Ambiakshi Tools VerifiedAEO Direct AnswerCIDR to Subnet Mask Conversion Table
Classless Inter-Domain Routing (CIDR) notation denotes the number of contiguous binary 1-bits in a subnet mask. For example, /24 corresponds to 24 ones followed by 8 zeros, translating in dotted decimal to 255.255.255.0 and allocating 256 total IP addresses with 254 usable for hosts.
Mask = (~0 << (32 − CIDR)) >>> 0; Usable Hosts = 2^(32 − CIDR) − 2
IPv4 CIDR & Subnet Calculator Engine
Calculate network boundaries, usable IP ranges, broadcast addresses, wildcard masks, and binary bit allocations from an IP and prefix. Compliant with RFC 4632 (CIDR), RFC 3021 (/31 point-to-point links), and RFC 1918 private networking.
Subnet Calculations
First address of the subnet
Last address (for broadcast packets)
254 usable host addresses
2^(8) − 2 hosts
Dotted decimal subnet mask
Inverse mask used in ACLs & OSPF
Legacy Class C (CIDR RFC 4632 standard)
Classless Inter-Domain Routing prefix
Binary Representation & Bit Boundary
First 24 bits represent the Network ID; remaining 8 bits represent the Host ID.
Subnet Splitting (Subdivide Network)
Frequently asked
Direct answers for search, answer engines, and generative crawlers.
A /24 network has a subnet mask of 255.255.255.0. It provides 256 total IP addresses, with 254 usable for client interfaces, servers, or gateways.