15 Into A Decimal. Percentage means 'out of 100 100 '. 5 in to decimal = 12.7 decimal. 1 in to decimal = 2.54 decimal. How to convert from percent to decimal. 3/5 is expanded to 6/10 by multiplying the numerator by 2 and denominator. Since 15 cannot be divided. 15 in to decimal = …