Profit Margin Calculator — Methodology

Step-by-step calculation

Calculate gross, operating, and net profit margin from revenue and cost figures in seconds.

1. 1

   Pick your region

   Toggle USA, UK, or South Africa to load the right currency symbol and pre-fill the corporate tax rate.

2. 2

   Enter total revenue

   Type your sales or revenue for the period in the Revenue field.

3. 3

   Enter cost of goods sold (COGS)

   Add the direct costs to produce or buy what you sold.

4. 4

   Add operating expenses (optional)

   Add rent, salaries, marketing, and overhead to unlock the operating margin result.

5. 5

   Read your margin tier

   Gross, operating, and net margin display with color-coded interpretation — green is healthy, amber is caution, red needs action.

Assumptions and overrides

Tax rate defaults reflect each region's headline corporate tax rate. Override the rate if your effective rate differs (e.g. UK small profits rate, US state tax additions).

Every region default on the calculator is editable. If your effective rate, fee, or threshold differs from the headline figure shown, type your own number into the field — the calculator recomputes instantly without leaving this page.

Primary sources

Region-tagged primary sources for the default rates, thresholds, and benchmarks used in this calculator.

• USAIRS — Form 1120 (US corporate tax 21%)
• UKGOV.UK — UK Corporation Tax rates (25% / 19% small profits)
• SASARS — Corporate Income Tax (27% standard)

Review cadence and corrections

This methodology and the underlying rate defaults are reviewed at least annually, and immediately following any change to the headline rate from IRS, HMRC, or SARS. Every substantive update is recorded on the public changelog. Spotted an error? See the corrections policy for how to report it.

See the full editorial policy for the standards every page on BusCalcTools is held to.