How to Get the Most Out of Our Mortgage Calculator
Our mortgage calculator looks straightforward, but a few of the inputs trip people up. Here's what each one really means and how to fill it in for a realistic estimate.
Home price
The full purchase price, before any down payment. Use the asking price for a rough estimate, or the price you've actually agreed once you have a contract.
Down payment %
How much you'll pay up front, as a percentage of the home price. 20% lets you avoid private mortgage insurance (PMI) on a conventional loan. Anything less and your lender will likely add PMI of roughly 0.3–1.5% per year of the loan balance.
Interest rate
The rate your lender has quoted you, not the headline rate in news articles. Rates vary based on credit score, loan-to-value ratio, and the lender's pricing on the day you lock. Even a 0.25% difference adds tens of thousands over 30 years on a typical loan.
Loan term
Most U.S. mortgages are 30 years. A 15-year loan typically gets a lower rate (roughly 0.5–0.75% less), saves substantial interest, but doubles your monthly principal payment.
Property tax & insurance
These vary enormously by location. Your realtor or the county assessor can give a typical figure for the area. Don't skip these — they're a real and ongoing cost.
Extra monthly payment
Optional but powerful. Plug in even $100 and look at the "payoff time" and "total interest" change — that's the magic of paying down principal earlier in the amortization curve.