Enter the relevant system or network values to calculate cidr from subnet mask and review the result in plain terms.
Inputs
This topic also has a deeper guide and a printable reference pack, so you can move from the live answer into the method, assumptions, and worked examples without leaving the topic cluster.
These are the main values the calculator uses. Keep the units consistent and, where relevant, match the assumptions explained in the related guide.
Enter a contiguous IPv4 subnet mask in dotted-decimal form.
Use this page when you want a fast cidr from subnet mask result for system planning, conversion work, or networking checks.
These pages apply the conversion or networking logic shown on the page. Review the wider system context before using the result operationally.
Use the Subnet Mask from CIDR Calculator to work out subnet mask from cidr for networking, storage, or systems planning.
Use the Wildcard Mask from CIDR Calculator to work out wildcard mask from cidr for networking, storage, or systems planning.
Use the Subnet Host Count Calculator to work out subnet host count for networking, storage, or systems planning.
Work out the network address, broadcast address, host range, and mask details for an IPv4 network from the address and prefix you enter.