The following formula is involved in the calculation of margin of safety values:

Margin of safety (percentage of sales):
where S_{E} is a company's expected sales and S_{B} is the company's breakeven sales.

The following references can be used to cite this margin of safety calculator:
 Soper, D.S. (2018) "Margin of Safety Calculator (Online Software)", http://www.danielsoper.com/fincalc. 
 Siegel, J. and Shim, J. (1997). "Schaum's Quick Guide to Business Formulas", New York, NY: McGrawHill. 