Small Business Working Capital: Formula, Needs & Funding

Last updated: October 2026

Small business working capital is the money available to run the business day to day: current assets (cash, receivables, inventory) minus current liabilities (payables, short-term debt, accrued bills). It is what covers payroll, inventory and rent while you wait for customers to pay. A positive number means you can meet near-term bills from near-term assets. A working capital ratio between about 1.2 and 2.0 is a common rule of thumb for a healthy cushion. When the gap is temporary, the usual ways to fund it are a line of credit, a short-term or SBA loan, invoice factoring or a merchant cash advance.

This guide covers the formula, how much working capital a small business needs, how to read your ratio, funding options compared side by side, options for startups and new businesses, and what "merchant working capital" means.

What is business working capital?

Working capital measures short-term liquidity. It comes from two parts of your balance sheet.

Current assets are things that turn into cash within about 12 months:

cash in the bank
accounts receivable (invoices customers owe you)
inventory and materials
prepaid expenses

Current liabilities are what you owe within about 12 months:

accounts payable to suppliers
the current portion of loans and credit card balances
accrued payroll, taxes and other bills

Profit and working capital are not the same thing. A business can be profitable and still run short of cash. That happens when it pays suppliers and staff weeks before its own customers pay, or when cash is tied up in inventory. This timing gap is the most common reason small businesses look for working capital funding.

Working capital formula, with an example

Working capital = current assets − current liabilities

Working capital ratio (current ratio) = current assets ÷ current liabilities

Example: a small trucking company has:

$20,000 in the bank
$50,000 in receivables from completed loads
$5,000 in parts inventory
$15,000 owed for fuel
$10,000 in truck payments due over the next 12 months

Its working capital is ($20,000 + $50,000 + $5,000) − ($15,000 + $10,000) = $50,000. Its ratio is $75,000 ÷ $25,000 = 3.0.

For variations of the formula, such as operating working capital, see our net working capital formula guide.

How to read your working capital ratio

Ratio	What it usually means
Below 1.0	Negative working capital. Short-term bills exceed short-term assets, so you depend on new sales or outside funding to pay them.
1.0 to 1.2	Thin cushion. One slow-paying customer or a slow month can cause a crunch.
About 1.2 to 2.0	A common rule-of-thumb range for a healthy cushion.
Well above 2.0	Comfortable, but check whether cash is stuck in old receivables or slow inventory.

Treat these ranges as rules of thumb, not standards. A restaurant that collects cash at the register can run safely on a lower ratio than a contractor waiting 60 days on invoices.

How much working capital does a small business need?

There is no single right number, but two methods give you a defensible target.

1. The cash conversion cycle method

Work out how many days your cash is tied up, then multiply by your daily operating costs:

Days sales outstanding (DSO): how long customers take to pay.
Days inventory outstanding (DIO): how long inventory sits before it sells.
Days payables outstanding (DPO): how long you take to pay suppliers.
Cash conversion cycle = DSO + DIO − DPO.

Example: a distributor spends about $2,000 a day on operating costs. Customers pay in 45 days, inventory turns in 30 days, and suppliers give 30-day terms. The cycle is 45 + 30 − 30 = 45 days, so the business needs about 45 × $2,000 = $90,000 just to carry normal operations. Add a buffer for slow months.

2. The cash buffer method

Many owners also keep a reserve measured in days or months of expenses. For context, a JPMorgan Chase Institute study of about 597,000 small businesses found:

the median business held only 27 days of cash outflows in reserve
a quarter held fewer than 13 days
labor-intensive industries, such as restaurants, held less

If your buffer is under a month and your sales are seasonal or your customers pay slowly, plan funding before you need it.

Small business working capital funding options compared

Needing outside money for working capital is normal. In the Federal Reserve's 2025 Small Business Credit Survey, 56% of employer firms that sought financing did so to meet operating expenses. 42% of applicants received the full amount they asked for. Here are the main options:

Option	How it works	Best for	Watch out for
Business line of credit	Draw, repay, draw again; interest only on what you use	Recurring, unpredictable gaps	Draw or maintenance fees; banks want strong credit and history
Short-term working capital loan	Lump sum repaid in fixed daily, weekly or monthly payments, often over 3 to 24 months	A one-time need with a clear payback, such as a bulk inventory order	A high effective APR when terms are short
SBA 7(a), SBA Express, CAPLines	Government-guaranteed bank loans and lines; working capital terms up to 10 years	Lowest cost if you qualify and can wait several weeks	Paperwork, collateral, U.S.-citizen ownership rule
Invoice factoring or financing	Advance against unpaid B2B invoices	Slow-paying commercial or government customers	Fees grow the longer invoices stay unpaid
Merchant cash advance (not a loan)	Sale of future receivables; remittances taken daily or weekly	Urgent needs, card-heavy or high-deposit businesses, weaker credit	Usually the most expensive option
Business credit card	Revolving card credit	Small purchases repaid within the grace period	High rates if you carry a balance
Platform financing	Shopify, PayPal, Square or Stripe advance repaid from a share of sales	Sellers whose sales mostly run through one platform	Size is limited to that platform's sales volume

Working capital loan vs. line of credit

A working capital loan gives you one lump sum for a known need, repaid on a fixed schedule. A line of credit is a standing limit you draw on as needs come up and reuse after you repay. If the gap repeats every month or season, a line usually costs less, because you pay only for what you use. Compare options in our business line of credit guide.

SBA working capital options

SBA 7(a) loans can fund working capital, with terms up to 10 years and a maximum of $5 million. Other SBA routes:

SBA Express: loans and revolving lines up to $500,000.
CAPLines: revolving lines for seasonal, contract-based and other cyclical working capital needs.
Working Capital Pilot: lines of up to $5 million with maturities up to 60 months.

Variable 7(a) rates are capped by loan size. They range from Prime + 3.0% on loans above $350,000 to Prime + 6.5% on loans of $50,000 or less. With Prime at 7.00% in late October 2026, that is a maximum of 10.00% to 13.50%.

Since March 1, 2026, every direct and indirect owner of a 7(a) or 504 borrower must be a U.S. citizen or U.S. national. Read what an SBA loan is for the full picture.

When invoice factoring fits

If your gap exists because B2B customers pay on net-30 to net-90 terms, factoring turns those invoices into cash now. Approval leans mainly on your customers' credit rather than yours. See invoice factoring.

How to calculate the cost of a working capital loan

Always convert offers to total dollars repaid and time:

Amortized loan: $50,000 at 15% APR over 12 months is about $4,513 a month, or about $4,155 in total interest.
Factor rate: $50,000 at a 1.30 factor means $65,000 repaid, a $15,000 cost whatever the term. Repaid over 6 months, that costs far more per year than the loan above.
Fees: add origination, draw and other fees to the cost before you compare.

How fast can you get working capital?

Timing depends on the product and on how quickly you provide documents:

SBA and bank loans usually take weeks.
Online lines of credit, short-term loans, factoring and merchant cash advances can often fund within days of a complete application.

Have these ready to move faster: 3 to 6 months of business bank statements, recent financial statements, your tax returns, and an accounts receivable aging report if you plan to factor. Faster money nearly always costs more, so plan ahead when you can.

Working capital for startups and new businesses

Most online lenders and revenue-based funders want 6 to 12 months or more of operating history and steady deposits. So a business under a year old has fewer options:

SBA microloans: up to $50,000 (the average is about $13,000), terms up to 7 years and rates generally 8% to 13%. They are made through nonprofit intermediaries and can be used for working capital and inventory.
SBA 7(a) for startups: possible with a solid plan, collateral and a 10% equity injection.
Equipment financing: the equipment secures the deal, which helps when you have little history.
Business credit cards and supplier trade credit for early inventory and supplies.
Owner capital, friends and family, or local CDFIs and economic development lenders.

To estimate how much working capital you need to start, add your startup costs to several months of operating expenses before break-even, then subtract any revenue you can reasonably expect in that time. More detail is in our guide to business financing for startups.

What does "merchant working capital" mean?

"Merchant working capital" usually means funding offered to businesses that take card payments, based on their sales volume rather than their balance sheet. In practice it is one of two things:

A merchant cash advance: a funder buys a portion of your future receivables and collects a percentage of your sales or deposits until the purchased amount is delivered. It is not a loan. See what a merchant cash advance is.
A payment processor's own program, such as PayPal Working Capital, Square Loans, Shopify Capital or Stripe Capital. These are repaid automatically from a share of the sales you process with them.

Before accepting either, check the total payback, the percentage withheld, and whether there is a minimum payment or maximum term.

Ways to improve working capital without borrowing

Invoice the day the work is done. Accept ACH and cards, and send reminders before due dates.
Offer an early-payment discount (for example, 2/10 net 30) only if it costs less than your financing.
Use your full supplier terms and ask long-standing vendors for net 45 or net 60.
Cut slow-moving inventory and reorder in smaller, more frequent batches.
Take deposits or progress payments on large jobs.
Forecast cash 13 weeks ahead, so you arrange funding before a gap rather than during one.

Finding working capital with FSE

FSE is an independent commercial finance brokerage working with 50+ lending partners across lines of credit, working capital loans, equipment financing, invoice-based funding and merchant cash advances. One application lets us compare what you may qualify for. Our application asks for at least one year in business and $10,000+ in monthly revenue. Approval and terms depend on each lender. Start a no-obligation application.

Small Business Working Capital: Formula, How Much You Need and How to Fund It