CIDR Calculator | Convert CIDR Notation to IP Ranges Instantly

CIDR Calculator

Enter a CIDR (IPv4 or IPv6) to calculate network details.

How to use & examples

To use the CIDR Calculator, simply enter a CIDR notation in the input field (e.g., 192.168.1.0/24 or 2001:db8::/64) and click Calculate. The tool will analyze the input and display details about the corresponding network, including the network address, usable IP range, and total number of hosts.

Examples of valid inputs:

  • IPv4 Examples:
    • 192.168.1.0/24 (Common private network)
    • 10.0.0.0/8 (Large private network)
    • 172.16.0.0/16 (Medium-sized private network)
    • 198.51.100.0/30 (Small subnet with only a few IPs)
  • IPv6 Examples:
    • 2001:db8::/32 (IPv6 documentation range)
    • fd00::/8 (Private IPv6 network)
    • 2001:db8:abcd::/48 (Larger subnet for enterprise use)
    • fe80::/10 (Link-local address range)

What is a CIDR calculator?

A CIDR (Classless Inter-Domain Routing) calculator is a valuable tool for network engineers, system administrators, and IT professionals who need to efficiently allocate and manage IP address space. CIDR notation simplifies subnetting by allowing flexible subnet masks instead of fixed class-based subnetting, making it crucial for modern IPv4 and IPv6 networking.

With this tool, users can input a CIDR range (e.g., 192.168.1.0/24 or 2001:db8::/64) and quickly determine the network address, broadcast address, usable host range, and subnet mask.

Features of a CIDR calculator

The CIDR block calculator allows you to get the following supernet information:

  • Valid network addresses
  • Subnet mask
  • Wildcard mask
  • Broadcast address
  • Host bits
  • Network bits
  • Subnets per network
  • Valid hosts per subnet

With this in mind, you can allocate IP addresses more efficiently using the CIDR calculator. The calculation results help you figure out how IP addresses are being used within a network.

A CIDR calculator translates IP address ranges.

The need for CIDR and CIDR calculators

The creators of Classless Inter-Domain Routing (CIDR) were motivated to solve the scalability issues created with the original class-based system. Therefore, Classless Inter-Domain Routing replaced the old method of labeling network systems as class A, class B, class C, and so on in order to impede the depletion of IPv4 address space and slow the growth of routing tables on routers.

The CIDR addressing scheme massively improved efficiency in allocating resources. By restructuring IP address assignments, the customer or organization receives an assignment of the number of IP addresses that they require rather than entire blocks of IP addresses.

One major benefit to Classless Inter-Domain Routing was its enabling of something called "route aggregation," in which one high-level route entry represents many lower-level routes. If nothing was done, then Internet growth would be halted. Using CIDR calculators, and CIDR overall, allows supernetting; grouping subnets into supernets guarantees systemic IP routing entries too.

Because CIDR can organize IP addresses into subnets, engineers deemed it to be the solution to increasing IP exhaustion.