| IP Address | |
| Network Address | |
| Subnet Mask | |
| Wildcard Mask (Cisco ACL) | |
| Broadcast Address | |
| First Usable Host | |
| Last Usable Host | |
| Total Addresses | |
| Usable Host Addresses | |
| CIDR Notation | |
| IP Class | |
| Private Range |
| CIDR | Subnet Mask | Wildcard | Total IPs | Usable Hosts | Common Use |
|---|
Click any row to calculate that CIDR using your entered IP address.
Enter an IPv4 address and select the CIDR prefix that matches the network you want to analyse. The calculator returns the network address, subnet mask, wildcard mask, broadcast address, first usable host, last usable host, total addresses and usable host count.
Use the result when checking whether a device has the correct IP settings, preparing DHCP scopes, documenting VLANs or validating firewall rules. For example, 192.168.10.25/24 belongs to the 192.168.10.0 network, while 192.168.10.25/27 belongs to a smaller 32-address block.
The wildcard mask is included because Cisco ACLs and some routing configurations use wildcard notation instead of subnet mask notation. A /24 subnet mask of 255.255.255.0 becomes a wildcard mask of 0.0.0.255.
What is a CIDR prefix? CIDR is the slash number after an IP address, such as /24 or /30. It tells you how many bits are used for the network portion of the address.
Why are usable hosts fewer than total addresses? In most IPv4 subnets, the first address is the network address and the last address is the broadcast address. Those two addresses are not assigned to normal hosts.
When should I use /30 or /31? A /30 is common for point-to-point links with two usable addresses. A /31 can be used in supported point-to-point environments, but it should only be used when the network equipment supports it.