IP Subnet Calculator
Calculate network addresses, host ranges, and subnet masks for IPv4 and IPv6 networks.
IPv4 Subnet Reference Table
| CIDR | Subnet Mask | Usable Hosts |
|---|---|---|
| /32 | 255.255.255.255 | 1 |
| /31 | 255.255.255.254 | 2 |
| /30 | 255.255.255.252 | 2 |
| /29 | 255.255.255.248 | 6 |
| /28 | 255.255.255.240 | 14 |
| /27 | 255.255.255.224 | 30 |
| /26 | 255.255.255.192 | 62 |
| /25 | 255.255.255.128 | 126 |
| /24 | 255.255.255.0 | 254 |
| /23 | 255.255.254.0 | 510 |
| /22 | 255.255.252.0 | 1,022 |
| /21 | 255.255.248.0 | 2,046 |
| /20 | 255.255.240.0 | 4,094 |
| /19 | 255.255.224.0 | 8,190 |
| /18 | 255.255.192.0 | 16,382 |
| /17 | 255.255.128.0 | 32,766 |
| /16 | 255.255.0.0 | 65,534 |
| /8 | 255.0.0.0 | 16,777,214 |
Understanding IP Subnetting
What is subnetting? Subnetting is the practice of dividing a network into smaller, more manageable pieces called subnets. This allows network administrators to efficiently allocate IP addresses, improve network performance, and enhance security through network segmentation.
CIDR Notation: Classless Inter-Domain Routing (CIDR) notation represents an IP address and its associated network mask. For example, 192.168.1.0/24 indicates that the first 24 bits are the network portion, leaving 8 bits (256 addresses) for hosts.
Key Addresses: In any subnet, the first address is the network address (identifies the subnet), and the last address is the broadcast address (used to send messages to all hosts in the subnet). All addresses in between are available for hosts.