CIDR Network Calculator
Parse IPv4/CIDR locally in the browser and calculate the standard network, subnet mask, wildcard mask, broadcast address, and available host range.
How to use the CIDR network calculator
IPv4 addresses are processed using integer arithmetic only in the current browser; the tool does not query DNS, IP services, or this site’s API.
Enter IPv4/CIDR
Enter an address and prefix length such as 192.168.1.10/24; the tool will normalize the host address to the network.
Check network range
View the network, broadcast, mask, wildcard mask, first and last addresses, total address count, and usable host count.
Copy or download
After confirming the result, you can copy the JSON summary or download the JSON file for easy inclusion in change records.
Limitations and Notes
- The initial release supports only IPv4, with the prefix length limited to 0–32; inputs of IPv6 will be rejected.
- /31 displays two usable addresses for point-to-point links, while /32 displays one address; more complex provider-specific conventions still require manual verification.
- The result is an address range calculation and does not mean that the subnet is necessarily usable in actual routing, ACL, or DHCP configurations.
FAQ
Can the input host address be something other than a network address?
Yes. The tool uses the prefix mask to calculate the network to which it belongs while preserving the original input address.
/31 Why are the network and broadcast addresses not deducted?
Point-to-point links typically use both addresses as endpoints, so the page displays them according to this common interpretation; please confirm with the device documentation.
Does the tool verify that an address is actually reachable?
No. It is a purely local arithmetic calculator that does not send probe packets or network requests.