CIDR to IP Range Calculator
Need the exact IP range represented by a CIDR block? Enter an IPv4 address and prefix to reveal the network boundary, broadcast address, usable host range and complete address span.
Finding an IP range from CIDR
The network address is produced by applying the subnet mask to the input address. The broadcast address sets every host bit to one. Those two values define the complete traditional IPv4 subnet range.
For a /24 there are eight host bits and 256 total addresses. A /26 leaves six host bits and therefore contains 64 addresses.
CIDR range example
192.168.10.77/27 falls inside the network 192.168.10.64/27. The block runs through 192.168.10.95. Under conventional subnetting, usable hosts are 192.168.10.65 through 192.168.10.94.
Why the input IP may not equal the network address
A CIDR expression can be typed with any address inside the block. The prefix determines the block size and alignment. The calculator normalizes the host address to the canonical network address before reporting the range.
Range size and prefix length
Each increase of one in the prefix halves the address count. A /24 has 256 addresses, /25 has 128, /26 has 64, /27 has 32 and /28 has 16.
What this calculator shows
The result panel reports the canonical network address, broadcast address, first and last conventional usable addresses, dotted-decimal subnet mask, wildcard mask, total IPv4 address count and usable-host count. The live 32-bit boundary updates with the CIDR prefix, so the relationship between prefix length, block size and address capacity is visible instead of hidden behind a static table.
How to read the result correctly
The calculator normalizes the IP address you enter to the network block that contains it. That means an input such as 192.168.1.42/24 correctly resolves to network 192.168.1.0/24. For prefixes /0 through /30, conventional IPv4 subnetting reserves the first address as the network identifier and the final address as broadcast. /31 and /32 have different practical semantics, so their address counts should not be interpreted with the ordinary “subtract two” rule.
Related subnet tools
You can also use the subnetting cheat sheet for a complete IPv4 prefix reference, browse individual CIDR prefix pages, try the IPv6 subnet calculator, or return to the main visual subnet calculator.
Frequently asked questions
How do I find an IP range from CIDR?
Calculate the network address by clearing all host bits and the broadcast address by setting all host bits to 1. Those are the first and last addresses of the block.
How many IP addresses are in a /24?
A /24 contains 256 total IPv4 addresses.
Is the broadcast address part of the CIDR range?
Yes. The full CIDR block includes both the network and broadcast addresses, although they are traditionally not assigned as ordinary host addresses.