How to Find Your Subnet Mask

Need to know your subnet mask? Here's how to find it on any device.

Windows

Method 1: Command Prompt

ipconfig

Look for "Subnet Mask" under your active adapter:

IPv4 Address. . . . . . . . . . : 192.168.1.100
Subnet Mask . . . . . . . . . . : 255.255.255.0

Method 2: Settings App

1. Open Settings → Network & Internet → Status
2. Click "Properties" under your WiFi/Ethernet
3. Scroll to "Network profile"
4. See "Subnet prefix length"

macOS

Method 1: Terminal

ifconfig

Look for "netmask":

en0: flags=...
inet 192.168.1.100 netmask 0xffffff00 ...

Method 2: System Settings

1. Open System Settings → Network
2. Select your active connection
3. Click "Details"
4. See "Subnet"

Linux

Terminal

ip addr show
# or
ip a

Look for "inet" and "netmask":

inet 192.168.1.100/24 brd 192.168.1.255 scope global enp0s3

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