IP Subnet Calculator

Calculate network and broadcast addresses, usable host ranges, and subnet masks from CIDR notation.

Subnet Results

Network Address192.168.1.0
Broadcast Address192.168.1.255
Subnet Mask255.255.255.0
CIDR Prefix/24
First Usable Host192.168.1.1
Last Usable Host192.168.1.254
Usable Hosts254
Total Addresses256
IP ClassClass C

How to Use the Subnet Calculator

Enter an IP address with CIDR prefix in the format 192.168.1.0/24. The calculator derives network address, broadcast, subnet mask, and usable host range.

Formula

Subnet mask = 32-bit mask with first N bits set. Network = IP AND mask. Broadcast = IP OR (NOT mask). Usable hosts = 2^(32−prefix) − 2.

Frequently Asked Questions

What is CIDR notation?

Classless Inter-Domain Routing (CIDR) notation like /24 represents the number of bits in the network portion of an IP address. /24 = 255.255.255.0 mask.

How many hosts can /24 support?

/24 gives 2^8 − 2 = 254 usable hosts. The first address is the network address and the last is the broadcast address.