Down Payment Calculator: Savings Goal & PMI

What Is a Down Payment Calculator?

A down payment calculator answers two questions at once: how long will it take to save the down payment, and how does the percentage you choose affect your monthly mortgage payment and PMI cost. The down payment is the upfront equity you contribute at closing, expressed as a percentage of the purchase price. Common targets are 3% (some conventional first-time-buyer programs), 3.5% (FHA minimum), 5%, 10%, 15%, and 20%, the threshold at which PMI drops off conventional loans.

Key Features

The calculator projects a savings timeline using your current balance, monthly contribution, and savings-account interest rate, then shows exactly when you reach each down payment target. The projection accounts for compound interest on your accumulating fund: a 4–5% high-yield savings account earning interest over two to four years of saving makes a real difference compared to a checking-account rate.

For any down payment below 20%, the calculator estimates PMI (typically 0.5–1.5% of the loan amount annually) and projects when it will drop off as equity builds. Results include a side-by-side comparison of 5%, 10%, 15%, and 20% down payment scenarios across monthly P&I, PMI cost, and total loan cost, so you can see the trade-off between saving longer for a larger down versus buying sooner with PMI in place. If you set a specific dollar or percentage target, the calculator shows your current progress against that goal.

How to Use the Down Payment Calculator

Step 1: Enter Home Purchase Target

Enter the home price you are targeting, the interest rate you expect on the mortgage, and your preferred loan term (30 or 15 years most commonly).

Step 2: Enter Savings Information

Enter your current saved amount (already set aside for the down payment), the amount you can add each month, and the interest rate your savings account earns (use a high-yield savings account rate if applicable).

Step 3: Enter a Specific Down Payment Target (Optional)

Enter a specific down payment percentage or dollar amount if you have a target in mind. The calculator will show how many months until you reach that goal.

Step 4: Review the Results

Results include:

• Savings timeline: months until each down payment milestone (5%, 10%, 15%, 20%)
• For each scenario: required down payment amount, resulting loan amount, monthly P&I payment, estimated PMI cost (if applicable), and total loan cost
• Total savings at target date (including interest earned)
• PMI elimination timeline for each scenario

Practical Examples

Example: Saving for a $400,000 Home

A couple has $25,000 saved and can add $1,500/month to their down payment fund. Their savings account earns 4.5%.

• 5% down = $20,000: already reached, they can buy now
• 10% down = $40,000: need $15,000 more at $1,500/month with interest, roughly 9.5 months away
• 20% down = $80,000: need $55,000 more, roughly 33 months away

At 5% down on a $400,000 home: loan = $380,000 at 7% for 30 years. Monthly P&I: $2,529. PMI: approximately $158/month until 20% equity is reached (approximately 7.5 years of payments). Total monthly: $2,687.

At 20% down: loan = $320,000. Monthly P&I: $2,130. No PMI. Total monthly: $2,130. Monthly savings: $557. But it takes 33 more months of saving to get there, during which rent payments continue.

Example: Should You Wait for 20% Down?

If the couple is currently paying $2,200/month in rent, buying at 5% down with a $2,687 monthly payment costs $487 more per month than rent. Waiting 33 months to reach 20% down costs $2,200/month × 33 = $72,600 in rent with no equity building. Buying now at 5% down builds equity over those 33 months and may be financially superior depending on the market.

Tips and Best Practices

Do not wait years for 20% down if the market is appreciating. The cost of waiting (rent payments and home price appreciation) can easily exceed PMI costs. Run the comparison with realistic assumptions about rent, home price trends, and PMI duration.

High-yield savings accounts matter for your timeline. A savings account earning 4.5% versus 0.5% on a $25,000 balance adds meaningful time-value to your savings. Use a high-yield savings account or money market account earmarked for your down payment.

PMI is not permanent. Conventional loan PMI is automatically cancelled when your loan balance reaches 78% of the original appraised value (Homeowners Protection Act). You can request cancellation earlier at 80% LTV by contacting your servicer. PMI is not a life sentence.

Factor in closing costs in your savings goal. Down payment savings calculators model the down payment only. Closing costs are an additional 2–5% of the loan amount. Your total cash needed at the table is down payment + closing costs. Plan for both.

Consider state and local first-time homebuyer assistance. Many states and municipalities offer down payment assistance programs (grants, zero-interest second mortgages, or deferred-payment programs) that can reduce the cash required by thousands of dollars. Research what is available in your area before finalizing your savings target.

Common Issues and Troubleshooting

PMI amount seems high or low. PMI rates vary by lender, loan amount, down payment size, and credit score. This calculator uses a typical range estimate. Your actual PMI quote will come from the lender and appear on the Loan Estimate.

Timeline seems longer than expected. Verify that the monthly contribution is realistic and sustainable. Also check whether you are earning competitive interest on your savings. Increasing your monthly savings by even $200–$300 can shave months off the timeline.

Privacy and Security

All calculations run locally in your browser with no data transmitted externally.

Frequently Asked Questions

What is the minimum down payment to buy a house? Conventional loans have a 3% minimum for first-time buyers (Fannie Mae HomeReady and Freddie Mac Home Possible programs). Standard conventional minimum is 5%. FHA requires 3.5% with 580+ credit score. VA and USDA loans can require 0% down for eligible borrowers.

When does PMI go away? For conventional loans, PMI is cancelled automatically when the loan balance reaches 78% of the original appraised value (not current market value). You can request cancellation at 80% LTV by contacting your servicer and demonstrating via a new appraisal that you have reached the threshold. FHA MIP rules are different and more complex.

Is it better to put more money down? More down payment means a lower payment, no PMI, and less total interest, but it also means more cash tied up in real estate rather than diversified investments. The optimal down payment depends on your opportunity cost of capital, housing market expectations, emergency fund adequacy, and interest rate environment.

Related Tools

• Affordability Calculator: determine how much house you can afford before deciding on a down payment amount
• Coming Soon: Closing Costs Calculator: estimate the additional cash needed at closing beyond the down payment
• Coming Soon: Mortgage Calculator: calculate your exact monthly payment for any loan amount and down payment scenario