To calculate gross margin percent use the formula selling price – total cost / selling price. The gross margin percent of the ice cream parlor's ice cream sundaes equals 44.5 percent ($2.00 ...

Columnist John D. Wagner explains why gross profit margin should not rise or fall with sales and reasons that it could.

For example, a company with revenue totaling $100,000 and costs of goods sold totaling $35,000, would have a gross profit of $65,000 and a gross profit margin of 65%.