Margin of Safety Units Calculator

About this calculator

Margin of safety measures how far current or projected sales sit above the break-even point — the volume at which total revenue equals total costs — calculated in units as actual unit sales − break-even units, and as a percentage as that difference divided by actual unit sales. A larger margin means more cushion before a sales decline pushes the business into a loss.

This calculator takes your actual unit sales and break-even volume (typically derived from fixed costs ÷ contribution margin per unit) and returns the margin of safety in both units and percentage. Management accountants and financial analysts use it in cost-volume-profit analysis to gauge how risky a product line or sales forecast is, and small-business owners use it to understand how much sales could drop before they stop covering their fixed costs.