Understanding Cash Flow: What Drives the Money In and Out of Your Business
Healthy cash flow keeps your business running. Even if you’re profitable on paper, timing differences between when money comes in and goes out can leave you short of cash. It’s common for businesses to confuse cash flow and profits, so we built this calculator to help you see how a few key drivers—sales growth, payment timing, and inventory—shape your cash position over time.
1. Sales & Profits
Your sales are the engine that powers everything else.
- Sales growth shows how fast your revenue increases month over month.
- Cost of Goods Sold (COGS) is what you spend to make or buy the products you sell.
- Operating expenses cover everything else: rent, salaries, marketing, software, etc.
Even if your sales are growing, high costs or slow payments can still create cash shortages.
2. Accounts Receivable (AR): When Customers Pay You
If you sell on credit (for example, net-30 terms), your customers don’t pay right away.
- The percentage of sales on credit is the percentage of your customers that get invoiced and then pay at some point in the future.
- Days to collect (AR days) show how long, on average, it takes for that money to arrive.
The longer it takes customers to pay, the more cash gets “stuck” in accounts receivable—money you’ve earned but can’t use yet because it’s not in your bank account yet.
Tip: Faster collections improve cash flow immediately.
3. Accounts Payable (AP): When You Pay Your Bills
You also don’t always pay suppliers immediately.
- Days to pay bills (AP days) show how long you wait before paying your vendors.
A longer payment window can help conserve cash in the short term, as long as you maintain good supplier relationships. Think of it as getting a short-term loan from your suppliers.
Tip: Extending payment terms boosts short-term cash, but pushing too far can hurt trust with suppliers.
4. Inventory: Cash Sitting on the Shelf
Inventory ties up money until you sell it.
The months of inventory on hand setting shows how much product you keep available on your shelves or in your warehouse.
Too much inventory eats up cash that could be used elsewhere. Too little, and you risk missing sales. Finding the right balance keeps cash moving smoothly through your business.
Tip: Reducing excess inventory frees up immediate cash.
Bringing It All Together
At the bottom of your calculator, you’ll see how these pieces combine to affect:
- Cash balance – how much money you actually have.
- Accounts receivable – how much customers owe you.
- Accounts payable – how much you owe others.
- Inventory on hand – how much cash is tied up in products that you’ve bought but haven’t sold yet.
By adjusting the numbers in the calculator, you can see why cash might rise or fall even when profits look good. This chart helps you understand how changes to sales growth, accounts receivable, accounts payable, and inventory can impact your cash and your profits.
Key Takeaway
Profit is important, but cash flow keeps your business alive. Understanding how sales timing, collections, payments, and inventory interact helps you make smarter decisions—whether that means tightening credit terms, managing supplier payments, or trimming inventory levels.
Next Steps
Download our free cash flow forecasting template to create a customized cash flow forecast for your business.