By dividing the gross profit by the gross income, you derive this gross profit margin. As an example, if your business grossed $20,000 in income with $15,000 in sales expenses, subtracting $15,000 from $20,000 gives you a gross profit of $5,000.Dividing $5,000 by $20,000 calculates a 0.25 gross profit margin.y dividing the gross profit by the gross income, you derive this gross profit margin. As an example, if your business grossed $20,000 in income with $15,000 in sales expenses, subtracting $15,000 from $20,000 gives you a gross profit of $5,000. Dividing $5,000 by $20,000 calculates a 0.25 gross profit margin.
Typical costs: 1  Stone countertops, including granite, other natural stone and quartz resin (engineered stone) cost $4-$150 per square foot, or $120-$4,500 for a typical 30 square foot kitchen countertop. 2  Laminate countertops cost $7-$30 per square foot, or $210-$900 for a typical kitchen.
Marble may be the costliest countertop material you consider. There are a few different grades of marble, but none could be considered cheap. Some of the worldâs finest sculptures are marble. You pay for the rich luxury and lustrous beauty of marble. Marble countertops: $125-$250 per square foot.