IP Address / Subnet Calculator

Calculate network details, host ranges, and subnet information from any IP address and CIDR prefix.

/0/32
192.168.1.0/24
Network Address192.168.1.0
Broadcast Address192.168.1.255
Subnet Mask255.255.255.0
Wildcard Mask0.0.0.255
First Usable Host192.168.1.1
Last Usable Host192.168.1.254
Total Addresses256
Usable Hosts254
IP ClassClass C
Private IP✅ Yes
Binary IP11000000.10101000.00000001.00000000
Binary Mask11111111.11111111.11111111.00000000

Frequently Asked Questions

What is a subnet?

A subnet (subnetwork) is a logical subdivision of an IP network. Subnetting divides a single network into smaller networks, improving security and performance. The subnet mask determines which portion of an IP address identifies the network and which identifies the host.

What is CIDR notation?

CIDR (Classless Inter-Domain Routing) notation uses a slash followed by a number (e.g., /24) to indicate how many bits of the IP address are used for the network portion. A /24 means the first 24 bits are the network address, leaving 8 bits (256 addresses) for hosts.

What is the difference between network and broadcast address?

The network address is the first address in a subnet (all host bits set to 0) and identifies the network itself. The broadcast address is the last address (all host bits set to 1) and is used to send data to all hosts on the subnet. Neither can be assigned to a device.

What are private IP ranges?

Private IP addresses are reserved for internal networks and are not routable on the public internet. The three private ranges are: 10.0.0.0/8 (Class A), 172.16.0.0/12 (Class B), and 192.168.0.0/16 (Class C). These are defined in RFC 1918.

How many usable hosts does a /24 subnet have?

A /24 subnet has 256 total addresses (2^8), but 2 are reserved: the network address and the broadcast address. This leaves 254 usable host addresses. For /31 subnets (point-to-point links), both addresses are usable per RFC 3021. A /32 is a single host.