Network

IPv4 Subnet Calculator

IPv4 Subnet Calculator



How the subnet calculator works


Step 1
Enter a CIDR block
Type an IPv4 address and prefix length, such as 192.168.1.0/24.


Step 2
Calculate
The tool computes the network address, subnet mask, broadcast address, usable host range and total usable hosts.


Step 3
Read the results
Use the output to plan IP address allocation, firewall rules or network documentation.




Frequently asked questions


What does the prefix length mean?
The number after the slash (for example /24) indicates how many bits of the address are used for the network portion; the rest are available for host addresses.


How are usable hosts calculated?
For most prefixes, the network and broadcast addresses are excluded from the usable range; /31 and /32 blocks are handled as special point-to-point or single-host cases.


Does this support IPv6?
No, this calculator is built for IPv4 CIDR notation only.