CIDR Subnet Calculator
Calculate IPv4 networks, broadcasts, masks, host ranges, membership, and subnet splits.
CIDR input
Enter an IP/prefix such as 10.0.0.0/8; all calculations run locally in the browser.
IP membership check
Enter an IP to check whether it belongs to the network above.
About CIDR Subnet Calculator
Calculate IPv4 networks, broadcasts, masks, host ranges, membership, and subnet splits. Processing happens locally in your browser, and the tool does not upload the entered content.
Privacy and compatibility
Results depend on browser capabilities and the supplied input. Review generated output before using it in production or formal documents.