Question: how to calculate a 30 percent markup?
Answer: You have calculated 30% of the cost. When the cost is $5.00 you add 0.30 × $5.00 = $1.50 to obtain a selling price of $5.00 + $1.50 = $6.50. This is what I would call a markup of 30%. 0.70 × (selling price) = $5.00.