IPv4 Subnet & CIDR Calculator
Calculate network range, broadcast IP, usable hosts, subnet mask, wildcard mask, and binary breakdown from any CIDR notation.
Batch workspace
Format multiple files locally in one run.
How to use the IP Subnet & CIDR Calculator
Paste code or file
Paste your raw TEXT text or upload directly.
Configure options
Choose indentation, dialect, or formatting preferences.
Format & export
Click format, then copy, download, or inspect in tree view.
What is a IP Subnet & CIDR Calculator?
Calculate network range, broadcast IP, usable hosts, subnet mask, wildcard mask, and binary breakdown from any CIDR notation. This tool re-indents and organizes code according to standard style conventions while checking for syntax validity. Everything executes 100% inside your browser, guaranteeing zero latency and complete privacy for API keys, user tokens, and confidential database schemas.
Frequently Asked Questions
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) specifies an IP address followed by a slash and the number of leading 1-bits in the routing mask (e.g. `/24` represents 255.255.255.0).
Why are 2 addresses subtracted from the total hosts in a subnet?
In standard subnets, the very first address is reserved for the Network ID, and the last address is reserved for the Subnet Broadcast.
Is my data uploaded when I use the IP Subnet & CIDR Calculator?
No. All processing runs entirely in your browser. Nothing is sent to a server unless you explicitly create a share link.
Does this tool work offline?
Yes. After the first visit, the PWA service worker can serve the page and run the formatter without a network connection.
What is the maximum input size?
Most tools accept up to about 5MB in the editor. Very large inputs are processed preferentially in a Web Worker and may download instead of filling the output pane.