IP Subnet Calculator: Network, Broadcast & CIDR Tool
Instantly calculate network addresses, broadcast addresses, usable host ranges, and CIDR masks. The tool updates in real-time as you type.
IP subnet calculator FAQ
IP Subnetting is the practice of dividing a single large network into smaller, more efficient sub-networks. This improves network performance and enhances security. A subnet mask dictates the size of these networks. You can use the calculator above as a cheat sheet to quickly find the exact host ranges and binary conversions for any given IP address and CIDR prefix.
What is a subnet mask?
A subnet mask is a 32-bit number that masks an IP address, dividing the IP address into network address and host address. It determines which part of the IP address belongs to the network and which part is available for assigning to devices.
How to find your subnet mask?
On Windows, open Command Prompt and type ipconfig. On Mac, go to System Settings > Network > Advanced > TCP/IP to view your Subnet Mask. You can also use the Use My Public IP button on this page to view your external network details.
How many IPs in a /24 subnet?
A /24 subnet (255.255.255.0) provides a total of 256 IP addresses. However, since the first address is reserved for the Network Address and the last for the Broadcast Address, there are 254 usable host IP addresses available for devices.