What this calculator does
It estimates profit, profit margin, and cost ratio from revenue and total cost. It is useful for small businesses that want a quick snapshot of performance.
Business / United States
How to use the profit margin calculator
This guide explains the inputs, formula, assumptions, example calculation, and common mistakes for the calculator.
Who should use it
Owners, managers, and operators who want to compare sales against costs for a single period such as a week, month, or quarter.
Input definitions
- Revenue: total sales for the same period
- Total cost: all costs you want included in the calculation
Formula
- Profit: revenue - total cost
- Profit margin: profit ÷ revenue
- Cost ratio: total cost ÷ revenue
Assumptions
- Revenue and total cost use the same time period
- Taxes, refunds, and unusual fees are excluded unless you include them in total cost
- The example uses USD, but the formula works for any currency
Quick example
A bakery earns $50,000 and has $30,000 in total cost.
Profit = 50,000 - 30,000 = 20,000
Profit margin = 20,000 ÷ 50,000 = 40%
Cost ratio = 30,000 ÷ 50,000 = 60%
How to interpret the result
A higher profit margin means more of each sales dollar remains after costs. A lower margin means costs are taking a larger share of revenue.
Common mistakes
- Using revenue from one period and cost from another
- Leaving out major fixed costs like rent or equipment depreciation
- Confusing profit margin with markup
Limitations and disclaimers
- This is a fast decision tool, not accounting or tax advice
- Real businesses may allocate overhead differently
- Discounts, refunds, freight, and platform fees can change the answer if you include them differently