Mortgage payment, affordability, rent vs buy and refinance math
Calculate principal & interest, sketch how much house a payment can support, compare 10-year rent vs buy cash flows, and estimate refinance break-even months. Free, private, no sign-up.
Tools
Mortgage payment (P&I)
Estimate monthly principal and interest, add tax/insurance/HOA inputs, and preview amortization sample rows. Private, educational, not a loan offer.
How much house
Sketch a home price from gross income, debts, a DTI rule of thumb, taxes/insurance and rate. Educational affordability only — not underwriting.
Rent vs buy
Compare roughly ten years of buying versus renting with appreciation, rent inflation, investment return on down payment and selling costs. Educational sketch only.
Refinance break-even
Estimate monthly P&I savings, closing and points cost, break-even months and net savings if you keep the home a set number of years.
Popular guides
How Mortgage Principal and Interest Works
Plain-English amortization: why early payments are interest-heavy and how term and rate shape principal and interest.
Understanding Debt-to-Income for Mortgages
Front-end and back-end debt-to-income concepts, why guidelines are not promises, and how payoff plans change DTI.
Refinance Costs and Break-Even Math
Closing costs, points, term resets and how to think about months to recover refinance costs.
A Practical Rent vs Buy Framework
Cash flow, opportunity cost, horizon risk and qualitative factors beyond a 10-year spreadsheet.
Reading a Loan Estimate
Walk through Loan Estimate sections: loan terms, projected payments, closing costs and comparisons shoppers should make.
First-Time Buyer Math Checklist
Down payment, closing costs, reserves, moving costs and payment stress tests for first-time buyers.
How we work
Calculators use transparent amortization and cash-flow arithmetic on the numbers you type. Guides cite the CFPB and related public sources. We are not a lender, broker or realtor. Read about HomeStack and our affiliate disclosure.