Is It Better to Put 20% Down or Pay PMI? (First-Time Buyer Math)
You’ve heard the rule a hundred times: put 20% down or you’re throwing money away on PMI. So you keep renting, keep saving, watching your down payment fund crawl upward while home prices climb even faster.
Here’s the uncomfortable question nobody asks: what is waiting actually costing you?
The 20%-down rule is solid advice — in theory. But for many first-time buyers, waiting two or three extra years to hit 20% costs far more than just paying PMI for a while. Let’s run the actual numbers on a $300,000 home and see which path really wins.
What PMI Actually Costs You
PMI — private mortgage insurance — protects the lender, not you. If you put down less than 20% on a conventional loan, the lender adds PMI to your monthly payment until you’ve built enough equity to drop it.
PMI typically costs 0.3% to 1.5% of the loan amount per year, depending mostly on your credit score and how much you put down. On a $270,000 loan (a $300K home with 10% down), that works out to roughly:
- Good credit (740+): ~$70–$115/month
- Fair credit (680–739): ~$115–$180/month
- Lower credit (620–679): ~$180–$270/month
So for a buyer with decent credit, we’re talking about roughly $100–$150 a month — real money, but hardly the financial catastrophe it’s made out to be. And here’s the part people forget: PMI isn’t forever. Once your loan balance drops to 80% of the home’s value, you can request cancellation. At 78%, it drops off automatically.
The Two Paths: Side-by-Side on a $300K Home
Let’s compare two buyers eyeing the same $300,000 home. We’ll use a 7% mortgage rate (an illustrative figure — plug in current rates when you run your own numbers) and assume the buyer putting 10% down has good credit, paying about $135/month in PMI.
Buyer A: Waits to save the full 20%
- Needs: $60,000 down payment
- Has saved: $30,000
- Still needs: $30,000
- Saving $1,000/month → 30 more months of waiting (2.5 years)
During those 2.5 years, Buyer A keeps renting. At $1,600/month rent, that’s $48,000 handed to a landlord — money that builds exactly zero equity.
Meanwhile, what happens to the $300,000 home? If prices rise just 3% a year (a modest assumption), it costs about $322,000 by the time Buyer A is ready. And 20% of $322,000 is $64,400 — the target moved while they were saving.
Buyer B: Buys now with 10% down and pays PMI
- Down payment: $30,000 (already saved)
- Loan: $270,000 at 7%
- Monthly principal + interest: ~$1,796
- PMI: ~$135/month
- Total: ~$1,931/month
Buyer B starts building equity on day one. After 2.5 years of payments, Buyer B has paid down roughly $8,000–$9,000 of principal. And if the home appreciated 3% a year, it’s worth ~$322,000. Add it up — $30,000 down + ~$8,500 in principal paid + ~$22,000 in appreciation = over $60,000 in equity.
The head-to-head
| Buyer A (waits for 20%) | Buyer B (buys now, pays PMI) | |
|---|---|---|
| Time to buy | 2.5 years | Now |
| Rent paid while waiting | ~$48,000 | $0 |
| PMI paid | $0 | ~$4,050 (30 months × $135) |
| Home price at purchase | ~$322,000 | $300,000 |
| Equity after 2.5 years | $0 (still renting) | ~$60,000+ |
PMI cost Buyer B about $4,000. Waiting cost Buyer A $48,000 in rent — plus a $22,000 more expensive house.
This is the math the “always put 20% down” advice quietly ignores. PMI is a few thousand dollars spread over a few years. Waiting is tens of thousands, gone forever.
When Waiting for 20% DOES Make Sense
Paying PMI isn’t automatically the right call. Waiting wins in these situations:
Your credit score is low. PMI gets pricey below 680 — $200 or more per month at this loan size. If a year of credit repair drops your PMI from $250 to $120 a month and gets you a better mortgage rate, waiting pays for itself twice over.
You’d be cash-strapped after closing. If 10% down leaves you with zero emergency fund, one broken furnace or roof leak puts you straight into credit card debt. Never buy a house with no cash cushion. That’s far riskier than any PMI payment.
Your local market is flat or falling. The math above assumes modest appreciation. If prices in your area are flat — or dropping — there’s no penalty for waiting. You might even buy the same house cheaper later.
You can hit 20% fast. If you’re only $5,000 short and can save it in four months, just wait. This whole analysis changes completely when the wait is measured in months, not years.
The Smart Middle Path Most Buyers Miss
Here’s what the debate usually misses: you don’t have to choose between 10% and 20%.
- 15% down cuts your PMI roughly in half compared to 5% down — and puts you much closer to the 20% cancellation line from day one.
- Lender-paid PMI (accepting a slightly higher mortgage rate instead of a monthly PMI charge) can win if you plan to sell or refinance within a few years.
- Piggyback loans (an 80-10-10 structure) avoid PMI entirely with a second, smaller loan — though the second loan’s interest rate is usually higher, so compare total costs.
The real question isn’t “PMI or no PMI.” It’s “what does each extra month of waiting cost me, versus each month of PMI?” Run both numbers for your own situation instead of following a blanket rule.
How Fast Can You Drop PMI?
Remember, PMI is temporary. On that $270,000 loan at 7%:
| Payment strategy | Time to reach 20% equity | Total PMI paid (approx.) |
|---|---|---|
| Minimum payments only | ~8 years | ~$13,000 |
| Extra $200/month toward principal | ~6 years | ~$9,700 |
Every extra principal payment shortens your PMI sentence. And if your home appreciates, you may be able to request cancellation even sooner with a new appraisal.
Want to compare scenarios with your own numbers? A free mortgage calculator that includes PMI estimates lets you plug in 10%, 15%, and 20% down side by side and see exactly how the monthly payment changes.
FAQ
How long do you pay PMI on a conventional loan?
Until your loan balance reaches 80% of the home’s original value — at that point you can request cancellation in writing. At 78%, your servicer must drop it automatically. With 10% down on a 30-year loan, that typically takes around 8 years of normal payments — less with extra principal payments or appreciation.
Is PMI tax deductible?
Generally no, not for most homeowners in recent tax years — the PMI deduction expired and had not been renewed as of this writing. Don’t count on a tax break; check current IRS rules or ask a tax professional.
Can I avoid PMI with less than 20% down?
Yes, several ways: VA loans charge no PMI for eligible veterans, USDA loans have no PMI in eligible rural areas (though they include a guarantee fee), piggyback 80-10-10 loans split the borrowing, and some lenders offer their own low-down-payment programs. Each has tradeoffs — always compare the total monthly cost, not just the PMI line.
Does PMI protect me if I can’t make payments?
No — PMI protects the lender, not you. If you default, the insurance covers the lender’s losses. You still lose the home and take the credit damage. Don’t confuse PMI with mortgage protection insurance, a separate product that covers your payments if you die or become disabled.
Is paying PMI stupid?
Not when the math works. Paying ~$135 a month for a few years while building tens of thousands in equity is one of the better trades in personal finance. What’s genuinely costly is staying on the sidelines for years to dodge PMI while paying rent and watching prices rise.
Bottom line
For most first-time buyers, buying with 10% down and paying PMI beats waiting years to save 20%. The PMI costs a few thousand dollars; the wait costs tens of thousands in rent and a more expensive house. Run your own numbers with your credit score, your rent, and your market — but don’t let three letters (P-M-I) keep you renting years longer than necessary.
