Utilities

IP Address Calculator

Calculate subnet masks, CIDR notation, and IP ranges

CIDR Notation

Advanced: separate IP & CIDR

IPv4 Address

CIDR Prefix

IPv6 Tool

About

Calculates IPv4 subnet details from a CIDR notation or IP/mask input, showing network address, broadcast address, usable host range, and total host count. Detects address class (A/B/C) and type (private, public, loopback, etc.), displays a binary view of the address and mask, and supports subnetting/supernetting calculations. Also handles IPv6 expand and compress formatting.

Network engineers constantly need to compute subnet boundaries, host ranges, and addressing details, but doing binary math by hand is slow and error-prone. This tool automates subnet calculations with clear visual output and also handles IPv6 address formatting.

Who should use this tool?

Network administrators planning IP allocations, DevOps engineers configuring VPC subnets, and students learning subnetting concepts.

Common use cases

Calculate the usable host range for a /24 subnet when assigning static IPs in an office network
Determine if two IP addresses are in the same subnet by checking network addresses
Subnet a /22 into smaller /26 subnets for a multi-tier application deployment
Expand a compressed IPv6 address like ::1 to its full notation for configuration files
Check if an IP is private or public when troubleshooting routing issues

How to Use

Enter an IPv4 address with CIDR notation (e.g., 192.168.1.0/24) or a subnet mask (e.g., 255.255.255.0)

View the calculated network address, broadcast address, and usable host range

Check the class/type detection to see if the address is private, public, loopback, or reserved

Toggle the binary view to see the address and mask in binary format for learning or debugging

Use the subnet calculator to divide a network into smaller subnets (subnetting)

Switch to IPv6 mode to expand (::1 → 0000:0000:0000:0000:0000:0000:0000:0001) or compress an IPv6 address

Examples

Input: '192.168.1.0/24'. Output: Network: 192.168.1.0, Broadcast: 192.168.1.255, Usable: 192.168.1.1-192.168.1.254 (254 hosts), Class C, Private.

Input: '10.0.0.0/8' subnet to /16. Output: 256 subnets, each with 65,534 usable hosts, network and broadcast listed per subnet.

Best Practices

Use CIDR notation for consistency; avoid classful addressing for modern network planning
Always subtract 2 from the total host count for network and broadcast addresses
Use the binary view to verify subnet boundaries when troubleshooting connectivity issues
For IPv6, always expand addresses before copying into config files to avoid typos

Common Mistakes

Forgetting to exclude the network and broadcast addresses from assignable host pools
Using /31 or /32 subnets without knowing they have 0 usable hosts for standard addressing
Confusing CIDR prefix length with subnet mask octets (e.g., /24 ≠ 255.0.0.0)
Not accounting for reserved addresses in cloud VPCs (AWS/GCP reserve 3-5 IPs per subnet)

FAQ

Does this work for IPv6 subnets? The calculator handles IPv6 expand/compress; full subnet calculation is IPv4.

What is the difference between subnetting and supernetting? Subnetting splits a network into smaller ones; supernetting combines multiple networks into a larger one.

How does class/type detection work? It identifies Class A (1-126), B (128-191), C (192-223) and special ranges like private (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16).

Can I calculate the subnet for a host IP without CIDR? Enter the IP and mask separately, e.g., 192.168.1.50 with mask 255.255.255.0.

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Learning Resources

Dive deeper with our comprehensive guides and tutorials.

IP Address Calculator - Beginner's Guide

5 min read

IP Address Calculator Advanced Techniques

8 min read

About

Who should use this tool?

Network administrators planning IP allocations, DevOps engineers configuring VPC subnets, and students learning subnetting concepts.

Common use cases

Calculate the usable host range for a /24 subnet when assigning static IPs in an office network
Determine if two IP addresses are in the same subnet by checking network addresses
Subnet a /22 into smaller /26 subnets for a multi-tier application deployment
Expand a compressed IPv6 address like ::1 to its full notation for configuration files
Check if an IP is private or public when troubleshooting routing issues

How to Use

Enter an IPv4 address with CIDR notation (e.g., 192.168.1.0/24) or a subnet mask (e.g., 255.255.255.0)

View the calculated network address, broadcast address, and usable host range

Check the class/type detection to see if the address is private, public, loopback, or reserved

Toggle the binary view to see the address and mask in binary format for learning or debugging

Use the subnet calculator to divide a network into smaller subnets (subnetting)

Switch to IPv6 mode to expand (::1 → 0000:0000:0000:0000:0000:0000:0000:0001) or compress an IPv6 address

Best Practices

Use CIDR notation for consistency; avoid classful addressing for modern network planning

Always subtract 2 from the total host count for network and broadcast addresses

Use the binary view to verify subnet boundaries when troubleshooting connectivity issues

For IPv6, always expand addresses before copying into config files to avoid typos

Common Mistakes

Forgetting to exclude the network and broadcast addresses from assignable host pools

Using /31 or /32 subnets without knowing they have 0 usable hosts for standard addressing

Confusing CIDR prefix length with subnet mask octets (e.g., /24 ≠ 255.0.0.0)

Not accounting for reserved addresses in cloud VPCs (AWS/GCP reserve 3-5 IPs per subnet)

FAQ

Does this work for IPv6 subnets? The calculator handles IPv6 expand/compress; full subnet calculation is IPv4.

What is the difference between subnetting and supernetting? Subnetting splits a network into smaller ones; supernetting combines multiple networks into a larger one.

How does class/type detection work? It identifies Class A (1-126), B (128-191), C (192-223) and special ranges like private (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16).

Can I calculate the subnet for a host IP without CIDR? Enter the IP and mask separately, e.g., 192.168.1.50 with mask 255.255.255.0.

IP Address Calculator

About

Who should use this tool?

Common use cases

How to Use

Examples

Best Practices

Common Mistakes

FAQ

Related Tools

Same Category — Utilities

Word Counter

Regex Tester

Markdown Preview

JSON Path Finder

Popular Tools

JSON Formatter

Base64 Encoder/Decoder

JWT Decoder

Learning Resources

Share

IP Address Calculator

About

Who should use this tool?

Common use cases

How to Use

Examples

Best Practices

Common Mistakes

FAQ

Related Tools

Same Category — Utilities

Word Counter

Regex Tester

Markdown Preview

JSON Path Finder

Popular Tools

JSON Formatter

Base64 Encoder/Decoder

JWT Decoder

Learning Resources

Share