Acquisition Calculator
Seller financing calculator
Estimate the monthly payment and total interest on a seller note. Compare a fully amortizing loan with an earlier balloon payoff, or model a period without payments or interest accrual.
Principal carried by the seller
Enter the rate offered by the seller
From close of deal to final payment
Model assumes no payments or interest accrual during this period.
Lump-sum payoff before end of term
Seller financing payment example
A $75,000 note at 7% repaid over five years costs about $1,485 per month. Total interest is about $14,105. A balloon brings the remaining balance due sooner; it does not make that balance disappear.
This calculator amortizes the note over the total term minus standby months. If you select an earlier balloon, the regular payment uses that same amortization period and the remaining principal is due at the balloon month, in addition to that month's payment.
Using a seller note with an SBA loan
Under SBA SOP 50 10 8 (effective June 1, 2025), a seller note can count toward required equity only when it is on full standby for the life of the SBA loan, and it cannot exceed half the required injection. A 24-month deferral alone does not meet that condition.
Full standby concerns payments; this calculator also assumes no interest accrual. Confirm accrual, repayment, and eligibility with your lender using the applicable SBA SOP. This tool does not certify compliance. How seller financing actually works.
When a balloon makes sense
A balloon makes the remaining principal due before the full amortization period ends. In this calculator, moving the balloon earlier does not change the regular monthly payment. Compare the payoff with cash you realistically expect to have available; refinancing is not guaranteed.