SubnetPad

/4 Subnet Calculator

Results update as you type

A /4 block contains 268,435,456 addresses. At this scale, blocks are primarily seen in IANA allocations and continental-level address management.

/1
/32

/4 = mask 240.0.0.0 • 268,435,454 usable addresses

Results for 0.0.0.0/4

Reserved (this network)Class A
Network addressThe first address — identifies the subnet itself
Broadcast addressThe last address — used to reach every device at once
Subnet maskSame as /4 in CIDR notation
First usable hostThe first IP you can assign to a device
Last usable hostThe last IP you can assign to a device
Usable hosts268,435,456 total addresses in this subnet
More detailsNeighboring subnets, wildcard mask, hex, reverse DNS, and binary breakdown

Neighboring /4 subnets

Wildcard mask
Used in Cisco ACLs and OSPF
CIDR notation
IP in hexadecimal
IP as 32-bit integer
Reverse DNS (PTR)
Host bits / subnet bits

Binary breakdown

IP address00000000.00000000.00000000.00000000
Subnet mask11110000.00000000.00000000.00000000
Network00000000.00000000.00000000.00000000
Broadcast00001111.11111111.11111111.11111111

Quick facts for /4

/4 reference guideBit split, overview, sizing tables, notable networks, and FAQ

Binary bit split

Network bits (4)Host bits (28)
Network bits
4
Host bits
28
Subnet mask
240.0.0.0
Wildcard mask
15.255.255.255
Total addresses
268,435,456
Usable hosts
268,435,454
Hosts formula
2^28 − 2
/24 relationship
1,048,576 × /24 networks

Overview

A /4 block contains 268,435,456 addresses. At this scale, blocks are primarily seen in IANA allocations and continental-level address management.

Common use cases

  • IANA global address space management
  • Continental internet exchange routing
  • Multicast address space (224.0.0.0/4)

Subnet sizing reference

Divide /4 into…

PrefixSubnetsHosts each
/52134,217,726
/6467,108,862
/7833,554,430
/81616,777,214

/4 fits inside…

SupernetHosts/4s inside
/3536,870,9102
/21,073,741,8224
/12,147,483,6468
/04,294,967,29416

Notable /4 networks

  • 224.0.0.0/4IPv4 multicast address space
  • 240.0.0.0/4Reserved address space

Frequently asked questions

Common questions about /4 networks, subnet masks, and use cases.

All CIDR prefix sizes

/0/1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/16/17/18/19/20/21/22/23/24/25/26/27/28/29/30/31/32