/2 vs /6 — Subnet Comparison
A /2 subnet is 16× larger than a /6. Every additional bit in the prefix halves the address space — the 4-bit difference between these two means /2 has 24 = 16 times as many addresses.
Key Differences
How 16 /6 Subnets Divide a /2
Example using 10.0.0.0/2 as the parent block.
| # | CIDR | Network | First Usable | Last Usable | Broadcast | Hosts |
|---|---|---|---|---|---|---|
| 1 | 0.0.0.0/6 | 0.0.0.0 | 0.0.0.1 | 3.255.255.254 | 3.255.255.255 | 67,108,862 |
| 2 | 4.0.0.0/6 | 4.0.0.0 | 4.0.0.1 | 7.255.255.254 | 7.255.255.255 | 67,108,862 |
| 3 | 8.0.0.0/6 | 8.0.0.0 | 8.0.0.1 | 11.255.255.254 | 11.255.255.255 | 67,108,862 |
| 4 | 12.0.0.0/6 | 12.0.0.0 | 12.0.0.1 | 15.255.255.254 | 15.255.255.255 | 67,108,862 |
| 5 | 16.0.0.0/6 | 16.0.0.0 | 16.0.0.1 | 19.255.255.254 | 19.255.255.255 | 67,108,862 |
| 6 | 20.0.0.0/6 | 20.0.0.0 | 20.0.0.1 | 23.255.255.254 | 23.255.255.255 | 67,108,862 |
| 7 | 24.0.0.0/6 | 24.0.0.0 | 24.0.0.1 | 27.255.255.254 | 27.255.255.255 | 67,108,862 |
| 8 | 28.0.0.0/6 | 28.0.0.0 | 28.0.0.1 | 31.255.255.254 | 31.255.255.255 | 67,108,862 |
| 9 | 32.0.0.0/6 | 32.0.0.0 | 32.0.0.1 | 35.255.255.254 | 35.255.255.255 | 67,108,862 |
| 10 | 36.0.0.0/6 | 36.0.0.0 | 36.0.0.1 | 39.255.255.254 | 39.255.255.255 | 67,108,862 |
| 11 | 40.0.0.0/6 | 40.0.0.0 | 40.0.0.1 | 43.255.255.254 | 43.255.255.255 | 67,108,862 |
| 12 | 44.0.0.0/6 | 44.0.0.0 | 44.0.0.1 | 47.255.255.254 | 47.255.255.255 | 67,108,862 |
| 13 | 48.0.0.0/6 | 48.0.0.0 | 48.0.0.1 | 51.255.255.254 | 51.255.255.255 | 67,108,862 |
| 14 | 52.0.0.0/6 | 52.0.0.0 | 52.0.0.1 | 55.255.255.254 | 55.255.255.255 | 67,108,862 |
| 15 | 56.0.0.0/6 | 56.0.0.0 | 56.0.0.1 | 59.255.255.254 | 59.255.255.255 | 67,108,862 |
| 16 | 60.0.0.0/6 | 60.0.0.0 | 60.0.0.1 | 63.255.255.254 | 63.255.255.255 | 67,108,862 |
FAQ
What is the difference between /2 and /6?
A /2 has 1,073,741,822 usable hosts
and a /6 has 67,108,862.
The subnet masks differ: /2 uses 192.0.0.0
while /6 uses 252.0.0.0.
Every additional bit in the prefix halves the number of addresses — so the 4-bit gap means
/2 is exactly 16× larger.
How many /6 subnets fit in a /2?
Exactly 16 /6 subnets fit perfectly inside one /2 with no wasted space. To split a /2 into /6s, 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.