Mortgage Calculator
Estimate your full monthly mortgage payment — principal & interest plus property tax, home insurance and HOA — from the home price, down payment, rate and term.
Inputs
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Results
Formula
- P = loan amount = home price − down payment
- r = monthly rate = annual rate / 12 / 100 · n = term in months
- Total monthly = M + tax/12 + insurance/12 + HOA
How It Works
The down payment is subtracted from the home price to get the loan amount. The standard fixed-rate amortization formula then gives the monthly principal & interest (P&I) payment.
Property tax and insurance are usually paid yearly, so they are divided by 12 and added — together with any monthly HOA fee — to produce the total monthly housing payment (often called PITI).
Worked Example
Given: Home price $400,000, down 20%, rate 6.5% p.a., 30 years, tax $4,800/yr, insurance $1,600/yr
Loan P = 400,000 − 80,000 = $320,000 · r = 6.5/12/100 = 0.005417 · n = 360
P&I = 320,000 × 0.005417 × (1.005417)360 / [(1.005417)360 − 1] ≈ $2,023
Total monthly = 2,023 + 400 + 133 ≈ $2,556
Engineering Notes
- Assumes a fixed-rate, fully amortizing loan; adjustable-rate (ARM) payments change after the fixed period.
- With less than 20% down, lenders typically add private mortgage insurance (PMI), which is not included here.
- Property tax and insurance change over time; the figures entered are treated as constant.
- Closing costs, points and escrow adjustments are excluded.
FAQ
What is PITI?
Principal, Interest, Taxes and Insurance — the four usual components of a monthly mortgage payment.
Why does 20% down matter?
At 20% or more, most lenders waive PMI, lowering the monthly cost.
15 vs 30 years?
A 15-year term has higher payments but far less total interest.
Related Calculators
This calculator uses established formulas and standard calculation methods to provide reliable results for planning, estimation and reference.