Down Payment Calculator

Use our free Down Payment Calculator to quickly estimate how much down payment you'll need and how it affects your monthly mortgage, based on home price and loan terms. Perfect for homebuyers and real estate investors.

Get Started

Down Payment Formula

Down Payment = Home Price × (Down Payment % ÷ 100) Loan Amount = Home Price − Down Payment Monthly P&I = Loan Amount × [ r(1 + r)^n ÷ ((1 + r)^n − 1) ] where: - r = monthly interest rate (APR ÷ 12) - n = total number of payments (years × 12)
Example:
Home Price = $400,000; Down Payment = 20% ($80,000); Loan = $320,000 APR = 6%; Term = 30 years (360 months) Monthly P&I = 320,000 × [0.005(1.005^360) ÷ ((1.005^360) − 1)] ≈ $1,919

Down payment size affects your loan balance, monthly payment, and whether you'll need private mortgage insurance (PMI).

How this down payment calculator works

This calculator estimates required down payment and resulting loan amount by applying standard mortgage formulas. It shows how larger down payments reduce monthly costs and long-term interest.

When to use this down payment calculator

To budget for a home purchase before applying for a loan

Comparing how different down payment percentages affect monthly payments

Determining if you can avoid PMI with 20% down

Planning savings goals for buying a home

Evaluating affordability across different property price points

Want to make your mortgage planning smarter?

Use ServiceAgent.ai to automate estimates, manage proposals, and track profitability—all from one dashboard.

Book a Free Demo
ServiceAgent ROI Calculator

Average Profit Margins by Industry

Understand how mortgage lending compares to other service industries. Below are typical profit margin ranges:

Mortgage Lenders

15–25%
net margin

Banks & Financial Institutions

20–30%
net margin

Real Estate Agents/Brokerages

15–30%
net margin

Roofing Contractors

20–40%
net margin

HVAC Contractors

10–20%
net margin

Plumbing Contractors

20–35%
net margin

Electrical Contractors

15–25%
net margin

Construction/Contracting

15–30%
net margin

These benchmarks help borrowers and financial planners evaluate whether their home financing strategy is competitive.

Frequently Asked Questions

It provides reliable estimates using your home price, down payment, and loan details.

Standard is 20%, but some loans allow as little as 3–5%.

Yes—larger down payments reduce monthly payments and total interest.

Yes—just enter the purchase price and desired down payment.

No—add PMI separately if your down payment is below 20%.

Yes—enter multiple scenarios to compare affordability.

No—this calculator shows principal and interest only.

Pair it with ServiceAgent.ai to generate automated affordability reports and proposals.

Looking for other useful tools?

Service Pricing Calculator

Labor Cost Calculator

Profit Margin Calculator