1. In Accounting, this is an amount in excess of a company’s breakeven point in sales revenue by actual sales revenue. A ratioed percentage. The bigger this margin, the less danger to the company by any abrupt fall in revenue. Formula: (Actual sales revenue minus Breakeven sales revenue) x 100 divided by Actual sales revenue. 2. In Occupational safety , this is the maximum amount of hazardous substance exposure that results in no measurable ill effects in test animals, divided by the human population’s actual amount of exposure.