This Is Money Mortgage Calculator

This mortgage calculator helps you estimate your monthly payments, total interest costs, and loan affordability. Whether you're a first-time homebuyer or looking to refinance, this tool provides clear insights into your mortgage options.

How to Use This Calculator

To get accurate mortgage estimates, follow these steps:

Enter the loan amount you're requesting
Select your loan term (typically 15, 20, or 30 years)
Input your current interest rate
Choose between monthly and bi-weekly payments
Click "Calculate" to see your results

The calculator will display your estimated monthly payment, total interest paid over the life of the loan, and the total amount paid (principal + interest).

Mortgage Payment Formula

The standard mortgage payment formula is:

M = P [i(1 + i)ⁿ] / [(1 + i)ⁿ - 1]

Where:

M = Monthly payment
P = Principal loan amount
i = Monthly interest rate (annual rate divided by 12)
n = Number of payments (loan term in years × 12)

This formula calculates the fixed monthly payment required to fully amortize a loan over its term.

Example Calculation

Let's calculate a $200,000 mortgage at 4.5% interest over 30 years:

Principal (P) = $200,000
Annual interest rate = 4.5% or 0.045
Monthly interest rate (i) = 0.045/12 = 0.00375
Number of payments (n) = 30 × 12 = 360

Plugging these into the formula:

M = $200,000 [0.00375(1 + 0.00375)³⁶⁰] / [(1 + 0.00375)³⁶⁰ - 1]

M ≈ $1,073.64 per month

Over 30 years, you would pay approximately $386,090 in total, with $186,090 going toward interest.

Interest-Only Loans

Interest-only loans require you to pay only the interest each month until the end of the loan term. The principal remains unpaid until the loan matures.

Interest-only payments are typically lower than amortizing payments but require you to pay the full principal at the end of the term.

For a $200,000 interest-only loan at 4.5%:

Monthly payment = $7,500 (4.5% of $200,000)
Total interest paid over 30 years = $270,000
Total amount paid = $470,000

Mortgage Affordability

Lenders typically recommend that your mortgage payment should not exceed 28% of your gross monthly income, with total debt payments (including mortgage, credit cards, etc.) not exceeding 36% of your income.

Maximum monthly payment = (Gross monthly income × 28%) / 100

Maximum total debt payments = (Gross monthly income × 36%) / 100

For example, if your gross monthly income is $5,000:

Maximum mortgage payment = $1,400
Maximum total debt payments = $1,800

Frequently Asked Questions

What is a mortgage payment?

A mortgage payment is the amount you pay each month to your lender to repay your home loan. This payment typically includes principal (the amount reducing your loan balance) and interest (the cost of borrowing).

How is mortgage interest calculated?

Mortgage interest is calculated based on the outstanding loan balance and the current interest rate. The most common method is simple interest for interest-only loans and amortized interest for traditional mortgages.

What factors affect mortgage payments?

Several factors influence your mortgage payment, including the loan amount, interest rate, loan term, and whether you choose a fixed or variable rate. Additional costs like property taxes and insurance may also apply.

Can I pay off my mortgage early?

Yes, you can pay off your mortgage early without penalty in most cases. Early repayment can save you money on interest and reduce your overall loan term. Check with your lender for specific terms.

What is a good mortgage rate?

A good mortgage rate depends on current market conditions, but generally, rates below 4% are considered excellent, 4-5% are good, and above 5% may be considered high. Always compare rates from multiple lenders.