Subnet and CIDR Calculator for IPv4 and IPv6: Network, Broadcast, Usable Range and Subnet Splitting
Type an address like 192.168.1.10/24, 10.0.0.0 255.255.255.0 or an IPv6 prefix such as 2001:db8::/32. This is pure arithmetic: it does not look up who owns an address (that needs an outside service).
Part of the suite: Web and network tools
| Network (CIDR) | |
|---|---|
| Subnet mask | |
| Wildcard mask | |
| Mask in binary | |
| Broadcast | |
| First usable IP | |
| Last usable IP | |
| Total addresses | |
| Usable hosts | |
| Address type |
| Network (CIDR) | |
|---|---|
| First address | |
| Last address | |
| Expanded | |
| Addresses |
FAQ
How many IPs are in a /24?
A /24 has 256 addresses, 254 usable (minus network and broadcast), with subnet mask 255.255.255.0.
How are /31 and /32 different?
A /31 is for a point-to-point link (RFC 3021): both addresses are usable and there is no broadcast. A /32 is a single host.
Does IPv6 have no broadcast?
Right. IPv6 uses multicast instead, and the standard subnet size is /64. The tool shows the first to last address of the prefix you enter.
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