Free Online CIDR Calculator | SkyConverterTools
Updated on: 31 Oct 2025 | By: SKY Team
Calculate network details, subnet masks, and usable IP ranges with the SkyConverterTools CIDR Calculator! Quickly analyze any CIDR notation to get comprehensive network information including subnet masks, network addresses, broadcast addresses, and usable IP ranges. Perfect for network administrators, developers, IT professionals, and anyone working with IP networking and subnetting.
1. What is CIDR Notation?
CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and IP routing that replaces the previous system based on Class A, Class B and Class C networks. CIDR notation is a compact representation of an IP address and its associated network mask, written as the IP address, a slash ('/'), and a decimal number representing the number of leading 1 bits in the network mask.
- Calculate subnet masks and network addresses
- Determine usable IP address ranges
- Analyze network and broadcast addresses
- Support for both IPv4 and CIDR notation
- 100% browser-based - no server processing required
2. Key Features of SkyConverterTools CIDR Calculator
- Comprehensive Network Analysis: Get complete network details from any CIDR notation.
- Subnet Mask Calculation: Automatically calculate subnet masks in dotted decimal format.
- IP Range Generation: Generate lists of usable IP addresses within the network.
- Network/Broadcast Addresses: Identify network and broadcast addresses automatically.
- Usable Host Count: Calculate the exact number of available host addresses.
- Export Capabilities: Copy IP lists to clipboard or download as CSV files.
- Sample Data: Test with common CIDR notations using sample data.
3. How to Use the CIDR Calculator
- Visit SkyConverterTools CIDR Calculator.
- Enter CIDR: Type a CIDR notation in the input field (e.g., 192.168.1.0/24).
- Set IP Count: Specify how many usable IP addresses you want to display.
- Calculate: Click the "Calculate" button to see network details and IP addresses.
- Copy Results: Use the "Copy All" button to copy all IP addresses to your clipboard.
- Download: Use the "Download CSV" button to save the IP list as a CSV file.
- Quick Actions: Use the sample data to test the tool or clear inputs with a single click.
4. Common CIDR Notations & Examples
| CIDR Notation | Subnet Mask | Usable Hosts | Common Use |
|---|---|---|---|
| 192.168.1.0/24 | 255.255.255.0 | 254 | Small LAN |
| 10.0.0.0/8 | 255.0.0.0 | 16,777,214 | Large private network |
| 172.16.0.0/12 | 255.240.0.0 | 1,048,574 | Medium private network |
| 192.168.0.0/16 | 255.255.0.0 | 65,534 | Medium LAN |
| 192.168.1.0/26 | 255.255.255.192 | 62 | Small subnet |
| 192.168.1.0/30 | 255.255.255.252 | 2 | Point-to-point links |
5. Network Information Provided
- Network Address: The base address of the network
- Broadcast Address: The address used for broadcasting to all hosts
- Subnet Mask: The network mask in dotted decimal format
- Wildcard Mask: The inverse of the subnet mask
- Total Hosts: Total number of addresses in the network
- Usable Hosts: Number of addresses available for devices
- First Usable IP: The first available host address
- Last Usable IP: The last available host address
6. Advanced Features
- IP Address Validation: Automatic validation of CIDR notation format
- Range Limiting: Control how many IP addresses are displayed in the list
- Clipboard Integration: Easy copying of IP address lists
- CSV Export: Download IP lists for use in spreadsheets or documentation
- Sample Networks: Pre-loaded common CIDR notations for testing
- Real-time Calculation: Instant results without page refresh
- Mobile Friendly: Works perfectly on all devices and screen sizes
7. Why Use SkyConverterTools CIDR Calculator?
- 100% Client-Side: All calculations happen in your browser for maximum privacy
- No Registration: Use immediately without creating an account
- Accurate Results: Precise network calculations using standard algorithms
- Professional Grade: Suitable for enterprise network planning
- Educational Value: Great for learning about networking and subnetting
- Free Forever: No hidden costs or limitations
8. Common Use Cases
- Network Planning: Design and plan IP address allocations for networks
- Subnetting Practice: Learn and practice subnetting concepts
- Troubleshooting: Verify network configurations and address ranges
- Documentation: Generate IP address lists for network documentation
- Cloud Infrastructure: Plan VPC and subnet configurations for cloud services
- Security Planning: Define firewall rules and security group configurations
9. Frequently Asked Questions (FAQs)
Q1: What is CIDR notation used for?
CIDR notation is used to represent IP address blocks and their associated network masks in a compact format, essential for efficient IP address allocation and routing.
Q2: How do I calculate the number of usable hosts?
The number of usable hosts is 2^(32 - n) - 2, where n is the number after the slash in CIDR notation. The calculator automatically computes this for you.
Q3: What's the difference between network address and broadcast address?
The network address identifies the network itself, while the broadcast address is used to send data to all hosts on the network. Neither can be assigned to individual devices.
Q4: Can I use this for IPv6 addresses?
Currently, the calculator supports IPv4 CIDR notation. IPv6 support may be added in future updates.
Q5: Why are two addresses subtracted for usable hosts?
Two addresses are reserved in each subnet: the network address (first address) and the broadcast address (last address), leaving the remaining addresses for actual devices.
Q6: Is there a limit to the number of IPs I can display?
For performance reasons, the tool may limit the number of IP addresses displayed in the list, but you can adjust this in the IP count setting.
10. Technical Details
Our CIDR Calculator uses JavaScript to perform all calculations client-side, including:
- Bitwise Operations: For subnet mask and network address calculations
- IP Address Parsing: To validate and process CIDR notation
- Range Generation: To create lists of usable IP addresses
- Export Functions: For clipboard and CSV file operations
- Input Validation: To ensure correct CIDR notation format
11. CIDR Notation Examples
Here are some common CIDR notations and their meanings:
- 192.168.1.0/24: 256 total addresses, 254 usable hosts, subnet mask 255.255.255.0
- 10.0.0.0/8: 16,777,216 total addresses, 16,777,214 usable hosts, subnet mask 255.0.0.0
- 172.16.0.0/12: 1,048,576 total addresses, 1,048,574 usable hosts, subnet mask 255.240.0.0
- 192.168.0.0/16: 65,536 total addresses, 65,534 usable hosts, subnet mask 255.255.0.0
- 192.168.1.0/26: 64 total addresses, 62 usable hosts, subnet mask 255.255.255.192
12. Why Choose SkyConverterTools?
SkyConverterTools offers a suite of secure, free, and efficient utilities for technical professionals and enthusiasts. From network calculations to file conversion and development tools, every utility is crafted for accuracy and ease of use.
- Browser-based processing for maximum privacy and performance
- Professional-grade calculation algorithms
- User-friendly interface with comprehensive results
- Trusted as part of the Sky Infinite Tools ecosystem
Try it now: https://skyconvertertools.com/cidr-calculator
13. Final Thoughts
The CIDR Calculator from SkyConverterTools provides professional network analysis capabilities with complete privacy and convenience. Whether you're planning enterprise networks, studying for certifications, or troubleshooting network configurations, our tool offers the precision and features needed for effective IP address management and subnetting.
Calculate. Plan. Optimize — with SkyConverterTools.
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