My cousin almost passed on a house because the listing payment on a flyer looked “impossible.” It was P&I only. Taxes in that county were brutal, HOA was $180, and they were putting 10% down so PMI was in play. Suddenly the number she needed for cash flow was $640 higher than the flyer. Nothing illegal—just a different layer of the stack.
What actually hits your checking account
Principal and interest are the part amortization tables love. Real life adds property tax (often as a monthly escrow slice), homeowner’s insurance, and sometimes PMI until you have enough equity. HOAs are separate envelopes but still real money. Underwriters care about the bundle; you should too before you fall in love with a rate quote.
Worked example: $412k buy, 10% down, 6.875%, 30y
Round numbers: $412,000 price, 10% down → roughly $370,800 financed. At 6.875% over 30 years, P&I lands near $2,440 (lenders round differently, but you’re in that zip code). Now add 1.15% tax rate on value → ~$395/mo, insurance at $1,450/yr → ~$121/mo, PMI sketch on the loan, plus HOA if any. That is the household truth test.
Plug your own tax rate and insurance into the mortgage payment calculator — it keeps P&I exact on the loan amount while you sanity-check escrow assumptions.
FAQ
Does a lower rate always mean a cheaper house?
Not if you stretch price or reset the term. A longer amortization lowers the payment while sometimes increasing lifetime interest. Compare both payment and total interest before bragging at brunch.
When does PMI go away?
Rules depend on loan program and paydown path. Some loans cancel near 78–80% LTV on the amortization schedule; others need appraisal or refinance. Your servicer letter matters more than blog prose.
Is this tax advice?
No. Deductions and SALT caps change with law and your situation. We’re modeling cash flow, not filing a return.