Mortgage Affordability Calculator
Estimate how much house your borrower can afford based on income, debts, and loan terms. Free for brokers and loan officers.
Pre-filled with the current 30-year average (Freddie Mac via FRED).
43% is a common conventional guideline. FHA allows up to 50%, VA up to 60%.
Estimated Affordability
Enter details to see results.
How mortgage affordability is estimated
A mortgage affordability estimate starts with income and a target DTI guideline. From there, you subtract the borrower's existing monthly debts to estimate how much room is left for a housing payment. Finally, that maximum payment is converted into an estimated home price based on the loan term, interest rate, down payment, and monthly escrow items.
This tool includes estimated taxes, insurance, HOA, and PMI (if the down payment is under 20%) so the result is closer to a real-world payment. Use it to set expectations early, then confirm the final numbers with lender pricing and AUS findings.
How brokers use this
Use this calculator during your first conversation with a borrower to set a realistic price range. Enter their income, monthly debts, and expected down payment to see what they can comfortably afford without blowing past DTI guidelines.
Once you have a target price range, create a loan file in BorrowerDocs and send your borrower a magic-link portal to start uploading income and asset docs.
FAQs
How much house can I afford based on my income?
Affordability is driven by income, existing monthly debts, interest rate, down payment, and a target DTI guideline. This calculator estimates a max housing payment and converts it to an estimated home price range based on the loan terms.
How does this mortgage affordability calculator work?
It works backward from a target back-end DTI. With the borrower's income and monthly debts, it calculates the maximum housing payment (PITI) and then estimates the home price that payment supports.
What DTI does this tool use?
The default target is 43% back-end DTI, a common benchmark for conventional scenarios. You can adjust it to match the loan program, AUS findings, and borrower profile.
Does this include property taxes, insurance, HOA, and PMI?
Yes. The affordability estimate includes an assumed property tax rate, homeowners insurance, HOA dues (if any), and PMI when the down payment is under 20%.
What interest rate should I use?
Start with today's market rate for the closest term (30-year or 15-year), then update it to the borrower's quoted rate once you have it. Small rate changes can materially change affordability.
Is this accurate for FHA, VA, or USDA?
This is an early-stage estimate. FHA/VA/USDA have program-specific factors (MI, funding fees, DTI tolerances, and AUS findings) that can change the outcome. Use the result as a starting point and confirm with your lender's guidelines.
How is this different from BorrowerDocs?
This is a standalone calculator. BorrowerDocs is the workflow that follows: a borrower portal and document checklist where clients upload income and asset docs to verify the numbers.
Start collecting docs for this loan
Create a free BorrowerDocs file and send your borrower a checklist portal to upload pay stubs, tax returns, and bank statements.
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