How to Calculate the ROI of a Small Business Loan

The ROI formula for borrowed money

Loan ROI equals extra profit minus total funding cost, divided by total funding cost. A positive result means the money paid for itself.

ROI = (extra profit - total cost of funding) / total cost of funding

Extra profit means profit you would not have earned without the money. Total cost means everything you repay above the amount received, including fees. Use the full repayment figure, not only the stated rate.

A worked example with round numbers

If $50,000 of funding costs $6,000 and adds $18,000 of profit, the net gain is $12,000 and the return is 200% on the cost.

This is an illustrative example. A bakery borrows $50,000 for a second oven and packaging line. Total repayment is $56,000, so the cost is $6,000. The new capacity adds $18,000 of profit over the repayment period.

• Net gain: $18,000 - $6,000 = $12,000
• ROI on cost: $12,000 / $6,000 = 200%

Now stress it. If the extra profit is only $5,000, the project loses $1,000. Always test a weaker case before you sign.

Estimating the extra profit honestly

Base the estimate on measurable inputs: added units, price, margin and timing. Use a conservative number, not a best case.

Work through the question in order:

1. How many extra sales will the money produce each month?
2. What is the margin on those sales after direct costs?
3. How long until the first sale arrives?
4. Does anything else get more expensive, like staff or rent?

For specific cases, see our equipment payback guide and marketing payback math.

Include the payment schedule, not just the total

Two offers with the same total cost can strain cash differently. Compare monthly-equivalent payments against the cash the project actually brings in.

A daily or weekly payment starts leaving your account before the project pays. Convert every offer to a monthly equivalent with this conversion guide, and confirm that operating cash can carry it. The total cost guide shows how to total every fee.

When the math says no

If extra profit does not clearly beat cost under conservative assumptions, wait, shrink the project, or fund it from cash flow.

Borrowing to cover ongoing losses does not produce a return. Borrowing for a project with unclear demand is a bet, not an investment. A smaller amount, a later start or a different product may fit better.

Three common mistakes in loan ROI math

The most common errors are counting revenue instead of profit, ignoring fees, and assuming the payoff starts on day one.

Revenue is not return. If new sales bring in $30,000 but cost $22,000 to deliver, the extra profit is $8,000, and that is the number to compare with funding cost. Fees are the second trap: origination charges and processing fees belong in total cost. Timing is the third. A new location may take three months to reach normal sales, so the first payments come from other cash. Build a month-by-month table and check that you can cover payments before the project earns.

Reviewing the result after the money is spent

Check actual results against your estimate at 30, 60 and 90 days. Adjust quickly if the project is behind.

Write down your projected extra profit before you borrow, then compare it with real numbers every month. If the project lags, find out why while there is still time to fix pricing, staffing or marketing. The review also teaches you how accurate your estimates are, which makes the next decision better.

Getting offers you can compare

Apply once and compare offers side by side on total cost, payback period and monthly-equivalent payment.

ROI Funder starts from the payback math and shows true cost before you sign. The range runs from $5,000 to $5,000,000 across working capital, term loans and other products. Typical fit: 500+ FICO, 6+ months in business, $20,000+ monthly revenue. Applying uses a soft credit pull and carries no obligation.