How to Calculate the Subnet Mask

A subnet mask is a specific multi-digit number that represents a sub-section of your computer's IP address. Your IP address is a number that allows your computer to connect to a network. Calculating a subnet mask can be done using a native Windows tool. This tool will automatically perform the calculation for you and display the results on screen.

Instructions

1. Click "Start."

2. Click "Control Panel."

3. Click "Network and Sharing Center."

4. Click the network connection listed under "Connections" in the Network and Sharing Center window. This will open the "Status" window for your active network connection. Only your active network connection will have a subnet mask.

5. Click "Details." The Network and Sharing Center application will calculate and display all properties relating to your network connection. The subnet mask is listed in the window on screen.

References

• Microsoft: Network and Sharing Center Operations Guide