Mortgage Calculator with Taxes, PMI & Extra Payments

Understanding the Four Elements of PITI

Lenders calculate your monthly mortgage payment as a composite figure called PITI:

• Principal: The money that directly repays your loan balance. Early in your mortgage, only a small fraction of your payment goes toward principal; over time, this reverses as equity builds.
• Interest: The fee charged by the lender for borrowing funds, determined by your loan rate. According to IRS Topic 504, mortgage interest on primary homes may be tax-deductible for itemizers.
• Taxes: Real estate property taxes assessed by your municipal and county tax authorities. Your mortgage servicer collects 1/12th of this estimated annual tax bill each month in an escrow account.
• Insurance: Hazard and homeowners insurance protecting the physical structure. Like taxes, this is held in escrow and paid out annually by your lender.

The Mechanics of Loan Amortization: Why Interest is Front-Loaded

Fixed-rate mortgages use an amortization schedule designed to keep your total monthly Principal and Interest payment exactly the same for all 360 months (on a 30-year loan). However, the internal distribution between principal and interest shifts constantly:

Because interest is calculated as a percentage of your remaining unpaid balance, the interest charge is highest in Month 1 when your loan balance is largest. On a $320,000 mortgage at 6.75%, your first monthly P&I payment of $2,075 includes approximately $1,800 in interest and only $275 in principal.

By Year 15, the split becomes roughly 50/50. By Year 25, the vast majority of your monthly payment goes toward eliminating principal. This mathematical reality is why making even small extra principal payments during the first five years yields such extraordinary long-term savings.

How PMI Works and When It Automatically Drops Off

When buying a home with less than 20% down, conventional lenders require Private Mortgage Insurance (PMI). PMI protects the lender in case you default on the loan. It typically costs between 0.5% and 1.5% of your original loan amount annually ($125–$375/month on a $300,000 loan).

Under the federal Homeowners Protection Act of 1998:

• At 80% Loan-to-Value (LTV): You have the legal right to submit a written request to your lender to cancel PMI once your regular payments bring your principal down to 80% of original value.
• At 78% LTV: The lender is legally required to automatically terminate PMI, provided your payments are current.

Our calculator projects your exact PMI drop-off month and date so you know precisely when to expect this monthly expense to disappear.

15-Year vs. 30-Year Mortgages: The Lifetime Cost Tradeoff

Choosing between a 15-year and a 30-year fixed loan is a balance between monthly cash-flow flexibility and total interest expense:

• 30-Year Mortgage: Lower required monthly payments give you breathing room to fund retirement accounts via a 401(k) or Roth IRA and invest for long-term growth. However, total interest paid often exceeds the original home loan itself.
• 15-Year Mortgage: Higher monthly payments build equity at rapid speed, offer lower interest rates (typically 0.5%–0.75% lower), and save $150,000–$250,000 in total interest on an average loan.

A popular middle ground is securing a 30-year mortgage for cash-flow safety, while voluntarily paying extra principal each month whenever your budget allows.

The Power of Extra Principal Payments

Because mortgage interest is charged monthly on your outstanding balance, prepaying principal delivers an immediate, risk-free return equal to your mortgage rate.

For example, adding $250 per month to a $320,000 30-year loan at 6.75% eliminates nearly 7 years of payments and saves over $100,000 in total interest. Use the "Extra Monthly Principal" input above to simulate custom payoff schedules. If you are comparing your existing mortgage to new market rates, evaluate refinancing options with our Refinance Calculator.

Common Mortgage Pitfalls to Avoid

• Ignoring Property Tax Increases: Property taxes can rise after purchase when the local municipality reassesses the home at its new purchase price.
• Overlooking HOA Special Assessments: In condominium and planned communities, HOA dues can increase, and unexpected capital repairs may result in lump-sum assessments.
• Draining All Savings on the Down Payment: Keep at least 3 to 6 months of living expenses in an emergency fund rather than putting every dollar toward the down payment.
• Not Shopping Multiple Lenders: The CFPB reports that obtaining loan estimates from at least three different lenders saves borrowers an average of $3,000 in upfront costs and thousands in interest.