Frequently Asked Questions
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation is a compact way to specify an IP address and its routing prefix, e.g. 192.168.1.0/24 where /24 means the first 24 bits are the network prefix.
What does this tool calculate?
It calculates the network address, broadcast address, number of usable hosts, and subnet mask from the CIDR input.
Is my data uploaded to a server?
No. All calculations run entirely in your browser using JavaScript.
Example input/output
Input: 192.168.1.0/24
Output: Network: 192.168.1.0 / Broadcast: 192.168.1.255 / Hosts: 254 / Mask: 255.255.255.0
How it works
This tool parses the CIDR prefix length, computes the 32-bit subnet mask by bit-shifting, calculates the network and broadcast addresses using bitwise AND and OR operations, and derives the host range. Processing runs in your browser.
Common use cases
- Verify subnet boundaries when configuring firewalls or VPCs.
- Calculate usable host counts for capacity planning.
- Look up broadcast and network addresses for network troubleshooting.