IPv4 / IPv6 CIDR Address Calculator
Calculate the range of IP addresses based on an IPv4 or IPv6 CIDR address
Enter a CIDR address and click the calculate button
Features
Supports both IPv4 and IPv6
Auto-detects the input format and calculates CIDR for both standards
Calculates the address range at once
Covers everything from the network address to the total number of addresses
Shows various masks and abbreviated forms
Supports subnet and wildcard masks and IPv6 abbreviated forms
Instant calculation with sample input
Just click a representative CIDR to show the result
How to Use
Enter a CIDR address
Enter CIDR notation like 192.168.1.0/24, or a single IP address, in the input field
Select the prefix length
When entering a single IP, choose from /0 to /128. If unselected, /32 is applied for IPv4 and /128 for IPv6
Press the run button to calculate
Press the run button, or the Enter key, to start calculating the address range
Check and copy the calculation result
Check the network address, number of usable addresses, and more in a list, and copy the values you need
Use Cases
Considering network design
Quickly grasp the address range and capacity of each segment when splitting subnets
IP design when building servers
Check in advance the range of a CIDR you specify when creating a cloud VPC or subnet
Firewall configuration
Verify in advance whether a CIDR written in allow/deny rules points to the intended IP range
Network study and exam prep
Use it to check answers to subnet calculation practice problems or confirm your understanding before a certification exam
Safety and Privacy
Runs entirely in your browser
Your input data is processed only within your browser and is never sent externally.
Processing only in your browser
CIDR calculation is processed entirely within your browser, and input data is not sent to any server.
Communications encrypted with HTTPS
Page loading is also encrypted by TLS, and content cannot be read by third parties.
No transmission to third parties
Input content is not sent to external services such as ad networks or trackers.
No automatic saving of results
calculation results and input suggestions are not stored on the server.
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