Profitability: gross and net margin
Gross margin is sales minus the direct cost of goods or services, divided by sales. It shows how much is left to pay overhead. Net margin is the final profit divided by sales. If gross margin is falling, look at pricing and direct costs. If gross margin is stable but net margin is falling, overhead is growing.
Compare against your own history first. Industry figures vary too widely to treat as targets.
Liquidity: can you pay your bills
The current ratio divides current assets by current liabilities. A figure above one means short-term assets exceed short-term debts. The quick ratio is stricter and leaves out inventory. These matter to lenders and show whether you can cover near-term bills.
A simpler test is months of cash: cash on hand divided by average monthly costs. It says how long you could operate if revenue stopped.
Leverage: how much debt
Debt to equity compares what you owe with the owner's stake. A higher figure means more reliance on borrowing. The debt service coverage ratio compares operating income with loan payments, and lenders often use it to decide whether you can afford more debt.
Neither number is good or bad by itself. A stable business can carry more debt than a volatile one.
Efficiency: how fast money moves
Days sales outstanding shows how long customers take to pay. Days payable shows how long you take to pay suppliers. Inventory turnover shows how often you sell and replace stock. Slow collections or stock tie up cash.
Track these monthly. Trends matter more than a single reading.
Using ratios without fooling yourself
Ratios depend on accurate books. If reconciliations are behind or categories are wrong, the ratios will mislead you. Calculate them on the same basis each time and write down how you did it.
Pick four or five that fit your business and put them in a small table next to your monthly report. A bookkeeper can set this up so the numbers update after every close. If a ratio changes sharply, ask what happened before reacting.
A tiny worked example
Imagine sales of one hundred thousand and direct costs of sixty thousand. Gross margin is forty percent. Overhead of thirty thousand leaves ten thousand profit, a net margin of ten percent. Next quarter sales rise to one hundred ten thousand, but direct costs climb to seventy thousand. Gross margin slips to about thirty-six percent, even though sales grew. The ratio exposes the cost problem that rising sales hid, and tells you to look at supplier prices or your own pricing.
Write down each ratio's formula next to the number, and note which accounts feed it. That way a change in your chart of accounts or a new bookkeeper does not silently alter the meaning. Lenders may calculate ratios their own way, so ask which definitions they use before you apply.
Worked example with numbers
Revenue $200,000, cost of goods sold $120,000, net income $24,000. Gross margin is $80,000 / $200,000 = 40%. Net margin is $24,000 / $200,000 = 12%. Current assets $45,000 and current liabilities $30,000 give a current ratio of 1.5. Compare each to last year and your industry before drawing a conclusion.
Mistakes that cost money
Comparing to the wrong industry. Looking at one ratio. Using unreconciled books.
Check your work
Recompute one ratio by hand from the statements.
Common questions
Which ratio matters most?
It depends on the business. Service firms watch margin and collections, product firms add inventory turnover.
Where do I find the numbers?
On the profit and loss and balance sheet. Most software can show them on a dashboard.
Are industry benchmarks reliable?
They can guide you, but your own trend is usually a better yardstick.
This guide is general information, not tax, legal or accounting advice. Rules, fees and due dates change; check with the IRS, the NJ Division of Taxation or a licensed professional for your situation.