/13 Subnet: Mask 255.248.0.0, 524,286 Usable Hosts

A /13 subnet has a subnet mask of 255.248.0.0 and contains 524,288 total IP addresses, of which 524,286 are usable host addresses (the network and broadcast addresses are reserved). A /13 contains 2,048 /24 networks.

Usable hosts in a /13 by platform

Cloud providers reserve more than the usual two addresses per subnet, so the same /13 gives you fewer usable IPs in the cloud than on a standard LAN.

Good to know

A /13 subnet has a 255.248.0.0 mask and 524,288 total addresses (524,286 usable). Each step from /13 to /14 halves the block; each step back to /12 doubles it.

How a /13 is calculated

• The /13 means the first 13 bits are the network portion, leaving 19 host bits.
• Total addresses = 2^(32 - 13) = 2^19 = 524,288.
• Usable hosts (standard) = 524,288 - 2 (network + broadcast) = 524,286.
• Subnet mask = 255.248.0.0; wildcard mask = 0.7.255.255.