/24 Subnet Mask Reference

The subnet mask for prefix length /24 is 255.255.255.0. A small IPv4 subnet with 256 total addresses and 254 usable host addresses.

Prefix Length/24
Subnet Mask255.255.255.0
Wildcard Mask0.0.0.255
Hex ValueFFFFFF00
Usable Hosts254
Network Bits24 / 32

Binary Representation

Subnet Mask11111111.11111111.11111111.00000000
Wildcard Mask00000000.00000000.00000000.11111111

1-bits (network): 24 ·  0-bits (host): 8 ·  Total: 32 bits

Common Uses for 255.255.255.0

  • Most common: office/home LAN
  • AWS/GCP default subnet
  • Kubernetes pod CIDR default
  • 254 usable hosts

Frequently Asked Questions

What is the subnet mask for /24?

The subnet mask for prefix length /24 is 255.255.255.0. In hexadecimal it is 0xFFFFFF00. The binary representation is 11111111.11111111.11111111.00000000.

What is the inverse (wildcard) mask of 255.255.255.0?

The wildcard mask (inverse mask) of 255.255.255.0 is 0.0.0.255. Wildcard masks are used in Cisco IOS ACLs and OSPF configurations to specify which bits of an IP address to match.

How many host IPs does 255.255.255.0 give?

With subnet mask 255.255.255.0 (/24), you get 256 total IPs, minus 2 reserved (network + broadcast) = 254 usable host addresses.

What CIDR prefix corresponds to 255.255.255.0?

The subnet mask 255.255.255.0 corresponds to CIDR prefix /24. This means 24 bits are used for the network portion and 8 bits for host addresses.

Complete Subnet Mask Reference /0–/32

PrefixSubnet MaskWildcardHexUsable Hosts
/00.0.0.0255.255.255.255000000004.294.967.294
/1128.0.0.0127.255.255.255800000002.147.483.646
/2192.0.0.063.255.255.255C00000001.073.741.822
/3224.0.0.031.255.255.255E0000000536.870.910
/4240.0.0.015.255.255.255F0000000268.435.454
/5248.0.0.07.255.255.255F8000000134.217.726
/6252.0.0.03.255.255.255FC00000067.108.862
/7254.0.0.01.255.255.255FE00000033.554.430
/8255.0.0.00.255.255.255FF00000016.777.214
/9255.128.0.00.127.255.255FF8000008.388.606
/10255.192.0.00.63.255.255FFC000004.194.302
/11255.224.0.00.31.255.255FFE000002.097.150
/12255.240.0.00.15.255.255FFF000001.048.574
/13255.248.0.00.7.255.255FFF80000524.286
/14255.252.0.00.3.255.255FFFC0000262.142
/15255.254.0.00.1.255.255FFFE0000131.070
/16255.255.0.00.0.255.255FFFF000065.534
/17255.255.128.00.0.127.255FFFF800032.766
/18255.255.192.00.0.63.255FFFFC00016.382
/19255.255.224.00.0.31.255FFFFE0008.190
/20255.255.240.00.0.15.255FFFFF0004.094
/21255.255.248.00.0.7.255FFFFF8002.046
/22255.255.252.00.0.3.255FFFFFC001.022
/23255.255.254.00.0.1.255FFFFFE00510
/24255.255.255.00.0.0.255FFFFFF00254
/25255.255.255.1280.0.0.127FFFFFF80126
/26255.255.255.1920.0.0.63FFFFFFC062
/27255.255.255.2240.0.0.31FFFFFFE030
/28255.255.255.2400.0.0.15FFFFFFF014
/29255.255.255.2480.0.0.7FFFFFFF86
/30255.255.255.2520.0.0.3FFFFFFFC2
/31255.255.255.2540.0.0.1FFFFFFFE2
/32255.255.255.2550.0.0.0FFFFFFFF1