15/20 as a Decimal 0.75 15/20 = 0.75 = 75% Copy 15/20 = 0.75 = 75%. Simplified: 3/4. Formula Used15 ÷ 20 = 0.75 Frequently Asked Questions What is 15/20 as a decimal?0.75.What is 15/20 as a percentage?75%.