In mathematics, radix point refers to the symbol used in numerical representations to separate the integral part of the number (to the left of the radix) from its fractional part (to the right of the radix). The radix point is usually a small dot, either placed on the baseline or halfway between the baseline and the top of the numerals. In base 10, the radix point is more commonly called the decimal point. However, radix point is the more general term used for other bases, since the "deci-" in decimal point implies 10.

Example in base 10: 100.5

100 is the integer to the left of the radix point and 5 is the fractional part to the right.

Example in base 2: 1100100.1

1100100 to the left of the radix is the binary representation for 100 base 10. To the right of the radix point is 1 which is the binary representation of the fraction 1/2.