How to read a profit and loss statement: a manager's guide
· 9 min read
You can read a profit and loss statement well without an accounting degree. You need to know what each line means, convert the numbers into a form you can compare, and ask two or three sharp questions about what moved. This guide walks you through that method, using one worked example from start to finish, so the next time a P&L lands in your inbox you can explain what it says in plain words.
What a profit and loss statement actually tells you
A profit and loss statement (also called a P&L, an income statement or a statement of profit or loss) shows what an organisation earned over a period and what it cost to earn it. The period is usually a month, a quarter or a year. It reads from top to bottom, starting with sales and ending with what’s left.
Two things are worth knowing before you look at a single number.
It measures earning, not cash. Revenue is recorded when the work is delivered, even if the customer pays two months later. Costs are recorded when they’re incurred, even if the bill is still sitting unpaid. So a P&L can show a healthy profit in a month when the bank balance went down.
Some costs on it aren’t cash this period. Depreciation spreads the cost of a large purchase, such as a machine or a vehicle, across the years you’ll use it. The money may have left the bank long ago, but the P&L shows a slice of it each period.
The lines, from top to bottom
Most P&Ls follow the same shape, whatever the organisation. The labels vary, so here is each line with the question it answers.
| Line | What it means | The question it answers |
|---|---|---|
| Revenue | What customers were charged for work delivered in the period | How much did we sell? |
| Cost of sales | Costs that rise and fall with each sale: materials, stock, direct labour | What did it cost to deliver what we sold? |
| Gross profit | Revenue minus cost of sales | What’s left to pay for running the place? |
| Overheads | Costs that don’t move with each sale: most salaries, rent, software, insurance | What does it cost just to be open? |
| Operating profit | Gross profit minus overheads | Does the core business make money? |
| Interest | The cost of borrowed money | What does our debt cost? |
| One-off items | Gains or costs that won’t recur | Is anything unusual distorting the year? |
| Tax | Income tax on the year’s profit | What do we owe on what we made? |
| Net profit | What’s left after interest and tax | What do the owners keep? |
In government and not-for-profit organisations, revenue is often called income or funding and profit is called a surplus. The logic is the same.
If you’re not sure which line your own team’s work affects, the chapter on how your organisation makes money walks a single dollar of revenue down the page and shows where each kind of role sits.
A five-step method for reading any P&L
1. Check what you’re looking at
Before anything else, confirm the period (a month, a quarter, year to date), the units (dollars or thousands) and what the comparison column is. Last year and budget tell you different things. Mixing them up is the most common way to reach a confident wrong answer.
2. Read the top line and the bottom line together
Note the percentage change in revenue and in profit. If they moved in the same direction by similar amounts, the story is probably simple. If revenue went up and profit went down, or profit held steady while revenue jumped, that gap is the thing you need to explain.
3. Turn every line into cents per dollar of revenue
Divide each line by revenue. A cost that rose $40,000 might have shrunk as a share of a larger business, and a cost that barely moved in dollars might have eaten into your margin if sales fell. Percentages let you compare periods fairly. This single step does more than any other to make a P&L readable.
4. Find the line that grew faster than revenue
Compare each line’s growth with revenue’s growth. The lines that outpaced revenue are where the margin went. Look closely at cost of sales, which often moves more than overheads and gets far less attention.
5. Take out the one-offs and say it in three sentences
Remove anything that won’t happen again, such as a gain on selling equipment or a relocation cost, and look at the underlying result. Then write three sentences: what happened, the main reason, and what you’d ask next. If you can’t write them, keep reading.
Worked example: Mehmet reads the laundry’s results
Mehmet is the operations manager at Larkspur Linen, a commercial laundry that washes sheets and towels for hotels. The quarterly results arrive with a note from the owner: “Profit steady on last year.” Mehmet wants to understand them before the next management meeting.
| Same quarter last year | This quarter | |
|---|---|---|
| Revenue | $1,500,000 | $1,650,000 |
| Cost of sales (laundry staff, chemicals, gas, power, delivery fuel) | $975,000 | $1,122,000 |
| Gross profit | $525,000 | $528,000 |
| Overheads (office salaries, rent, insurance, IT) | $300,000 | $309,000 |
| Depreciation (washers, dryers, vans) | $75,000 | $90,000 |
| Operating profit | $150,000 | $129,000 |
| Interest | $15,000 | $24,000 |
| One-off: gain on selling the old washer | $0 | $30,000 |
| Profit before tax | $135,000 | $135,000 |
Step 1. Both columns are full quarters, in dollars, compared with last year.
Step 2. Revenue is up 10%. Profit before tax is exactly flat. A business that grew by a tenth and earned no more is the question to answer.
Step 3. Mehmet converts the main lines into shares of revenue.
| Share of revenue | Last year | This quarter |
|---|---|---|
| Cost of sales | 65.0% | 68.0% |
| Gross margin | 35.0% | 32.0% |
| Overheads and depreciation | 25.0% | 24.2% |
| Operating margin | 10.0% | 7.8% |
Step 4. Overheads and depreciation together grew by about 6%, slower than revenue, so they aren’t the main problem. Cost of sales grew by about 15%. Gross margin fell three points, and three points on $1,650,000 of revenue is about $49,500 of gross profit that would have been there at last year’s margin.
Step 5. The $30,000 gain from selling the old washer won’t happen again. Without it, profit before tax would have been $105,000, down more than a fifth on last year. The “steady” headline is propped up by a one-off.
Mehmet’s three sentences:
Revenue grew 10%, but cost of sales grew about 15%, so gross margin fell from 35% to 32%, which cost roughly $49,500 this quarter. Higher depreciation and interest from the new washer took another $24,000. Underlying profit before tax fell from $135,000 to $105,000; the flat headline comes from a one-off gain on the old washer.
His two questions for the bookkeeper: which part of cost of sales grew fastest (wages, chemicals, energy or fuel), and was the new hotel contract signed in the spring priced on last year’s costs?
The P&L tells Mehmet what moved, not why. The questions are how he finds out.
The chapter on reading an income statement uses a similar method on a different kind of business, with an exercise to practise it on a fresh set of figures.
What a P&L won’t show you
Mehmet’s results say nothing about whether Larkspur has enough money in the bank. The new hotel contract may pay on 60-day terms, which means a quarter of extra revenue can sit in unpaid invoices while wages and gas bills go out every week. The new washer may have been paid for in cash this year, even though the P&L shows only one quarter’s depreciation.
That’s why a profitable business can still be short of money. If you’re planning a large purchase or signing a big contract, look at when the cash moves as well as how much profit it makes. The chapter on why profit isn’t cash shows how to map that month by month.
Mistakes to avoid
- Comparing dollars instead of shares. “Wages went up $50,000” sounds alarming until you see wages fell as a share of revenue.
- Ignoring cost of sales. Overheads are visible and easy to argue about. Margin lost on each sale is often larger and quieter.
- Trusting the headline. “Profit steady” or “record revenue” can each hide the real story. Always look below operating profit for unusual lines.
- Treating depreciation as a saving. It’s a real cost of using equipment, but cutting it doesn’t put cash back in the bank.
- Stopping at what. The P&L shows what changed. Finish with a question for someone who knows why.
Your 15-minute checklist
Use this the next time a P&L arrives.
- Confirm the period, the units and the comparison column.
- Write down the percentage change in revenue and in profit.
- Convert cost of sales, gross profit, overheads and operating profit into shares of revenue.
- Circle any line that grew faster than revenue.
- List the one-off items and work out the underlying profit.
- Write your three-sentence summary.
- Send your two best questions to finance.
Once you know which lines matter most for your team, you may want to track one of them every month. The article on OKRs vs KPIs explains how to turn a number like gross margin into something you watch and act on.
The short version
A P&L is a fixed shape with a handful of lines. Check what you’re reading, compare shares rather than dollars, find what outgrew revenue, and strip out the one-offs. Do that a few times and you’ll be the person in the meeting who can explain the numbers, not just repeat them.
If you’d like to build this into a habit with guided exercises, the first module of Business Skills Essentials, “How a business works”, covers business models, income statements and cash flow.