🔢 Free IPv4/IPv6 Subnet Calculator Tool

A subnet calculator is a free online tool that helps network administrators and IT professionals determine key network parameters like network address, broadcast address, subnet mask, and the number of usable hosts for both IPv4 and IPv6 networks.

It's essential for efficient network planning, VLSM (Variable Length Subnet Masking), CIDR notation, and optimizing IP address allocation in enterprise or home networks. For example, it can help divide a /16 network into smaller /24 subnets. Try our free IPv4 subnet calculator above to see it in action! 🔢

CIDR (Classless Inter-Domain Routing) notation uses a forward slash followed by a number (e.g., 192.168.1.0/24) to indicate the network prefix length. This defines how many bits are used for the network portion versus hosts.

• /24 = Subnet mask 255.255.255.0 (254 usable hosts)
• /16 = Subnet mask 255.255.0.0 (65,534 usable hosts)
• /8 = Subnet mask 255.0.0.0 (16,777,214 usable hosts)

Enter your IP and CIDR in our tool for instant calculations. It's perfect for free online subnetting practice! 📊

IPv4 subnetting uses 32-bit addresses with dotted-decimal subnet masks (e.g., 255.255.255.0), while IPv6 uses 128-bit hexadecimal addresses with prefix lengths only (e.g., /64). IPv6 offers enormous address space, making subnetting simpler and more scalable.

For instance, an IPv6 /64 prefix provides over 18 quintillion host addresses per subnet, compared to IPv4's limited options. Our IPv6 subnet calculator handles both – test it now for accurate results! 🌐

For IPv4 subnetting:

• Number of subnets = 2^(number of borrowed bits from host portion)
• Number of usable hosts per subnet = 2^(remaining host bits) - 2 (subtracting network and broadcast addresses)

Example: Borrowing 3 bits from a /24 network gives 8 subnets with 30 hosts each. Our free subnet calculator automates this – no math required! Check out our Port Checker for more network tools. 📡

Absolutely! MyIP.casa's subnet calculator is 100% free, accurate for IPv4 and IPv6, and privacy-focused (no data logging). It works offline after loading and requires no registration – ideal for network engineers, students, and developers.

We've tested it against standard tools like Cisco's subnetting charts. Enjoyed it? Share on TikTok or buy us a coffee below! ☕

Subnetting divides a larger network into smaller, more efficient subnetworks to improve security, reduce broadcast traffic, and optimize IP address usage. It's crucial for routers, firewalls, and cloud setups like AWS or Azure.

For example, subnetting a Class C network (/24) into /27 subnets creates 8 smaller networks with 30 hosts each. Use our tool to plan yours! 🛡️

IPv6 subnetting focuses on prefix lengths (e.g., /48 to /64). Start with your global prefix and allocate bits for subnets. Common practice: Use /64 for LANs and /56 for sites.

Example: From 2001:db8::/48, you can create 256 /56 subnets. Our IPv6 subnet tool calculates this instantly – privacy-protected! 🔒

Common errors include forgetting the -2 for hosts (network/broadcast), miscalculating borrowed bits, or ignoring IPv6 nibble boundaries. Always double-check with a reliable tool.

Tip: Start with small subnets and scale up. Our calculator prevents these mistakes – try it for free! ⚠️