Amortiza Loan Planner

Use this when the user wants a mortgage calculator, loan calculator, or amortization calculator result: the monthly (or biweekly/weekly) payment, an amortization schedule or table, total interest, payoff date, a mortgage calculator with extra payments or for paying off early, or a full PITI payment with property tax, insurance, HOA and PMI. Takes the loan amount or home price with down payment, rate, and term. Returns exact payment, totals, interest and time saved by extra payments, a yearly summary, and a CSV of the full schedule. Fixed-rate loans only; does not model adjustable rates, interest-only or balloon loans, and does not look up current rates. Do not use for rent-vs-buy advice or choosing a lender.

Use this when the user wants to compare 2 to 4 loan or mortgage options side by side, such as 15-year vs 30-year, different interest rates, paying discount points, or a mortgage calculator for refinance options. Shared values (loan amount, rate, term) go at the top level and each scenario overrides what differs. Returns payment, total interest, upfront costs, total cost, payoff date and the break-even month for points or fees, plus a comparison CSV. Fixed-rate loans only; does not look up current rates or recommend a lender. Do not use for a single loan (use calculate_loan).