PMI Calculator
Private Mortgage Insurance Estimate
What Is a PMI Calculator?
A PMI calculator estimates the private mortgage insurance charge that may apply when a buyer makes a down payment of less than 20% of the home price. PMI is an added insurance cost commonly associated with mortgages that have a loan-to-value ratio above 80%.
This PMI calculator subtracts your down payment from the home price, calculates the resulting loan-to-value ratio, and applies the selected annual PMI rate to the estimated loan amount. It then divides the annual cost by 12 to show an estimated monthly PMI payment.
The tool is useful for homebuyers, borrowers, and homeowners who want to understand how a smaller down payment could affect monthly housing costs. It also displays the mortgage balances equal to 80% and 78% of the original home price. These balances are used by the calculator as request and automatic cancellation thresholds.
How the PMI Calculator Formula Works
The calculator first converts the entered down payment percentage into a dollar amount. It then subtracts that amount from the home price to estimate the initial loan balance.
In these formulas, H is the home price, p is the down payment percentage, D is the down payment amount, and L is the estimated loan amount.
The calculator next finds the loan-to-value ratio, also called LTV. LTV compares the estimated loan amount with the original home price.
If the LTV is above 80%, the calculator treats PMI as required. It multiplies the loan amount by the selected annual PMI rate. The annual amount is then divided by 12.
Here, r is the selected annual PMI rate written as a decimal. The available rates are 0.30%, 0.50%, 0.80%, and 1.10%. The calculator labels these choices as excellent, good, fair, and below-average credit estimates.
Worked PMI Example
Assume a home price of $350,000, a 10% down payment, and a 0.50% annual PMI rate.
- Down payment: $350,000 × 10% = $35,000.
- Loan amount: $350,000 − $35,000 = $315,000.
- LTV: $315,000 ÷ $350,000 = 90.00%.
- Annual PMI: $315,000 × 0.005 = $1,575.
- Monthly PMI: $1,575 ÷ 12 = $131.25.
The calculator would also display an 80% balance of $280,000 and a 78% balance of $273,000. If the entered down payment produces an LTV of exactly 80% or less, the calculator sets both annual and monthly PMI to $0.00.
How to Use the PMI Calculator: Step by Step
- Enter the home price. Type the full purchase price into the “Home Price ($)” field. Use a positive dollar amount.
- Enter the down payment percentage. Add the percentage of the home price you plan to pay upfront. The field allows percentage values from 0 to 100 and supports one-decimal increments.
- Select an estimated annual PMI rate. Choose 0.30%, 0.50%, 0.80%, or 1.10% from the menu. The default selection is 0.50%, labeled “Good Credit.”
- Select Calculate. The calculator will estimate your loan amount, LTV, annual PMI, monthly PMI, and applicable threshold balances.
- Review the plain-English summary. The summary explains whether the calculated LTV is above 80% and whether the tool has added PMI.
- Use Reset to start again. Reset clears both number fields, returns the PMI rate to 0.50%, and hides the previous results.
The main result is the estimated monthly PMI cost. This amount represents the annual PMI estimate divided into 12 equal monthly amounts. It is separate from principal, interest, property taxes, homeowners insurance, association dues, and other possible housing expenses. A $0.00 result means the calculator found an LTV of 80% or less, not that a lender has approved the loan without mortgage insurance.
What Your PMI Calculator Results Mean
Monthly and Annual PMI Cost
The monthly PMI result is the estimated amount added to a monthly mortgage payment under the calculator’s formula. The annual PMI figure is the estimated loan amount multiplied by the selected rate. The calculator applies the rate to the initial estimated loan amount rather than reducing it over time.
Loan Amount and LTV
The loan amount is the home price minus the down payment. The LTV shows that loan amount as a percentage of the home price. A higher down payment lowers both the estimated loan balance and LTV. Under this calculator’s logic, PMI applies only when LTV is above 80%.
| Displayed Result | How the Calculator Determines It |
|---|---|
| Loan Amount | Home price minus down payment |
| Loan-to-Value Ratio | Loan amount divided by home price |
| Annual PMI | Loan amount multiplied by the selected annual rate |
| Monthly PMI | Annual PMI divided by 12 |
| Request Cancellation Balance | 80% of the original home price |
| Automatic Cancellation Balance | 78% of the original home price |
Cancellation Thresholds
For results above 80% LTV, the calculator displays two threshold balances. The request balance equals 80% of the original home price. The automatic balance equals 78% of the original home price. These are balance targets only. The calculator does not estimate how many months it will take to reach them.
Important Limitations
This calculator provides an estimate, not a lender quote or legal determination. The selected PMI rates are fixed examples. The tool does not use your actual credit score, debt-to-income ratio, mortgage term, interest rate, property type, loan program, payment history, appraisal, fees, or lender pricing.
Actual PMI costs and cancellation rules may vary by mortgage product, lender requirements, payment status, federal rules, and other conditions. The calculator also does not identify whether a loan uses private mortgage insurance or another form of mortgage insurance. Confirm actual charges and removal requirements with the lender or loan servicer.
Frequently Asked Questions
How much is PMI per month?
Monthly PMI depends on the loan amount and the selected annual PMI rate. This calculator multiplies the estimated initial loan amount by 0.30%, 0.50%, 0.80%, or 1.10%, then divides the result by 12. For a $315,000 loan at 0.50%, the estimated monthly PMI is $131.25.
How do I calculate PMI on a mortgage?
Subtract the down payment from the home price to find the estimated loan amount. Multiply that loan amount by the annual PMI rate, then divide by 12 for the monthly cost. This calculator performs those steps only when the resulting loan-to-value ratio is greater than 80%.
Do I need PMI with a 20% down payment?
Under this calculator’s logic, PMI is not required when the down payment produces an LTV of 80% or less. A 20% down payment normally creates an 80% LTV when no other amounts are added to the loan. The calculator therefore displays annual and monthly PMI of $0.00.
What PMI rate should I choose?
Choose the rate that best fits the estimate you want to test. The calculator offers 0.30% for excellent credit, 0.50% for good credit, 0.80% for fair credit, and 1.10% for below-average credit. These labels are preset examples and are not based on information from a lender.
What is the difference between PMI and LTV?
PMI is an estimated insurance cost, while LTV is a ratio. LTV compares the loan amount with the home price. This calculator uses LTV to decide whether to calculate PMI. If LTV is above 80%, it applies the selected PMI rate to the estimated initial loan balance.
When can I request PMI cancellation?
The calculator displays a request cancellation balance equal to 80% of the original home price. For a $350,000 home, that balance is $280,000. This is a mathematical threshold used by the tool. Actual eligibility may also depend on the mortgage, lender requirements, payment history, and applicable cancellation rules.
How accurate is this PMI calculator?
The calculator accurately applies its displayed formula to the values you enter, but the result is only an estimate. It uses one of four preset annual rates and does not obtain a personalized lender quote. Your actual PMI may differ because of underwriting, credit, property details, loan terms, fees, or lender rules.