CIDR Calculator

Subnet engineer's workbench — IPv4 analysis · subnet splitting · supernetting · IPv6 tools

IPv4 / CIDR Analysis

Subnet Splitter

Analyze a CIDR above first, then split the network into N equal subnets.

subnets

Supernetting

Enter CIDR blocks (one per line or comma-separated) to find their common supernet.

IPv6 Utilities

Common Prefix Reference

Prefix Subnet Mask Hosts Notes
/8255.0.0.016,777,214private 10.0.0.0/8
/12255.240.0.01,048,574private 172.16.0.0/12
/16255.255.0.065,534private 192.168.0.0/16
/24255.255.255.0254Common LAN segment
/25255.255.255.128126Half of /24
/26255.255.255.19262Quarter of /24
/27255.255.255.22430Eighth of /24
/28255.255.255.24014Common VLAN
/29255.255.255.2486Small segment
/30255.255.255.2522Point-to-point link
/31255.255.255.2542RFC 3021 P2P
/32255.255.255.2551Host route