12/20 as a Decimal 0.6 12/20 = 0.6 = 60% Copy 12/20 = 0.6 = 60%. Simplified: 3/5. Formula Used12 ÷ 20 = 0.6 Frequently Asked Questions What is 12/20 as a decimal?0.6.What is 12/20 as a percentage?60%.