CIDR Calculator
Enter an IPv4 address in CIDR notation to get its network address, broadcast address, subnet mask, and usable host range.
| Field | Value |
|---|---|
| CIDR Notation | 192.168.1.0/24 |
| Network Address | 192.168.1.0 |
| Broadcast Address | 192.168.1.255 |
| Subnet Mask | 255.255.255.0 |
| Wildcard Mask | 0.0.0.255 |
| Total Addresses | 256 |
| Usable Hosts | 254 |
| Usable Host Range | 192.168.1.1 – 192.168.1.254 |
| IP Class | C |
| IP Type | Private |
/24) that states how many leading bits identify the network. A shorter prefix (like /16) covers more addresses; a longer one (like /28) covers fewer. Everything here is computed locally — nothing is sent to a server.Your Data Never Leaves Your Device
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The CIDR Calculator is a free, client-side tool that breaks down an IPv4 CIDR block into everything you need for subnetting: network address, broadcast address, subnet mask, wildcard mask, and the usable host range.
Enter an address like 192.168.1.0/24 and every field updates instantly — no server round-trip, no signup. Useful for planning VLANs, writing firewall rules, or just double-checking how many hosts a given prefix actually covers.
FAQ
CIDR (Classless Inter-Domain Routing) notation writes an IP address together with a slash and a prefix length, like 192.168.1.0/24. The prefix states how many leading bits of the address identify the network — the rest identify hosts within it.
Total addresses in a block equal 2^(32 - prefix). Two of those are reserved (the network address and the broadcast address), so usable hosts equal that total minus 2 for any prefix of /30 or shorter. A /31 or /32 has no usable host range in the traditional sense.
The subnet mask marks network bits with 1s and host bits with 0s (e.g. 255.255.255.0 for a /24). The wildcard mask is its bitwise inverse (0.0.0.255) and is used by tools like Cisco ACLs that expect the host bits marked instead.
RFC 1918 reserves three ranges for private networks: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. Addresses in those ranges are never routable on the public internet.
Not yet — this calculator currently supports IPv4 CIDR blocks only.