Calculate subnets visually with a CIDR slider, binary bit visualization, and full network details. Copy any result instantly.
What is IP Subnet Calculator?
An interactive IP subnet calculator that goes beyond the basics. Slide the CIDR prefix length and watch network vs host bits shift in a color-coded binary display in real-time. See network address, broadcast address, usable host range, subnet mask, wildcard mask, IP class, and private address status — all copyable with one click. Includes a quick-reference cheat sheet of common CIDR prefixes.
How to Use
Enter an IP address in the four octet fields (press Tab or dot to jump between octets)
Drag the CIDR slider or use the subnet mask dropdown to set the prefix length
Watch the binary visualization update — blue bits are the network portion, green bits are the host portion
Copy any result row by hovering and clicking the copy button
Click a row in the cheat sheet to quickly jump to that CIDR prefix
Frequently Asked Questions
What is a subnet?
A subnet (subnetwork) is a logical division of an IP network. The CIDR prefix length determines how many bits identify the network vs. individual hosts.
What do the colors in the binary view mean?
Blue bits represent the network portion (determined by the subnet mask) and green bits represent the host portion available for individual devices.
What is the difference between total hosts and usable hosts?
Total hosts is 2^(host bits). Usable hosts subtracts 2 because the first address is the network address and the last is the broadcast address (except for /31 and /32).
Is my data sent anywhere?
No. All calculations are performed entirely in your browser using JavaScript bitwise operations. Nothing is sent to any server.
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