/24 Subnet Mask: How Many IPs?
256 addresses, 254 usable, mask 255.255.255.0.
A /24 is the classic network size, with mask 255.255.255.0. Most home and small office LANs are exactly one /24.
Subnet mask for /24
The /24 subnet mask is 255.255.255.0: 24 bits for the network and 8 for hosts.
| Subnet mask | 255.255.255.0 |
|---|---|
| Mask in binary | 11111111.11111111.11111111.00000000 |
| Wildcard mask | 0.0.0.255 |
| Total addresses | 256 |
| Usable hosts | 254 |
| In /24 terms | It is one /24. |
| Example (10.0.0.0/24) | 10.0.0.0 - 10.0.0.255 |
Usable addresses in cloud subnets
Cloud providers reserve extra addresses in every subnet, so fewer than 254 are available to your machines.
| AWS | 251 usable |
|---|---|
| Azure | 251 usable |
| Google Cloud | 252 usable |
| Oracle Cloud | 253 usable |
Limits and reserved counts are commonly documented values; check your provider's current documentation before you plan around them.
Other sizes
/16 | /22 | /23 | /24 | /25 | /26 | /27 | /28 | /29 | /30
Split a block into /24 subnets with the subnet splitter, or calculate any block with the CIDR calculator.
FAQ
How many usable IP addresses are in a /24?
254 usable addresses out of 256. The network and broadcast addresses are reserved.
What is the subnet mask for /24?
255.255.255.0, with wildcard mask 0.0.0.255.
How many usable addresses does a /24 have in AWS?
251, because AWS reserves five addresses in every subnet.