What 3%, 5%, and 20% Down Payments Actually Cost Over Ten Years

The short answer surprises most buyers. On a ten-year horizon, the 20% down payment is not only the cheapest option in equity terms, it is also the cheapest in total cash spent. The crossover arrives around year eight. After that point, the small down payment has cost more money out of pocket, not less. That ordering holds across a wide band of interest rates, so the conclusion does not depend on where the market happens to sit.

How We Modeled Down-Payment Comparison

The assumptions are stated plainly.

A $400,000 purchase, 30-year fixed, with one illustrative interest rate held identical across all three scenarios.

These are illustrations, not offers, and your own numbers will differ.

Mortgage insurance does the real work here.

The Urban Institute’s Housing Finance Policy Center puts borrower-paid private mortgage insurance between 0.46% and 1.50% of the loan amount annually, driven mainly by credit score and loan-to-value.

We modeled 0.80% at 97% LTV and 0.65% at 95% LTV, both comfortably inside that band. Appreciation is modeled at 3% a year. Closing costs are excluded as broadly similar across scenarios.

What Each Down Payment Buys

Two buyers purchase identical $400,000 homes on the same day. One puts down 3%, the other 20%. The 20% buyer commits $68,000 more at closing and spends the first several years clearly behind on cash.

That advantage erodes month by month. By month 96 — exactly eight years in — the 3% buyer’s cumulative outlay passes the 20% buyer’s. Both have spent about $284,000 at that moment. From there the gap widens in the opposite direction.

At ten years the 20% buyer has spent roughly $335,500 in total, including the original $80,000. The 3% buyer has spent roughly $352,800. The buyer who put down less has paid about $17,300 more in cash and holds roughly $58,400 less equity.

The reason is not mysterious. A larger loan carries more interest in every payment, and mortgage insurance runs alongside it for years — two costs compounding quietly while the headline advantage gets the attention. Our guide to Fannie Mae down payment requirements covers which low-down programs you can qualify for; this is what they cost once you have one.

Case Study Two: The Request Most Borrowers Never Make

This is the case study you can act on.

Under the Homeowners Protection Act, mortgage insurance terminates automatically when the balance is first scheduled to reach 78% of the home’s original value. On our 3%-down loan that arrives in month 151 — twelve and a half years in. Waiting for it means paying mortgage insurance through the entire ten-year window, about $31,000.

But Fannie Mae’s servicing rules permit borrower-initiated termination based on current value. A loan seasoned more than five years qualifies at 80% LTV; between two and five years the threshold tightens to 75%. The request requires a property valuation with an interior and exterior inspection and a clean payment history — current on the loan, nothing 30 days late in the past year, nothing 60 days late in the past two.

With 3% annual appreciation, our 3%-down borrower clears that bar in month 61, just past the five-year mark. Acting then instead of waiting removes mortgage insurance roughly seven and a half years early: about $15,300 saved inside the ten-year window, closer to $23,300 over the life of the loan.

Nobody sends a reminder. The automatic termination is automatic. The earlier cancellation is not — you have to ask.

Why “Invest the Difference” Usually Doesn’t Work Here

The standard counterargument is that the 3% buyer keeps $68,000 and invests it. The math is less forgiving than it sounds.

Over ten years the 3% buyer makes roughly $85,300 more in payments. To break even on that alone, the invested $68,000 would need to return about 8.5% annually — and clearing that bar only draws level on payments. It does nothing about the $58,400 equity gap.

The argument can work when mortgage rates sit low relative to expected returns. It does not work when borrowing costs are elevated. Check the arithmetic against your own numbers rather than accepting the slogan.

What This Comparison Does Not Settle

A ten-year model assumes you stay ten years, and most buyers do not. Sell in year four and the small down payment may well have been right, because the crossover has not happened yet.

It also assumes the choice exists. For many buyers it does not — waiting years to accumulate 20% while rents and prices move is its own cost, one this model does not capture. A buyer who cannot reach 20% is not making a mistake by putting 3% down. They are making the only move available, and the right response is to plan the mortgage insurance exit from day one.

These figures also move with credit score, local appreciation and loan pricing. The ordering is stable; the dollar amounts are not. If student loans shape what you can put down, our guide on buying a house with student loan debt covers that interaction, and first-time buyers should check whether a mortgage credit certificate applies, since it offsets cost from a direction this comparison ignores. Buyers weighing assistance programs should also review first-time home buyer programs before committing cash they may not need to spend.

Frequently Asked Questions

Does putting 20% down always beat a smaller down payment?

No. It wins on a ten-year hold in this model, but the advantage depends on staying long enough to reach the crossover, which lands near year eight. Sell earlier and the smaller down payment usually looks better, because you have not yet paid enough extra interest and mortgage insurance to overtake the larger upfront commitment. Time horizon matters more than the percentage itself. Decide how long you realistically expect to keep the home first.

How long does mortgage insurance actually last on a 3% down loan?

Longer than most buyers expect. On scheduled amortization alone the balance does not reach the automatic termination threshold until well past the ten-year mark, so it runs the entire first decade. Appreciation changes that, but only if you act — borrower-initiated cancellation based on current value requires a written request, a qualifying loan-to-value, a valuation and a clean payment history. The automatic path is slow; the faster path requires you to start it.

Is 5% down meaningfully better than 3% down?

Modestly, and less than the two-point gap suggests. The smaller loan reduces both interest and mortgage insurance, and the lower loan-to-value typically earns a better insurance factor. In this model the 5% buyer ends ten years with several thousand dollars more equity and a few thousand less spent. Real, but not decisive. If you are choosing between them, the stronger consideration is usually whether keeping the extra cash in reserve serves you better.

References

1. Experian. (2026, May 7). How much does private mortgage insurance (PMI) cost? 
2. Fannie Mae. (2019). Servicing guide B-8.1-04: Termination of conventional mortgage insurance. 
3. Homeowners Protection Act of 1998, 12 U.S.C. §§ 4901–4902. 

Disclosure: RefiGuide.org is an advertising marketplace, not a licensed mortgage lender or broker. Home loans are matched with participating NMLS-licensed institutions.