CIDR Calculator
Convert between CIDR notation and IP ranges, calculate subnet information
Convert CIDR to IP Range
Enter a valid IPv4 address (e.g., 192.168.1.0)
Number of network bits (0-32)
CIDR Analysis Results
Network Information
Common CIDR Examples
Class A private network
Class B private network
Class C private network
Typical home network
Small subnet
Point-to-point link
Subnet Mask Reference
CIDR Tips
CIDR /24 = 254 usable host addresses
Each CIDR bit doubles or halves the network size
First and last IPs are reserved (network/broadcast)
Private IP ranges: 10.x.x.x, 172.16-31.x.x, 192.168.x.x
Understanding CIDR Notation
What is CIDR?
CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and routing Internet Protocol packets. It replaced the older classful addressing system and allows for more efficient use of IP address space.
CIDR Notation Format
- •IP Address: The network or host address
- •Slash (/): Separates IP from prefix length
- •Prefix Length: Number of network bits (0-32)
How Subnetting Works
Step 1: Subnet Mask
Convert CIDR prefix to binary subnet mask
Step 2: Network Address
Apply mask to find network portion
Step 3: Host Range
Calculate available host addresses
Key Concepts
Network Address
First address in subnet, identifies the network
Broadcast Address
Last address in subnet, used for broadcast traffic
Host Addresses
Addresses between network and broadcast for devices