Enter an IPv4 address with a CIDR prefix (e.g. 192.168.1.10/24) or an IP with a mask to get the network address, broadcast, usable host range, mask, wildcard and total host count.
| CIDR | — |
|---|---|
| Subnet mask | — |
| Wildcard | — |
| Network address | — |
| Broadcast | — |
| First usable host | — |
| Last usable host | — |
| Total addresses | — |
| Usable hosts | — |
CIDR (Classless Inter-Domain Routing) represents a subnet using the
IP/prefix notation, where the prefix (0–32) indicates how many bits of the address
identify the network. The rest identify the hosts. For example,
/24 reserves 24 bits for the network and 8 for hosts, resulting in 256 addresses (254
usable, once the network and broadcast addresses are subtracted).
The subnet mask is the prefix in decimal form (/24 =
255.255.255.0). The wildcard is the bitwise inverse of the mask
(0.0.0.255), used in router ACLs. The network address is the
first in the range; the broadcast is the last.
A /32 describes a single host (1 usable address, with no distinct
network or broadcast). A /31 follows RFC 3021: on point-to-point
links, both addresses are usable, with no network/broadcast reserved — that's
why the tool shows 2 usable hosts in that case, instead of zero.
Yes. You can type 192.168.1.10 255.255.255.0 (IP and mask separated by a
space) — the mask is converted to the equivalent prefix, as long as it's contiguous.
No. This calculator covers only IPv4 (32-bit addresses, prefix 0–32).