Use this free mortgage payment calculator to estimate your monthly mortgage payment, see exactly how much interest you’ll pay over the life of the loan, and view a full year-by-year amortization schedule. Adjust the loan amount, interest rate, and term to instantly compare scenarios — no sign-up required.
How the Mortgage Payment Formula Works
Your monthly payment on a fixed-rate mortgage is calculated with the standard amortization formula:
Where:
- M = your monthly payment (principal + interest)
- P = the loan principal (amount borrowed)
- r = your monthly interest rate (annual rate ÷ 12)
- n = total number of monthly payments (years × 12)
Early in the loan, most of each payment goes toward interest. As the balance falls, an increasing share goes toward principal — that shift is exactly what the chart above visualizes.
Worked Example
Suppose you borrow $350,000 at a 6.5% annual rate for 30 years:
- Monthly rate: 6.5% ÷ 12 = 0.5417% (r = 0.005417)
- Number of payments: 30 × 12 = 360
- Monthly payment: 350,000 × [0.005417 × (1.005417)360] ÷ [(1.005417)360 − 1] ≈ $2,212.24
- Total interest over 30 years: roughly $446,000 — more than the original loan itself
Try the same loan at 15 years in the calculator above: the payment rises, but total interest falls dramatically.
What This Calculator Does (and Doesn’t) Include
This tool calculates principal and interest on a fixed-rate loan. Your real monthly housing cost will typically also include property taxes, homeowners insurance, and possibly PMI (private mortgage insurance, usually required when your down payment is under 20%) and HOA fees. As a rule of thumb, add 25–35% on top of the principal-and-interest figure for a realistic total.
Frequently Asked Questions
How much house can I afford?
A common guideline is the 28/36 rule: keep your total housing payment under 28% of gross monthly income, and all debt payments under 36%. If you earn $8,000/month, that suggests a housing budget of about $2,240/month including taxes and insurance.
Should I choose a 15-year or 30-year mortgage?
A 15-year loan carries a higher monthly payment but a lower interest rate and far less total interest. A 30-year loan maximizes flexibility with a lower required payment — and you can always pay extra toward principal to shorten it voluntarily.
How do extra payments affect my mortgage?
Extra payments go directly to principal, which reduces every future interest charge. Even one extra payment per year on a 30-year mortgage typically shortens the loan by 4–5 years.
What is amortization?
Amortization is the process of paying off a loan with fixed payments where the interest/principal split changes over time. Open the amortization schedule above to see the year-by-year breakdown for your exact numbers.
Does this calculator include taxes and insurance?
No — it computes principal and interest only, because taxes and insurance vary widely by location. Add your local property tax and insurance estimates for a complete monthly figure.