Down Payment Calculator

Your down payment is the largest upfront cost in buying a home. It determines your loan amount, monthly payment, and whether you need Private Mortgage Insurance (PMI). A 20% down payment avoids PMI entirely. This calculator shows the impact of different down payment amounts on your total housing costs.

How to Use This Tool

Enter the total home price you are considering.
Enter your planned down payment percentage.
Enter the expected mortgage interest rate.
Enter the loan term in years (30 or 15 are most common).
Click Calculate to see your down payment, loan amount, and monthly costs.

The Formula

Down payment = Home Price x Down Payment %. Mortgage payment uses the amortization formula: M = P x [r(1+r)^n] / [(1+r)^n - 1] where P is loan amount, r is monthly rate, n is number of payments. PMI is charged when down payment < 20%.

Why It Matters

You are a first-time homebuyer with $70,000 saved. For a $350,000 home, a 20% down payment ($70,000) avoids PMI entirely. But with only 10% down ($35,000), you keep $35,000 in reserves — though you will pay ~$150/month in PMI. This calculator shows the tradeoff between monthly cost and emergency savings.