Canonical formula calculator
Gross Profit Margin
How much of every dollar you keep before operating costs.
Total sales over the period.
Direct costs of producing what you sold.
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Add context for case suggestions
Optional — helps us match this calculation against relevant case studies (coming soon).
What this tells you
Gross profit margin is the percentage of revenue left after the direct cost of producing what you sold. It is the first profitability gate — before rent, salaries, software, or marketing. A low gross margin means there is not enough room to absorb operating costs, no matter how well the rest of the business runs.
When to use it
Use this calculator whenever you change pricing, change supplier costs, or evaluate a new product line. Run it monthly to track margin trend. A small monthly slide compounds — gross margin drift is one of the most common patterns in the Blackbox case library.
What it doesn’t tell you
Gross margin ignores operating expenses, marketing spend, founder draw, and taxes. A 70% gross margin business can still be losing money. Pair this metric with operating margin, net profit margin, and burn rate to see the full picture.
Coming soon
Cases, plays, and benchmarks for this metric will appear here as the Moonshot knowledge libraries grow. For now: log in to track your number over time and Moonshot will surface trend warnings when the substrate fills in.