Network & IP
CIDR Subnet Calculator
Enter an IPv4 CIDR block and get the network, broadcast, host range, and host counts for that subnet.
All processing happens in your browser. This tool currently supports IPv4 CIDR notation.
Input
Use standard IPv4 CIDR notation such as 10.1.5.0/28 or
192.168.1.0/24.
Output includes network address, broadcast address, first/last host, total addresses, and usable hosts (with special handling for /31 and /32).
Results
Copy the summary into your notes, diagrams, or firewall / routing tickets.
Subnet summary
Network:
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Netmask:
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Broadcast:
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First host:
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Last host:
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Total addresses:
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Usable hosts:
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