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Down Payment Calculator
How much is the down payment on a house? This down payment calculator works it out from the home price and the percent you put down — and shows the loan amount, the loan-to-value, and whether PMI applies.
How to use this calculator
- Enter the home price.
- Enter the down payment as a percent of the price.
- Enter the rate and term to see the monthly principal and interest too.
- The calculator shows the down payment in dollars, the loan, and whether PMI applies.
Formula and method
Down payment = home price × down payment percent. Loan amount = home price − down payment. Loan-to-value (LTV) = loan / home price. When LTV is over 80% — that is, when the down payment is under 20% — most lenders charge PMI. Principal and interest come from the standard amortization formula on the loan amount.
Worked example
$400,000 home, 10% down: the down payment is $40,000, the loan is $360,000, loan-to-value is 90%, and PMI applies. Principal and interest at a 6.5% example rate over 30 years are $2,275.44 a month.
20% down on the same home is $80,000, the loan is $320,000, loan-to-value is 80%, and no PMI applies. Principal and interest are $2,022.62 a month. 5% down is $20,000, the loan is $380,000, loan-to-value is 95%, and principal and interest are $2,401.86 a month.
Frequently asked questions
How much is 10% down on a $400,000 house?
$40,000, leaving a $360,000 loan at 90% loan-to-value. PMI applies, and at a 6.5% example rate over 30 years the principal and interest are $2,275.44 a month.
How much is 20% down on a $400,000 house?
$80,000, leaving a $320,000 loan at 80% loan-to-value. No PMI applies at 20% down, and principal and interest at a 6.5% example rate over 30 years are $2,022.62 a month.
Is 20% down always needed to buy a house?
No. Many buyers put down 3%, 5% or 10%, and some loan programs allow even less. Less down means a bigger loan, a bigger monthly payment and PMI — but it also means you can buy sooner. The 20% figure matters because it is the point where PMI drops away.
What is a good down payment on a house?
It depends on your savings, the price and your plans. 20% avoids PMI and keeps the payment lower. A smaller down payment keeps cash in hand for moving, repairs and emergencies. There is no single right answer — compare the monthly cost of each option above.
Does a bigger down payment lower the interest rate?
Sometimes, a little. Lenders may offer a slightly better rate at a lower loan-to-value, but the main saving from a bigger down payment is the smaller loan and no PMI — not the rate.
Sources and method. Standard amortization formula: monthly rate r = annual rate / 12, n = years × 12, payment M = P × r × (1+r)n / ((1+r)n − 1). PMI usually ends when the loan balance reaches 80% of the home value (Consumer Financial Protection Bureau guidance). Affordability uses the 28/36 rule of thumb used by many lenders. Rates in examples are examples only, not live market rates. Results are estimates, not financial advice.
Estimate, not financial advice. This calculator uses the standard amortization formula and the numbers you type in. It is not a loan offer and not financial advice. A lender will check your credit, income and debts and quote its own rate and fees before you borrow.