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IP Subnet Calculator

Work out network, broadcast, and usable host ranges for any IPv4 or IPv6 block with a visual map, config snippets, and reverse lookup.

IPv4 Subnet Calculator

Do you want to find your real IP address ? Click here!

IPv6 Subnet Calculator

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IP Subnet Calculator

We provide an IP Subnet Calculator which is basically a networking tool that helps you calculate important subnet and IP address information without performing manual binary calculations. You have to enter an IPv4 or IPv6 address with its subnet mask or CIDR prefix to quickly find the network range, usable addresses, host capacity, and other networking details.

The calculator itself supports IPv4 and IPv6 subnet calculations, CIDR sizing, bulk subnet splitting, binary breakdowns, and configuration ready output. Its useful for network administrators, developers, DevOps engineers, system administrators, and networking students.

IPv4 Subnet Calculator

The IPv4 Subnet Calculator calculates subnet information for IPv4 addresses using traditional subnet masks or CIDR notation such as /24, /25, /26, and /30.

For example, a 192.168.1.0/24 network contains 256 total addresses and traditionally provides 254 usable host addresses.

Example: 192.168.1.0/24
  • Network Address: 192.168.1.0
  • Broadcast Address: 192.168.1.255
  • Subnet Mask: 255.255.255.0
  • Wildcard Mask: 0.0.0.255
  • First Usable Host: 192.168.1.1
  • Last Usable Host: 192.168.1.254
  • Total Addresses: 256
  • Usable Hosts: 254

IPv4 Features

  • Calculate IPv4 network addresses
  • Calculate broadcast addresses
  • Find first and last usable hosts
  • Calculate total and usable hosts
  • Convert CIDR prefixes to subnet masks
  • Calculate wildcard masks
  • Identify private IPv4 address ranges
  • Identify the legacy IPv4 network class
  • View binary IP and subnet mask breakdowns
  • Copy calculated network values
  • Generate configuration ready output

IPv6 Subnet Calculator

The IPv6 Subnet Calculator provides subnet information for IPv6 addresses using prefix lengths such as /48, /56, and /64.

It calculates the IPv6 network prefix, first and last addresses, total address capacity, compressed and expanded address formats, reverse DNS information, and the different parts of an IPv6 address.

Example: 2001:db8:85a3::/64
  • Network: 2001:db8:85a3::
  • Prefix Length: /64
  • Total Addresses: 18,446,744,073,709,551,616
  • Subnet ID: 0000
  • Interface ID: 64 bits

IPv6 Features

  • Calculate IPv6 network prefixes
  • Calculate first and last IPv6 addresses
  • Calculate total IPv6 addresses
  • Expand compressed IPv6 addresses
  • Compress expanded IPv6 addresses
  • Generate reverse DNS information
  • Calculate solicited node multicast information
  • Show global routing prefix
  • Show subnet ID
  • Show interface ID
  • Identify documentation address ranges
  • Analyze IPv6 address structure

What CIDR Do I Need?

The What CIDR Do I Need? feature helps you choose the appropriate IPv4 subnet size based on the number of usable hosts you require.

For example, if you need 100 usable hosts, a /25 network provides 126 traditionally usable addresses, making it large enough for the requirement.

CIDRUsable HostsFits 100 Hosts?
/23510✓
/24254✓
/25126✓
/2662✕
/2730✕

IPv4 Bulk Split

The IPv4 Bulk Split feature allows you to divide a larger IPv4 network into multiple smaller subnets. This is useful when creating separate network segments, VLANs, office networks, or other infrastructure ranges.

For example, a 192.168.1.0/24 network can be divided into four separate /26 subnets.

#NetworkBroadcastUsable RangeUsable Hosts
1192.168.1.0/26192.168.1.63192.168.1.1 – 192.168.1.6262
2192.168.1.64/26192.168.1.127192.168.1.65 – 192.168.1.12662
3192.168.1.128/26192.168.1.191192.168.1.129 – 192.168.1.19062
4192.168.1.192/26192.168.1.255192.168.1.193 – 192.168.1.25462

IPv6 Bulk Split

The IPv6 Bulk Split feature lets you divide a larger IPv6 network into smaller subnet prefixes.

For example, a 2001:db8::/48 network can be divided into /64 networks, producing 65,536 separate subnets. Because large IPv6 networks can contain thousands of subnets, the calculator displays a manageable portion of the generated results.

#NetworkLast Address
12001:db8::/642001:db8::ffff:ffff:ffff:ffff
22001:db8:0:1::/642001:db8:0:1:ffff:ffff:ffff:ffff
32001:db8:0:2::/642001:db8:0:2:ffff:ffff:ffff:ffff

Ready to Use Network Configuration

The calculator can also provide configuration friendly information that can be used when setting up network interfaces and infrastructure. Depending on the calculation, you can view output suitable for environments such as Cisco IOS, Linux, Windows, and JSON based configurations.

This makes it easier to move from subnet planning to network configuration without manually converting the calculated values.

Who Can Use This IP Subnet Calculator?

This tool is useful for anyone who works with IP addressing or network configuration, including:

  • Network administrators
  • System administrators
  • Software developers
  • DevOps engineers
  • Cloud engineers
  • IT support professionals
  • Cybersecurity professionals
  • Networking students
  • Network engineering students

Frequently Asked Questions

What is CIDR?

CIDR stands for Classless Inter Domain Routing. It represents an IP network using an address followed by a prefix length, such as 192.168.1.0/24. The /24 indicates that the first 24 bits belong to the network portion.

How many usable hosts are in a /24 network?

A typical IPv4 /24 network contains 256 total addresses and traditionally provides 254 usable host addresses. The network and broadcast addresses are normally reserved.

What is the difference between a subnet mask and CIDR?

A subnet mask uses dotted decimal notation, such as 255.255.255.0, while CIDR uses a prefix length such as /24. Both describe the same network boundary.

What is a wildcard mask?

A wildcard mask is the inverse of a subnet mask and is commonly used in networking configurations such as Cisco access control lists and routing protocols. For example, the wildcard mask for 255.255.255.0 is 0.0.0.255.

What CIDR should I use for 100 hosts?

A /25 IPv4 network provides 128 total addresses and 126 traditionally usable host addresses, so it can accommodate 100 hosts.

What is an IPv6 /64 network?

An IPv6 /64 network contains 64 network bits and 64 interface bits, providing 264 possible addresses. A /64 is the conventional subnet size commonly used for an IPv6 LAN.

Can I calculate IPv6 subnets with this tool?

Yes. The calculator supports IPv6 prefix calculations, address ranges, compressed and expanded addresses, reverse DNS information, and bulk IPv6 subnet splitting.

Can I split one network into multiple subnets?

Yes. The IPv4 Bulk Split and IPv6 Bulk Split features allow you to divide a parent network into smaller subnet ranges and view the resulting networks and address ranges.

Is the IP Subnet Calculator free?

Yes. The calculator is available as a free online networking tool and lets you perform subnet calculations without manually working through binary calculations.