9/15 as a Decimal 0.6 9/15 = 0.6 = 60% Copy 9/15 = 0.6 = 60%. Simplified: 3/5. Formula Used9 ÷ 15 = 0.6 Frequently Asked Questions What is 9/15 as a decimal?0.6.What is 9/15 as a percentage?60%.