Understanding PMI
If your down payment is below 20% on a conventional loan, your lender will typically require private mortgage insurance (PMI) as a condition of the loan. PMI protects the lender against loss if you default โ it does not protect you as the borrower. This calculator estimates your monthly PMI cost based on your loan amount and an annual PMI rate you can adjust.
A worked example
On a $340,000 loan (a $360,000 home with 5.6% down) at a 0.75% annual PMI rate, PMI costs about $213/month โ $340,000 ร 0.0075 รท 12. At a stronger 0.4% rate, more typical for borrowers with excellent credit, the same loan costs about $113/month. That gap shows why credit score matters even for buyers who've already decided to put down less than 20%: it changes your PMI rate, not just your interest rate.
What determines your PMI rate
- Credit score: the biggest driver โ higher scores get meaningfully lower rates.
- Loan-to-value ratio: a 15% down payment gets a lower rate than a 3% down payment.
- Loan type: fixed-rate vs. adjustable-rate loans can price PMI differently.
- PMI structure: borrower-paid monthly PMI is most common, but single-premium and lender-paid PMI (folded into the rate) are alternatives worth asking about.
When PMI goes away
PMI isn't permanent. As you pay down your loan (or your home appreciates), your equity grows, and once you reach 20โ22% equity, PMI can typically be cancelled or is automatically removed under federal law. This calculator shows how much principal you still need to pay off to hit that 20% equity threshold at today's home value.
Deciding how large a down payment to make in the first place? The Down Payment Calculator compares PMI across different down payment levels.