The IPv4 CIDR to Range tool will specifically show you the start and end IPv4 address in the range and netmask and wildcard bits, as well as the number of hosts.

What is CIDR? Classless Inter-Domain Routing (CIDR) is an expansion of the IP addressing system that allows for a more efficient and appropriate allocation of addresses. CIDR changed fixed fields into variable-length fields, allowing addresses to be assigned with more granularity. The CIDR IP address includes a number that tells how the address is split between networks and hosts. For example, in the CIDR address 209.173.53.167/20 the /20 indicates that the first 20 bits are used for network ID and the remaining 12 (there are 32 bits in the IP address) are used for host ID.

Enter CIDR