What PMI costs by down payment
PMI is priced on risk, so the rate falls as your down payment rises. The figures below use a $400,000 home at 6.66% over 30 years, which was the Freddie Mac 30-year average on 30 July 2026, with representative rates for each LTV tier. The last two columns are the part most tables leave out: how long you pay, and what that adds up to.
| Down payment | Loan | LTV | PMI rate | PMI per month | Months to 80% LTV | Total PMI paid |
|---|---|---|---|---|---|---|
| 3% | $388,000 | 97% | 1.10% | $356 | 135 | $48,015 |
| 5% | $380,000 | 95% | 0.95% | $301 | 126 | $37,905 |
| 10% | $360,000 | 90% | 0.62% | $186 | 97 | $18,042 |
| 15% | $340,000 | 85% | 0.43% | $122 | 58 | $7,066 |
The spread is wider than the monthly figures suggest. Going from 3% down to 15% down cuts the monthly PMI from $356 to $122, which looks like a saving of $234 a month. Over the period you actually pay it, the difference is $48,015 against $7,066, because a larger down payment shortens the duration as well as the rate. That compounding of two effects is why PMI is one of the strongest arguments for waiting to buy until you can put down more, and one of the weakest for a 3% programme if you have any realistic route to 10%.
How to calculate PMI yourself
Three steps, and no lender-specific information is needed for the estimate. If you want the whole payment rather than the PMI line on its own, our mortgage calculator with PMI, taxes and insurance gives you the full PITI figure a lender will quote.
1. LTV = loan ÷ home value
2. Look up the annual PMI rate for that LTV band
3. Monthly PMI = loan × annual rate ÷ 12
Worked on the 5% row above: a $380,000 loan on a $400,000 home is 95% LTV. At an annual rate of 0.95%, that is $380,000 × 0.0095 = $3,610 a year, or $301 a month. The figure appears in your monthly payment alongside principal, interest, taxes and insurance, which is why PMI is easy to miss when comparing quotes: two lenders can show the same rate and different PMI.
When PMI stops, and the two dates that matter
There are two thresholds under the Homeowners Protection Act of 1998 and they are eleven months apart on a typical loan.
At 80% of original value you may request cancellation. On the 5% example that is month 126, about 10.5 years in, with $37,905 of PMI paid. At 78% of original value your lender must terminate it automatically. That is month 137, about 11.4 years, with $41,214 paid.
The gap between those two dates is worth $3,309 on this loan, and it goes to whoever remembers. Nobody writes to tell you the 80% date has arrived, so the request has to come from you. Both thresholds are measured against the home's original value rather than its current value, which is why a rising market does not accelerate either date. Rising value can help through a different route: a new appraisal showing 75% or 80% current LTV, which most lenders will consider after two years, and which is a separate process from the statutory schedule above.
How this calculator works
Private Mortgage Insurance (PMI) is required by most conventional lenders whenever your down payment is below 20%, which means whenever your loan-to-value (LTV) ratio is above 80%:
LTV = loan amount ÷ home value
When PMI applies, its monthly cost is loan amount × annual PMI rate ÷ 12, where the annual PMI rate is risk-based and generally falls between about 0.3% and 1.5% depending on your LTV and credit profile. This is one of the most commonly misunderstood parts of a mortgage: PMI protects the lender rather than you, against the risk of a low-down-payment loan, but it's a cost you pay, and it's removable. Under the Homeowners Protection Act of 1998, you can request cancellation once your amortization schedule shows your balance reaching 80% of your home's original value, and your lender must automatically terminate PMI once the balance reaches 78% of that original value, provided you're current on payments.
Worked example
Take a $350,000 home purchased with a $332,500 loan (a 5% down payment) at 6.5% over 30 years, a 95% loan-to-value ratio. Because LTV is above 80%, PMI is required, at an estimated annual rate of 0.72%, working out to $199.50 a month. Based on the amortization schedule, the balance is projected to fall to the 80% cancellation threshold ($280,000) around month 124 (about 10.3 years in), and to the 78% automatic termination threshold ($273,000) around month 135 (about 11.3 years in), by which point the borrower will have paid roughly $26,933 in total PMI premiums.
What affects your result
- Down payment size, the biggest lever: crossing 20% down avoids PMI entirely, while 3-5% down means paying PMI for many years.
- Interest rate and term, a lower rate or shorter term builds equity faster, reaching the 80%/78% thresholds sooner.
- Extra principal payments, paying down your balance faster than scheduled moves the cancellation and termination dates earlier than this baseline estimate.
- Credit score and loan type, better credit typically earns a lower PMI rate at the same LTV; this calculator uses a standard tiered estimate that you can override if you have an actual quote.
A note on accuracy
PMI rates are individually underwritten and vary by insurer, credit score, and loan program, treat the rate here as a reasonable planning estimate, not a quote. Cancellation and termination months are projected from a standard amortization schedule and assume no missed payments or extra principal payments beyond what you've entered. For official rules on PMI cancellation rights, see the Consumer Financial Protection Bureau.