Down Payment Calculator · filed Oct 9, 2026
Down payment vs PMI cost
Every extra dollar of down payment buys off a slice of mortgage insurance. The question is what the insurance actually costs you — in full, over the life of the loan — so you can price the bigger check against it. Here is the full PMI schedule on a $400,000 home at 7% on a 30-year conventional loan.
The insurance ledger
| Down | PMI / mo | Drops | Total PMI paid |
|---|---|---|---|
| 3.5% ($14,000) | $289.50 | month 148 (12y 4m) | $42,846 |
| 5% ($20,000) | $228.00 | month 142 (11y 10m) | $32,376 |
| 10% ($40,000) | $156.00 | month 115 (9y 7m) | $17,940 |
| 20% ($80,000) | — | — | $0 |
PMI estimated by loan-to-value band (roughly 0.32%–0.90% of the loan per year); totals are monthly PMI times months to the 78% automatic drop. Your lender quotes by credit score.
Reading the trade
Moving from 3.5% to 10% down costs $26,000 more at closing and buys off about $24,906 in lifetime PMI — nearly dollar for dollar — while also cutting the monthly payment by over $300 and the drop date by nearly three years. That is the steepest-value step on the board.
Moving from 10% to 20% costs $40,000 more at closing and buys off $17,940 in PMI — a worse exchange rate on insurance alone, though it also cuts the monthly payment by $422 and saves $55,804 in lifetime interest ($502,232 vs $446,428). The insurance is no longer the reason; the interest is.
The trap row is FHA at 3.5% down: $176.92 a month in MIP that never drops, totaling about $63,691 over 30 years — more than any conventional PMI schedule. The conventional 3.5%-down file is cheaper over time precisely because its insurance has an end date.
The comparison that decides it
Total PMI at 3.5% down is $42,846. The cash gap from 3.5% to 20% down is $66,000, which takes 44 months to save at $1,500 a month. So the honest comparison is never “$42,846 in insurance vs $0” — it is “$42,846 in insurance over 12 years while you own the home, vs 44 months of rent plus whatever the price does while you wait.” At $2,000 a month in rent, the wait costs $88,000 before the price moves at all.
Two escape hatches belong in every plan: conventional PMI can be requested off at 80% loan-to-value (no need to wait for the automatic 78%), and a refinance or reappraisal that proves 20% equity ends it early. Price your own file in the Down Payment Calculator — the drop month is dated on every run.
Filed under down payments
- Down Payment CalculatorRun the ladder at your price, rate, and loan program.
- How Much Down Payment on $400k?The four standard checks — 3.5%, 5%, 10%, 20% — posted line by line.
- Is 20% Down Necessary?The myth, the PMI math, and the wait-it-out arithmetic.
- FHA Down Payment Requirements3.5% at 580+, 10% at 500–579, and the two MIP premiums priced out.
- How Much Do I Need to Buy a House?Down payment plus closing costs plus reserves — the whole cash picture.