Subnet Expert

CIDR /3 Subnet Reference

Detailed information about IPv4 /3 subnets

/3 Subnet Details

A /3 network is extremely large, allowing for millions of hosts. These are typically reserved for major infrastructure or internet service providers.

Key Information

CIDR Notation/3
Subnet Mask224.0.0.0
Binary Subnet Mask11100000 00000000 00000000 00000000

Host Information

Total Addresses536,870,912
Usable Hosts (Standard)536,870,910
AWS Usable IPs536,870,905
Azure Usable IPs536,870,905
GCP Usable IPs536,870,906

Using /3 in Networks

A CIDR /3 subnet has 536,870,910 usable IP addresses for hosts. This is a relatively large subnet that can be further divided into smaller subnets if needed.

Organizations typically use subnets of this size for large-scale deployments or when planning for future growth.

Cloud Provider Considerations

Cloud providers reserve some IP addresses in each subnet for internal use, resulting in fewer usable IPs:

  • AWS: 536,870,905 usable IPs(reserves 5 IPs per subnet)
  • Azure: 536,870,905 usable IPs(reserves 5 IPs per subnet)
  • GCP: 536,870,906 usable IPs(reserves 4 IPs per subnet)

When planning your cloud infrastructure, consider these reserved addresses to accurately size your subnets.

Subnet Calculator

Use our interactive subnet calculator to visualize and manipulate subnets with ease.

Go to Subnet Calculator

Other CIDR References

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