$100,000 salary: how much house can you afford?

Here's the thing about "how much house can I afford" calculators: most of them show you the cautious textbook number and stop there, which is a little like a doctor only ever giving you the worst-case diagnosis. On $100,000, the honest answer is a range — and where you actually land in that range comes down to your other debt more than almost anything else.

The math, across all three tiers

On $100,000 a year, gross monthly income is $8,333. Here's what that means at each lending tier:

The Typical tier — 38% front-end — is the one that matches how conventional underwriting actually starts: lenders look at the housing-only ratio first, and 38% is where our real-world broker experience says that ratio lands for approved borrowers, before other debt ever enters the picture. That's a $135,000 gap from the Conservative number, which is exactly why "how much house can I afford" answers vary so wildly depending on who's answering.

What that actually looks like month to month

Take the Typical-tier home at $510,000. Put 20% down ($102,000), borrow $408,000, and at 6.5% your principal and interest lands around $2,579/month. Add roughly $588 for taxes and insurance and you're at about $3,167 total — right at that 38% front-end line.

Drop to the Conservative tier at $375,000 and your all-in payment falls to about $2,333/month — noticeably more breathing room, but also a smaller home for the same income. Neither number is "correct." They're two honest answers to two different questions: what can you qualify for, versus what leaves you room to breathe.

Don't have $102,000 sitting around? Here's what actually changes

Most people reading a $100K affordability guide don't have 20% down saved up, and that's normal, not a problem. Here's what the same $3,167/month budget buys you across the three most common down payment options — the home price moves more than at lower incomes, but the cash you need moves even more:

Cash needed upfront, to scale. Home price shown above each bar.

The home price is about $100,000 lower with 5% down versus 20% down — a bigger drop in dollar terms than at lower incomes, since the whole scale is bigger. But the cash you need on day one drops by roughly $81,500. For most buyers, that trade is still worth it: the cash sitting in your account today usually matters more than $100,000 of home price you weren't using anyway.

One honest caveat: "cash needed" above covers the down payment only. Real cash to close usually has two more pieces — here's why that matters.

The three buckets of cash to close

Every home purchase involves three separate pots of money, and mixing them up is where first-time buyers get caught off guard at the closing table:

• Down payment — starts at 3.5% for FHA, sometimes as low as 3% on certain conventional programs.
• Closing costs — lender fees, title insurance, appraisal, and similar costs, typically 2-5% of the purchase price.
• Prepaids — upfront funding for your property tax and insurance escrow, plus a small amount of prepaid interest.

Buckets two and three are often rolled into the loan or covered through seller concessions, so they don't always mean more cash out of pocket — but they still affect your loan amount and monthly payment. Knowing all three exist before you're sitting at the closing table is the whole point.

PMI vs. FHA MIP, in plain English

PMI shows up on conventional loans when you put down less than 20%. It's not a scam — it's what lets the lender approve a smaller down payment at all — and it goes away automatically once you hit 20% equity. Cost depends heavily on credit score, roughly 0.5% to 1.5% of the loan per year.

FHA MIP works differently: every FHA loan carries it, no matter the down payment, and it usually sticks around for the life of the loan unless you refinance into a conventional loan later. It has an upfront piece (1.75% of the loan, usually rolled in) plus a smaller annual piece (around 0.5-0.55%).

Bottom line: at $100K income, the gap between the 5%-down and FHA numbers is small, but the gap to 20% down is real money either way. It's your credit score (FHA is more forgiving), how much cash you have today, and whether you plan to refinance out of MIP down the road that should decide it — not the home price alone.

Mistakes that quietly cost $100K earners the most

• Assuming the Typical tier is debt-sensitive when it isn't. The Typical tier ($510,000) is set by the 38% front-end ratio, which only looks at housing costs — it doesn't move for a car payment or student loan until that debt tops roughly $792/month. The Maximum tier ($640,000) is the one that's back-end driven, and it takes the full hit: a $500/month car payment pulls it down to about $560,000, an $80,000 swing from one payment.
• Anchoring on the Maximum number because the income "supports" it. $640,000 is what an automated underwriting system might approve with strong credit and no other debt. It is not automatically what makes sense — property taxes, insurance, maintenance, and lifestyle costs all scale up with a bigger home, well beyond the mortgage payment itself.
• Forgetting HOA fees aren't in the math above. If the home has an HOA, that fee eats directly into your housing budget dollar-for-dollar — a $300/month HOA on a higher-end property functions the same as a meaningfully higher mortgage payment.
• Ignoring how much a credit score swing changes this. A 620 vs. a 760 score can move your rate by half a point or more — worth well over $50,000 in buying power on the exact same $100,000 salary.