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Amortization Schedules
| Month | Payment | Interest | Principal | Balance | Cum. Interest |
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| Month | Payment | Interest | Principal | PMI | Balance | Cum. Interest |
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How this calculator works
Monthly payment formula: \( M = P \cdot \frac{r(1+r)^n}{(1+r)^n-1} \) where \(P\) is principal, \(r\) is monthly rate, and \(n\) is months. Current payment is derived from remaining balance, current APR, and remaining term. New payment is based on the newly computed principal after payoff, cash-out, and optional rolled-in costs and points.
Loan size when rolling costs: Let base be payoff + cash-out and fees be lender + third-party + government costs. If you roll costs in and points are k (e.g., 1 point = 0.01), the new principal solves \( L = \frac{base + fees}{1-k} \). If you pay costs upfront, then \( L = base \) and upfront costs = fees + \(k \cdot L\).
Break-even: We show a simple break-even (total costs divided by first-month savings) and a modeled break-even that sums monthly savings until they offset costs, accounting for PMI dropping off. NPV: Monthly savings are discounted at your chosen rate over your horizon; upfront costs count as a cash outflow at month 0.
APR estimate: We approximate by solving the rate that equates the present value of scheduled payments to the amount financed (new principal minus prepaid finance charges = points + fees).
Disclaimers: This tool is for education only and is not advice. Rates, fees, and PMI rules vary by lender and product. Taxes and insurance are pass-through escrow items and not finance charges. Always verify details with a licensed professional.