How to Find Your Subnet Mask on Windows, macOS, Android, and iPhone

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Your subnet mask is one of those network details you rarely think about until you need it. It helps your device understand which addresses are on your local network and which must be reached through a router. Whether you are troubleshooting Wi-Fi, setting a static IP address, configuring a printer, or helping tech support, knowing where to find it can save time.

TLDR: On Windows, use Command Prompt and run ipconfig, or check your network adapter details in Settings. On macOS, open Network settings or run ifconfig in Terminal. On Android, look in your Wi-Fi network details, where the subnet may appear as a prefix length. On iPhone, tap the information icon next to your Wi-Fi network and check the IP address section.

What Is a Subnet Mask, in Plain English?

A subnet mask is a number that separates the network portion of an IP address from the device portion. For example, a typical home network might use an IP address like 192.168.1.25 with a subnet mask of 255.255.255.0. In simple terms, this means devices with addresses beginning with 192.168.1 are usually part of the same local network.

You may also see subnet information written as a CIDR prefix, such as /24. This is just another way of writing the subnet mask. For most home users, /24 equals 255.255.255.0.

How to Find Your Subnet Mask on Windows

Windows gives you several ways to find your subnet mask, but the fastest method is through Command Prompt.

Method 1: Use Command Prompt

  1. Press Windows + R to open the Run box.
  2. Type cmd and press Enter.
  3. In Command Prompt, type ipconfig and press Enter.
  4. Look for your active connection, such as Wireless LAN adapter Wi-Fi or Ethernet adapter.
  5. Find the line labeled Subnet Mask.

You will see something like:

  • IPv4 Address: 192.168.1.42
  • Subnet Mask: 255.255.255.0
  • Default Gateway: 192.168.1.1

If you have multiple adapters, such as VPNs, virtual machines, Ethernet, and Wi-Fi, make sure you are reading the one that is actually connected to your network.

Method 2: Use Windows Settings

  1. Open Settings.
  2. Go to Network & Internet.
  3. Select Wi-Fi or Ethernet, depending on your connection.
  4. Click your active network or connection properties.
  5. Scroll to the network details section and look for IPv4 subnet mask.

This method is more visual and helpful if you are not comfortable using command-line tools.

How to Find Your Subnet Mask on macOS

On a Mac, you can find the subnet mask through System Settings or by using Terminal. The menu names can vary slightly depending on your macOS version, but the process is similar.

Method 1: Use System Settings

  1. Click the Apple menu in the top-left corner.
  2. Choose System Settings or System Preferences.
  3. Open Network.
  4. Select your active connection, such as Wi-Fi or Ethernet.
  5. Click Details or Advanced.
  6. Look under TCP/IP for the subnet mask.

On many Macs, you will see the IP address, router, and subnet mask grouped together. If the connection is using DHCP, these values are assigned automatically by your router.

Method 2: Use Terminal

If you like a quicker technical route, open Terminal and enter:

ifconfig

Look for the active interface. Wi-Fi is often listed as en0 or en1, depending on the Mac. You may see a line containing inet followed by your IP address and a netmask value. macOS may display the netmask in hexadecimal, such as 0xffffff00, which corresponds to 255.255.255.0.

How to Find Your Subnet Mask on Android

Android is a little trickier because phone manufacturers customize menus. A Samsung phone, Google Pixel, and OnePlus device may all show network details in slightly different places. Still, the general path is usually similar.

  1. Open Settings.
  2. Tap Network & Internet, Connections, or a similar option.
  3. Tap Wi-Fi.
  4. Select your currently connected Wi-Fi network.
  5. Look for Network details, Advanced, or IP settings.

On some Android devices, you may see a traditional subnet mask such as 255.255.255.0. On others, you may see Network prefix length, such as 24. This means the same thing as /24, which equals 255.255.255.0.

Common conversions include:

  • /24 = 255.255.255.0
  • /25 = 255.255.255.128
  • /26 = 255.255.255.192
  • /16 = 255.255.0.0

If Android does not show enough detail, you can also check your router’s admin page or use a trusted network information app. However, for privacy and security, avoid installing random apps that request unnecessary permissions.

How to Find Your Subnet Mask on iPhone

On an iPhone, subnet information is found in the Wi-Fi details screen. The process is simple, but you need to be connected to the Wi-Fi network first.

  1. Open Settings.
  2. Tap Wi-Fi.
  3. Find the network you are connected to.
  4. Tap the information icon, shown as a small i in a circle.
  5. Scroll to the IPv4 Address section.
  6. Look for Subnet Mask.

You will typically see your IP Address, Subnet Mask, and Router listed together. If your iPhone is using automatic configuration, these values come from the router through DHCP. If you switch to manual IP configuration, you may need to enter the subnet mask yourself.

Why You Might Need Your Subnet Mask

For everyday browsing, streaming, and messaging, you may never need to touch your subnet mask. But it becomes useful in several situations:

  • Setting a static IP address: Printers, security cameras, and servers often need stable addresses.
  • Troubleshooting connection problems: A wrong subnet mask can stop devices from communicating properly.
  • Configuring routers or firewalls: Network rules often depend on subnet ranges.
  • Understanding your local network: It helps identify which devices should be reachable directly.

Quick Tips for Reading Subnet Information

If you are on a typical home network, your subnet mask will most likely be 255.255.255.0. This is the standard setup for many consumer routers and supports up to 254 usable device addresses on the local network.

If you see a prefix length instead of a subnet mask, do not worry. A prefix like /24 is simply a shorter notation. For most basic troubleshooting, knowing that /24 equals 255.255.255.0 is enough.

Also, remember that your subnet mask is different from your default gateway. The gateway is usually your router’s address, while the subnet mask defines the size of your local network.

Final Thoughts

Finding your subnet mask is easier than it sounds once you know where to look. Windows and macOS provide both graphical and command-line options, while Android and iPhone place the information inside Wi-Fi network details. Whether it appears as 255.255.255.0 or as a prefix like /24, the subnet mask is a small but important piece of your network identity. The next time a device refuses to connect, a printer disappears, or a support technician asks for network details, you will know exactly where to find it.