What is the difference between gross profit and net income on a P&L?

Gross profit is revenue minus cost of goods sold — what remains after paying for the products or direct labor you sold. Net income is what remains after all expenses: operating costs, interest, depreciation, and taxes. A business can show healthy gross profit and still post a net loss if overhead outruns the margin.

How often should a small business review its profit and loss statement?

Monthly, once the books are reconciled for the month. A P&L reviewed quarterly or annually tells you what already went wrong; a monthly review, compared against the prior month and the same month last year, is early enough to change pricing, spending, or staffing before a bad trend compounds.

Why does my P&L show a profit when my bank account is shrinking?

The P&L records income when earned and expenses when incurred, not when cash moves. Loan principal payments, owner draws, equipment purchases, and growing accounts receivable all consume cash without appearing as expenses. The cash flow statement, not the P&L, explains where the money went.

What is a comparative profit and loss statement?

A comparative P&L shows two or more periods side by side — this month versus last month, or this year versus last year — so changes in each line stand out. Most small-business accounting software produces one with a single setting. It is the single most useful format for a monthly owner review.

How to read a profit and loss statement, top to bottom

The profit and loss statement — the P&L, or income statement — answers one question: over a defined period, did the business earn more than it spent? It reads top to bottom like a subtraction problem. Revenue sits at the top. Costs come out in layers — first the direct cost of what you sold, then the cost of running the operation, then interest and taxes. What survives at the bottom is net income.

That layered structure is the whole point. A P&L that only showed the bottom line would tell you whether you made money. The layers tell you why — whether the problem (or the strength) lives in pricing, in direct costs, or in overhead. This guide walks the statement line by line, shows a full sample, and lists the question each line should raise when you read your own.

Revenue: the top line

Revenue (or sales, or income — software uses all three labels) is what the business earned from its ordinary activities during the period. Two things matter here for a reader.

First, earned, not collected. On accrual-basis books, revenue appears when you deliver the work or ship the product, even if the invoice is unpaid. On cash-basis books, it appears when the money arrives. Know which basis your books are on before you read anything else; the IRS's Publication 538 covers the two methods, and the distinction changes what every line means.

Second, revenue should be gross of nothing and net of returns. Refunds, discounts, and returns belong as a contra-revenue line (often "Returns and allowances") subtracted just below sales, not buried in expenses. If your P&L shows a single revenue number, ask your bookkeeper whether refunds are netted inside it.

The question this line raises: is revenue growing, flat, or shrinking — and compared to what? A revenue number without a prior period beside it is nearly useless.

Cost of goods sold and gross profit

Cost of goods sold (COGS) is the direct cost of whatever produced the revenue: materials and inventory for a product business; direct labor and subcontractors for a service business. The test is causation — if the cost scales with each sale, it is COGS; if it would exist at zero sales (rent, the office manager, software subscriptions), it is an operating expense. We treat the boundary in detail in COGS vs. operating expenses.

Revenue minus COGS is gross profit, and gross profit divided by revenue is gross margin — the single most diagnostic percentage on the statement. It measures whether your pricing covers your direct costs with enough left over to fund everything else.

Here is how the top half of an illustrative P&L cascades down to the bottom line:

The P&L as a waterfall — where each dollar of revenue goes$

Illustrative service business, one month. Each bar is the amount remaining after the prior layer of cost.

The question this layer raises: is gross margin stable? A margin that drifts from 55% to 48% over three months means your costs rose or your pricing slipped — and you want to know which before the drift reaches the bottom line.

Operating expenses

Below gross profit sit the operating expenses — sometimes labeled "overhead" or "SG&A" (selling, general, and administrative). Rent, non-direct payroll, insurance, marketing, software, professional fees, utilities. These are the costs of existing as a business, largely independent of any single sale.

Read this section for two things:

Concentration. Usually three to five lines are 80% of the total. Payroll and rent dominate most small businesses. The small lines matter less than owners think; the big lines matter more.
Trend. Operating expenses should grow slower than revenue. When they grow faster, the business is buying growth with margin — sometimes a deliberate choice, but it should be a choice.

Operating income versus net income

Gross profit minus operating expenses is operating income — the profit of the business as a business, before financing and one-off items. Below it come the lines that are real costs but say nothing about operations: interest expense on loans, depreciation and amortization (the spread-out cost of equipment and other assets — see where depreciation appears on the statements), gains or losses on selling assets, and income tax for entities that pay it directly.

The distinction earns its keep in two situations. If operating income is healthy but net income is thin, the business works and the balance sheet is the problem — too much debt, or too much depreciating equipment. If operating income itself is negative, no refinancing will save you; the operation needs repricing or restructuring.

A full sample P&L, read aloud

The statement below is a complete comparative P&L for an illustrative design studio, June 2026 against May 2026.

Line	June 2026	May 2026	Change
Service revenue	58,500	52,000	+6,500
Product revenue	3,200	4,100	−900
Returns and allowances	(1,700)	(600)	−1,100
Total revenue	60,000	55,500	+4,500
Direct labor (COGS)	21,400	18,900	+2,500
Subcontractors (COGS)	4,300	3,200	+1,100
Materials (COGS)	1,300	1,400	−100
Total COGS	27,000	23,500	+3,500
Gross profit	33,000	32,000	+1,000
Gross margin	55.0%	57.7%	−2.7 pts
Admin payroll	12,600	12,600	—
Rent and utilities	4,800	4,800	—
Software and subscriptions	2,100	1,850	+250
Marketing	3,400	1,900	+1,500
Insurance and professional fees	2,300	2,300	—
Total operating expenses	25,200	23,450	+1,750
Operating income	7,800	8,550	−750
Interest expense	(900)	(920)	+20
Depreciation	(800)	(800)	—
Net income	6,100	6,830	−730

Now read it the way a practiced eye does — not top to bottom, but question by question:

Revenue grew 8%. Good. But $1,100 of new returns partially offset it — one bad project, or a pattern? That line was $600 last month. Ask.
Gross margin fell 2.7 points. Revenue rose $4,500 but COGS rose $3,500 — the new work was won at thinner margin, or direct labor is running less efficiently. This is the month's most important finding, and net income alone would never have surfaced it.
Marketing nearly doubled. Was that planned? If the $1,500 bought the revenue growth, fine — but then the combination of paid growth and thinner margin means this month's growth cost almost exactly what it earned.
The fixed lines behaved. Rent, admin payroll, insurance — unchanged. Nothing to investigate.
Net income fell $730 in a month revenue rose $4,500. That sentence is the whole review. The business grew and made less money doing it. Every question above is a thread of that one finding.

That is what "reading" a P&L means: the numbers are answers, and your job is to reconstruct the questions.

Comparative periods: never read one column

A single-period P&L is a photograph with nothing in frame for scale. Always run the report against at least one comparison:

Prior month catches sudden changes — the doubled marketing line above.
Same month last year catches seasonal businesses lying to themselves ("June is always slow" is checkable).
Year to date versus prior year to date smooths out lumpy months and shows the real trajectory.
Budget versus actual, if you budget, is the strongest comparison of all — covered in budget vs. actual reports.

A useful discipline for percentage reading is the common-size statement, where every line is expressed as a percent of revenue; see common-size statements.

What the P&L cannot tell you

The P&L is one of three statements, and it is silent on two subjects. It says nothing about cash — a profitable month can end with less money in the bank, because loan principal, owner draws, inventory purchases, and unpaid invoices never touch the income statement. And it says nothing about what you own and owe — that is the balance sheet's job, walked through in the balance sheet, explained. The three statements reconcile to each other in a precise mechanical way; the cash flow statement guide shows how.

One tax note for owners who do their own returns: the P&L your software produces is a book statement. The taxable income on your return will differ — meals limitations, depreciation methods, and timing rules all diverge. If your business files on the cash basis while keeping accrual books, the year-end conversion is its own topic; Publication 583 covers recordkeeping basics, and the self-employed tax center covers the filing side.

A monthly reading procedure

End with a routine you can actually run. Once the month is reconciled:

Run the comparative P&L — this month against last month and against the same month last year.
Check total revenue and ask what changed and why.
Compute gross margin and compare it to your trailing average; investigate any move over two points.
Scan operating expenses for any line that changed more than 10% or $500, whichever is larger.
Read operating income before net income — separate the operating story from the financing story.
Write down, in one sentence, what the month's statement says. If you cannot write the sentence, you have not finished reading.

Twenty minutes, once a month. It is the highest-return habit in small-business finance.