Network Calculator

For help with any of the calculators, click here. If you think the calculator is wrong because it shows the first and last ('all zeroes' and 'all ones') subnets as being available, click here for an explanation.

Subnet Mask Calculator

Enter the TCPIP Network Address:
Force as Class: Default Class A Class B Class C
Enter the required number of sub-networks:
OR enter the required number of nodes/hosts per network (including network & broadcast addresses)***:

Network Class:
Subnet Mask: or
Nodes/Hosts per Network (including network and broadcast addresses)***:

*** To add support for RFC3021 which allows for /31 networks, the subnet mask calculator has changed to accomodate this. To do this, the number of hosts now include the network and broadcast addresses since these are used for hosts in /31 networks.

Network/Node Calculator

Enter the Subnet Mask:
Enter the TCPIP Address:

Broadcast Address:

IP Address Converter

Enter the dotted decimal TCPIP Address:
or Enter the binary TCPIP Address:
or Enter the hex TCPIP Address:
or Enter the decimal TCPIP Address:

Subnet Mask Converter

Enter the dotted decimal Subnet Mask
or Enter the number of bits in the subnetmask /