Subnet Calculator
Enter an address with a prefix (192.168.1.10/24) or a mask (10.0.0.1 255.255.240.0). IPv6 prefixes such as 2001:db8::/48 work too.
Runs in your browser — nothing is uploadedSubnet
Binary
Subnets
| # | Network | Host range | Broadcast |
|---|
How to use Subnet Calculator
- Type an IP address with a /prefix or a subnet mask.
- Read the network, broadcast, mask and usable host range.
- Optionally split the network into smaller subnets and copy the list.
Questions
How many usable hosts are in a /24?
254. A /24 has 256 addresses; the first is the network address and the last is the broadcast address. /31 (point-to-point links, RFC 3021) and /32 (single host) are special cases where every address is usable.
What is a wildcard mask?
The inverse of the subnet mask (0.0.0.255 for a /24). Cisco ACLs and OSPF use wildcard masks to match address ranges.
Does IPv6 have broadcast addresses?
No. IPv6 uses multicast instead, so every address in the prefix is usable. LANs normally use a /64.