What’s the 28/36 rule?

PITI ≤ 28% of gross monthly income; total debt payments ≤ 36%. Lenders often go beyond these in pre-approvals; they’re still a useful personal guardrail.

Should I use gross or net income?

Lenders use gross. For personal budgeting, net is more realistic. We recommend running both.

Money & Finance · Free tool

Mortgage Affordability Calculator

See how much house you can afford based on income and debt. Uses the 28/36 rule lenders actually use.

Updated April 2026

Home price ($)Down payment (%)Rate (%)Term (years)Property tax (% / yr)Insurance ($ / yr)

Monthly payment (PITI)

$2,493

P&I

$2,043

Tax

$350

Insurance

$100

Loan amount: $315,000

What it does

A mortgage affordability calculator that shows full PITI on various home prices. Lenders use the 28/36 rule: PITI should be no more than 28% of your gross monthly income, and total debt payments (PITI + car + student loans + minimum credit card payments) should stay under 36%.

Run prices up and down until the PITI lands at or below 28% of your gross monthly. Then pressure-test it: could you still hit all your other financial goals (emergency fund, retirement, kids) at that payment? If the answer is “only if nothing goes wrong,” go lower.

Example input & output

Input

Gross monthly income: $9,000 (example)
28% of that: $2,520
If your target PITI ≤ $2,520/mo: about a $310,000 home with 10% down at 6.75%.

Output

Home price: $310,000
Down: $31,000
P&I: $1,810/mo
Taxes: $310/mo
Insurance: $80/mo
Total PITI: $2,200/mo

Pre-approvals often stretch higher than the 28% rule; just because a lender will lend it doesn’t mean you should borrow it.

How to use it

Start with a candidate home price.
Enter your realistic down payment.
Enter today’s mortgage rate.
Add property tax rate and insurance estimate.
Check PITI against 28% of your gross monthly income.

When to use this tool

Early in the home-buying process.
When a pre-approval comes back higher than you expected — check whether you can actually afford it.

When not to use it

As the only decision input — budget priorities (retirement, kids, travel, job risk) matter too.

Common use cases

Figuring out a realistic home-price range before shopping.
Running the 28/36 check on a lender’s pre-approval amount (often higher than you should actually spend).
Comparing what different down-payment amounts enable.

Frequently asked questions

What’s the 28/36 rule?: PITI ≤ 28% of gross monthly income; total debt payments ≤ 36%. Lenders often go beyond these in pre-approvals; they’re still a useful personal guardrail.
Should I use gross or net income?: Lenders use gross. For personal budgeting, net is more realistic. We recommend running both.