CIDR range expander
For full subnet details (mask, broadcast, host count), see the IP subnet calculator. This tool focuses on the start/end IP range.
First IP
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Last IP
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Total addresses
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What is CIDR range expander?
A CIDR block like 10.0.0.0/28 represents a contiguous range of addresses — this shows exactly where that range starts and ends, and optionally lists every address inside it.
How to use it
Enter a CIDR block to see its first and last IP, the total address count, and (for smaller blocks) the full list of every address, capped at 1024 to stay practical.
Example
192.168.1.0/28 -> first 192.168.1.0, last 192.168.1.15, 16 total addresses.