Start with the income statement, not the bank balance
A bank balance shows timing. Profit shows whether the business earned more than it spent during a period. You need both, but they answer different questions. Start by separating the main layers:
- Revenue: the value of sales or services delivered in the period, before expenses.
- Cost of goods sold (COGS): the direct cost of delivering what you sold, such as materials, contractor labour tied to a project, or payment processing directly tied to sales.
- Gross profit: revenue minus COGS.
- Operating expenses: the ongoing cost of running the business, such as software, rent, insurance, and admin support.
- Net profit before tax: revenue minus all business expenses.
The key discipline is consistency. Pick a period, use the same categories each time, and do not move an expense between categories just to make a number look better.
A worked example
Imagine a small service business reviewing one month. The figures below are illustrative, not benchmarks.
| Line | Amount |
|---|---|
| Revenue | $48,000 |
| Cost of goods sold | $18,000 |
| Gross profit | $30,000 |
| Operating expenses | $12,000 |
| Marketing expenses | $4,000 |
| Other expenses | $2,000 |
| Net profit before tax | $12,000 |
The calculation is:
$48,000 - $18,000 = $30,000
Net profit before tax
$48,000 - ($18,000 + $12,000 + $4,000 + $2,000) = $12,000
If the example business sets aside an estimated 20% for tax on positive profit, the tax estimate is $2,400 and the after-tax profit is $9,600. That is an estimate for planning, not tax advice.
Calculate the margins
Absolute profit is useful, but margin makes it easier to compare months, products, or price changes.
Gross profit / revenue
$30,000 / $48,000 = 62.5%
Net margin before tax
Net profit before tax / revenue
$12,000 / $48,000 = 25%
After-tax margin
$9,600 / $48,000 = 20%
A higher margin is not automatically better. A business may deliberately accept a lower margin to win a strategic account. What matters is that the trade-off is visible and intentional.
Use the Profit Calculator to apply the same formulas to your own numbers, including a simple break-even estimate.
Find the break-even point
Break-even revenue is the sales needed to cover fixed expenses after accounting for the gross margin. In this simplified model, fixed expenses are operating, marketing, and other expenses.
Fixed expenses / gross margin ratio
$18,000 / 0.625 = $28,800
In the example, revenue above $28,800 would begin to cover fixed costs under those assumptions. This is not a cash-flow forecast. It assumes the gross margin and expense mix stay reasonably stable.
When break-even is not available: if gross profit is zero or negative, selling more does not automatically cover fixed costs. Fix the gross margin or cost structure first.
Build a monthly review routine
- Close the month. Make sure sales, refunds, and expenses are recorded in the correct period.
- Reconcile the bank and payment accounts. Match transactions so the records reflect what actually happened.
- Separate COGS from operating costs. Consistent categories make the gross margin meaningful.
- Calculate gross profit, net profit, and both margins. Compare them with the previous month and the same month last year if available.
- Review the largest changes. A revenue increase with a falling margin deserves a closer look than a small rounding difference.
- Choose one action. Adjust a price, renegotiate a supplier cost, reduce a low-value expense, or follow up on receivables.
Keep the review short enough to repeat. A 30-minute monthly habit is more useful than an elaborate annual analysis that arrives too late to change a decision.
Common mistakes
- Treating owner draws as a business expense. A draw is a distribution of profit, not an operating cost. Record it separately.
- Forgetting tax reserves. Profit before tax is not the same as money available to spend.
- Mixing personal and business spending. It makes both bookkeeping and decision-making harder.
- Ignoring refunds and chargebacks. Revenue should reflect the period after those adjustments are known.
- Calling every cost "COGS". That distorts gross margin and hides the real cost of delivery.
- Comparing revenue only. A larger month can still be less profitable if delivery costs rise faster.
Quick review checklist
- Revenue and refunds are recorded for the same period.
- COGS includes only direct delivery costs.
- Operating, marketing, and other expenses are categorised consistently.
- Gross profit, net profit, and margins have been recalculated.
- Tax reserve and owner draws are handled separately from expenses.
- Break-even assumptions are written down and reviewed.
- The review ends with one specific action.
If you want a repeatable structure instead of building a spreadsheet from scratch, the Small Business Profit & Finance Toolkit includes profit and loss, pricing, break-even, and monthly review templates.
Put this guide into practice
Check your own revenue, costs, and break-even point. Use the free Profit Calculator to apply the steps in your browser. If you want editable templates around this workflow, the Small Business Profit & Finance Toolkit includes profit and loss, pricing, break-even, and monthly review spreadsheets with a usage guide.