Selling Price after a 25% Markup is applied to an item that Cost $100

Given: Cost = $100,  Markup = 25%
Markup as a Decimal: 25% = 0.25
Formula:
Selling Price = Cost * (1 + Markup as a Decimal)
Selling Price = $100 * (1 + 0.25)
Selling Price = $100 * 1.25
Selling Price = $125
Notes:
Markup Amount = Selling Price – Cost = $125 – $100 = $25
Profit = Markup Amount = $25
Profit Margin =   =   = 0.2 = 20%