Enter values and select Calculate to see your result.
Find an IPv4 network, subnet mask, address range and host count
/31 treats both addresses as point-to-point hosts; /32 represents one host. Other prefixes exclude network and broadcast from usable hosts.
How to use the Subnet Calculator
Find IPv4 network, broadcast, usable host range and host count from an address and CIDR prefix.
- Enter a valid IPv4 address.
- Enter a CIDR prefix from 0 to 32.
- Calculate network, mask, broadcast and hosts.
Subnet Calculator formula
Network address = IP address AND subnet mask; usable hosts depend on prefix and special cases.
Worked example
Inputs: 192.168.1.10 with a /24 prefix.
What to expect: Network is 192.168.1.0, broadcast .255 and usual usable range .1 through .254.
How to read your result
A /31 and /32 are special cases; verify plans against network equipment.
Frequently asked questions
What does /24 mean?
24 bits identify the network and 8 bits remain for addresses.
Are network and broadcast usable?
Usually no for ordinary IPv4; /31 and /32 have special behavior.