IP Address & Subnet Calculator
Online tool for IPv4 address subnet calculation, CIDR notation conversion, and network information display.
About IP Address & Subnet Calculator
Calculate IPv4 address subnets, convert CIDR notation, and display network information in one place. Enter an IP address and CIDR prefix length or subnet mask to calculate network address, broadcast address, usable host range, and more. All processing runs in your browser. No data is sent to any server.
Frequently Asked Questions (FAQ)
Q. What is the difference between CIDR notation and subnet mask?
A. CIDR notation (e.g., /24) is a concise notation indicating the number of bits in the network portion. A subnet mask (e.g., 255.255.255.0) represents the same information in dotted decimal notation. They can be converted to each other: /24 = 255.255.255.0.
Q. What are private IP addresses?
A. Private IP addresses are used within local networks and are not directly routed on the internet. Three ranges are reserved: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.