A /13 has a mask of 255.248.0.0, so the second octet steps in blocks of 8. With about half a million addresses it’s an ISP- or cloud-scale block. You’ll see prefixes this size in BGP tables and in the address lists cloud providers publish, rather than on a home or office network.
Facts
- Prefix
- /13
- Subnet mask
- 255.248.0.0
- Wildcard mask
- 0.7.255.255
- Binary mask
- 11111111.11111000.00000000.00000000
- Total addresses
- 524,288
- Usable hosts
- 524,286
- Example range
- 10.0.0.0/13: 10.0.0.0 – 10.7.255.255
- Typical use
- Large ISP allocations.
Try it
Try: , ,
- CIDR block
- 10.0.0.0/13
- IP range
- 10.0.0.0 – 10.7.255.255
- Addresses
- 524,288
- Usable hosts
- 524,286
- Subnet mask
- 255.248.0.0
- Wildcard mask
- 0.7.255.255
Frequently asked questions
How many hosts are in a /13?
A /13 has 524,288 addresses. Subtracting the network and broadcast addresses leaves 524,286 usable hosts.
What is the subnet mask for /13?
/13 is 255.248.0.0 (wildcard mask 0.7.255.255). In binary that’s 13 ones followed by 19 zeros.