Business Loan Calculator
Estimate payments, total interest, and full amortization for a business loan. Source-cited, APR- and origination-fee-aware, with extra-payment modeling.
- Total repayment
- $393,193
- Total interest
- $138,193
- Total fees
- $5,000
- Payoff
- July 2036
Interest is 35% of everything you'll repay ($138,193 of $393,193). Add even a small extra payment under Advanced options — the interest savings are biggest in the first few years.
| # | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | $3,234.94 | $1,255.77 | $1,979.17 | $248,744.23 |
| 2 | $3,234.94 | $1,265.71 | $1,969.23 | $247,478.51 |
| 3 | $3,234.94 | $1,275.73 | $1,959.20 | $246,202.78 |
| 4 | $3,234.94 | $1,285.83 | $1,949.11 | $244,916.95 |
| 5 | $3,234.94 | $1,296.01 | $1,938.93 | $243,620.93 |
| 6 | $3,234.94 | $1,306.27 | $1,928.67 | $242,314.66 |
| 7 | $3,234.94 | $1,316.61 | $1,918.32 | $240,998.05 |
| 8 | $3,234.94 | $1,327.04 | $1,907.90 | $239,671.01 |
| 9 | $3,234.94 | $1,337.54 | $1,897.40 | $238,333.46 |
| 10 | $3,234.94 | $1,348.13 | $1,886.81 | $236,985.33 |
| 11 | $3,234.94 | $1,358.81 | $1,876.13 | $235,626.53 |
| 12 | $3,234.94 | $1,369.56 | $1,865.38 | $234,256.96 |
View the TypeScript implementation on GitHub: packages/calc/src/business-loan.ts · view tests
Business loan math at a glance
Key facts
- The payment formula
- M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the principal, r is the periodic rate (annual rate ÷ payments per year), and n is the total number of payments. Each payment has a shrinking interest portion and a growing principal portion.
- APR vs. interest rate
- The APR bundles the interest rate with mandatory fees — origination, packaging, underwriting — into an all-in annualized cost. Per CFPB Regulation Z (12 CFR §1026.22), lenders must disclose APR on most consumer credit; on business loans it is best practice but not always required.
- Typical origination fee
- On SMB term loans the origination fee typically runs 1–6% of the principal, either deducted from the funded amount at closing or added to the balance. Either way, it raises the effective APR.
- What extra payments do
- Every dollar of extra principal reduces the balance tomorrow's interest is charged on. On a 10-year, $250K loan at 9.5%, adding $500 per month shortens payoff by about 26 months and saves roughly $35K in interest.
- Tax treatment
- Interest on business loans is generally tax-deductible as a business expense (IRC §163) when proceeds fund legitimate business purposes; principal repayments are not deductible, and origination fees are typically amortized over the life of the loan.
Formula conventions per CFPB, Truth in Lending Act (Regulation Z), 12 CFR Part 1026 (§1026.14 and §1026.22). Updated April 2026.
What this means
The monthly payment is fixed — that's the point of amortization. What changes month to month is the split between interest (computed on the current balance) and principal (the scheduled payment minus that interest). Early payments are mostly interest; late payments are mostly principal. Extra payments change this shape: every extra dollar skips past interest entirely and reduces the balance that tomorrow's interest is computed against.
The total-interest number is the honest cost of the loan. If you borrow $250,000 for 10 years at 9.5%, the interest you'll pay over the full term can be a meaningful fraction of what you borrowed — sometimes more than half. That's the number to weigh against what the borrowed capital lets you build or buy.
When I weigh financing decisions with operators, the total-interest figure matters less on its own than next to the return the borrowed capital generates. I’ve seen founders fixate on shaving the rate while ignoring the bigger question — whether the asset or growth the loan funds clears the loan’s all-in cost. A higher-rate loan against a project that returns well above it beats a cheap loan against one that doesn’t.
Worked example
A $150,000 equipment loan at 8.5% APR over 7 years, paid monthly, has a scheduled payment of $2,378 and total interest of roughly $49,714. Adding $200 of extra principal each month pays the loan off 13 months early and saves approximately $6,811 in interest — a real return of roughly 4.5× on the $16,800 of extra principal applied. The tradeoff is cash locked up monthly in the extra payment, which isn't available for working capital or opportunistic inventory.
Frequently asked questions
The information and tools on this website are for general educational purposes only and do not constitute financial, investment, legal, or tax advice. Consult a licensed professional for decisions specific to your situation.