Estimate the monthly payment, amount financed, and balloon balance due when a seller finances part or all of a property or business sale.
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$
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yrs
yrs
Results
Calculated
Monthly Payment
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Principal & interest, amortized
Amount Financed
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Sale price minus down payment
Balloon Balance Due
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Remaining principal at balloon date
Total Interest Paid
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Through the balloon date or full term
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How to use the Seller Financing Calculator
Enter the sale price, the buyer's down payment, the annual interest rate the seller is charging, and the amortization term used to size the monthly payment. If the deal includes a balloon payment — common in seller financing — enter the number of years until the full balance is due; use 0 if the loan is fully amortized with no balloon. Click Calculate to see your results, or Reset to start over.
Understanding the inputs
The amount financed is the sale price minus the down payment — this is the principal the buyer repays to the seller over time. The amortization term determines how the monthly payment is calculated: a longer term produces a smaller payment. The balloon term is separate — it is when the buyer must pay off whatever principal is still outstanding, typically by refinancing with a bank or selling the asset.
Interpreting the results
The monthly payment is the amount due each month toward principal and interest, calculated with the standard loan amortization formula. The balloon balance due shows how much principal remains unpaid at the balloon date — the lump sum the buyer needs to refinance or pay off. If the balloon term is 0 or reaches the full amortization term, the loan pays itself off completely with no balloon due. Total interest paid reflects everything the seller earns in interest through that date.
Frequently Asked Questions
What is seller financing?
Seller financing, also called owner financing, is when the seller acts as the lender: instead of the buyer getting a mortgage from a bank, the buyer pays the seller directly in monthly installments based on an agreed sale price, down payment, interest rate, and term.
How is the monthly payment calculated?
The monthly payment uses the standard loan amortization formula, M = P x [i(1+i)^n] / [(1+i)^n - 1], where P is the amount financed (sale price minus down payment), i is the monthly interest rate, and n is the number of monthly payments in the amortization term.
What is a balloon payment in seller financing?
Many seller financing deals amortize the loan over a long period, such as 20 or 30 years, to keep monthly payments affordable, but require the full remaining balance to be paid off much sooner - often 3 to 7 years in - through a lump-sum balloon payment, usually funded by refinancing with a bank.
Is seller financing better than a bank loan?
Neither is universally better. Seller financing can close faster and work around strict bank underwriting, and it lets the seller earn interest income, but it typically carries a higher interest rate and a shorter balloon term than a conventional mortgage. Compare the monthly payment and balloon date against bank loan terms before deciding.
Practical Guide for Seller Financing vs Bank Loan Calculator
Seller Financing vs Bank Loan Calculator is most useful when the inputs reflect the situation you are actually planning around, not a best-case estimate. Treat the result as a decision aid: it gives you a structured way to compare assumptions, spot outliers, and decide what to verify next. For Finance work, the most important review lens is cash flow, timing, rates, risk tolerance, and the reliability of each assumption.
Start with a baseline run using values you can defend. Then change one assumption at a time and watch which output moves the most. If one input dominates the result, spend your verification time there first. If several inputs have similar influence, use a conservative scenario and an optimistic scenario to create a practical range instead of relying on a single exact number.
Before acting on the result, compare the result with bank statements, invoices, amortization schedules, or accounting exports before making a commitment. This is especially important when the calculator supports a purchase, project plan, performance target, or operational decision. The calculator can make the math consistent, but the quality of the conclusion still depends on current data, clear units, and assumptions that match your real constraints.
When the output looks surprising, slow down and inspect each input in order. A small change in one high-leverage field can move the final number more than several low-leverage fields combined. For Seller Financing vs Bank Loan Calculator, that means you should first confirm the value with the greatest scale, then confirm the value with the greatest uncertainty, then rerun the calculator with conservative and optimistic assumptions. This sequence turns the calculator from a single answer into a practical decision range.
Review Checklist
Confirm every input uses the unit and time period requested by the calculator.
Run a low, expected, and high scenario so the answer has a useful range.
Check whether rounding or a missing decimal place changes the decision.
Update the calculation monthly or whenever income, rates, expenses, or balances change materially.