/6 vs /8 — Subnet Comparison
A /6 subnet is 4× larger than a /8. Every additional bit in the prefix halves the address space — the 2-bit difference between these two means /6 has 22 = 4 times as many addresses.
16 million IPs — Class A network
Typical Uses
- →Entire Class A private range (10.0.0.0/8)
- →Large ISP or carrier allocations
- →Enterprise-wide addressing plan
Key Differences
How 4 /8 Subnets Divide a /6
Example using 10.0.0.0/6 as the parent block.
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 8.0.0.0/8 | 8.0.0.0 | 8.0.0.1 | 8.255.255.254 | 8.255.255.255 | 16,777,214 |
| 2 | 9.0.0.0/8 | 9.0.0.0 | 9.0.0.1 | 9.255.255.254 | 9.255.255.255 | 16,777,214 |
| 3 | 10.0.0.0/8 | 10.0.0.0 | 10.0.0.1 | 10.255.255.254 | 10.255.255.255 | 16,777,214 |
| 4 | 11.0.0.0/8 | 11.0.0.0 | 11.0.0.1 | 11.255.255.254 | 11.255.255.255 | 16,777,214 |
FAQ
What is the difference between /6 and /8?
A /6 has 67,108,862 usable hosts
and a /8 has 16,777,214.
The subnet masks differ: /6 uses 252.0.0.0
while /8 uses 255.0.0.0.
Every additional bit in the prefix halves the number of addresses — so the 2-bit gap means
/6 is exactly 4× larger.
How many /8 subnets fit in a /6?
Exactly 4 /8 subnets fit perfectly inside one /6 with no wasted space. To split a /6 into /8s, just increment the last 2 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.