CIDR / Subnet Calculator
Compute network, broadcast, host range, count, and mask for any IPv4 CIDR.
Total addresses
256
Usable hosts
254
Prefix
/24
Host bits
8
Network
192.168.1.0/24
Broadcast
192.168.1.255
First usable
192.168.1.1
Last usable
192.168.1.254
Subnet mask
255.255.255.0
Wildcard mask
0.0.0.255
Network (binary)
11000000.10101000.00000001.00000000
Mask (binary)
11111111.11111111.11111111.00000000
Next adjacent
192.168.2.0/24
Class
C (192.0.0.0–223.255.255.255)
Visibility
Private (RFC 1918)
About CIDR
CIDR notation packs an IP address and a prefix length into one string: 10.0.0.0/24is "the first 24 bits identify the network; the remaining 8 are host bits."
- /30 — 4 addresses, 2 usable. Tiny point-to-point links.
- /29 — 8 addresses, 6 usable. Small server VLANs.
- /24 — 256 addresses, 254 usable. Classic Class C.
- /16 — 65,536 addresses. Classic Class B.
/31 and /32 are special — the first describes a point-to-point pair (RFC 3021), the second a single host.
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