is a loan with a constant interest rate and a monthly payment that amortizes the balance to zero over the term — usually 15 or 30 years. Your payment stays the same; what changes month to month is how it splits between interest and principal.
// THREE NUMBERS THAT MATTER
- Monthly payment (P&I) — principal + interest only. Taxes, insurance, and HOA are separate.
- Total interest paid — at 7% on a 30-year $400k loan, you pay roughly $560k in interest alone.
- Amortization curve — early payments are almost all interest. It takes years before most of the payment touches principal.
// THE POWER OF EXTRA PRINCIPAL
A small extra principal payment each month compounds dramatically. Add $200/month to a 30-year loan and you'll typically pay it off 4–6 years early and save tens of thousands in interest. The extra payment calculator below shows the exact numbers.
Related: Rent vs Buy, Auto Loan, Compound Interest.
§ 02 / FAQ
Questions. Answered.
How is a mortgage payment calculated?+
A fixed-rate mortgage uses the formula M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1], where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12 ÷ 100), and n is the total number of monthly payments (years × 12). The result is the level payment that amortizes the loan over its term.
What does this calculator include?+
This is a principal-and-interest (P&I) calculator for fixed-rate loans. It does not include property taxes, homeowners insurance, PMI, or HOA dues — your actual escrowed monthly payment will be higher. For a complete housing cost, add estimated tax + insurance + HOA on top of the number shown here.
What is amortization?+
Amortization is the gradual payoff of a loan through regular payments. Early on, most of each payment is interest; late in the loan, most is principal. The schedule below the result shows how that shift happens year by year — useful if you’re deciding whether to pay extra or refinance.
How do I handle a down payment?+
Enter the loan amount (purchase price − down payment), not the purchase price. If you’re buying a $500,000 house with 20% down ($100,000), enter $400,000 as the loan amount.
Does extra principal matter?+
A lot. Paying extra principal early shortens the term and saves enormous interest because you’re knocking out future compounding. Even $100/month extra on a 30-year loan can save years and tens of thousands in interest. Use the EXTRA / MO field above to model it — the schedule and savings update live.
Does the URL update so I can share or bookmark a calculation?+
Yes. As you type, the URL updates to /mortgage/400000-6.5-30 (loan-rate-years). Copy the URL bar to share, or use the SHARE button in the answer bar.
§ 04 / TOOLS
Related calculators.
§ 05 / READING