What is 10% of 90? 9 10% of 90 Copy 10% of 90 = 9. Formula UsedResult = (10 ÷ 100) × 90 = 9 Frequently Asked Questions What is 10% of 90?9. (10 ÷ 100) × 90 = 9.How to calculate 10%?Multiply by 0.1 (or multiply by 10 then divide by 100).