CodeBeautifyCIDR / Subnet Calculator
Enter an IPv4 address in CIDR notation to calculate its network range, subnet mask, and usable host count.
Network Address—
Broadcast Address—
Subnet Mask—
Wildcard Mask—
First Usable Host—
Last Usable Host—
Total Addresses—
Usable Hosts—
CIDR (Classless Inter-Domain Routing) notation, like 192.168.1.0/24, packs an IP address and its subnet size into one string — this calculator expands it into the full network details.
Frequently asked questions
How do I calculate a subnet from CIDR notation online?
Enter an address like 192.168.1.0/24 and click Calculate. The network address, broadcast address, mask, and usable host range are computed instantly.
Why is the usable host count 2 less than the total addresses?
The first address in a subnet is reserved as the network address and the last as the broadcast address, so they are excluded from the usable host range (except for /31 and /32, which are special cases).