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.
1 Some manufacturers require a minimum purchase. 2  Slab granite countertops--solid pieces of granite custom cut to the width and shape of a countertop -- cost $60-$100 per square foot depending on the color and rarity of the granite, the style of edging. 3  Expect to pay $1,800-$3,000 for a typical kitchen, installed. For Do-It-Yourselfers, granite tile countertops cost $4-$19 per square foot, or $120-$570 for a typical kitchen with 30 square feet of counter space.