Profit margin is measured on the selling price; markup is measured on the cost. That is why a 40% margin is a 66.67% markup, not 40%. Use amounts excluding VAT.

Profit margin
40%

How the result is reached

Selling price€100.00
Cost of the product€60.00
Profit€40.00
Profit margin (on the price)40%
Markup (on the cost)66.67%

Educational estimate, not financial advice. It works out the gross margin of one product (price minus cost); it does not include business overheads (rent, salaries, taxes), which lower the net margin.

Profit Margin Calculator by Calculadora Capital

Profit Margin Calculator