IPRangeExplorer

/7 vs /11 — Subnet Comparison

A /7 subnet is 16× larger than a /11. Every additional bit in the prefix halves the address space — the 4-bit difference between these two means /7 has 24 = 16 times as many addresses.

/7
Full reference →
Total IPs 33,554,432
Usable Hosts 33,554,430
Subnet Mask 254.0.0.0
Wildcard Mask 1.255.255.255
/11
Full reference →
Total IPs 2,097,152
Usable Hosts 2,097,150
Subnet Mask 255.224.0.0
Wildcard Mask 0.31.255.255

Key Differences

16×
more IPs in /7 than /11
16
/11 subnets fit inside one /7
4
bits of difference in prefix length

How 16 /11 Subnets Divide a /7

Example using 10.0.0.0/7 as the parent block.

# CIDR Network First Usable Last Usable Broadcast Hosts
1 10.0.0.0/11 10.0.0.0 10.0.0.1 10.31.255.254 10.31.255.255 2,097,150
2 10.32.0.0/11 10.32.0.0 10.32.0.1 10.63.255.254 10.63.255.255 2,097,150
3 10.64.0.0/11 10.64.0.0 10.64.0.1 10.95.255.254 10.95.255.255 2,097,150
4 10.96.0.0/11 10.96.0.0 10.96.0.1 10.127.255.254 10.127.255.255 2,097,150
5 10.128.0.0/11 10.128.0.0 10.128.0.1 10.159.255.254 10.159.255.255 2,097,150
6 10.160.0.0/11 10.160.0.0 10.160.0.1 10.191.255.254 10.191.255.255 2,097,150
7 10.192.0.0/11 10.192.0.0 10.192.0.1 10.223.255.254 10.223.255.255 2,097,150
8 10.224.0.0/11 10.224.0.0 10.224.0.1 10.255.255.254 10.255.255.255 2,097,150
9 11.0.0.0/11 11.0.0.0 11.0.0.1 11.31.255.254 11.31.255.255 2,097,150
10 11.32.0.0/11 11.32.0.0 11.32.0.1 11.63.255.254 11.63.255.255 2,097,150
11 11.64.0.0/11 11.64.0.0 11.64.0.1 11.95.255.254 11.95.255.255 2,097,150
12 11.96.0.0/11 11.96.0.0 11.96.0.1 11.127.255.254 11.127.255.255 2,097,150
13 11.128.0.0/11 11.128.0.0 11.128.0.1 11.159.255.254 11.159.255.255 2,097,150
14 11.160.0.0/11 11.160.0.0 11.160.0.1 11.191.255.254 11.191.255.255 2,097,150
15 11.192.0.0/11 11.192.0.0 11.192.0.1 11.223.255.254 11.223.255.255 2,097,150
16 11.224.0.0/11 11.224.0.0 11.224.0.1 11.255.255.254 11.255.255.255 2,097,150

FAQ

What is the difference between /7 and /11?

A /7 has 33,554,430 usable hosts and a /11 has 2,097,150. The subnet masks differ: /7 uses 254.0.0.0 while /11 uses 255.224.0.0. Every additional bit in the prefix halves the number of addresses — so the 4-bit gap means /7 is exactly 16× larger.

How many /11 subnets fit in a /7?

Exactly 16 /11 subnets fit perfectly inside one /7 with no wasted space. To split a /7 into /11s, just increment the last 4 bits of the network address for each new subnet.

Which should I choose?

Choose based on how many hosts you need. Use the hosts → prefix calculator on the homepage to find the right size for your requirements.