IPv4 CIDR Subnet Calculator
Calculate an IPv4 subnet from an address and CIDR prefix.
Calculate IPv4 network boundaries
CIDR prefixes describe how many leading bits identify the network. The calculator reports the network, broadcast and conventional usable-host range.
Point-to-point and host routes may treat usable addresses differently, and this tool does not cover IPv6.
How to use the IPv4 CIDR Subnet Calculator
- Enter or upload the information requested by the tool.
- Run the tool and review the result for accuracy.
- Copy or download the result, then test it in its intended context.
Practical example
Use a small known sample first so you can compare the output before processing a larger value.
What this tool cannot guarantee
The result reflects the supplied input and browser implementation; project-specific syntax and runtime behavior still require testing.
Continue this workflow with the HTTP Header Parser
Frequently asked questions
Is the IPv4 CIDR Subnet Calculator free to use?
Yes. It is available without an account or paid subscription.
Is my input uploaded or stored?
The core operation runs in your browser. Avoid pasting secrets into any web page unless the individual tool explicitly explains how the data is handled.
Should I review the result before using it?
Yes. Check the output for your project and test it in the intended environment before production use.