A LITTLE CLARITY, BEFORE A BIG DECISION
Your next move.
With the math in view.
Stay, sell, keep a rental, rent somewhere else, or buy. Compare cash flow and wealth over time, then stress-test the mortgage behind the decision.
Built for the
“what if?”
Illustrative inputs · Your numbers stay in your browser
Zoom into the mortgage.
Estimated monthly ownership cost
Includes a maintenance reserve. Starts with your first payment month.
The ownership cost over time
Mortgage principal and interest can end before the ownership expenses do. Move the slider to inspect each year.
Principal grows as interest shrinks
Scheduled monthly principal and interest, before extra payments. Extra principal also reduces the next month’s interest.
Where the money goes
First monthA little rate change. A real difference.
WHAT IFSame home, down payment and term. See how the initial monthly ownership cost changes.
These are scenarios, not available offers. Fees and points stay unchanged.
Price that fits your monthly budget
Your current scenario, in context
Housing ratio uses principal, interest, tax, insurance, HOA and PMI. Total debt ratio adds other required debts. Both use gross income and exclude maintenance reserves and optional extra principal.
What’s left after closing?
The maximum price is a first-month budget calculation with a fixed dollar down payment. It does not limit price by your cash balance, predict qualification, or account for future cost growth.
Interest saved by your extra payments
The path to zero
Loan balanceExtra principal reduces debt, but puts cash into the home. Consider your emergency reserve, other debt rates, and alternative uses of the money. Taxes, insurance, HOA and maintenance continue after the mortgage is paid off.
SIDE BY SIDE
Same question. Different assumptions.
Pin your current numbers as Scenario A, then edit the inputs to explore Scenario B. Compare the same number of years, including what you still owe.
Principal payments turn cash into equity; they aren’t a borrowing expense. The cost comparison includes interest, PMI, ownership costs and your maintenance reserve, plus closing fees and points less credits. Prepaids are excluded to avoid counting the same bills twice. Home appreciation, investment returns, selling costs and tax benefits are not modeled.
CHECK THE MATH
Your amortization schedule
CSV includes all monthly rows, cost assumptions, extra payments and remaining balance. Payments and balances use full precision internally; displayed values are rounded to cents.
A TOOL YOU CAN QUESTION
Good math starts with
visible assumptions.
Use a real Loan Estimate and local ownership costs for a useful result. The example is just a starting point.
How is the monthly payment calculated?
For a fixed-rate, fully amortizing loan, the principal and interest payment is:
P is the loan amount (price minus down payment), r is the annual interest rate divided by 100 and then 12, and n is the term in months. At 0% interest, M = P ÷ n.
Each month, interest = starting balance × r. The rest of the scheduled payment reduces principal. Extra principal is applied afterward. The final payment and any extra are capped at the amount actually owed.
Why is the total higher than the mortgage payment?
The loan payment only repays principal and interest. The ownership budget also includes property taxes, assessments, insurance, HOA, PMI when applicable, and a maintenance reserve. Utilities, moving costs and extraordinary repairs are additional.
In California, property tax estimates should reflect the purchase’s assessed value and local levies. An old listing’s tax bill may not reflect your bill after purchase. Verify assessments and insurance quotes for the property.
When does PMI go away?
This model covers borrower-paid PMI on a conventional US mortgage. The home price is used as original value; if the appraisal is lower, the actual lender calculation will differ. No PMI is charged when the initial loan is 80% or less of that value.
Scheduled 78%: PMI stops in the month the original, no-extra-payment schedule reaches 78% of original value, or the month after the term’s midpoint, whichever comes first. Extra payments do not advance that scheduled cutoff.
Request at 80%: the model assumes approval when the actual balance reaches 80% of original value and removes PMI from the following month. You must request cancellation and meet payment history, lien and property-value requirements. Real approval may take longer. The scheduled automatic cutoff still applies.
FHA, VA, USDA, lender-paid insurance and high-risk exceptions follow other rules. This tool does not model those programs. CFPB: PMI cancellation ↗
What about biweekly payments, points and tax deductions?
To approximate 26 half-payments per year, add one scheduled principal-and-interest payment as an annual extra. This is a monthly approximation, not a true biweekly schedule: lender timing, daily interest and how partial payments are handled can change the result.
Points are included as cash paid at closing; enter the actual discounted rate from the lender’s quote. This tool does not assume a fixed rate reduction per point. APR includes financing charges and differs from the note rate used to compute your payment.
No income-tax benefit is subtracted. Deductibility depends on itemizing, debt limits, filing status, jurisdiction and current law. A combined federal/state rate shortcut can materially overstate savings.
What does the fixed-mortgage comparison leave out?
This fixed-mortgage tab holds the home’s value constant and uses nominal dollars. Equity is price minus remaining debt. It does not assume appreciation, rent savings, returns on invested cash, inflation discounting, resale expenses or tax deductions. A larger down payment changes liquidity and opportunity cost even when the expense comparison looks better. The Housing Options planner above models rent, appreciation, selling costs and invested cash explicitly.
Costs continue through the selected comparison horizon even if the loan is paid off earlier. Maintenance is money set aside, not a prediction of repair bills. Prepaids and escrow are included in cash to close but not added again to the cumulative cost. Credits are assumed to offset modeled closing costs; actual eligibility varies.
The schedule ends when the loan is paid off. Escrow refunds, prepaid timing and post-payoff ownership expenses are not part of that loan schedule. First-month affordability assumes ordinary required payments; extra principal is optional and shown separately.
How do sharing and saving work?
“Share mortgage” puts your fixed-mortgage inputs and pinned comparison into the link’s fragment (the part after #). Anyone with that link can read those numbers. Keep private income and cash amounts out of a link you don’t want to share; enter zero for them before copying. The site does not upload these values. “Share housing plan” also includes the housing planner, ARM inputs, property addresses and source notes. Anyone with the link can read them.
“Save on this device” stores the scenario in this browser only. The site has no accounts or third-party analytics. Its web host receives ordinary page requests; the calculator does not transmit form values. Downloaded CSV files and printed reports also contain your scenario inputs.
Read beyond the calculator.
Source guidance checked October 5, 2026. This tool is educational and is not affiliated with the CFPB. Confirm actual terms with your lender or servicer.