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.
Formica is one of the most popular and recognizable brand names of laminate countertops. Typical costs: Custom laminate countertops--with the laminate cut and glued to the base in a factory to custom specifications--cost $7-$30 per square foot, depending on the brand, color, finish and edge style. 1  A typical kitchen with 30 square feet of countertop area costs $210-$900, not including professional installation. With professional installation, laminate countertops cost $40-$65 per square foot; $1,200-$1,950 for a typical kitchen. Home improvement stores such as Lowe's and Home Depot sell prefabricated sections of laminate countertop for $50-$200 per section.