Salary to mortgage, plainly
The three tiers — 28%, 33%, 38% — are different opinions about how much of your gross monthly income should go toward housing (principal, interest, taxes, insurance, and PMI if applicable). We then subtract your existing monthly debts and back-solve for the home price whose monthly cost matches what's left.
Lean (28%) mirrors the classic front-end rule and leaves plenty of room for retirement savings, kids, and surprises. Balanced (33%) is a middle path many dual-income households find livable. Stretch (38%) is closer to what a lender will approve — fine if your career trajectory is steep and you don't expect lifestyle creep.
For a deeper walkthrough on the 28/36 rule and other affordability heuristics, read How much house can I afford? Or jump to the full mortgage calculator once you have a target price.