What is IPv4 Subnet & CIDR Calculator?
IPv4 Subnet & CIDR Calculator is a networking utility for system administrators, network engineers, and DevOps professionals. IP sub-netting divides IP networks into smaller subnet ranges for efficient routing and security isolation. The calculator parses IP addresses and CIDR notation (e.g., 192.168.1.0/24), instantly displaying network address, broadcast address, subnet mask, wildcard mask, usable host IP ranges, and total host capacity.
How to use IPv4 Subnet & CIDR Calculator
Enter an IPv4 address and select a CIDR prefix (/8 to /32) or subnet mask (e.g. 255.255.255.0). The calculation output updates automatically, displaying Network IP, First Usable Host, Last Usable Host, Broadcast IP, Wildcard Mask, and Binary Bit Representation.
Key features
- Calculates Network Address, Broadcast Address, Host Range, and IP Counts
- Supports CIDR notation (/8 to /32) and dotted decimal subnet masks
- Displays binary bitwise representations of IP addresses and netmasks
- Classful IP network classification (Class A, B, C)
- 100% private browser client-side execution
Common use cases
- Designing Virtual Private Cloud (VPC) subnets in AWS, Google Cloud, or Azure
- Configuring network router subnets, VLANs, and firewall rules
- Studying network engineering principles and CCNA certifications
Technical details & standards
The calculator executes 32-bit integer bitwise bit-shift operations on IPv4 addresses client-side. All calculations run 100% client-side in your browser.
Frequently asked questions
How many usable hosts are in a /24 subnet?
A /24 subnet contains 256 total IP addresses, minus 2 reserved addresses (network and broadcast), leaving 254 usable host IPs.
Is my data safe?
All processing happens entirely in your browser. Your data never leaves your device and is never sent to or stored on a server.
Does it work offline?
Yes. Once the page has loaded, most tools keep working without an internet connection.