Need an SBA 504 Loan Calculator?

To estimate your SBA 504 monthly payment instantly, enter the five core variables into an online SBA 504 calculator and the tool will compute a single monthly figure in seconds. The calculator assumes a fixed‑rate amortization with monthly compounding, rounds the result to the nearest cent, and treats the loan term as the combined length of the CDC and bank portions (commonly 10 - 20 years). Verify the interest rates, term length, and any lender‑specific fees before relying on the estimate, because these elements can differ by lender and project.

• Total project cost (or desired loan amount)
• Down‑payment amount or percentage
• CDC loan interest rate (often around 3.5% but varies)
• Bank loan interest rate (varies by lender)
• Loan term in years (typically 10 - 20)

Safety note: Always confirm the rates, fees, and term details with your lender before finalizing any financing decision.

Generate a full SBA 504 amortization table by calculating two separate loan tranches - bank (first‑mortgage) and CDC (second‑mortgage) - and then combine their monthly figures, preserving any balloon balance that remains at the end of the term.

• Identify tranche details - For each component, note the principal amount, interest rate, amortization period (often 10 - 25 years), and any scheduled balloon payment (commonly due after 10 - 20 years).
• Compute monthly payment per tranche - Use the standard amortizing formula: Payment = P × r / [1  -  (1 + r)^‑n], where P is the tranche principal, r is the monthly rate (annual ÷ 12), and n is the total months of the amortization period (excluding the balloon). This yields the fixed monthly amount that will be paid until the balloon date.

• Build each tranche's schedule - For every month, calculate:

  • Interest = prior balance × monthly rate
  • Principal = payment  -  interest
  • New balance = prior balance  -  principal

  Continue until the month before the balloon; the remaining balance becomes the balloon amount.

• Merge the two schedules - Align months of the bank and CDC tables. For each period, add the two payments, interest totals, and principal totals; keep separate columns if you want to see each lender's share. The combined 'Balance' column should reflect the sum of the two remaining balances.
• Add the final balloon row - At the scheduled balloon month, list the remaining combined balance as a lump‑sum payment, then set the balance to zero. The resulting table includes columns for Period, Total Payment, Total Interest, Total Principal, and Remaining Balance, covering the entire loan life from start to balloon payoff.

The SBA 504 loan is split into three parts: the bank/lender share (about 50 % of the total project cost), the CDC share (up to 40 % of the total), and the borrower's equity (the remaining 10‑15 %). The bank's portion is a conventional term loan whose annual rate follows a market index (e.g., SOFR) plus a lender‑specific spread; the CDC's portion is a fixed‑rate loan set by the SBA, typically lower than the bank rate.

For a $1 million project, the split would look like this under the usual assumptions: a $500,000 bank loan at, say, 5.5 % APR (variable), a $400,000 CDC loan at 3.8 % APR (fixed), and $100,000 borrower equity. Adjust the percentages and rates to match your lender's offer and the CDC's current fixed rate, then confirm both rates in the loan agreement before finalizing the calculation.

The standard SBA 504 equity requirement is 10 percent of the total project cost; in other words, multiply the cost by 0.10 to get the down‑payment amount. This figure can rise if the SBA or the lender flags higher risk factors, so always confirm the exact equity needed in the loan commitment.

The CDC's portion of the financing is generally 40 percent of the same total project cost, calculated as total cost × 0.40. This amount is independent of the down‑payment - once the 10 percent equity is set aside, the remaining 90 percent is split between the CDC (40 percent) and the bank (typically 50 percent).

Be aware that the 10 percent equity rule is not absolute: start‑ups, projects in niche industries, or borrowers with limited cash reserves may be asked to contribute more. Verify the exact percentages in the lender's term sheet before finalizing your calculations. (Next: include lender and CDC fees in your estimate.)

Add the lender's fees and the CDC's guarantee fee to the loan amount you're modeling, and note which costs you'll pay at closing versus those that roll into the balance.

• Lender origination fee - usually 0.5‑1% of the total loan; often financed, but some lenders require cash at closing.
• Underwriting or processing fee - a flat amount (e.g., $1,000‑$3,000); typically paid upfront.
• Appraisal fee - cost of the property appraisal; paid at closing.
• Environmental/phase‑I study - required for many commercial projects; paid upfront.
• Title insurance and recording fees - vary by state; generally paid at closing.
• CDC guarantee fee - 2% of the CDC portion of the loan; can be financed into the CDC balance or paid upfront depending on the CDC's policy.
• CDC closing costs - include document preparation and filing; often financed but sometimes required upfront.

How the fees affect your estimate

1. Sum all financed fees and add that total to the CDC or bank loan balance before running the payment formula.
2. Sum all upfront fees and include the amount in your cash‑required column.
3. Re‑run the calculator with the higher loan principal; the monthly payment will increase proportionally to the financed fees.

Double‑check the loan commitment and CDC agreement for the exact fee percentages and whether each item is financed or due at closing, then adjust your calculator inputs accordingly.

Confirming eligibility starts with three basics: the business must meet SBA size standards, the loan purpose must be for real‑estate acquisition, renovation, or equipment tied to an operating business, and the borrower must provide a minimum down payment of 10 % (15 % for special‑purpose properties). These criteria are consistent across most SBA 504 programs, though some CDCs may impose tighter rules, so verify the specific lender's guidelines before proceeding.

Dollar limits vary by project type. For typical commercial real‑estate projects, the CDC portion is usually capped at $5 million, making the total loan limit around $5.5 million after the borrower's equity. Manufacturing, energy, or other qualifying industries often allow a CDC share of $10 - $20 million, which raises the overall project ceiling accordingly. Always ask the CDC and your bank for the exact limits that apply to your situation, as state or program‑year caps can differ.

Below are three worked‑through 504‑loan scenarios. Each uses the same baseline assumptions so you can see how the numbers change with project size.

Assumptions (apply to all examples)

1. Total project cost = purchase price + eligible improvements.
2. Down payment = 10 % of total cost.
3. CDC (SBA) portion = 40 % of the remaining balance, interest = 2.5 % annually, 20‑year term, monthly compounding.
4. Bank portion = 60 % of the remaining balance, interest = 4.5 % annually, 20‑year term, monthly compounding.
5. SBA guarantee fee (≈0.75 % of CDC loan) and loan‑origination fee (≈1 % of bank loan) are rolled into the respective loan balances.
6. Monthly payment = principal + interest calculated with the standard amortization formula.

1. Small retail store - $1 million project

1. Calculate equity and loans
   • Down payment: 10 % × $1,000,000 = $100,000
   • Balance after down: $900,000
   • CDC loan: 40 % × $900,000 = $360,000
   • Bank loan: 60 % × $900,000 = $540,000
2. Add fees
   • CDC fee: 0.75 % × $360,000 ≈ $2,700 → CDC balance = $362,700
   • Bank fee: 1 % × $540,000 = $5,400 → Bank balance = $545,400
3. Monthly payments
   • CDC: $362,700 × [0.025/12 ÷ (1‑(1+0.025/12)^‑240)] ≈ $1,928
   • Bank: $545,400 × [0.045/12 ÷ (1‑(1+0.045/12)^‑240)] ≈ $3,459
4. Total 504‑loan payment ≈ $5,387 per month.

2. Mid‑size manufacturing plant - $5 million project

1. Equity and loans
   • Down payment: $500,000
   • Post‑down balance: $4,500,000
   • CDC loan: $1,800,000
   • Bank loan: $2,700,000
2. Fees
   • CDC fee: $13,500 → CDC balance = $1,813,500
   • Bank fee: $27,000 → Bank balance = $2,727,000
3. Monthly payments
   • CDC: ≈ $9,640
   • Bank: ≈ $17,310
4. Total 504‑loan payment ≈ $26,950 per month.

3. Large office building - $20 million project

1. Equity and loans
   • Down payment: $2,000,000
   • Post‑down balance: $18,000,000
   • CDC loan: $7,200,000
   • Bank loan: $10,800,000
2. Fees
   • CDC fee: $54,000 → CDC balance = $7,254,000
   • Bank fee: $108,000 → Bank balance = $10,908,000
3. Monthly payments
   • CDC: ≈ $38,560
   • Bank: ≈ $69,240
4. Total 504‑loan payment ≈ $107,800 per month.

What to double‑check

• Verify the current CDC and bank rates; they can differ by lender or market conditions.
• Confirm the exact fee percentages in your loan commitment documents.
• Re‑run the calculations with your own numbers using the same steps to ensure accuracy.

SBA 504 loans typically produce lower monthly payments than conventional term loans when you compare the same loan amount, term, and compounding method, but they require a larger down‑payment and include CDC‑specific fees.

SBA 504 payment profile (example assumes a $500,000 project, 20‑year term, 5 % fixed CDC rate, 5 % fixed bank rate, 10 % down‑payment, and CDC fee rolled into the loan). The CDC portion (usually 40 % of the total) is financed at a lower rate, while the bank portion (about 50 % of the total) carries a modest rate; the combined effect yields a payment that is often 5‑10 % lower than a single‑rate conventional loan. The down‑payment requirement (typically 10‑20 %) and the CDC guarantee fee increase upfront costs, so the borrower must have more equity at closing.

Conventional loan payment profile (same $500,000 amount, 20‑year term, single fixed rate around 6‑7 % and no CDC fee). Because the entire balance is financed at a higher blended rate, the monthly payment is usually higher than the SBA 504 scenario. Down‑payment requirements are often lower (as little as 5 % for some lenders), and there are no CDC fees, simplifying the cash‑outlay at closing but raising the recurring payment amount.

Check your lender's current rates, fees, and eligibility criteria before deciding which structure fits your cash flow and equity position.

Use the calculator's 'what‑if' panel to see how a higher rate or longer term shifts your monthly payment. Start with the baseline you modeled earlier (the loan amount, original term, and current interest rate) and then apply incremental changes.

Try these common stress‑test scenarios, keeping the baseline constant:

• +0.5 percentage‑point rate → see the new payment per month;
• +1.0 percentage‑point rate → compare the increase;
• +2.0 percentage‑point rate → evaluate worst‑case affordability;
• +5‑year term (e.g., 20 → 25 years) → observe how extending repayment lowers each payment but raises total interest;
• combined +1 % rate and +5‑year term → gauge the combined effect.

After each scenario, note whether the revised payment still fits your cash‑flow projection. If a result feels uncomfortable, consider a larger down payment, a shorter term, or negotiating a lower rate before committing. Always verify the final numbers against the lender's disclosed terms, as actual rates and fees may differ.

Most SBA 504 loans impose a penalty if the CDC share is prepaid within the first five years and the bank share within the first two years; the charge is usually a declining percentage of the remaining principal (for example, 2 % in year 1, 1 % in year 2, then 0 % after the penalty period).

take the current remaining balance of each loan segment, multiply it by the applicable penalty rate for the year you plan to prepay, and add the two results. If you have $400,000 left on the CDC loan in year 3 with a 1 % penalty, the CDC penalty would be $4,000. Do the same for the bank portion, then sum the amounts to get the total prepayment cost.

When you refinance, treat the penalty as an upfront cash outflow that reduces the net savings from a lower interest rate or longer term. Add the penalty (and any refinancing fees) to the new loan balance in your calculator, then compare the revised monthly payment and total interest cost to the original schedule. Because penalty schedules and waiver provisions vary by lender, always verify the exact terms in your loan agreement before proceeding.