Discount percentage = (Original price – Sale price) ÷ Original price × 100
Find the difference between the original price and the discounted price
Divide the difference by the original price
Multiply the result by 100
Discount amount = Original price – Sale price
Discount percentage = Discount amount ÷ Original price × 100
If the original price is 200 and the sale price is 150, discount percentage = (200 – 150) ÷ 200 × 100 = 25%