Subnet Calculator
Calculate network details from IP address and CIDR/subnet mask.
Results
About Subnet Calculator
A subnet calculator divides a network into smaller subnetworks (subnets). This helps in efficient IP address allocation, improved network security, and reduced broadcast traffic. Enter any IP address and select a CIDR prefix to calculate network details instantly.
📘 How It Works
IP Address Input
Enter any valid IPv4 address in dotted decimal format (e.g., 192.168.1.100).
CIDR/Subnet Selection
Choose a CIDR prefix length (/0 to /32) or enter a subnet mask. The calculator converts between them.
Network Calculation
Network address is calculated by ANDing the IP with the subnet mask. Broadcast address has all host bits set to 1.
Host Range
First usable host is network address + 1, last usable is broadcast - 1. Total hosts = 2^(32-CIDR) - 2.
💡 Common Use Cases
Network Planning
Design network segments and allocate IP address ranges for different departments or VLANs.
Troubleshooting
Verify if two IP addresses are on the same network segment for connectivity issues.
Firewall Rules
Calculate correct CIDR blocks for firewall ACLs and security group configurations.
Cloud Infrastructure
Plan VPC subnets and peering configurations in AWS, Azure, or GCP.