SBA Loan Payment Calculator

Enter your loan details to see your estimated monthly payment, total interest cost, and full amortization schedule. Works for SBA 7(a) loans, conventional business loans, and seller notes.

This page is built for acquisition modeling, not just generic loan math. A buyer needs to know whether the business can support the payment after closing, how much equity injection is required, and how the debt layer interacts with seller financing, assumed liabilities, and working-capital needs. Use the calculator to pressure-test a purchase price before you send an LOI or ask a lender for a term sheet.

When to Use This Calculator

Use this calculator when you have a target purchase price and want to estimate the monthly payment on the bank-financed portion of the acquisition. It is most useful after you have a preliminary valuation range, a rough down payment target, and a sense of whether the seller may carry a standby note. If you are still deciding what the business is worth, start with the SDE / EBITDA calculator first, then bring the likely debt amount back here.

The result is also useful for comparing deal structures. A lower purchase price with a shorter term may produce a higher payment than a higher purchase price with a longer amortization. A seller note on standby can reduce the cash due at closing without immediately increasing monthly debt service. A real estate-heavy acquisition may qualify for a longer amortization than a pure goodwill acquisition. Those differences can determine whether the deal clears lender underwriting.

Inputs and Assumptions

Loan amount should be the total bank debt you expect to borrow, not necessarily the full purchase price. If the seller is financing part of the price or you are bringing an equity injection, subtract those amounts before entering the loan amount. Down payment is the cash equity you contribute outside the loan. For an SBA acquisition, this may include buyer cash, eligible investor equity, or in some cases a seller note that meets lender and SBA requirements.

Annual interest rate should reflect the fully loaded note rate quoted by the lender. SBA 7(a) rates are negotiated between borrower and lender but are subject to SBA maximums tied to a base rate. The calculator does not forecast future rate resets; if your loan is variable, run a downside case at a higher rate so you can see how sensitive cash flow is to payment changes.

Loan term controls amortization. A 10-year term is a common acquisition assumption for goodwill-heavy deals, while real estate can support a longer period. The calculator treats payments as level monthly payments and assumes the loan amortizes fully over the selected term.

How to Read the Results

The monthly payment is only the starting point. Multiply it by 12 to estimate annual debt service, then compare that annual debt service to normalized SDE or EBITDA. Lenders usually want a cushion between cash flow and required payments. If the business earns $250,000 in dependable SDE and the modeled annual debt service is $210,000, the deal leaves very little room for taxes, working capital, repairs, or buyer salary. If debt service is $140,000, the same business has a much healthier margin of safety.

The amortization schedule shows why early cash flow can feel tight. In the first years of an amortizing loan, a larger share of the payment goes to interest. That matters if you plan to refinance, resell, or raise new debt soon after closing because the principal balance may not decline as quickly as expected.

Worked Example

Assume a buyer is acquiring a service business for $750,000. The lender finances $600,000, the buyer contributes $75,000, and the seller carries a $75,000 standby note. At a 10.5% annual rate over 10 years, the bank loan produces a monthly payment that must be supported by post-close cash flow. If the business has $220,000 of verified SDE, the buyer should compare the annual payment to that SDE, then reserve additional cash for payroll timing, insurance renewals, equipment repairs, and transition expenses. A deal that looks affordable on purchase price alone can fail once monthly debt service and working capital are modeled together.

SBA 7(a) Loan Basics

The SBA 7(a) loan is the most common financing tool for small business acquisitions. Key parameters:

• Maximum loan amount: $5 million
• Maximum term: 10 years for working capital and equipment; 25 years for real estate
• Down payment: typically 10% for acquisitions (seller note can satisfy part of this)
• Interest rate: variable, tied to the Wall Street Journal Prime Rate plus a lender spread. As of mid-2026, fully-loaded rates are commonly 10%—11.5% for acquisition loans.
• Guarantee fee: SBA charges a guaranty fee on the guaranteed portion (2%—3.5% depending on loan size), typically rolled into the loan amount
• Prepayment penalty: applies only to loans with terms 15 years or longer, in the first 3 years

How SBA Loan Payment is Calculated

SBA 7(a) loans use standard amortizing loan math: each monthly payment covers interest accrued on the outstanding balance plus a portion of principal. Early payments are mostly interest; later payments are mostly principal. This calculator uses the standard annuity formula:

Monthly Payment = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1]

Where P = principal (loan amount minus down payment), r = monthly interest rate (annual rate ÷ 12), and n = total number of payments (years × 12).

Model the Full Deal Stack

An SBA loan is one layer in a deal structure. Use the AcquireCalc deal calculator to model how the SBA loan interacts with seller financing, asset-based funding, and earnouts — and see your true cash needed at closing.