Real Estate Multi-Tool Workspace

Home Buyer Mortgage & Housing Decision Desk

Model your true monthly homeownership commitment before making an offer. Simultaneously calculate Principal & Interest, local county property taxes, hazard insurance, private mortgage insurance (PMI) requirements, and lifetime debt service costs.

Home Buyer Financial Decision Desk

$2,902 / month

Principal & Interest: $2,335 | Tax & Ins: $567

Loan & Property Parameters

Home Purchase Price ($)

Down Payment (%)

Down Payment ($)

Interest Rate (%)

Term (Years)

Property Tax (%/yr)

Home Insurance ($/yr)

Monthly HOA Dues ($/mo)

Loan Principal

$360,000

Loan-to-Value (LTV): 80%

Total Lifetime Interest

$480,600

Over 30 years

Monthly Payment Breakdown

P&I: $2335

Tax: $450

Ins: $117

Specialized mortgage calculators:

Mortgage•Refinance•FHA Loan•HELOC•Down Payment

The PITI Formula & Lending Ratios

Lenders evaluate prospective borrowers using the Front-End Debt-to-Income (DTI) ratio, which measures total monthly housing expenses (Principal, Interest, Property Taxes, and Homeowners Insurance — PITI) against gross monthly income. Most conventional conforming loans require front-end DTI to remain below 28% to 36%.

When down payments are below 20% (Loan-to-Value greater than 80%), conventional mortgage guidelines mandate Private Mortgage Insurance (PMI), which typically adds 0.5% to 1.5% of the total loan balance per year until 20% equity is established.

Worked Numeric Example: 20% Down vs. 10% Down

Evaluating a $450,000 home purchase under a 30-year fixed loan at 6.75% interest with 1.2% annual property taxes ($450/month) and $1,400/year homeowners insurance ($117/month):

20% Down Payment ($90,000 down, $360,000 loan): Monthly Principal & Interest is $2,335. Total monthly PITI equals $2,902/month ($2,335 P&I + $450 taxes + $117 insurance). PMI is $0.
10% Down Payment ($45,000 down, $405,000 loan): Monthly Principal & Interest is $2,627. Adding an estimated 0.75% PMI ($253/month) along with taxes and insurance results in a total monthly PITI of $3,447/month.
Buyer Takeaway: Putting 20% down saves $545 per month ($253 in avoided PMI plus $292 in reduced principal & interest financing costs).

Client-Side Privacy & Processing Note

All mortgage modeling, down payment calculations, and PDF export rendering execute entirely inside your local web browser runtime. Zero income figures, purchase prices, or loan specifications are transmitted across network requests or stored on remote servers.