urlkit[ CHECK / /24 ]
IPv4 subnet calculator
Find a CIDR subnet’s range, masks and conventional host count.
02 / Your result
Your result will appear here.
Start with your own input or try an example.
What it does
Turn an IPv4 address and prefix into a clear subnet summary before filling out a router setting, documenting an address plan, or reviewing a network rule. See the canonical subnet, netmask, wildcard mask, full range, and host range. Everything is calculated locally; no addresses are contacted.
Useful when
- Check which subnet contains a device address.
- Compare a network rule with the address range you intended.
- Document the masks and conventional host count for an address plan.
How to use it
- Enter an IPv4 address with a CIDR prefix, such as 192.168.1.42/24.
- Calculate the subnet and review its range, masks, and prefix-specific notes.
- Copy the summary or download notes for your configuration record.
A few useful details
Why does /31 show two endpoints?
RFC 3021 allows both addresses on a /31 point-to-point link to identify endpoints, with no directed broadcast address. Both devices must support that use. The result describes this specific case, not a conventional multi-device LAN.
What does /32 mean here?
It describes exactly one IPv4 address, commonly used as a host route. There is no separate host range or directed broadcast address.
Are all the listed host addresses available to use?
No. The conventional count excludes the subnet and broadcast addresses only. Reserved ranges, existing assignments, provider reservations, and device settings may reduce what you can use. This calculator does not scan or check availability.
Can I enter a hostname or IPv6 address?
This tool accepts only four decimal IPv4 octets followed by /0 through /32. Hostnames, IPv6, leading-zero octets, and abbreviated or hexadecimal forms are not accepted.