🌐 IP Subnet Calculator
Calculate network address, broadcast, usable hosts, and wildcard mask instantly. Features binary visualization and CIDR slider.
📡 IP Address Details
Enter IPv4 address (e.g., 192.168.1.1)
Number of network bits (1-32)
CIDR: Classless Inter-Domain Routing
Usable Hosts: 2^(32-CIDR) - 2
Network Bits: CIDR | Host Bits: 32-CIDR
📚 What is a Subnet Calculator?
A Subnet Calculator is an essential tool for network engineers and IT professionals. It allows you to divide a single IP network into smaller, manageable subnetworks (subnets). This improves network performance, security, and efficient IP address management.
🔢 Understanding CIDR
Classless Inter-Domain Routing (CIDR) is a method for allocating IP addresses and IP routing. The CIDR notation (e.g., /24) tells you how many bits are used for the Network ID.
Example: /24 means 24 bits are network, 8 bits are host. Total hosts = 2^8 - 2 = 254.
📊 IP Address Classes
- Class A: 1.0.0.0 to 126.255.255.255 (Large networks, /8 default)
- Class B: 128.0.0.0 to 191.255.255.255 (Medium networks, /16 default)
- Class C: 192.0.0.0 to 223.255.255.255 (Small networks, /24 default)
- Class D: 224.0.0.0 to 239.255.255.255 (Multicast)
- Class E: 240.0.0.0 to 255.255.255.255 (Experimental)
❓ Frequently Asked Questions
How many hosts are in a /24 network?
A /24 network has 2^8 = 256 total addresses. Subtracting Network and Broadcast addresses leaves 254 usable hosts.
What is a Wildcard Mask?
A wildcard mask is the inverse of a subnet mask. It tells a router which parts of an IP address must match. Example: Mask 255.255.255.0 = Wildcard 0.0.0.255. Used in access control lists (ACLs).
What is the difference between network address and broadcast address?
Network address is the first IP in a subnet, used to identify the network itself. Broadcast address is the last IP, used to send data to all devices in the network. Neither can be assigned to hosts.
What subnet mask should I use for 100 hosts?
For 100 usable hosts, you need at least 128 addresses (2^7). A /25 subnet (255.255.255.128) provides 126 usable hosts, which is sufficient for 100 hosts.
⚠️ Disclaimer: This calculator follows standard IPv4 subnetting rules. For IPv6 subnetting, use dedicated IPv6 calculators. Always verify with network equipment configuration.