What is 50% of 30? 15 50% of 30 Copy 50% of 30 = 15. Formula UsedResult = (50 ÷ 100) × 30 = 15 Frequently Asked Questions What is 50% of 30?15. (50 ÷ 100) × 30 = 15.How to calculate 50%?Multiply by 0.5 (or multiply by 50 then divide by 100).