Subnet Calculator
Calculate network details from CIDR notation.
Network Address
192.168.1.0
Broadcast Address
192.168.1.255
Subnet Mask
255.255.255.0
Wildcard Mask
0.0.0.255
First Usable
192.168.1.1
Last Usable
192.168.1.254
Total Hosts
256
Usable Hosts
254
CIDR Prefix
/24
IP Class
Class C
Private
Yes
Binary Mask
11111111.11111111.11111111.00000000
Examples
| Input | Result |
|---|---|
| 192.168.1.0/24 | Network: 192.168.1.0, Broadcast: 192.168.1.255, 254 usable hosts |
| 10.0.0.0/8 | Network: 10.0.0.0, Broadcast: 10.255.255.255, 16,777,214 usable hosts |
| 172.16.0.0/12 | Subnet mask: 255.240.0.0, Class B, Private range |
| 192.168.100.50/28 | Network: 192.168.100.48, Usable: .49-.62, 14 hosts |
About this tool
Enter an IP address with CIDR prefix and get a full breakdown of the subnet. The calculator shows the network and broadcast addresses, subnet mask, wildcard mask, first and last usable host, total and usable host count, IP class, and whether the address falls in a private range.
This is handy for network planning, firewall rule setup, or just understanding how a particular subnet carves up the address space. All calculations run in your browser.
Frequently asked questions
What is CIDR notation?
CIDR notation combines an IP address with a prefix length (like /24) that indicates how many bits define the network portion. A /24 means the first 24 bits are the network, leaving 8 bits for hosts.
How are usable hosts calculated?
Total addresses in a subnet is 2 raised to the power of host bits. Subtract 2 for the network address and broadcast address to get usable hosts. A /24 has 256 addresses total and 254 usable.
What is a wildcard mask?
A wildcard mask is the inverse of a subnet mask. Where the subnet mask has 1s, the wildcard has 0s and vice versa. It is used in access control lists on Cisco routers and other networking equipment.