IP Subnet Calculator

The IP Subnet Mask Calculator enables subnet network calculations using network class, IP address, subnet mask, subnet bits, mask bits, maximum required IP subnets and maximum required hosts per subnet.

Results of the subnet calculation provide the hexadecimal IP address, the wildcard mask, for use with ACL (Access Control Lists), subnet ID, broadcast address, the subnet address range for the resulting subnet network and a subnet bitmap.

For classless supernetting, please use the CIDR Calculator. For simple ACL (Access Control List) wildcard mask calculations, please use the ACL Wildcard Mask Calculator.

About the Subnet Calculator

1. The subnet calculator implements a classful / classed IP addressing scheme where the following rules are adhered to:

Class A addresses have their first octet in the range 1 to 126 (binary address begins with 0).

The above is generally accepted as being 'normal', however, certification students should keep in mind that, in some certification programs, the final two points are regarded as inacceptible.

For classless subnetting, you can use the CIDR calculator.