IPv4 Subnet Calculator
Calculate the subnet mask, wildcard mask, network and broadcast addresses, and usable host range for an IPv4 CIDR block. IPv4 input must contain exactly four decimal octets from 0 through 255. Calculate it clearly with Figur.
IPv4 Subnet Calculator
Calculate the subnet mask, wildcard mask, network and broadcast addresses, and usable host range for an IPv4 CIDR block. IPv4 input must contain exactly four decimal octets from 0 through 255.
Method and assumptions
Figur parses a four-octet IPv4 address and /0–/32 CIDR prefix, applies the bit mask to obtain network and broadcast addresses, and derives wildcard mask, total addresses, and usable range.
- Input is strict decimal IPv4; IPv6, DNS, routes, and device configurations are not supported.
- For /0–/30 it excludes network and broadcast from the host range; /31 retains two point-to-point endpoints and /32 identifies one address.
- Counts are theoretical and do not subtract addresses reserved by equipment, providers, or local policy.
Addressing reference, not network configuration or security advice. Verify routes, assignments, and equipment requirements before deployment.
Sources and references
Frequently asked questions
Are /31 addresses usable?
Yes. A /31 point-to-point subnet has two usable endpoint addresses and no reserved network or broadcast host addresses.
What does /32 mean?
A /32 identifies one address; it has one total and usable address, with that address as its range.