Mortgage Calculator — Monthly Payment & Total Cost

Calculate your monthly mortgage payment including principal, interest, property taxes, and homeowner's insurance. See the full cost breakdown over the life of your loan — essential for home buying decisions.

How the Formula Works

Monthly P&I: P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1]

Total Interest: (Monthly Payment × Number of Payments) − Loan Amount

Total Monthly Payment: P&I + Monthly Property Tax + Monthly Insurance

Example: $400,000 home, $80,000 down, 6.5% rate, 30 years → Monthly P&I ≈ $2,023. Total interest paid ≈ $408,280.

Frequently Asked Questions

How is a mortgage payment calculated?

Monthly payment = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], where P is the loan amount, r is the monthly interest rate (annual ÷ 12), and n is the total number of payments.

What is a good mortgage interest rate?

Rates vary by market conditions. Historically, 3–4% was considered excellent. In 2024, rates around 6–7% are common for 30-year fixed mortgages. Your credit score significantly impacts your rate.

How much down payment do I need?

Conventional loans typically require 5–20%. FHA loans allow as little as 3.5%. Putting down 20% avoids PMI (private mortgage insurance), saving $100–$300/month.

What is the difference between a 15-year and 30-year mortgage?

A 15-year mortgage has higher monthly payments but you pay far less interest overall — often saving $100,000+ compared to a 30-year loan. A 30-year mortgage has lower monthly payments but costs more long-term.

What is PMI and when do I need it?

PMI (Private Mortgage Insurance) is required when your down payment is less than 20%. It typically costs 0.5–1.5% of the loan amount annually and can be removed once you reach 20% equity.