CIDR/Subnet Calculator

Calculate subnet details from CIDR notation — instantly in your browser.

100% Browser-Based

Files Never Leave Your Device

No Server Uploads

Zero Data Collection

How It Works

Type an IP address with prefix length (e.g., 192.168.1.0/24)

Click Calculate or press Enter to compute subnet details

View network address, broadcast, mask, usable range, and more

Network address, broadcast, subnet mask, wildcard mask, usable IP range, host count

View binary forms of network address and subnet mask

Automatically identifies the IP address class (A-E)

One-click copy for any calculated value

What is CIDR notation?

CIDR (Classless Inter-Domain Routing) notation combines an IP address with a prefix length (e.g., 192.168.1.0/24) to define a network range.

What prefix lengths are supported?

All prefix lengths from /0 to /32 are supported, including /31 and /32 point-to-point links.