Loan & Mortgage Calculator

Calculate loan payments and amortization schedule.

Loan Details
Months Years
Payment Summary

Monthly Payment

$1,264.14

Total Payment $455,085.82
Total Interest $255,085.82
Principal vs Interest Over Time

How It Works

Monthly payment formula: M = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], where P = principal, r = monthly interest rate (annual rate ÷ 12), n = total number of payments.

Worked example — $300,000 mortgage at 6.5% for 30 years:

  • Monthly rate r = 6.5% ÷ 12 = 0.5417%
  • n = 30 × 12 = 360 payments
  • Monthly payment = $1,896
  • Total paid = $682,560 — total interest = $382,560

Early in a loan, most of each payment covers interest. For the example above, month 1 allocates roughly $1,625 to interest and only $271 to principal. By month 180 (year 15), the split is roughly equal.

Extra monthly payments reduce the principal faster, shortening the loan term and cutting total interest significantly. Adding $200/month to the example above saves over $60,000 in interest and pays off the loan 6 years early.

Frequently Asked Questions

How is a monthly mortgage payment calculated?

Using the amortization 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), and n is the number of monthly payments. A $250,000 loan at 7% for 30 years gives a monthly payment of about $1,663.

How much does a higher interest rate really cost over a 30-year mortgage?

The difference is substantial. On a $300,000 mortgage: at 5% you pay about $280,000 in total interest; at 7% that rises to about $419,000 — a difference of roughly $139,000 over the life of the loan.

Does paying extra each month really save money?

Yes, significantly. Extra payments reduce the principal directly, which reduces future interest charges. On a 30-year $300,000 loan at 6.5%, an extra $200/month saves over $60,000 in interest and cuts the loan term by about 6 years.

What is amortization?

Amortization is the process of spreading loan payments over time. Each payment covers interest on the remaining balance and reduces the principal. Early payments are mostly interest; later payments are mostly principal. An amortization schedule shows this breakdown for every payment.

What is the difference between APR and interest rate?

The interest rate is the base cost of borrowing. APR (Annual Percentage Rate) includes the interest rate plus fees (origination fees, points, etc.), expressed as an annual rate. APR is the more complete measure of the true cost of a loan.