What is 40% of 50? 20 40% of 50 Copy 40% of 50 = 20. Formula UsedResult = (40 ÷ 100) × 50 = 20 Frequently Asked Questions What is 40% of 50?20. (40 ÷ 100) × 50 = 20.How to calculate 40%?Multiply by 0.4 (or multiply by 40 then divide by 100).