Mamble Calculators

Calculates front-end (housing-only) and back-end (all-debt) debt-to-income ratios given gross monthly income and monthly debt obligations. Returns whether the borrower likely qualifies for conventional financing (back-end DTI ≤ 43%) and remaining monthly debt capacity. Use when a user wants to know their DTI, whether they qualify, or how much additional debt they can take on.

Calculates the full monthly mortgage payment breakdown including principal & interest, property tax, homeowners insurance, PMI, and HOA fees. Also returns total interest paid over the loan term. Use when a user wants to know their expected monthly housing cost, how down payment affects payment, or the total cost of a loan. Set includeSchedule=true to receive the full month-by-month amortization schedule.

Calculates monthly PMI cost, LTV ratio, and the estimated month/year when PMI can be removed (accounting for principal paydown and home appreciation). Returns total PMI cost until removal and the payment difference with vs. without PMI. Use when a user wants to know their PMI cost, when they can cancel PMI, or whether to make a larger down payment to avoid PMI entirely.

Estimates a potential prepayment penalty from user-entered balance, prepayment amount, and penalty terms (none, percent of prepayment, percent of balance, months of interest, or flat fee). Returns separated remaining balance, prepayment, penalty, and estimated cash required to prepay. Optional comparison only when comparisonMode is set with user-supplied savings. Educational only — not legal interpretation.

Compares 15-year (program A) and 30-year (program B) fixed-rate mortgages on the same loan amount with separate user-supplied rates. Returns monthly P&I, total interest, principal paid and equity built through expected ownership, payoff dates, interest saved with 15-year term, additional equity with 15-year, and months until cumulative interest savings exceed extra 15-year payments. Educational only — not live pricing.

Compares buying (program A) vs renting (program B) over expected stay years. Returns separated ownership cash flow, home equity, renter investment portfolio (opportunity cost), net worth at horizon assuming home sale, break-even year, and yearly snapshots. User-supplied appreciation, rent growth, and investment return — educational only, not investment or tax advice.

Compares FHA (program A) and conventional (program B) loans on the same property and down payment. Returns monthly loan payments, total monthly housing (with tax/insurance), upfront cash, and estimated loan cost over the user's expected ownership years. FHA UFMIP and annual MIP rates and conventional PMI rate are user assumptions — not live lender pricing or an approval decision. Identifies lower monthly loan payment and lower loan cost over ownership; optional break-even ownership years when cumulative loan costs intersect.

Compares two mortgage loan options (Loan A vs Loan B) on the same property. Returns monthly payment, total interest, upfront costs, and total lifetime cost for each loan, plus the difference in monthly payment, upfront cost, and lifetime cost between them. Identifies which loan has the lower lifetime cost. Supports comparing different rates, terms, points, and closing costs. Use when a user has two loan offers and wants to know which is better.

Estimates the maximum home price a buyer can afford based on income, debts, down payment, and expected mortgage rate. Applies the standard 28/43 DTI rule: housing payment ≤ 28% of gross income (front-end) and all debts ≤ 43% (back-end). Returns max home price, required down payment, total cash needed at closing, estimated monthly payment breakdown (P&I, tax, insurance, PMI, HOA), front-end and back-end DTI ratios, and which constraint is binding. Use when a user asks "how much house can I afford?" or "what is my buying power?".

Estimates potential buyer closing costs and cash to close from user-supplied itemized lines: loan costs, title/settlement, prepaids, escrow reserves, and credits. Returns category subtotals, net closing costs, down payment, cash to close, prepaid interest per day, and recurring monthly escrow. Educational only — not live title/escrow quotes or Loan Estimate/Closing Disclosure.

Generates an educational fixed-rate amortization summary: monthly P&I, total interest, illustrative payoff date, year-by-year principal/interest totals with cumulative amounts, and first-five-year milestones (remaining balance, interest share). Full month-by-month schedule is available via API with includeSchedule=true — omitted from MCP/widget by default. Not for ARM, interest-only, or loans with extra payments (use analyze_extra_payments).