Mortgage Rate Calculator

A mortgage rate calculator turns three numbers – loan amount, interest rate, and term – into a clear monthly payment. You see exactly what you will owe each month before you ever talk to a lender. That instant feedback helps you set a realistic home-buying budget and compare offers.

The calculator above runs the standard amortization formula. Change any input and the monthly principal-and-interest payment updates immediately. You can also add property taxes and insurance to see the full housing cost.

How Does a Mortgage Rate Calculator Work?

Every fixed-rate mortgage follows the same math. The calculator solves for the monthly payment \(M\) that pays off the loan with exactly \(n\) equal payments at a fixed periodic interest rate:

Where:

• P = original loan principal (the amount borrowed)
• r = monthly interest rate (annual rate divided by 12, expressed as a decimal)
• n = total number of monthly payments (loan term in years × 12)

For example, a $250,000 loan at 6.75% for 30 years:

• \(P = 250{,}000\)
• \(r = 0.0675 \div 12 = 0.005625\)
• \(n = 360\)

The calculator runs this computation instantly. You enter the numbers; it returns the payment, total interest, and often a full amortization schedule.

Why Your Mortgage Rate Matters

A seemingly small rate difference reshapes your long-term cost. On a $300,000 loan over 30 years, the total interest paid varies dramatically:

A 1% increase adds over $200 to the monthly payment and nearly $73,000 in extra interest.

Lenders set your individual rate based on multiple factors:

• Credit score. A score above 760 unlocks the lowest published rates; below 620 pushes rates significantly higher.
• Down payment. A larger down payment reduces the loan-to-value ratio, often earning a rate discount.
• Loan type. Conventional, FHA, VA, and jumbo loans each carry different rate structures.
• Loan term. 15-year loans typically carry rates 0.5–1% lower than 30-year loans.
• Market conditions. The 10-year Treasury yield, inflation data, and Federal Reserve policy move rates daily.

Fixed vs. Adjustable Mortgage Rates

The calculator handles both fixed and adjustable-rate mortgages, but you need to understand the trade-offs.

Fixed-rate mortgage. The rate never changes. Your principal-and-interest payment stays identical from month 1 to month 360. This predictability makes budgeting simple and protects you if market rates rise. The trade-off: initial rates are higher than ARM starting rates.

Adjustable-rate mortgage (ARM). The loan starts with a low fixed rate for an initial period – often 5, 7, or 10 years. After that, the rate adjusts annually based on a benchmark index (such as SOFR) plus a margin. Common 5/1 or 7/1 ARMs cap how much the rate can increase per adjustment and over the loan’s life.

ARMs make sense when you plan to sell or refinance before the first adjustment. They carry more risk if you stay long-term and rates rise.

How to Use the Mortgage Rate Calculator

Three core inputs drive every calculation:

1. Loan amount. Enter the amount you plan to borrow after your down payment.
2. Interest rate. Input the annual rate a lender has quoted or the rate you want to test. The calculator uses this to derive the monthly rate.
3. Loan term. Choose the repayment period in years. Common terms are 30, 20, and 15 years.

For a more complete picture, add optional fields if the calculator provides them:

• Annual property tax. Enter your county’s effective tax rate multiplied by the home’s assessed value.
• Homeowners insurance. Annual premium divided by 12 joins the monthly payment.
• Private mortgage insurance (PMI). If your down payment is less than 20%, lenders typically require PMI, which adds a monthly cost.

The calculator outputs:

• Monthly principal and interest (P&I)
• Total monthly payment (including taxes, insurance, PMI if entered)
• Total interest paid over the full term
• Amortization schedule showing the split between principal and interest for every payment

Understanding Your Amortization Schedule

In the early years of a mortgage, most of each payment covers interest. Over time, the balance shifts toward principal. An amortization schedule shows this progression month by month.

For the $250,000 loan at 6.75% above:

• Payment 1: $1,621.50 – $215.00 toward principal, $1,406.50 toward interest
• Payment 180 (year 15): $1,621.50 – $561.78 principal, $1,059.72 interest
• Payment 360: $1,621.50 – $1,612.22 principal, $9.28 interest

Seeing the schedule helps you evaluate extra payments. An additional $100 per month toward principal on this loan saves about $48,000 in interest and pays off the loan nearly 6 years early.

Current Mortgage Rate Trends (2026)

Rates have moderated from the 2023–2024 peaks but remain elevated by historical standards. As of April 2026, the average 30-year fixed mortgage rate in the United States is approximately 6.85%, while the 15-year fixed rate averages 6.12%, according to the Freddie Mac Primary Mortgage Market Survey. Adjustable-rate mortgages, such as the 5/1 ARM, average around 6.30%.

Rates shown are national averages and for illustrative purposes only. Your actual rate will depend on credit profile, loan characteristics, and the lender’s pricing on the day you lock.