Home Affordability Calculator (28/36 Rule)

How this calculation works

The 28/36 rule is a lender guideline, not a law. Your binding constraint is whichever is smaller: 28% of gross income for housing, or 36% minus your other required debt payments.

The estimate solves for the home price whose all-in P&I plus property taxes fits that budget, at your down payment and rate.

How this Home Affordability Calculator (28/36 Rule) works — 2026 guide

“How much house can I afford?” is the most important number in home buying — and the 28/36 rule is the standard lenders use to answer it. This affordability calculator takes your household income, existing debts, down payment, mortgage rate, and property tax rate, applies both the 28% housing cap and the 36% total-debt cap, and returns the maximum home price plus the all-in monthly payment (principal, interest, and taxes). It shows which constraint actually binds — usually your other debt payments, not the housing cap.

How to use it in 3 steps

1. Enter your annual household income and minimum monthly debt payments.
2. Add your down payment, expected rate, and local property-tax rate.
3. Read your max affordable home price, allowed housing payment, and estimated PITI.

Who this is for

First-time buyers setting a budget, movers comparing price ranges, and anyone checking whether their target home is realistic. Pair with the [loan amortization calculator](/tools/loan-amortization-calculator/) to model the actual mortgage.

Data sources & authoritative references

This calculator is built on official U.S. rules and published statistics. Key sources:

• Consumer Financial Protection Bureau — How much house can you afford
• Federal Reserve — 30-year fixed mortgage averages (PMMS)
• US Census — State property tax rates