Enter both as separate loan scenarios. The calculator shows monthly payment, total interest paid, and total cost of ownership for each. A 15-year typically has a lower rate and cuts total interest by 50-60%, but the monthly payment is 40-50% higher. The amortization chart shows you when the crossover point happens.

Private Mortgage Insurance (PMI) is required on conventional loans when your down payment is under 20%. It typically costs 0.5-1.5% of the loan amount annually. Under the Homeowners Protection Act, lenders must cancel PMI when your loan-to-value reaches 80% based on the original purchase price. The calculator tracks your LTV monthly so you know exactly when you're PMI-free.

One discount point costs 1% of the loan amount and typically reduces your rate by 0.25%. To evaluate it, calculate your monthly payment savings and divide the upfront cost by that savings — that's your break-even in months. If you plan to keep the loan longer than the break-even period, points make sense. The comparison tool lets you model both scenarios side by side.

Mortgage rates vary significantly by credit score. Borrowers with scores above 760 typically get the best rates advertised. Each 20-point band below 760 adds roughly 0.125-0.25% to your rate. Get a real rate quote from at least three lenders before using those numbers in the calculator — advertised rates are often best-case.