IPv4 Subnet Calculator
Calculate CIDR ranges, subnet masks, wildcard masks, broadcast addresses, and usable IPv4 hosts.
Subnet Input
Enter a host address, CIDR prefix, or subnet mask. Results update locally in your browser.
Network CIDR
192.168.1.0/24
Usable hosts
254
Total addresses
256
Host bits
8
Network address
192.168.1.0
First address in the subnet
Broadcast address
192.168.1.255
Last address in the subnet
First usable host
192.168.1.1
After the network address
Last usable host
192.168.1.254
Before the broadcast address
Subnet mask
255.255.255.0
Wildcard mask
0.0.0.255
Network bits
/24
Binary Breakdown
Octets are grouped for easier inspection.
11000000.10101000.00000001.0000101011000000.10101000.00000001.0000000011111111.11111111.11111111.0000000000000000.00000000.00000000.1111111111000000.10101000.00000001.11111111Common Subnets
Start from a familiar CIDR block and adjust from there.
How IPv4 Subnetting Works
IPv4 subnetting splits a 32-bit address into a network portion and a host portion. The CIDR prefix, such as /24, tells you how many bits identify the network.
The subnet mask is the dotted-decimal version of that prefix. A /24 prefix becomes 255.255.255.0, leaving 8 host bits for addresses inside the subnet.
Common Network Planning Uses
- Plan LAN, VLAN, VPC, and container network ranges
- Check whether an address belongs inside a CIDR block
- Calculate firewall wildcard masks and access rules
- Find usable host ranges before assigning addresses
- Compare /30, /31, and /32 point-to-point or host routes