Business Line of Credit Calculator
Estimate your monthly payment, total interest, and daily interest cost — based on what you actually draw, not your full limit.
How to use this calculator
A business line of credit works differently from a term loan, and this calculator is built to reflect that difference. With a term loan, you borrow a lump sum once and repay it on a fixed schedule. With a line of credit, you're approved for a limit, but you only borrow — and only pay interest on — the portion you actually draw. The calculator models that reality. Here's what each input does:
Credit Limit. The maximum amount the lender approves you to access. It's not what you owe — it's your ceiling. Setting your limit here lets the calculator show your utilization, which is one of the quiet factors that affects both your rate and your future borrowing power.
Draw Amount. The portion of your limit you're actually borrowing right now. Your interest and your monthly payment are calculated on this number — not on your full limit. If you have a $100,000 line but only draw $50,000, you pay interest on $50,000. The calculator caps your draw at your credit limit and shows your utilization percentage beside it.
Rate — APR or Monthly. Use the toggle to match how your offer is actually quoted. Bank and credit-union lines are quoted as an APR. Many online and alternative lenders quote a monthly rate instead. Set the toggle to match your quote so the math reflects your real offer.
Repayment Term. How long you take to pay back the draw, in months. A shorter term means higher monthly payments but less total interest; a longer term lowers the monthly payment but costs more overall
Draw Fee (optional). Some lenders charge a fee each time you draw, expressed as a percentage of the draw. If your offer includes one, open this field and enter it; the calculator folds it into your total repayment so you see the true all-in cost.
Once your inputs are set, the calculator returns your estimated monthly payment, total repayment, total interest paid, any draw fee, daily interest cost, utilization percentage, and estimated payoff date. The next sections explain what those numbers mean and why they move the way they do.
How a business line of credit payment is calculated
You pay interest on your draw, not your limit. The single most important thing to understand about a line of credit is that an unused limit costs you nothing in interest. If you're approved for $100,000 and never touch it, your interest is zero. The moment you draw $50,000, interest begins accruing on that $50,000 — and only that $50,000. Draw more, and the interest base grows. Pay it down, and it shrinks
Your payment is built on three things: the draw, the rate, and the term. The calculator amortizes your draw — spreading principal and interest into level monthly payments. Your credit limit never enters this calculation; only what you actually drew does.
The balance falls as you repay it. Because each payment chips away at your principal, the balance you're paying interest on shrinks every month. By the midpoint of the term you owe roughly half; near the end, almost nothing. So total interest in dollars is always less than "rate × full draw × years" would suggest
Daily interest. The calculator surfaces your daily interest cost — what your outstanding draw costs you every single day it stays out. The math: your draw amount times your annual rate, divided by 365. A $50,000 draw at a 12% annual rate costs roughly $16.44 a day. That's the lens to view a line of credit through: not "what's my monthly payment" but "what is this costing me per day, and how fast can I bring it back down?"
Understanding your results
Estimated Monthly Payment. The amount you'd pay each month to pay off your current draw over the selected term. Adjust the draw, rate, or term and this updates instantly.
Total Repayment. The sum of everything you pay over the life of the draw — your principal, all the interest, and any draw fee. This is the true all-in figure: what you borrowed plus what it cost to borrow it.
Draw Amount. Repeated in the results as a reminder that this — not your limit — is the principal you're actually repaying.
Total Interest Paid. The portion of your repayment that's pure cost of capital, separate from any fee. This is a number to minimize, but read it alongside the rate, not on its own.
Draw Fee. If you entered one, this shows the flat fee in dollars. It's a one-time charge on the draw, not compounded into your interest — but it's real money, so the calculator adds it into your total repayment.
Daily Interest Cost. What your outstanding draw costs you per day. The single most useful metric on the page.
Utilization %. Your draw divided by your credit limit. Drawing $50,000 against a $100,000 limit is 50% utilization.
Estimated Payoff Date. The month and year your draw would be fully repaid at the current payment. LimeLyne calculators always compute this from today's actual date, so it's never stale.
What actually affects your rate and your cost
Your draw size. More principal means more interest, in direct proportion. The discipline a line rewards is drawing only what you genuinely need for the gap you're funding — not the full limit just because it's available.
Your term. A longer term lowers the monthly payment but keeps your balance — and therefore your daily interest — outstanding longer. A shorter term costs less in total interest but comes with a higher monthly payment. One thing worth keeping in mind: on a short term, the total interest figure can look small even when the rate is relatively high, because you're paying the balance down quickly. It's helpful to compare offers by their rate rather than by the total interest dollars alone.
The rate you're quoted — and whether it's annual or monthly. When comparing offers, confirm how each rate is expressed. Bank lines of credit are typically quoted as an annual rate (APR). Many alternative lenders quote a monthly rate instead. The APR/Monthly toggle on this calculator lets you model either.
What actually qualifies you for a given rate. Here's the disclosure most marketplaces don't advertise. The advertised minimums on business lines of credit are frequently not the real minimums. You'll see business lines of credit marketed with a "550 credit score minimum." Realistically, genuinely competitive line-of-credit pricing tends to require stronger personal credit (commonly 650+), real time in business, and consistent revenue.
We tell you this for a reason that's honest and also self-interested in the right way: a calculator that lets you model a rate you'll never be offered isn't doing you any favors. Set the rate in this tool to reflect your actual credit profile, not the lowest advertised figure, and the results become genuinely useful for planning.
Bank vs. alternative lender: two ways a line of credit can be structured
"Business line of credit" covers two different structures, and they're quoted differently. Knowing which one you're looking at helps you read your offer accurately and model it correctly here.
Bank lines of credit are quoted as an APR (an annual rate), interest accrues on your drawn balance, and they typically don't charge a fee each time you draw. They tend to have stricter qualification requirements — stronger personal credit, established time in business, solid financials, and sometimes collateral or an existing banking relationship — so they're accessible to a narrower set of borrowers. Set this calculator's toggle to APR to model a bank-style line of credit.
Alternative lender lines of credit are built for broader access and faster funding. They often approve quickly and with more flexible requirements, which is why they're the practical route for many businesses. They're frequently quoted as a monthly rate rather than an APR, and some charge a draw fee when you pull funds.
Monthly rate. Many alternative lenders express the rate per month rather than an annual APR — for example, "1.5% per month." Because it's a monthly figure, it isn't directly comparable to an annual APR. Flip this calculator's toggle to Monthly and enter the monthly figure to see the resulting payment.
Draw fee. A per-draw fee — commonly around 1% to 3% of each draw — is a flat fee applied when you draw funds. It doesn't compound with your interest; it's a one-time amount on each draw. Open the optional Draw Fee field and enter your lender's percentage so it's included in your total repayment.
The calculator's toggle and optional draw-fee field let you model either structure accurately.
How to reduce what a line of credit costs you
Draw only what you need, when you need it. Because interest accrues only on your outstanding draw, the simplest cost-control move is to resist drawing the full limit. Fund the specific gap — the payroll bridge, the inventory order, the receivable you're waiting on — and leave the rest of the line untouched and free.
Pay it down as fast as the cash flow allows. Every day a draw stays out has a daily interest cost. Bringing the balance down early doesn't just reduce your remaining payments; it shrinks the daily interest base immediately. On a revolving line, an early paydown is one of the highest-return uses of spare cash you have.
Use the revolving nature deliberately. The point of a line is that you can repay and redraw. Treat it as a tool for short, self-liquidating needs — borrow against a receivable, repay when it lands, and you've used the line exactly as intended at minimal cost. Carrying a large balance indefinitely turns a flexible tool into an expensive one.
Know how your line is priced. How your line is priced — an annual APR, a monthly rate, whether there's a draw fee — shapes your total cost alongside the rate number itself. Whichever structure your offer uses, model it accurately here so you're comparing real payments rather than headline figures.
Watch your utilization at renewal. Lines come up for review. Sustained high utilization can read as strain; disciplined utilization can support a limit increase or a better rate next cycle. The utilization figure in this calculator is the same number a lender watches — so watch it too.
With a business line of credit, you only pay interest on what you actually draw — which means having access to a line of credit costs you nothing until you use it.
Frequently Asked Questions
Common questions about how the calculator works and what the numbers mean.
Your payment is calculated on the amount you draw, not your total credit limit. The calculator amortizes your draw over your chosen repayment term using your rate — spreading principal and interest into level monthly payments. An unused portion of your limit costs nothing; interest accrues only on what you've actually borrowed.
Only what you use. This is the defining feature of a line of credit. If you're approved for $100,000 and draw $50,000, you pay interest on $50,000. The remaining $50,000 sits available at no interest cost until you draw it. This is what makes a line cheaper than a term loan for needs you can't fully predict.
Daily interest cost is what your outstanding draw costs you each day it stays out, calculated as your draw amount times your annual rate divided by 365. We surface it because it's the most actionable number on a revolving product: it turns an abstract annual rate into a concrete daily price, which is what makes paying a draw down early feel as worthwhile as it actually is.
Utilization is your draw divided by your credit limit, shown as a percentage. Drawing $50,000 on a $100,000 line is 50% utilization. It matters because lenders watch it at renewal as a health signal, and because chronically high utilization often means your line is undersized. The calculator displays it so you can borrow deliberately rather than maxing out by habit.
Because interest accrues over time. A shorter term keeps your balance outstanding for fewer months, so less total interest accumulates — even though each payment is larger. A longer term lowers the monthly payment but keeps the balance (and the daily interest) alive longer, raising the total cost.
One caution: on a very short term, the total interest dollars can look small even when the rate is high, because you pay the balance down quickly. Compare offers by the rate, not just the dollar total.
Not necessarily, and this is one of the most common ways borrowers misjudge an offer. Because your balance falls as you repay it, the interest in dollars is always less than "rate times full draw times years" would suggest — you never hold the full amount for the full term.
On a short repayment period especially, a high rate can still produce a modest-looking interest total. It helps to look at the rate itself, and confirm whether it's quoted annually or monthly, when comparing offers.
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