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CIDR Calculator

Break down a CIDR block into its addresses.

What Is a CIDR Calculator?

The CIDR Calculator takes a CIDR notation such as 192.168.1.0/24 or 2001:db8::/32 and returns the details of the block: the subnet mask, network address, broadcast address (for IPv4), first and last usable hosts, and the total number of addresses.

How to Use This CIDR Calculator

  1. 1
    Enter a blockType a CIDR notation like 10.0.0.0/8.
  2. 2
    Review the detailsRead the mask, network, broadcast, and host ranges.
  3. 3
    Copy the networkUse the copy button to copy the network address.

Frequently Asked Questions

Classless Inter-Domain Routing. CIDR notation uses an address followed by a slash and a prefix length to describe a block of IP addresses.
A /24 contains 256 addresses; a /16 contains 65,536. The smaller the number after the slash, the larger the block.
Yes. The tool handles both IPv4 and IPv6 CIDR blocks, showing the network and range for each.

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