/8 vs /10 — Subnet Comparison
A /8 subnet is 4× larger than a /10. Every additional bit in the prefix halves the address space — the 2-bit difference between these two means /8 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
4 million IPs — quarter of a /8
Typical Uses
- →Major regional segment in enterprise
- →Large cloud region allocation
Key Differences
How 4 /10 Subnets Divide a /8
Example using 10.0.0.0/8 as the parent block.
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 10.0.0.0/10 | 10.0.0.0 | 10.0.0.1 | 10.63.255.254 | 10.63.255.255 | 4,194,302 |
| 2 | 10.64.0.0/10 | 10.64.0.0 | 10.64.0.1 | 10.127.255.254 | 10.127.255.255 | 4,194,302 |
| 3 | 10.128.0.0/10 | 10.128.0.0 | 10.128.0.1 | 10.191.255.254 | 10.191.255.255 | 4,194,302 |
| 4 | 10.192.0.0/10 | 10.192.0.0 | 10.192.0.1 | 10.255.255.254 | 10.255.255.255 | 4,194,302 |
FAQ
What is the difference between /8 and /10?
A /8 has 16,777,214 usable hosts
and a /10 has 4,194,302.
The subnet masks differ: /8 uses 255.0.0.0
while /10 uses 255.192.0.0.
Every additional bit in the prefix halves the number of addresses — so the 2-bit gap means
/8 is exactly 4× larger.
How many /10 subnets fit in a /8?
Exactly 4 /10 subnets fit perfectly inside one /8 with no wasted space. To split a /8 into /10s, just increment the last 2 bits of the network address for each new subnet.
Which should I choose?
/8 is typically used for: Entire private Class A or ISP allocation. /10 is better for: Enterprise regional segment. Choose the smallest prefix that comfortably fits your host count — over-allocating wastes address space, but under-allocating means painful renumbering later.