An SBA loan calculator estimates your monthly payment by combining three inputs: loan amount, interest rate, and repayment term. Enter $250,000 at 11% over 10 years and you'll see roughly $3,444/month — that's the principal-and-interest payment you'd owe each month for the life of the loan.
The calculator is just math. The hard part is knowing which numbers to plug in. Here's how to use one accurately, what it doesn't include, and a worked example.
The formula behind the math
If you want to do it yourself:
Monthly Payment = P × [r(1+r)^n] / [(1+r)^n - 1]
Where:
- P = principal (loan amount)
- r = monthly interest rate (annual rate divided by 12)
- n = total number of payments (years × 12)
Most people don't run that math by hand. Use our SBA loan calculator → — same formula, instant result.
Worked example: $250K SBA 7(a) at 11% over 10 years
Plug in:
- P = $250,000
- r = 0.11 / 12 = 0.00917
- n = 120 (10 years × 12 months)
Result: $3,444/month in principal-and-interest payments.
Over the full 10 years:
- Total payments: $3,444 × 120 = $413,280
- Total interest paid: $413,280 - $250,000 = $163,280
The interest is more than 60% of the original loan amount. That's the cost of borrowing at 11% for 10 years.
What interest rate should you use?
For an SBA 7(a) loan in 2026, plug in 11% as a safe estimate.
Actual rates depend on:
- Prime rate (currently ~7.5%)
- Loan size (smaller loans get higher margins)
- Term length (longer terms get higher margins)
| Loan size | Term | Typical rate (Prime + margin) | |---|---|---| | Under $50K | 10 years | Prime + 4.75% (≈ 12.25%) | | $50K–$250K | 10 years | Prime + 3.75% (≈ 11.25%) | | Over $250K | 7+ years | Prime + 2.75% (≈ 10.25%) | | Real estate-backed | 25 years | Prime + 2.25% (≈ 9.75%) |
⚠️ VERIFY: Joe to confirm Prime rate at launch and update these tables when Prime moves more than 50 bps.
For SBA 504 loans, rates are different. The bank portion (50% of loan) is at conventional bank rates (7–10%); the CDC portion (40%) is at a fixed debenture rate (currently ~6%). The blended rate runs 6–7%.
What term length should you use?
The maximum term depends on the loan's purpose:
- Working capital: Up to 10 years
- Equipment: Up to 10–15 years (depending on equipment useful life)
- Real estate: Up to 25 years
- Combined uses: Weighted average of the above
Longer terms mean lower monthly payments but more total interest paid. Compare:
| Term | Monthly payment ($250K @ 11%) | Total interest | |---|---|---| | 5 years | $5,435 | $76,118 | | 10 years | $3,444 | $163,280 | | 15 years | $2,841 | $261,335 | | 25 years | $2,450 | $485,008 |
Stretching to 25 years cuts your monthly payment by 30% but triples your total interest. There's no "right" answer — it depends on your cash flow needs and how aggressively you want to deleverage.
What the calculator doesn't include
Three costs not in the principal-and-interest math:
1. SBA guarantee fee
The SBA charges a one-time fee on most 7(a) and 504 loans:
- Loans up to $150K: No fee (since 2023)
- $150K–$700K: 2.0% of the guaranteed portion
- $700K–$1M: 2.25%
- $1M–$5M: 3.5% on the first $1M, 3.75% above
For a $250K loan with 75% SBA guarantee: 2.0% × $187,500 = $3,750 fee. Usually financed into the loan, so it just slightly bumps your effective rate.
2. Packaging fees
If you use a loan packager (a specialist who organizes your application), expect to pay 1–3% of the loan amount as their fee. Worth it for complex files; unnecessary for simple ones.
3. Closing costs
Title insurance, recording fees, attorney costs, environmental studies (for real estate). For a working-capital loan, these are typically under $2,000. For a real-estate-backed loan, they can hit $10,000+.
Build a 5% buffer into your monthly cash-flow planning to cover all three.
Comparing scenarios in the calculator
The most useful thing about a calculator is testing scenarios side by side. Try these:
Scenario A: Conservative
- $200K, 11.5%, 10 years
- Monthly: $2,813
- Total interest: $137,560
Scenario B: Base case
- $250K, 11%, 10 years
- Monthly: $3,444
- Total interest: $163,280
Scenario C: Stretch
- $350K, 10.5%, 10 years
- Monthly: $4,720
- Total interest: $216,431
If your business can comfortably handle Scenario C, you have headroom. If only Scenario A fits comfortably in your cash flow, that's your real maximum.
The DSCR calculation lenders use: ideally your monthly payment should be no more than 70% of your monthly net operating income. So if your business nets $5,000/month after expenses, your max sustainable monthly loan payment is around $3,500.
FAQ
Why is my calculated payment higher than competitor calculators?
Other calculators sometimes hide guarantee fees, default to the longest possible term, or use yesterday's lower rates. Ours defaults to a realistic 10-year scenario at 11%. Toggle the term and rate sliders to see different scenarios.
Can I use a fixed-rate or variable-rate calculation?
Most SBA 7(a) loans are variable-rate (Prime + margin). The calculator estimates your starting payment; the payment adjusts when Prime moves. SBA 504 has a fixed debenture portion, so the 504 calculation is more stable.
How accurate is a calculator estimate vs. an actual loan offer?
Within 5–10% in most cases. Lenders may quote a slightly different rate based on their pricing model, and they'll add fees the calculator doesn't include. Use the calculator for planning; use the lender quote for decisions.
Should I extend the term to lower my monthly payment?
Only if you need the cash flow flexibility. Extending the term costs you significant interest. A general rule: take the shortest term you can comfortably afford with a 30% safety margin. If $3,444/month at 10 years is comfortable but $5,435/month at 5 years would stress you, take the 10-year. Don't stretch to 15 or 25 just to lower the payment if you don't need to.
Do alternative loan calculators work the same way?
The principal-and-interest math is identical. But many alternative loans (revenue-based financing, MCAs) don't have a fixed monthly payment — RBF takes a % of monthly revenue, MCAs take a daily slice of card sales. For those, a standard calculator doesn't apply; you'd want a "factor rate" calculator instead.
Ready to find your real loan terms? Get pre-qualified in 2 minutes → — see actual rate and term offers based on your business profile. Free, no credit pull, no obligation.
