A free online subnet calculator for network engineers and IT professionals. Enter an IP address and CIDR prefix to get the network address, broadcast address, usable host range, subnet mask, wildcard mask, total hosts, IP class, and binary representations. Supports all CIDR values from /0 to /32.
Enter an IP address in dotted decimal notation.
Select the CIDR prefix length (0-32) using the slider or quick buttons.
View the network address, broadcast, host range, and mask.
Check binary representations and IP class details.
CIDR (Classless Inter-Domain Routing) notation uses an IP address followed by a slash and a number (e.g., 192.168.1.0/24) that indicates how many bits are used for the network prefix.
Usable hosts = 2^(32-CIDR) - 2. The -2 accounts for the network address (first) and broadcast address (last), which cannot be assigned to hosts.
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