What affects affordability?
- Income: higher income can support a larger payment
- Existing debt: monthly debt payments reduce borrowing room
- Down payment: larger down payments lower loan amount
- Taxes and insurance: these add to monthly housing cost
- PMI and HOA: can materially change affordability
Why the estimate can change fast
Even if the home price stays the same, affordability can shift quickly when interest rates rise or when HOA, PMI, taxes, and insurance are added to the monthly total.
Best way to estimate
The strongest estimate is the one that includes your down payment, loan term, interest rate, taxes, insurance, PMI, and HOA together instead of looking only at principal and interest.