# CIDR Calculator Calculate network information from CIDR notation. Supports IPv4 and IPv6. > Canonical page: https://elysiatools.com/en/tools/cidr-calculator - **Category:** Network - **Keywords:** cidr, calculator, network, subnet, ipv4, ipv6, netmask, broadcast ## Overview The CIDR Calculator is a precise network utility designed to instantly derive essential subnet information from IPv4 and IPv6 CIDR notation. By entering your network address and prefix length, you can quickly determine the netmask, broadcast address, host range, and total number of available IP addresses. ## Inputs - **CIDR Notation** (text): Enter CIDR notation: IPv4: 192.168.1.0/24 IPv6: 2001:db8::/32 ## When to use - When planning network architecture and defining subnet boundaries for your infrastructure. - When troubleshooting connectivity issues to verify if an IP address falls within a specific range. - When configuring firewall rules or access control lists that require precise network masks. ## How it works - Enter your network address in CIDR format (e.g., 192.168.1.0/24 or 2001:db8::/32) into the input field. - The tool automatically parses the prefix length to calculate the corresponding subnet mask. - The system generates a detailed breakdown including the network address, first and last usable host IPs, and the total host count. - Review the calculated output to verify your network configuration parameters. ## Use cases - Network administrators designing segmented VLANs for enterprise environments. - Security engineers defining precise IP ranges for firewall and security group policies. - Developers verifying IP address allocation within cloud-based virtual private clouds. ## Frequently asked questions ### Does this tool support both IPv4 and IPv6? Yes, the CIDR Calculator fully supports both IPv4 and IPv6 address formats. ### What information does the calculator provide? It provides the netmask, network address, broadcast address, and the range of usable host IP addresses. ### Is the subnet mask calculation accurate for all prefix lengths? Yes, the tool calculates the subnet mask based on standard CIDR bit-length rules for any valid prefix. ### Can I use this for large network blocks? Yes, the tool handles any valid CIDR notation, from small subnets to large network blocks. ### Do I need to install any software to use this? No, this is a web-based utility that runs directly in your browser without requiring any installations. ## Related tools - [IPv4 to IPv6](https://elysiatools.com/en/tools/ipv4-to-ipv6): Convert IPv4 addresses to IPv6 addresses. Supports IPv4-mapped and IPv4-compatible formats. - [NB-IoT LTE-M Cat-M1 CoAP LwM2M Cellular IoT Packet Analyzer](https://elysiatools.com/en/tools/nb-iot-lte-m-cat-m1-coap-lwm2m-cellular-iot-packet-analyzer): Decode hex captures from cellular IoT devices: CoAP headers/options (block-wise, Observe), LwM2M TLV object trees with registry names, SMS-DELIVER UDH port addressing unwrapping CoAP-over-SMS, link-format registrations and DTLS record summaries. - [Integer to IPv4](https://elysiatools.com/en/tools/integer-to-ipv4): Convert integers to IPv4 addresses. Supports batch conversion of multiple integers. - [Integer to IPv6](https://elysiatools.com/en/tools/integer-to-ipv6): Convert integers (128-bit) to IPv6 addresses. Supports batch conversion. - [IPv4 to Integer](https://elysiatools.com/en/tools/ipv4-to-integer): Convert IPv4 addresses to integers. Supports batch conversion of multiple addresses. - [IPv6 to Integer](https://elysiatools.com/en/tools/ipv6-to-integer): Convert IPv6 addresses to integers (128-bit). Supports batch conversion. - [IP Info](https://elysiatools.com/en/tools/ip-info): Get real information about IP addresses including location and ISP details using geolocation database - [WHOIS Lookup](https://elysiatools.com/en/tools/whois-lookup): Query WHOIS domain registration information including registrar, dates, and name servers ## Samples - [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion - [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion - [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion - [Web Image Processing Rust Samples](https://elysiatools.com/en/samples/web-image-processing-rust): Web Rust image processing examples including image read/save, scaling, and format conversion ## Related content - [Network Triage, Packet Inspection, and Endpoint Debugging](https://elysiatools.com/en/hubs/network-triage-debugging): Inspect captures, replay webhooks, validate addresses and CIDR ranges, check DNS, WHOIS, hosts files, TLS, and user agents, then record a focused network diagnosis. - [Network Address Conversion and Evidence Preparation](https://elysiatools.com/en/hubs/network-convert): Validate addresses, convert IPv4 and IPv6 formats, normalize URL and webhook inputs, and package DNS, hosts, port, WHOIS, and packet evidence for review.