AtlasCalcsUtility Calculation Suite
2026-09-21 7 min read

SBA 504 Loan Calculator

The SBA guarantee, guaranty fee and resulting payments for a business loan. Live calculator with worked steps, charts.

Calculator

Loan Amount Help
$

The amount you borrow, before fees are deducted.

SBA Loan Programme
Annual Interest Rate(%)
%
Loan Term(years)
years
Extra Months(months)
months
Payment Frequency
Advanced options (1)
SBA Guaranty Fee (% of guaranteed portion)(%)
%

This business & sba loans calculator runs on the standard amortisation model: interest is charged on the outstanding balance each month, and anything extra you enter is applied to principal immediately.

Results

Optimal

Total Monthly Payment

$8,002.58/month

Bank and CDC portions combined.

Bank Portion (50%)

$500,000

8.50% — typically a 10-year term with a 20-year amortisation.

CDC / Debenture Portion (40%)

$400,000

9.25% debenture rate.

Borrower Contribution (10%)

$100,000

Bank Payment

$4,339.12/month

CDC Payment

$3,663.47/month

Total Interest Over the Term

$1,020,620

Total Project Cost

$1,000,000

Live results update as you type — currently showing total monthly payment of $8,002.58 /month on 12 payments a year. Replace the defaults with your own quote for an exact comparison.

Visualizations

Monthly Payment by Portion

4,339Bank
3,663CDC

504 Structure

Bank 50%50%
CDC 40%40%
Borrower 10%10%

Formula

The SBA guarantees a percentage of the loan and charges the lender a fee on that guaranteed portion. The borrower keeps the full amortisation at the note rate.

Guaranty fee = Guaranteed portion × fee % Guaranteed portion = Amount × guarantee %

Variables

SymbolNameUnitDescription
AmountLoan amountcurrencyTotal amount financed
Guarantee %SBA guaranteepercent75%, 85% or 50% depending on programme and size
FeeGuaranty feecurrencyCharged on the guaranteed portion

Explanation

This is how much of the loan is guaranteed, what the guaranty fee costs and what the resulting payments look like.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

SBA 504 splits the project 50% bank, 40% certified development company and 10% borrower.

Bank = 50 ÷ 90 · CDC = 40 ÷ 90 of the financed amount
Financed amount:$900,000
Result: $500,000 bank + $400,000 CDC
Step 2

Price each portion on its own rate and term.

P = A × i ÷ (1 − (1 + i)^−n)
Bank rate:8.50%
CDC rate:9.25%
Result: $4,339.12 + $3,663.47
Step 3

Add the borrower contribution and total the payments.

Total monthly = bank + CDC
Result: $8,002.58 /month
Final Answer
$8,002.58

Worked Examples

See how the calculator works with different scenarios.

Scenario

The sba 504 loan calculator run on the values above, showing the full calculation path rather than only the answer.

Inputs

Amount:900000
Rate:8.5
Years:20
Frequency:monthly (12 per year)

Calculation

1. SBA 504 splits the project 50% bank, 40% certified development company and 10% borrower. → $500,000 bank + $400,000 CDC 2. Price each portion on its own rate and term. → $4,339.12 + $3,663.47 3. Add the borrower contribution and total the payments. → $8,002.58 /month

Result

Total Monthly Payment: $8,002.58 /month

Interpretation

504 structure on $900,000: $500,000 bank at 8.50% plus $400,000 CDC at 9.25% gives $8,002.58 /month with a $100,000 borrower contribution.

Understanding Your Result

Your Result: Total Monthly Payment: $8,002.58 /month

Typical range: 504 projects require a 10% borrower contribution (15% for startups) and combine a 50% bank loan with a 40% SBA debenture, usually over 20 years.

What This Means

This is how much of the loan is guaranteed, what the guaranty fee costs and what the resulting payments look like.

Why It Matters

504 structure on $900,000: $500,000 bank at 8.50% plus $400,000 CDC at 9.25% gives $8,002.58 /month with a $100,000 borrower contribution.

Professional Interpretation

504 structure on $900,000: $500,000 bank at 8.50% plus $400,000 CDC at 9.25% gives $8,002.58 /month with a $100,000 borrower contribution.

How this is calculated

The SBA guarantees a percentage of the loan and charges the lender a fee on that guaranteed portion. The borrower keeps the full amortisation at the note rate.

What drives the result

Commercial lenders look at the source of repayment first and the collateral second. Revolving facilities price on utilisation and committed balances, asset-based lines advance a percentage of eligible collateral, and government-guaranteed loans trade a fee for a longer term and a lower rate.

Recommendations

  • •504 debentures are fixed-rate and asset-backed — they suit owner-occupied real estate and heavy equipment rather than working capital.
  • •Confirm current debenture pricing with the CDC: the rate is set when the debenture is sold, not at application.

Educational Content

Introduction

Business credit is priced on structure as much as on rate: guaranty fees, advance rates against collateral, draw periods and annualised factoring costs all sit on top of the interest rate. These calculators put the whole facility — not just the note — into one view.

Concept Explanation

Commercial lenders look at the source of repayment first and the collateral second. Revolving facilities price on utilisation and committed balances, asset-based lines advance a percentage of eligible collateral, and government-guaranteed loans trade a fee for a longer term and a lower rate.

Applications

▸Comparing a term loan with a line of credit for a working-capital need
▸Sizing a borrowing base from receivables and inventory
▸Measuring the all-in cost of invoice factoring against a bank facility
▸Modelling the SBA guaranty fee and amortisation on a small-business loan

Benefits

  • •Shows the full cost of the facility including fees and unused-line charges
  • •Converts each collateral class into available borrowing power
  • •Reveals the cash-flow pattern across draw and repayment periods
  • •Makes government-guaranteed structures comparable with conventional credit

Limitations

  • •Advance rates, eligible collateral definitions and covenants vary by lender
  • •Financial covenants, reporting requirements and cross-default clauses are not modelled
  • •Personal guarantees and lien positions affect pricing beyond the numbers shown
  • •Business credit is underwritten on the business plan and management, not only on ratios

Best Practices

  • •Ask what happens to pricing if utilisation stays low for a quarter
  • •Model the facility at 80% of the borrowing base you think you have
  • •Compare the annualised cost of any alternative financing with a bank line before signing
  • •Check whether the guaranty fee can be financed or must be paid at closing

Common Misconceptions

Myth: The lowest rate is the cheapest facility
Truth: Commitment fees, servicing charges and collateral reporting can make a low-rate facility more expensive.
Myth: Government guarantees mean relaxed underwriting
Truth: The guarantee transfers risk to the agency; lenders still apply their own credit standards.

Practical Tips

  • •Ask for the fee breakdown in writing, including packaging, servicing and closing charges.
  • •Compare the all-in cost with a conventional loan at the same term before choosing the guaranteed route.

Common Mistakes

Assuming the guarantee covers the whole loan
Only the guaranteed portion is backed; the lender retains the rest of the risk.
Overlooking the programme ceiling
Amounts above the ceiling need a split structure with conventional lending.

Assumptions

This calculator makes the following assumptions to provide estimates:

Current programme fees and guarantee percentages: SBA fee schedules and guarantee levels change; confirm with the lender.

Limitations

Be aware of these limitations when using this calculator:

Limitation: Advance rates, eligible collateral definitions and covenants vary by lender
Limitation: Financial covenants, reporting requirements and cross-default clauses are not modelled
Limitation: Personal guarantees and lien positions affect pricing beyond the numbers shown
Limitation: Business credit is underwritten on the business plan and management, not only on ratios

Frequently Asked Questions

Answers to common questions about this calculator.

Who pays the guaranty fee?
The borrower pays it, but the lender collects and remits it. It is usually financed into the loan or paid at closing.
How is 504 different from 7(a)?
504 is a fixed-asset structure: a bank provides 50%, a certified development company provides 40% with an SBA-guaranteed debenture, and the borrower contributes 10%.
Who uses the sba 504 loan calculator?
It is used by borrowers comparing business loan offers, by advisers checking a quote before a client signs, and by lenders and brokers sanity-checking a payment, ratio or fee structure. It sits in the Business & SBA Loans group of the Loans & Lending section of Atlascalcs.
How accurate is the sba 504 loan calculator?
Every figure follows directly from the inputs using standard amortisation mathematics, so it is accurate to the quality of the values you enter. Lenders round payments and apply their own day-count conventions, so expect small differences against a formal statement or payoff quote.
How current are the rates and thresholds used here?
The calculator uses the figures you enter, so update the rate to your actual offer or current market quote. Ratio thresholds, poverty guidelines and programme rules reflect the conventions described in the references and change periodically.
Does rounding change the results?
Every calculation runs on full precision and rounds only for display. Lenders round payments to the nearest cent or dollar, so expect a small difference between these figures and a formal statement or payoff quote.
Should I use the payment or the total cost to compare offers?
Use the payment to judge cash flow and the finance charge or APR to judge cost. When two offers differ on both, the all-in cost over the period you expect to hold the loan is the decisive measure.
Can I use this calculator for a business or commercial loan?
Yes. The payment, amortisation, ratio and cost calculators apply the same amortisation mathematics to commercial loans; the difference is in the fees, covenants and collateral rules, which you should enter explicitly.
What information should I have ready before applying?
Your exact rate and term, the fee schedule, any required add-ons, and your gross income and existing monthly obligations. With those five numbers every figure on this page can be tied back to a lender quote.

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Related Guides

Deepen your understanding with these educational resources.

Glossary

Technical terms used in mortgage calculations explained in plain language.

SBA guaranty fee
A fee the SBA charges the lender for guaranteeing a portion of a small-business loan.
APR (Annual Percentage Rate)
The yearly cost of credit expressed as a rate, including interest and most upfront finance charges.
Amortisation
Repaying a debt through a schedule of payments that gradually shifts the split from interest to principal until the balance reaches zero.
Origination fee
A charge levied by the lender for arranging the loan, usually a percentage of the amount financed.

Authoritative References

Trusted sources and standards referenced by this calculator.

Applicable Standards

Level-payment (simple-interest) amortisation, payments assumed in arrearsAPR computed by discounting the actual payment stream to net proceedsDebt ratios computed on gross income for lender comparisonsMoney rounded for display only; all calculations run at full precision

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Page Information

Last Updated:

2026-09-21

Version:

2.0.0

License:

Free to use for educational and professional purposes.