Why the business loan payoff calculator matters
Business borrowing goes wrong when the payment is sized off an optimistic revenue month rather than the floor month, so the debt-service test matters more than the headline rate. This page turns that decision into a handful of inputs you can defend in a budget review: volume, unit cost, rate of adoption, and time. The output is a planning baseline, not a promise — it tells you whether the idea deserves a vendor quote, a pilot, or a pass.
- • Biggest swing factor: existing debt payments, which eat the borrowing capacity first
- • Second-order factor: the interest rate, which compresses the loan size fast above 10%
- • Often ignored: the term, since a shorter term raises the payment sharply
What actually changes the answer
existing debt payments, which eat the borrowing capacity first moves this number first, then the interest rate, which compresses the loan size fast above 10%. Run a conservative case and an upside case before you commit. If the maths only works in the upside case, treat it as a time-boxed test with a kill date rather than a line in next year's plan.
What to do with the result
Size the loan against your worst three months of the last year, not the average, then keep one payment in reserve.
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Read the guideFAQ
What does the business loan payoff calculator work out?
It applies Max payment = min(36% × monthly income − existing debt, 28% × monthly income); Loan = payment × [(1 − (1 + i)^−n) ÷ i] to the values you enter for annual business revenue ($), existing monthly debt payments ($), cash you can put down ($), loan interest rate, loan term in years. Business borrowing goes wrong when the payment is sized off an optimistic revenue month rather than the floor month, so the debt-service test matters more than the headline rate.
How accurate is this business loan payoff calculator?
A capacity estimate using standard debt-to-income ratios. Actual underwriting adds credit score, time in business and collateral. Replace the defaults with your own invoice, usage export, payroll data, statement, or vendor quote before making a commitment — the maths is exact, so the answer is only as good as the inputs you feed it.
Which input should I stress-test first?
existing debt payments, which eat the borrowing capacity first. Re-run with a pessimistic value for it; if the decision flips, that assumption is the thing you need real data on before signing anything. After that, check the interest rate, which compresses the loan size fast above 10% and the term, since a shorter term raises the payment sharply.
Which scenario should I start from?
Start with the preset closest to your situation — cautious budget, today's numbers, stronger position — then edit the sliders. Presets are realistic starting points, not benchmarks to match, and every change updates the result instantly.
What should I do after running the numbers?
Size the loan against your worst three months of the last year, not the average, then keep one payment in reserve. A useful planning benchmark to compare against: Lenders typically want total debt service below 36% of income, and many SBA lenders want a 1.25x coverage ratio.
Can I share or save this calculation?
Yes. Your inputs are written into the page URL, so copying the link shares the exact scenario you are looking at — the person who opens it sees the same numbers. You can also export the inputs and results to CSV or PDF from the result card and keep it with the rest of your workings.
How this calculator is built
Independently maintained
Written by Sam Doshi and the RevenueLab editorial team. We don't sell the data feeds this tool is built on.
Sourced from primary data
Benchmarks come from public AdSense / Stripe / IRS disclosures and reader-submitted data — never third-party "$X per view" claims. Full methodology.
Last editorial review
Reviewed on a rolling quarterly cycle. Dated reviews are published on the methodology record for each calculator.
Editorial standards
See our editorial policy and disclaimer. Results are estimates, not advice.