Subnet Calculator
Enter an IPv4 address with its prefix to find the containing network and available host range. Host bits are cleared automatically, so an address such as 192.168.1.42/24 is accepted.
CIDR prefixes from /0 through /32 are supported.
The result uses the network containing your address. A /31 assumes a point-to-point connection; a /32 represents one endpoint.
Network (CIDR)
192.168.1.64/26
- Subnet mask
- 255.255.255.192
- Wildcard mask
- 0.0.0.63
- First host
- 192.168.1.65
- Last host
- 192.168.1.126
- Broadcast address
- 192.168.1.127
- Total addresses
- 64
- Usable hosts
- 62
Reading a CIDR result
The number after the slash counts network bits. IPv4 has 32 bits altogether, leaving 32 minus the prefix for addresses within the block. A /24 contains 256 addresses; a /26 contains 64. Increasing the prefix by one halves the block size.
For ordinary subnets through /30, two positions are reserved: the first identifies the network and the last is its directed broadcast. The displayed host count subtracts those positions. It does not subtract a gateway or addresses you reserve for infrastructure.
A /26 worked example
For 192.168.1.70/26, the containing block starts at 192.168.1.64 and ends at 192.168.1.127. Hosts run from .65 through .126, giving 62 positions before local reservations. Its dotted mask is 255.255.255.192; the wildcard is 0.0.0.63.
A /31 is treated as a two-endpoint link under RFC 3021, with neither endpoint removed. A /32 identifies one address. These exceptions explain why the usual “subtract two” shortcut gives the wrong result for very small blocks.