/26 subnet mask (255.255.255.192)

A /26 network has 6 host bits, 64 addresses and 62 usable hosts. It is 1/4 of a /24.

/26 at a glance

Netmask: 255.255.255.192
Wildcard mask: 0.0.0.63
Hex mask: 0xFFFFFFC0
Binary mask: 11111111.11111111.11111111.11000000
Host bits: 6
Total addresses: 64
Usable hosts: 62 (minus network and broadcast)
Compared with a /24: 1/4 of a /24

Calculate a /26 in the subnet calculator

Typical uses of a /26

A /26 has 62 usable hosts. Azure requires a subnet of at least /26 for AzureFirewallSubnet and AzureBastionSubnet, so /26 is a familiar number in Azure hub networks.

Example /26 ranges

Network	Network address	First usable	Last usable	Broadcast	Next /26
10.0.0.0/26	10.0.0.0	10.0.0.1	10.0.0.62	10.0.0.63	10.0.0.64/26	calculate
172.16.0.0/26	172.16.0.0	172.16.0.1	172.16.0.62	172.16.0.63	172.16.0.64/26	calculate
192.168.1.0/26	192.168.1.0	192.168.1.1	192.168.1.62	192.168.1.63	192.168.1.64/26	calculate
203.0.113.0/26	203.0.113.0	203.0.113.1	203.0.113.62	203.0.113.63	203.0.113.64/26	calculate

The /26 boundary falls in the fourth octet, so /26 networks start every 64 in that octet (4 per /24): 0, 64, 128, 192.

How many /26s fit

In a	Number of /26 subnets
/8	262,144
/16	1,024
/20	64
/24	4

What a /26 contains

Smaller block	How many
/28	4
/29	8
/30	16
/32	64

Splitting a /26

Into	Subnets	Usable hosts each
/27	2	30
/28	4	14
/29	8	6
/30	16	2

/26 in AWS, Azure and Google Cloud

Platform	Allowed subnet sizes	/26 allowed?	Usable after reservation
AWS VPC	/16 to /28	Yes	59 (5 reserved)
Azure VNet	/2 to /29	Yes	59 (5 reserved)
Google Cloud VPC	/4 to /29	Yes	60 (4 reserved)

Cloud providers reserve addresses in every subnet (first four and the last address (network, VPC router, DNS, future use, broadcast) on AWS), so the usable count there differs from the classic 2^n - 2.