IPv4 Subnet Calculator
Compute subnet mask, network range, usable IPs and binary format
TL;DR Summary & Citation: [IPv4 Subnet Calculator] is used to Compute subnet mask, network range, usable IPs and binary format. Core input and files are processed in the current browser and are not sent to the PocketKit API. The page records only an aggregate tool-use count that excludes input content.
How IPv4 subnet calculation works
The tool converts the IP and mask/prefix to 32-bit binary and applies bitwise operations to derive the network and broadcast addresses, usable host range and count, and wildcard mask. Purely local.
Usage Guidelines & Tips
- A /24 has 254 usable hosts and each -1 to the prefix roughly doubles the addresses; /31 and /32 are point-to-point/single-host cases.
- When planning, derive the prefix from the host count you need, then split ranges to avoid overlap.
Frequently Asked Questions
1. Why does a /24 have 254 usable hosts, not 256?
The first address of a subnet is the network address and the last is the broadcast address; neither can be assigned to a host, so 256 - 2 = 254.
2. Are the CIDR prefix and subnet mask the same thing?
They are two notations for the same information: /24 equals 255.255.255.0, and the tool converts between them.