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IP Range Calculator

Calculate the usable IP range, network address, broadcast, and host count from CIDR input.

Tool

Use this free IP Range Calculator to find the network address, first usable IP, last usable IP, broadcast address, subnet mask, and total host capacity for an IPv4 subnet. It is useful for subnetting practice, network planning, VLAN design, firewall rules, access lists, lab work, and quick troubleshooting when you need to understand exactly which IP addresses belong to a subnet.

About this tool

Use this free IP Range Calculator to find the network address, first usable IP, last usable IP, broadcast address, subnet mask, and total host capacity for an IPv4 subnet. It is useful for subnetting practice, network planning, VLAN design, firewall rules, access lists, lab work, and quick troubleshooting when you need to understand exactly which IP addresses belong to a subnet.

Use ip range calculator when you need a fast browser-based result without extra setup. It works well for quick checks, one-off tasks, and routine formatting or calculation work.

When to use IP Range Calculator

IP Range Calculator vs related tools

IP Range Calculator vs My IP Address

IP Range Calculator is for subnet math and range planning. My IP Address is for identifying the current public IP that a device or connection is using. If your question is "what subnet does this belong to?", use the range calculator. If your question is "what is my current public IP?", use the IP address tool.

IP Range Calculator vs IPv4 Validator

IP Range Calculator tells you the subnet boundaries and usable hosts. IPv4 Validator only checks whether an IPv4 address is syntactically valid. If you need planning and subnet details, the calculator is the better fit.

Helpful next steps

If you need to confirm the format of an address first, use IPv4 Validator. If you want to check the public IP currently visible to the internet, open My IP Address. If you are troubleshooting a domain or server after subnet planning, you may also want DNS Lookup or WHOIS Lookup.

Common subnetting mistakes

Learn more

Why use this tool

How to use

  1. Paste an IPv4 address with CIDR notation such as 192.168.1.10/24 into the input box
  2. Click Run Tool to calculate the subnet details
  3. Review the network address, broadcast address, usable host range, and subnet mask
  4. Use the result for planning, troubleshooting, documentation, or study
  5. If needed, test another CIDR block to compare subnet sizes and ranges

Examples

Example

Input

192.168.1.10/24

Output

Network: 192.168.1.0
Broadcast: 192.168.1.255
Usable range: 192.168.1.1 - 192.168.1.254

Useful for common LAN subnets where almost the entire last octet is available for hosts.

Example

Input

10.0.0.5/30

Output

Network: 10.0.0.4
Broadcast: 10.0.0.7
Usable range: 10.0.0.5 - 10.0.0.6

Helpful for understanding very small subnets often used on routed links.

Example

Input

172.16.5.20/16

Output

Network: 172.16.0.0
Broadcast: 172.16.255.255
Usable range: 172.16.0.1 - 172.16.255.254

Useful when checking large internal networks with many available hosts.

Example

Input

192.168.50.33/27

Output

Network: 192.168.50.32
Broadcast: 192.168.50.63
Usable range: 192.168.50.33 - 192.168.50.62

Helpful when designing smaller VLANs or branch office segments.

Example

Input

10.25.7.99/8

Output

Network: 10.0.0.0
Broadcast: 10.255.255.255
Usable range: 10.0.0.1 - 10.255.255.254

Useful for understanding how broad a large private range can be.

Example

Input

203.0.113.10/29

Output

Network: 203.0.113.8
Broadcast: 203.0.113.15
Usable range: 203.0.113.9 - 203.0.113.14

Useful when working with small public IP allocations or lab ranges.

Example

Input

192.168.1.25/32

Output

Network: 192.168.1.25
Broadcast: 192.168.1.25
Usable range: single host

Helpful when checking single-host routes, ACL entries, or exact match addresses.

Example

Input

192.168.1.300/24

Output

Invalid IPv4/CIDR input

The calculator rejects invalid octets or malformed CIDR values.

Common errors

Entering an IP without CIDR notation

Fix: Include the prefix length, for example 192.168.1.10/24 instead of just 192.168.1.10.

Confusing the network address with the first usable host

Fix: Remember that the network address identifies the subnet itself and is not normally assigned to a host.

Using the broadcast address as if it were a usable host

Fix: The broadcast address is reserved for the subnet and is not normally assigned to a device.

Assuming all subnet sizes have the same number of usable hosts

Fix: Check the prefix length carefully because a /24, /27, and /30 have very different host capacity.

Mixing host IP planning with ACL or route notation

Fix: Decide whether you need a subnet range, a single host entry, or a summarized network before using the result.

FAQ

What does an IP range calculator do?

An IP range calculator shows the network address, broadcast address, usable host range, and other subnet details based on an IPv4 address and CIDR prefix.

What is the difference between network address and first usable IP?

The network address identifies the subnet itself, while the first usable IP is the first address that can normally be assigned to a host.

What is the difference between broadcast address and last usable IP?

The broadcast address is reserved for the subnet, while the last usable IP is the final host address that can normally be assigned.

Can I use this tool for subnetting practice?

Yes. It is useful for learning CIDR, subnet masks, network boundaries, and host counts.

Why does a /30 subnet only show a small usable range?

A /30 subnet contains only four total addresses, and after reserving the network and broadcast addresses, only two are left for hosts.

What happens with a /32 address?

A /32 represents a single host address rather than a normal multi-host subnet.

Can I use this for firewall and routing work?

Yes. It is useful for understanding subnet boundaries when writing rules, routes, ACLs, and documentation.

Does this tool work with private and public IPv4 ranges?

Yes. The subnet math is the same whether the address belongs to a private or public range.

Can this help me tell whether two hosts are in the same subnet?

Yes. By checking the network boundaries, you can see whether two IP addresses belong to the same subnet.

When should I use a CIDR calculator instead of doing the math manually?

Use a calculator when you want a fast accurate answer during planning, support work, or exam practice without doing binary subnet math by hand.

Use cases

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