Subnet Calculator
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Subnet Details
Network Address
192.168.0.0/24
First Usable IP
192.168.0.1
Last Usable IP
192.168.0.254
Broadcast Address
192.168.0.255
Total Usable Hosts
254
Total Available Host
256
Subnet Mask
255.255.255.0
Wildcard Mask
0.0.0.255
Binary Subnet Mask
11111111.11111111.11111111.00000000
IP Type
Private (Class C)
How to Use the Subnet Calculator
The IPv4 Subnet Calculator is designed to quickly determine the complete network profile of any given IP address and subnet mask. Follow the steps below to calculate your network ranges:
- Enter your IP Address: Type a valid IPv4 address (e.g.,
192.168.0.1) into the IP Address field. - Set the Subnet Mask or CIDR: You can either type the subnet mask directly (e.g.,
255.255.255.0) or use the interactive slider to adjust the CIDR prefix (e.g.,/24). - Analyze the Results: The calculator updates in real-time. Review your Network Address, Usable Host Range, and Broadcast Address immediately in the details panel above.
Tip: Use the Copy or Download buttons located at the top right of the Subnet Details panel to instantly export your results to your clipboard or a text file for documentation.
Subnetting Frequently Asked Questions
Why can't I assign the first and last IP addresses in a subnet to my devices?
The first IP address is strictly reserved as the 'Network Address,' which routers use to identify the subnet itself. The last IP address is the 'Broadcast Address,' which is used to broadcast messages to every single device on that specific subnet simultaneously. Because they have special network functions, neither can be assigned to an individual computer or host.
Can I use a /31 or /32 subnet mask?
Yes, in specific networking scenarios. A /32 mask represents a single 'host route,' often used for router loopback interfaces. A /31 mask provides exactly two IP addresses with no designated network or broadcast address. This is commonly used for point-to-point serial links between two routers to strictly conserve IP address space (as defined by RFC 3021).
What does 'IP Type: Link-Local (APIPA)' mean in the results?
APIPA (Automatic Private IP Addressing) is a fallback feature where devices automatically self-assign an IP address in the 169.254.0.0/16 range if they cannot reach a DHCP server. These addresses are 'Link-Local,' meaning devices can communicate with other devices on the exact same local physical segment, but they cannot be routed to the internet.
How does changing the CIDR prefix affect my network size?
Decreasing the CIDR prefix (e.g., from /24 to /23) borrows bits from the network portion and gives them to the host portion, effectively doubling the number of available IP addresses. Conversely, increasing the prefix (e.g., from /24 to /25) cuts the available host addresses in half, allowing you to create smaller, more isolated network segments.
What is a loopback address?
A loopback address (typically 127.0.0.1 in IPv4) is a special reserved IP address used to test network software on the local machine without actually sending data out to the physical network card. Any data sent to a loopback address is instantly routed back to the host device.