What is 20% of 20? 4 20% of 20 Copy 20% of 20 = 4. Formula UsedResult = (20 ÷ 100) × 20 = 4 Frequently Asked Questions What is 20% of 20?4. (20 ÷ 100) × 20 = 4.How to calculate 20%?Multiply by 0.2 (or multiply by 20 then divide by 100).