A /24 subnet mask is 255.255.255.0, with 256 addresses and 254 usable hosts.
| CIDR prefix | /24 |
|---|---|
| Subnet mask | 255.255.255.0 |
| Subnet mask (binary) | 11111111.11111111.11111111.00000000 |
| Wildcard mask | 0.0.0.255 |
| Network bits / host bits | 24 / 8 |
| Total addresses | 256 |
| Usable hosts | 254 |
| /24 subnets in a /8 | 65,536 |
| /24 subnets in a /16 | 256 |
The mask ends exactly on an octet boundary, so every address in a /24 block shares its first 3 octets. The most common subnet size: 254 usable hosts and a mask of 255.255.255.0. The default for home routers and most office VLANs.
| Network | First usable host | Last usable host | Broadcast |
|---|---|---|---|
| 192.168.1.0/24 | 192.168.1.1 | 192.168.1.254 | 192.168.1.255 |
A /24 subnet mask is 255.255.255.0. In binary that is 11111111.11111111.11111111.00000000: 24 network bits followed by 8 host bits. The wildcard mask is 0.0.0.255.
A /24 holds 256 addresses in total. Subtracting the network and broadcast addresses leaves 254 usable hosts.
A /16 divides into 256 subnets of size /24, because each extra mask bit doubles the number of subnets.
Calculate this over HTTP: curl https://networkcalc.com/api/ip/192.168.1.0/24.
See the Subnet Calculator API.