IP Subnet Calculator
Compute network address, broadcast, host range, and subnet mask from an IPv4 address and CIDR prefix.
Subnet Details
What is the IP Subnet Calculator?
The IP Subnet Calculator performs IPv4 subnet math to determine the network address, broadcast address, usable host range, subnet mask, wildcard mask, and IP class from any valid IP address and CIDR prefix.
How to Use
- Enter a valid IPv4 address (e.g., 192.168.1.1).
- Enter the CIDR prefix (0-32), such as 24 for a /24 network.
- Click Calculate Subnet to view the full subnet breakdown.
Frequently Asked Questions
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation appends a slash and a number to an IP address, such as 192.168.1.0/24. The number represents the count of leading 1 bits in the subnet mask.
What is a wildcard mask?
A wildcard mask is the inverse of a subnet mask. It is used in access control lists (ACLs) and routing protocols to define which bits must match.
Why are the first and last addresses reserved?
The first address in a subnet is the network address, and the last is the broadcast address. These cannot be assigned to individual hosts.
Does this calculator support IPv6?
No, this tool currently supports IPv4 only. IPv6 subnetting uses 128-bit addresses and is handled differently.