This calculator returns a variety of information regarding Internet Protocol version 4 (IPv4) and IPv6 subnets including possible network addresses, usable host ranges, subnet mask, and IP class, among others.
Our professional IP Subnet Calculator is an essential tool for network administrators, IT professionals, and cybersecurity experts working with Internet Protocol networks. Calculate complete subnet information for both IPv4 and IPv6 addresses, including network addresses, usable host ranges, CIDR notation, subnet masks, and IP class details with enterprise-grade accuracy.
Whether you're designing corporate networks, troubleshooting connectivity issues, preparing for certification exams, or optimizing IP address allocation, our calculator provides comprehensive subnet analysis that saves time and eliminates manual calculation errors. Perfect for network engineers, system administrators, and IT students mastering IP networking fundamentals.
Complete calculations for both IPv4 (32-bit) and IPv6 (128-bit) addressing schemes.
Get network address, broadcast address, usable hosts, wildcard mask, and CIDR notation.
Real-time results with detailed breakdowns for efficient network planning and troubleshooting.
Enterprise-level accuracy trusted by network engineers and IT professionals worldwide.
Input your IPv4 or IPv6 address (e.g., 192.168.1.1 or 2001:db8::1).
Enter subnet mask (255.255.255.0) or CIDR notation (/24) for IPv4, prefix for IPv6.
Get instant comprehensive subnet information and network characteristics.
Review network range, usable hosts, broadcast address, and subnet properties.
| Class | Range | Default Mask | Purpose | Networks/Hosts |
|---|---|---|---|---|
| A | 1.0.0.0 - 126.255.255.255 | 255.0.0.0 | Large Networks | 126 / 16M hosts |
| B | 128.0.0.0 - 191.255.255.255 | 255.255.0.0 | Medium Networks | 16K / 65K hosts |
| C | 192.0.0.0 - 223.255.255.255 | 255.255.255.0 | Small Networks | 2M / 254 hosts |
| D | 224.0.0.0 - 239.255.255.255 | N/A | Multicast | Multicast Groups |
| E | 240.0.0.0 - 255.255.255.255 | N/A | Experimental | Reserved |
255.255.255.0
254 Hosts
255.255.0.0
65,534 Hosts
255.0.0.0
16M Hosts
255.255.255.252
2 Hosts
IPv4 uses 32-bit addresses with subnet masks (like 255.255.255.0) or CIDR notation (/24), while IPv6 uses 128-bit addresses with prefix lengths (like /64). IPv4 subnetting is primarily concerned with address conservation, while IPv6 subnetting focuses on hierarchical network design with abundant address space. Our calculator handles both protocols with appropriate calculations for each.
For IPv4: Usable hosts = 2^(32-CIDR) - 2. The subtraction accounts for the network address and broadcast address. For example, a /24 subnet has 2^(32-24) - 2 = 256 - 2 = 254 usable hosts. For IPv6, the calculation is similar but typically doesn't subtract broadcast addresses. Our calculator automatically performs these calculations and displays usable host ranges.
CIDR (Classless Inter-Domain Routing) notation represents subnet masks as a slash followed by the number of network bits (e.g., /24). It replaced the classful network system, allowing for more flexible and efficient IP address allocation. CIDR enables Variable Length Subnet Masking (VLSM) and route aggregation, which are essential for modern internet routing efficiency.
Use IPv6 for new network deployments, IoT devices, mobile networks, and when IPv4 addresses are unavailable. IPv6 offers vastly larger address space (340 undecillion addresses), built-in security features, simplified network configuration, and better support for modern networking needs. However, IPv4 is still widely used and necessary for compatibility with existing infrastructure.
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