CIDR Calculator
Calculate IP ranges from CIDR notation
CIDR Notation
Enter CIDR (e.g., 192.168.1.0/24)
Calculate subnet details from CIDR notation. Enter a CIDR block (e.g., 10.0.0.0/24) and get the network address, broadcast address, usable host range, total IP count, and subnet mask. Essential for network planning, cloud VPC design, and firewall rule configuration.
Key Features
- ✓CIDR to subnet mask conversion
- ✓Network and broadcast address calculation
- ✓Usable host range and count
- ✓Wildcard mask calculation
- ✓Supernet and subnet aggregation
- ✓IPv4 and IPv6 CIDR support
How to CIDR Calculator
- 1
Enter CIDR notation
Type a CIDR block like 10.0.0.0/24.
- 2
View subnet details
See network address, broadcast, host range, and IP count.
- 3
Plan your network
Use the results for VPC design, firewall rules, or ACLs.
Common Use Cases
- •Planning AWS VPC and Azure VNet subnets
- •Calculating firewall rule IP ranges from CIDR blocks
- •Designing office and data center IP addressing schemes
- •Converting between CIDR notation and subnet masks
Frequently Asked Questions
What does /24 mean in CIDR?▼
The number after the slash indicates how many bits are used for the network portion. /24 means the first 24 bits are the network, leaving 8 bits for hosts — giving 256 IPs (254 usable) with a 255.255.255.0 subnet mask.
How many IPs are in a /16?▼
A /16 contains 65,536 IP addresses (2^16 = 65,536). After subtracting network and broadcast, 65,534 are usable for hosts.