55/100 as a Decimal 0.55 55/100 = 0.55 = 55% Copy 55/100 = 0.55 = 55%. Simplified: 11/20. Formula Used55 ÷ 100 = 0.55 Frequently Asked Questions What is 55/100 as a decimal?0.55.What is 55/100 as a percentage?55%.