Business Loan Calculator: Estimate Payments and Rates

Before you sign anything, you should know exactly what a loan will cost you every month and over its full life. A business loan calculator turns three numbers - the amount you borrow, the interest rate, and the term - into a payment figure you can actually plan around. This guide shows you how the math works, walks through real examples, and explains the rate ranges you're likely to see in 2026 so your estimates land close to reality.

How Do I Calculate Business Loan Payments?

For most standard business loans - term loans from a bank, SBA loans, and many online loans - payments are calculated using an amortizing formula. That means every payment is the same size, and each one covers a shrinking slice of interest and a growing slice of principal until the balance hits zero.

The monthly payment formula is:

M = P × [ r(1 + r)^n ] / [ (1 + r)^n − 1 ]

Where:

M = your monthly payment
P = the principal (the amount you borrow)
r = the monthly interest rate (your annual rate ÷ 12)
n = the total number of payments (years × 12)

The key step people miss is converting the annual rate into a monthly one. A 12% annual rate becomes 0.12 ÷ 12 = 0.01 per month. Skip that and your numbers will be wildly off.

A Worked Example

Say you borrow $100,000 at a 10% annual rate over 5 years (60 months).

P = 100,000
r = 0.10 ÷ 12 = 0.008333
n = 60

Run those through the formula and your monthly payment comes to roughly $2,125. Over the full 60 months you'll pay about $127,500, which means roughly $27,500 in interest on top of the amount you borrowed.

That last figure - total interest - is the number a good business loan calculator surfaces that a lender's glossy monthly quote often buries. A low monthly payment can still hide a high total cost if the term is long.

Try It Yourself

You don't need to do the algebra by hand. Any spreadsheet will do it in one line. In Excel or Google Sheets:

=PMT(rate/12, term_in_months, -loan_amount)

For the example above: =PMT(0.10/12, 60, -100000) returns 2,124.70. Enter the loan amount as a negative number so the result comes back positive. From there you can change any input and watch the payment move - which is the whole point of running the numbers before you commit.

The Inputs That Move Your Payment

Three levers control everything a calculator tells you.

Loan Amount

Borrow only what your plan actually requires. It's tempting to round up "just in case," but every extra dollar carries interest for the full term. If you're still sizing the raise, work backward from a real budget in your business plan rather than a round guess.

Interest Rate

Rate is where credit profile, lender type, and loan structure collide. Rough 2026 ranges look like this:

Bank term loans: roughly 6.8%-11% APR for strong-credit borrowers (SoFi)
SBA 7(a) loans: commonly 9.75%-14.75%, with maximum rates capped on a sliding scale by loan size (NerdWallet)
SBA 504 loans: around 5%-7% for the fixed portion
Online / alternative lenders: frequently 14%-45%+ APR, and higher for riskier borrowers

Your business credit score is the single biggest thing you control here. Pushing from "fair" to "good" can shave several points off your rate - which, on a six-figure loan, is thousands of dollars.

Term Length

A longer term lowers the monthly payment but raises total interest, because you're borrowing the money for longer. A shorter term does the reverse: higher monthly cost, lower total cost. There's no universally "right" term - it depends on how much monthly cash flow you can comfortably give up without starving day-to-day operations.

APR vs. Interest Rate: Don't Confuse Them

The interest rate is the cost of borrowing the principal. The APR (annual percentage rate) folds in origination fees, closing costs, and other charges, so it reflects the true cost of the loan. Two loans can advertise the same interest rate but carry very different APRs once fees are counted.

When you compare offers, compare APRs. A calculator that only uses the base rate will understate what you actually pay, so add known fees to your principal or use the lender's stated APR as your rate input for a more honest estimate.

When the Standard Calculator Doesn't Apply

Amortizing math covers most term loans, but two common products work differently:

Business lines of credit charge interest only on what you draw, and the balance revolves. Payments float with your usage rather than following a fixed schedule. If that structure fits your needs better, read up on how a business line of credit works before modeling it like a term loan.
Merchant cash advances (MCAs) don't use an interest rate at all. They use a factor rate and take a slice of daily sales, which can translate to an eye-watering effective APR. The standard formula will mislead you here - use a dedicated MCA payoff calculator instead.

From Estimate to Decision

Once you have a payment figure, run it against your monthly cash flow. A healthy rule of thumb: the payment shouldn't consume a slice of revenue that leaves you unable to absorb a slow month. Building a simple cash flow analysis alongside your loan estimate turns "can I get approved?" into the more useful question - "can I comfortably repay this?"

And before you settle on a lender, shop around. Rates, fees, and terms vary enough between providers that the same loan amount can cost meaningfully more or less depending on where you sign. Comparing the best small business loans - and understanding the trade-offs of an SBA loan - is worth the afternoon it takes.

The Bottom Line

Calculating a business loan payment comes down to three inputs and one formula: principal, monthly rate, and number of payments, run through the standard amortization equation (or a one-line spreadsheet function). Do that before you borrow and you'll see not just the monthly payment but the total interest - the number that actually tells you whether a loan is a smart move or an expensive one.

Run your numbers with a business loan calculator first, then compare a few real offers side by side before you commit to any lender.