Business Loan Calculator for SBA Loans

An SBA loan calculator computes monthly repayments and total interest cost across the three main SBA programs — 7(a), 504, and Express — using current Prime-linked pricing and SBA guarantee-fee tiers. The 7(a) program is the SBA's general-purpose loan up to $5 million, 504 is fixed-asset and real-estate financing up to $5.5 million per project, and Express is a fast-track product up to $500,000 with a reduced 50% SBA guarantee (versus 75-85% on standard 7(a)). The SBA.gov SOP 50 10 7 and the SBA's quarterly fee notices are the authoritative sources for current program rules.

The three SBA programs each have a distinct rate cap, fee structure, and process timeline that the calculator's "loan amount + rate + term" inputs only partially capture — so context matters when interpreting the monthly payment number.

SBA-7(a) — general purpose, up to $5M - Maximum variable rate: Prime + 3.0% on loans above $350k, Prime + 4.5% on $50k-$350k, Prime + 6.0% on $25k-$50k, Prime + 6.5% on loans up to $25k (tiered to reflect underwriting cost on smaller loans) - Maximum fixed rate: tied to a quarterly SBA peg (typically Treasury-plus a small spread) - Term: up to 10 years for working capital, 25 years for real estate - Collateral: SBA requires lender to take all available collateral up to the loan amount; lender may not decline solely for lack of collateral if other underwriting is strong - Personal guarantee: required from any owner ≥20% equity; spousal guarantee may also be required in community-property states (AZ, CA, ID, LA, NV, NM, TX, WA, WI)

SBA-504 — fixed assets and real estate, up to $5.5M debenture - Structure: 50% bank first mortgage at market rate / 40% CDC-SBA debenture at sub-market fixed / 10% borrower equity - 504 debenture rate: ~6% fixed in 2026 (10-year Treasury plus a spread, set monthly by the CDC at debenture pricing) - Term: 10, 20, or 25 years (25-year option added in recent SBA reforms) - Use of funds restricted: must be fixed-asset purchase (real estate, heavy equipment) — no working capital or business acquisition

SBA Express — fast-track, up to $500k - 36-hour SBA decision - 50% SBA guarantee (vs 75-85% on standard 7(a)) means lender takes more risk and prices it accordingly - Maximum rate: Prime + 4.5% on loans above $50k, Prime + 6.5% below $50k - Often used for lines of credit and quick working-capital needs

SBA guarantee fees (tiered by loan size, 2026): - $0 - $1,000,000: 0% during current SBA fee-waiver windows (verify against the current SBA fee notice, as these are reset annually) - $1,000,001 - $1,500,000: 0.55% - $1,500,001 - $2,000,000: 0.75% - $2,000,001 - $5,000,000: 0.85% (subject to annual review) - All fees are charged on the guaranteed portion only, not the full loan amount

Worked example: A US food manufacturer takes a $500,000 SBA-7(a) loan at Prime + 2.75% — with Prime at 7.75% that's 10.5% APR — to fund a new processing line, 10-year fully-amortising. Using M = P × [r(1+r)^n] / [(1+r)^n − 1] with r = 0.105/12 = 0.00875 and n = 120, the monthly payment is $6,746.75. Total paid = $809,610. Total interest = $309,610 — about 62% of the original principal paid in interest over the 10-year term. The SBA guarantee fee on this loan (current waiver) is $0; outside the waiver window at 0% / 0.55% / 0.75% / 0.85% tiers, a $500k loan would carry no guarantee fee since it's below the $1M threshold.

SBA eligibility — the gating questions before rate math matters: - For-profit, US-based, operating in an eligible industry - Meets SBA size standards by NAICS code (most retail, manufacturing, and services are under 500 employees; some industries use revenue thresholds) - Owner has invested reasonable equity - Demonstrated repayment ability from business cash flow - Has exhausted other non-SBA financing options (or can demonstrate they would not be available)

Process timeline: SBA Express decisions in 36 hours, standard 7(a) decisions in 30-90 days, 504 in 60-120 days. The 504 timeline is the longest because the CDC, SBA, and bank all underwrite separately.

For authoritative current data, the SBA's SOP 50 10 7 (Small Business Lender Operating Procedures) sets all 7(a) and 504 underwriting and pricing rules, the SBA quarterly fee notices publish current guarantee fees, and individual CDCs (Certified Development Companies) publish current 504 debenture rates. Pair this calculator with /business-loan-calculator/us for conventional alternatives and /cash-flow-calculator/us to model affordability of the projected monthly payment.