Calculate an IPv4 network address, subnet mask, broadcast address, usable IP range and host count from CIDR notation. Supports /0–/32 and preset masks; this is a calculator, not a network scanner.
Enter the address and prefix length to instantly view subnet information.
Only IPv4 is supported with CIDR 0–32; addresses with leading zeros are not accepted.
Total number of addresses
256
Available host addresses
254
/31 counts as a point-to-point link, with both addresses available; /32 represents a single host. The number of available addresses does not represent the number of devices actually online on the network.
This subnet has 256 addresses, and the typical available host addresses are 254; does not represent the actual number of online devices.
IPv4 has a total of 32 bits, /24 indicates that the first 24 bits are the network prefix, and the remaining 8 bits can represent 2⁸ = 256 addresses, corresponding to the mask 255.255.255.0.
This tool interprets /31 as a point-to-point link, both addresses are available; /32 represents a single host. Both network and broadcast addresses are no longer deducted from ordinary subnets.
No. Only IPv4 math is done here, no IP probing, no device scanning, and no access to entered addresses. IPv6 is not supported by current tools.
Use IPv4's 32-bit address and CIDR mask to calculate network boundaries, and then derive the address range and host number. /31 is processed as a point-to-point link, /32 is processed as a single host; the calculation does not include device online status.
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