SubnetPad

/5 Subnet Calculator

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A /5 block contains 134,217,728 addresses. This scale appears in large RIR allocations and some very large national ISP routing tables.

/1
/32

/5 = mask 248.0.0.0 • 134,217,726 usable addresses

Results for 0.0.0.0/5

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 /5 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 hosts134,217,728 total addresses in this subnet
More detailsNeighboring subnets, wildcard mask, hex, reverse DNS, and binary breakdown

Neighboring /5 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 mask11111000.00000000.00000000.00000000
Network00000000.00000000.00000000.00000000
Broadcast00000111.11111111.11111111.11111111

Quick facts for /5

/5 reference guideBit split, overview, sizing tables, notable networks, and FAQ

Binary bit split

Network bits (5)Host bits (27)
Network bits
5
Host bits
27
Subnet mask
248.0.0.0
Wildcard mask
7.255.255.255
Total addresses
134,217,728
Usable hosts
134,217,726
Hosts formula
2^27 − 2
/24 relationship
524,288 × /24 networks

Overview

A /5 block contains 134,217,728 addresses. This scale appears in large RIR allocations and some very large national ISP routing tables.

Common use cases

  • Large RIR block allocations
  • National backbone addressing
  • Internet exchange route filtering

Subnet sizing reference

Divide /5 into…

PrefixSubnetsHosts each
/6267,108,862
/7433,554,430
/8816,777,214
/9168,388,606

/5 fits inside…

SupernetHosts/5s inside
/4268,435,4542
/3536,870,9104
/21,073,741,8228
/12,147,483,64616

Frequently asked questions

Common questions about /5 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