/4 Subnet Mask Reference

The subnet mask for prefix length /4 is 240.0.0.0. A massive IPv4 subnet with 268.435.456 total addresses and 268.435.454 usable host addresses.

Prefix Length/4
Subnet Mask240.0.0.0
Wildcard Mask15.255.255.255
Hex ValueF0000000
Usable Hosts268.435.454
Network Bits4 / 32

Binary Representation

Subnet Mask11110000.00000000.00000000.00000000
Wildcard Mask00001111.11111111.11111111.11111111

1-bits (network): 4 ·  0-bits (host): 28 ·  Total: 32 bits

Common Uses for 240.0.0.0

  • Large network segment
  • ISP/enterprise allocation

Frequently Asked Questions

What is the subnet mask for /4?

The subnet mask for prefix length /4 is 240.0.0.0. In hexadecimal it is 0xF0000000. The binary representation is 11110000.00000000.00000000.00000000.

What is the inverse (wildcard) mask of 240.0.0.0?

The wildcard mask (inverse mask) of 240.0.0.0 is 15.255.255.255. 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 240.0.0.0 give?

With subnet mask 240.0.0.0 (/4), you get 268.435.456 total IPs, minus 2 reserved (network + broadcast) = 268.435.454 usable host addresses.

What CIDR prefix corresponds to 240.0.0.0?

The subnet mask 240.0.0.0 corresponds to CIDR prefix /4. This means 4 bits are used for the network portion and 28 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