What is 1% of 90? 0.9 1% of 90 Copy 1% of 90 = 0.9. Formula UsedResult = (1 ÷ 100) × 90 = 0.9 Frequently Asked Questions What is 1% of 90?0.9. (1 ÷ 100) × 90 = 0.9.How to calculate 1%?Multiply by 0.01 (or multiply by 1 then divide by 100).