3/7 as a Decimal 0.42857143 3/7 = 0.42857143 = 42.857143% Copy 3/7 = 0.42857143 = 42.857143%. Formula Used3 ÷ 7 = 0.42857143 Frequently Asked Questions What is 3/7 as a decimal?0.42857143.What is 3/7 as a percentage?42.857143%.