Reading the small business loan numbers
Small business loan rates run wide (8-30% APR), so the payoff math swings further than on consumer loans. The headline 'months saved' figure above is the straight amortization story; the real decision sits one layer below it.
First check whether your loan is amortizing APR-based or factor-rate (MCAs, some online lenders). On factor-rate products, prepayment usually saves zero — you owe the full payback amount regardless. The calculator above assumes amortizing; do not apply its output to an MCA without confirming the contract has an early-payoff discount clause.
If it's a normal amortizing loan, the prepayment-vs-reinvest decision turns on after-tax math. Business loan interest is typically deductible, so a 12% APR for a business in a 25% effective bracket acts like ~9%. Compare that to what the next $10k of working capital, inventory, or marketing would actually return inside the business — and be honest. Most operators overestimate marginal returns on cash and underestimate the certainty of saved interest.
Worked example: $100k term loan at 11% over 60 months
Base monthly payment ~$2,174. Total interest paid over the life of the loan: about $30,400. That's the amortizing baseline.
Add $250/month from month one — and the loan pays off about 7 months earlier (53 months instead of 60). Total interest drops to roughly $26,800. Savings: about $3,600 nominal. After applying a 25% effective tax-deduction adjustment on the lost interest deduction, your true post-tax savings are closer to $2,700.
Now compare to a factor-rate alternative. A $100k MCA at a 1.30 factor over 12 months means $130k owed regardless of when you pay. Same $250/month extra → $0 saved. That's the gap between amortizing and factor-rate prepayment math: the calculator above only applies to the first kind.
Small business loan reality checks before you prepay
Beware factor-rate loans (MCAs, OnDeck-style)
Merchant cash advances and some online business loans use a factor rate (e.g., 1.3) instead of APR. Total payback = principal × factor. Prepayment usually does NOT save interest — you owe the full factor regardless. This calculator assumes amortizing APR-based loans; don't use it for factor-rate products.
Origination fees are real interest
Online lenders (Funding Circle, Bluevine, OnDeck) often charge 2-5% origination fees off the top — that's effectively additional interest. Add the fee back to your principal mentally to see your true APR. The lower the term, the more an origination fee distorts the effective rate.
Lines of credit aren't amortizing
A business line of credit accrues interest only on the drawn amount, with minimum payments often interest-only. This calculator handles term loans (fixed schedule). For LOC payoff, draw your current balance into 'principal' and treat it as a balloon payment.
Tax-deductibility changes the math
Business loan interest is generally tax-deductible, which lowers your effective rate by your marginal tax bracket. A 10% APR for a business in a 25% tax bracket is effectively ~7.5%. This can flip the prepay-vs-invest math compared to a personal loan.
Confirm the lender accepts extra principal
Most reputable online lenders accept extra principal payments without penalty, but some legacy bank loans require pre-arrangement or charge fees. Ask before sending a large lump sum — wrong account routing is a common cause of payments being held in suspense.
What most small business loan calculators don't tell you
Three things competitors typically miss. First: factor-rate vs amortizing. A meaningful share of online business loans (especially MCAs and revenue-based financing) are factor-rate products where prepayment saves nothing. Most calculators on the open web silently treat all business loans as amortizing, producing inflated 'savings' figures for borrowers who can't actually capture them.
Second: origination fees inflate effective APR more than borrowers realize, especially on shorter terms. A 5% origination fee on a 36-month loan adds roughly 3 percentage points to your effective rate; on a 60-month loan it adds about 2 points. The headline rate the lender quotes is almost always lower than what you actually pay.
Third: the prepay-vs-reinvest decision should be done at after-tax rates on both sides. Business loan interest is deductible (so the loan is cheaper than its nominal rate), but reinvested cash that generates revenue is taxed (so business returns are smaller than the gross figure). Comparing nominal loan APR to gross expected return is apples-to-oranges and consistently biases toward 'reinvest' when prepay is actually the right call.
Frequently asked questions
Is a small business loan the same as an SBA loan?
No. SBA loans are partially guaranteed by the U.S. Small Business Administration and have specific rules (rate caps, prepayment penalty on 15+ year loans, eligibility limits). Non-SBA small business loans (from banks, credit unions, or online lenders like Bluevine, OnDeck, Funding Circle) follow lender-specific terms — typically higher rates, shorter terms, less regulation. We have a separate SBA loan calculator linked below.
Should I pay off business debt or invest in the business?
The question is: what does your next $1 earn in the business vs. what does it cost to borrow? If the loan rate (after tax) beats the return your business makes on that cash, pay down the loan. If the business earns more, invest. Be honest — most businesses earn less on new dollars than on dollars already deployed.
Are merchant cash advances calculated the same way?
No — and this calculator doesn't apply to MCAs. MCAs use a factor rate (e.g., 1.3 means $100k turns into $130k owed regardless of payoff timing). Prepayment usually saves zero. If you have an MCA, check the contract for a 'discount on early payoff' clause — some have it, most don't.
Why this isn't an SBA loan calculator
If your business loan didn't come through the SBA, you're usually in a faster, rougher market: bank term loans, online lenders (OnDeck, Bluevine, Funding Circle), CDFIs, and short-term working-capital products. The money can arrive faster, but the trade is usually shorter terms, higher pricing, and less standardized payoff behavior.
The most common shape is still a regular amortizing term loan — one disbursement, level monthly payments, somewhere between one and five years on online lenders and longer on bank paper. Rates run higher than the SBA equivalents because no government guarantee is sitting behind the lender. Origination fees of a few percent are routine. Some online lenders price as factor-rate products instead, which behave very differently from amortizing loans — see factor rate for why prepayment usually doesn't save you anything on those.
Qualification is the other big split. SBA 7(a) wants the full paperwork — tax returns, multi-year financials, a debt-service-coverage analysis — but rewards the work with longer terms and lower rates. Non-SBA online lenders run a fraction of that (six months of bank statements, a credit pull, automated underwriting) but charge for the speed in the rate.
For payoff math, the practical things that change: prepayment penalties are uncommon on non-SBA term loans, so extras usually save you all the future interest; factor-rate products wipe those savings out entirely; higher rates lean the prepay-vs-invest call more toward prepay; and the shorter typical terms make early-year extra payments hit harder than on a 25-year SBA 7(a).
SBA vs non-SBA: when each fits
| SBA 7(a) | Non-SBA | |
|---|---|---|
| Price of money | Prime plus a small spread, capped by the SBA according to loan size. | Higher than SBA, sometimes by a lot. Factor-rate products are higher again, in a different shape. |
| Typical runway | Seven to ten years on most loans, longer when real estate is the collateral. | One to five years on most loans; some lines roll continuously. |
| Prepayment penalty | On loans of 15 years or longer, 5% / 3% / 1% in years 1, 2, and 3 (per CFR 13 §120.223). Shorter SBA loans usually have no penalty. | Uncommon on plain term loans. Factor-rate products usually don't reward early payoff at all. |
| Speed | A month or longer is typical. | Days to a few weeks. |
| Best when | You can wait, you want a longer payoff runway, and what you really care about is keeping the rate down. | You need money fast, or SBA underwriting won't approve you in time. |
If you're running this calculator for an SBA 7(a) loan, switch to the SBA loan payoff calculator — it has the SBA prepayment-penalty schedule and the Prime-pegged pricing built in.
Where this small business loan calculator's math stops being honest
The math is exact for fixed-rate amortizing loans with monthly payments, but it doesn't capture every situation. Cases where the output above will mislead you:
- Factor-rate products (MCAs, some Bluevine/OnDeck offerings) are not modeled. Total payback = principal × factor regardless of payoff timing; do not use this calculator for those.
- Origination fees (2-5% on most online lenders) are not added to principal automatically. For true APR, mentally add the fee to your starting balance before reading the savings figure.
- Lines of credit (revolving) accrue interest only on drawn balance with often interest-only minimums; the calculator assumes a fixed-amortization term loan.
- Tax-deductibility of business loan interest is not applied. Your effective rate is lower than the nominal APR by your marginal tax bracket — confirm with your CPA before deciding prepay vs reinvest.
Sources and references
- SBA — small business financing options overview — comparison framework for SBA vs. non-SBA business loans
- CFPB — small business lending guide — regulatory context on factor-rate disclosure and APR equivalents
- IRS Publication 535 — business expenses (interest deduction) — rules on deducting business loan interest
- PayoffMath SBA loan calculator — use this instead if your loan is SBA-guaranteed
Related guides
Related calculators
Other loan-type calculators
Same math, tuned to typical numbers and rules for each loan type.
Business loan calculators
Home loan calculators
Calculator and notes maintained by James L. Wu. Built for amortizing business debt. If your contract uses a factor rate, daily debits, or a fixed payback amount, the payoff savings shown here won't behave the way the math suggests. Not financial advice — confirm specifics against your loan documents. See methodology for the formulas + assumptions and the editorial policy for sourcing. Last refreshed April 2026.