Online Subnet Calculator
Calculate IPv4 network parameters including subnet mask, wildcard mask, network address, broadcast address, and usable IP host ranges instantly.
Free Online Subnet Calculator
A subnet calculator is an essential networking utility used by system administrators, cybersecurity professionals, and network engineers to calculate IPv4 network details. By entering an IP address and selecting a CIDR prefix, this tool instantly breaks down the network address, broadcast address, netmask, wildcard mask, and usable host range.
How to Use the Subnet Calculator
- Enter any valid IPv4 address (e.g.,
192.168.1.10) into the IP address field. - Select the appropriate CIDR prefix (e.g.,
/24) or subnet mask from the dropdown menu. - Click Calculate Subnet to instantly generate complete network configurations.
- Review your usable host ranges, broadcast addresses, and total host capacities.
Understanding IPv4 Subnetting & CIDR Notation
Classless Inter-Domain Routing (CIDR) is a method for allocating IP addresses and routing IP packets. A CIDR notation consists of an IP address followed by a slash and a number representing the number of bits set to 1 in the subnet mask (e.g., /24 equals 255.255.255.0).
Key Terms Explained:
- Network Address: The first address in any subnet, used to identify the network itself (e.g.,
192.168.1.0). - Broadcast Address: The last address in a subnet, used to transmit data to all devices on that network segment.
- Usable Host Range: The pool of IP addresses assignable to individual network devices, workstations, or servers.
- Wildcard Mask: The inverse of a subnet mask, frequently used in router access control lists (ACLs).
Frequently Asked Questions (FAQ)
What is a /24 subnet?
A /24 subnet uses a subnet mask of 255.255.255.0 and provides 256 total IP addresses, of which 254 are usable host addresses after accounting for the network and broadcast addresses.
Are private IP addresses supported?
Yes, you can calculate subnets for private IPv4 blocks such as 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 as well as public IPs.
Is this subnet calculator free?
Yes, this tool runs entirely client-side in your browser, requires no registration, and is completely free to use.