Subnet for 1000 hosts
A network that needs 1000 hosts fits in a /22, mask 255.255.252.0, with 1,022 usable addresses.
A network built for 1000 hosts needs a /22. The mask is 255.255.252.0, and its 1,022 usable addresses leave 22 spare for growth.
The next smaller block, a /23, only allows 510 usable addresses, which is not enough for 1000 hosts. That makes /22 the smallest block that fits.
Enter any address below to see the exact network, broadcast, and host range for a /22 block.
Calculate a /22 network
Accepts CIDR (192.0.2.0/24), IP + mask (192.0.2.0 255.255.255.0), or a bare IP (defaults to /24).
11000000.00000000.00000010.0000000011111111.11111111.11111100.00000000Example: 192.0.2.0/22
Taking 192.0.2.0/22 as a worked example, a /22 block breaks down like this:
| Network address | 192.0.0.0 |
|---|---|
| Usable range | 192.0.0.1 - 192.0.3.254 |
| Broadcast address | 192.0.3.255 |
| Total addresses | 1,024 |
| Usable hosts | 1,022 |
Frequently asked questions
What subnet mask do I need for 1000 hosts?
A network with 1000 hosts fits in a /22, which uses the mask 255.255.252.0 and provides 1,022 usable addresses.
How many addresses does a /22 block have in total?
A /22 has 1,024 total addresses, 1,022 of them usable (the total minus the network and broadcast addresses, except for /31 and /32).
Does a /22 waste any addresses for 1000 hosts?
Yes, 22 addresses of headroom. A /22 provides 1,022 usable addresses for the 1000 you need, and the next smaller block, a /23, does not hold enough.
How do I work this out myself?
Find the smallest power of two, minus two, that is at least 1000. That takes 10 host bits, which leaves a /22 prefix. See how to calculate a subnet mask for the full method.