Business Loan Affordability Calculator
Instead of guessing at a loan amount, start with the monthly payment your business can comfortably handle. This calculator works backwards to show the maximum loan that fits your payment, plus the total interest and total repaid.
How the affordability calculator works
Most loan tools ask how much you want to borrow and tell you the payment. This one flips that around. You already know what your monthly cash flow can spare, so it starts there and finds the biggest loan that keeps the payment at that level. This "reverse amortization" approach keeps you anchored to what you can actually sustain rather than to a number a lender is willing to lend.
where r is the monthly interest rate (annual rate ÷ 12) and n is the total number of monthly payments (years × 12). When the rate is zero, Max loan = Payment × n.
For example, a $2,000 monthly payment at 8% over five years supports a loan of about $98,637. Over those 60 payments you would repay $120,000 total, of which roughly $21,363 is interest. Nudge the rate down or the term up and the maximum loan grows, because the same payment now buys more borrowing power. This is exactly the math a lender runs when they size an offer to your budget.
The total interest and number-of-payments figures matter as much as the headline number. A longer term unlocks a bigger loan, but it also stretches out interest, so you pay more overall. Use the calculator to find the sweet spot where the loan amount covers what you need without a term so long that interest balloons or a payment so high that a slow month puts you at risk.
What changes how much you can borrow
- Monthly payment budget — the direct lever; doubling the payment roughly doubles the loan you can support.
- Interest rate — a lower rate means more of each payment reduces principal, so you can borrow more.
- Term length — more months spread the payment further and raise the maximum loan, at the cost of extra interest.
Borrow smart, not just big
- Leave a cushion — target a payment below your true ceiling so slow months do not threaten the loan.
- Confirm the payment against your debt-service coverage ratio before you apply.
- Check the APR including fees, since fees reduce the cash you actually receive.
- Model the exact loan with the business loan calculator to see the full amortization.
Frequently asked questions
How much of a business loan can I afford?
Start from the monthly payment your cash flow can comfortably cover, then work backwards. This calculator uses reverse amortization to turn that payment, your rate, and your term into the largest loan amount that fits the payment.
How is the maximum loan amount calculated?
It uses the present-value form of the amortization formula: Max loan = Payment × (1 − (1 + r)−n) ÷ r, where r is the monthly rate and n is the number of payments. When the rate is zero, the maximum loan is simply the payment multiplied by the number of payments.
Should I borrow the maximum amount I can afford?
Usually not. The maximum leaves no cushion for slow months or unexpected costs. Many owners target a payment well below the maximum, or aim for a debt-service coverage ratio comfortably above 1.25, so the business stays resilient.
Does a longer term let me borrow more?
Yes. A longer term spreads the same monthly payment over more months, so the same payment supports a larger loan. The trade-off is that a longer term also means you pay more total interest over the life of the loan.
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This calculator is for educational and informational purposes only and does not constitute financial, legal, or lending advice. Results are based on the values you enter and standard amortization math; a lender may qualify you for more or less. Confirm all terms with a qualified lender before making decisions.