If you need to divide this network into smaller subnets:
| Subnets | CIDR | Subnet Mask | Hosts per Subnet |
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Use our free subnet calculator to instantly calculate network addresses, broadcast addresses, subnet masks, and usable host ranges for any IPv4 network. This essential networking tool helps NOC technicians, network engineers, and system administrators plan IP addressing schemes, troubleshoot routing issues, and design efficient network topologies. Calculate CIDR notation, determine available host counts, and visualize binary representations of IP addresses and subnet masks—all processed instantly in your browser with complete privacy.
A subnet calculator is a tool that performs CIDR (Classless Inter-Domain Routing) calculations to determine network parameters from an IP address and subnet mask.
Network engineers use subnet calculators daily when planning network architectures, configuring routers and firewalls, troubleshooting connectivity issues, and documenting network infrastructure. Manual subnet calculations are error-prone and time-consuming—a calculator provides instant, accurate results and helps visualize how IP addressing works at the binary level.
Enter an IP and CIDR prefix (e.g., 192.168.1.0/24) to get the network address, broadcast address, usable host range, subnet mask, and total/usable host count — all computed instantly, no lookup tables needed.
A /24 subnet has 256 total addresses (254 usable hosts) with mask 255.255.255.0. A /25 subnet has 128 total addresses (126 usable hosts) with mask 255.255.255.128. The /25 divides a /24 network in half. Each increase in prefix length cuts the network size in half.
If you have a /22 network and need /24 subnets, you gain 2 subnet bits (24 - 22 = 2). With 2 bits, you can create 2^2 = 4 subnets. Each additional bit doubles the number of subnets: 1 bit = 2 subnets, 2 bits = 4 subnets, 3 bits = 8 subnets, etc.
Generally no—the network address (first IP) and broadcast address (last IP) are reserved and cannot be assigned to hosts. The exception is /31 subnets used for point-to-point links between routers, where RFC 3021 allows using both addresses.
A /32 subnet represents a single IP address with mask 255.255.255.255. All 32 bits are network bits, leaving zero host bits. This is used in routing tables to specify exact host routes or in firewall rules to match a specific IP address.
If you calculate a subnet for IP 192.168.1.50/24, the network address is 192.168.1.0, not 192.168.1.50. Your input IP might be a host address within the subnet. The calculator determines the actual network address by applying the subnet mask. Make sure you understand which address you're starting with—network address or host address within a network.
To divide a /24 into smaller subnets, increase the prefix length. For 4 equal subnets, use /26 (adds 2 bits: 2^2 = 4). For 8 subnets, use /27 (adds 3 bits: 2^3 = 8). Each subnet will have fewer host addresses. A /24 split into four /26 subnets gives you 62 usable hosts per subnet instead of 254 in the original /24.