CIDR / Netmask Converter
Convert between CIDR prefix length, dotted subnet mask and wildcard mask, and see the network range for any IP.
Convert
Enter a number 0–32 or a dotted mask.
Result
Enter an IP and prefix.
Prefix reference
CIDR vs netmask
A CIDR prefix such as /24 is shorthand for the number of leading 1 bits in a subnet mask. /24 equals 255.255.255.0 and leaves 8 host bits, i.e. 256 addresses. The wildcard (inverse) mask used by some ACLs is the bitwise NOT of the subnet mask.