What is a subnet calculator and why do I need one?

A subnet calculator is a tool that helps network engineers and developers calculate IP address ranges, CIDR notation, subnet masks, and network boundaries. It's essential for proper network planning, security segmentation, and avoiding IP conflicts in cloud environments like AWS, Azure, and GCP.

How do I calculate CIDR notation manually?

CIDR notation uses a slash followed by a number (like /24) to indicate how many bits are used for the network portion. For example, /24 means the first 24 bits are for the network, leaving 8 bits for hosts (256 total IPs, 254 usable). Our calculator does this instantly with visual representations.

Does this subnet calculator work for AWS VPC planning?

Yes! Our calculator specifically accounts for AWS VPC reserved IP addresses. AWS reserves the first 4 IPs and the last IP in every subnet, so a /24 subnet in AWS only provides 251 usable IPs instead of 254. We show both standard and AWS-specific calculations.

Is my network information secure when using this calculator?

Absolutely! All calculations happen entirely in your browser using JavaScript. No network information is sent to our servers or stored anywhere. Your IP addresses and network details remain completely private and secure.

Free Online Subnet Calculator | IPv4 CIDR & Network Calculator

IPv4 Subnet Calculator

Advanced Features

🔍 Compare Two Subnets

Compare two subnets to see if they overlap, contain each other, or are completely separate.

Subnet 1

Subnet 2

Comparison Results

Subnet 1

192.168.1.0/24

Range: 192.168.1.0 - 192.168.1.255

Subnet 2

192.168.2.0/24

Range: 192.168.2.0 - 192.168.2.255

Separate Subnets

The subnets are completely separate - they do not share any IP addresses.

🚀 More Advanced Features Coming Soon

We're working on additional advanced features including:

VLSM (Variable Length Subnet Masking) Calculator
Subnet Aggregation Tool
IP Address Range Calculator
Network Planning Assistant

Why Our Subnet Calculator CRUSHES The Competition!

CLOUD READY!

BUILT for AWS, Azure, and GCP! Our subnet calculator handles cloud-specific requirements that others COMPLETELY MISS! No more wasted IPs or subnet conflicts!

100% SECURE!

ZERO data leaves your device! Unlike other calculators that send your network details to who-knows-where, we calculate EVERYTHING right in your browser!

DEVELOPER OBSESSED!

Created BY network engineers FOR developers! Get the binary notation, subnet details, and network insights that other calculators DON'T EVEN SHOW YOU!

Why Our Subnet Calculator Will CHANGE YOUR LIFE!

Listen up! A subnet calculator isn't just some "nice-to-have" tool - it's an ABSOLUTE NECESSITY for ANYONE working with networks! Our subnet calculator INSTANTLY gives you EVERYTHING you need to know about your network with just a few clicks!

What Our Subnet Calculator DELIVERS:

Network Address: The FOUNDATION of your subnet (192.168.1.0) - GET THIS WRONG and NOTHING works!
Broadcast Address: The CRITICAL last address (192.168.1.255) that MOST calculators get WRONG!
Valid Host Range: The EXACT IPs you can use - NO MORE GUESSING which addresses are available!
Total Hosts: Know PRECISELY how many devices your network can handle BEFORE you hit capacity!
CIDR Notation: The POWER-USER shorthand (/24) that PROFESSIONAL network engineers use!
Binary Representation: See what's happening UNDER THE HOOD - something other calculators DON'T EVEN OFFER!

And that's not all! Our subnet calculator has SPECIAL FEATURES for AWS, Azure, and GCP that account for those SNEAKY reserved IPs that other calculators COMPLETELY IGNORE!

Why PROPER Subnetting Will SAVE Your Projects

Let me be CRYSTAL CLEAR about this - proper subnet planning is NOT optional if you want:

BULLETPROOF network security through proper segmentation
LIGHTNING-FAST performance by eliminating unnecessary broadcast traffic
MAXIMUM efficiency in IP address usage - no more wasted addresses!
FUTURE-PROOF cloud infrastructure that scales WITHOUT painful redesigns
INSTANT troubleshooting when network issues arise

Whether you're building the next big cloud application, setting up Docker networks, or just trying to make sense of your home lab, our subnet calculator gives you the EXACT information you need to GET IT RIGHT THE FIRST TIME!

Want to become a SUBNETTING MASTER? Check out our COMPREHENSIVE Subnetting Guide for Developers that will take you from CONFUSED to CONFIDENT!

MASTER Our Subnet Calculator in MINUTES!

Listen up! A subnet calculator isn't just another tool - it's the SECRET WEAPON that top network engineers, cloud architects, and developers RELY ON DAILY! I'm about to show you how to LEVERAGE this powerful subnet calculator to TRANSFORM how you plan, design, and manage your networks!

What Makes Our Subnet Calculator a GAME-CHANGER?

Our subnet calculator is the ULTIMATE SOLUTION that INSTANTLY calculates EVERYTHING you need from just an IP address and subnet mask. Here's why it's CRITICAL for your success:

FLAWLESS network planning and segmentation - NO MORE security holes!

PERFECT IP address allocation - NEVER waste valuable addresses again!

CRYSTAL-CLEAR network visualization - SEE exactly how your network is structured!

LIGHTNING-FAST CIDR notation calculations - SAVE HOURS of manual work!

FOUR SIMPLE STEPS to Subnet Mastery!

1. DROP IN Your IP Address

Just type your base IP address (like 192.168.1.0) into the calculator's field - it's THAT simple!

2. SELECT Your Subnet Mask Format

Our subnet calculator gives you MULTIPLE options in the dropdown menu:

Traditional decimal notation (like 255.255.255.0) for CLASSIC networking
Modern CIDR notation (like /24) for POWER USERS!

3. BUILDING for AWS? We've Got You COVERED!

Just check the 'Calculate for AWS Network' box and our subnet calculator will AUTOMATICALLY account for those RESERVED IPs that other calculators MISS!

4. GET INSTANT RESULTS That BLOW AWAY the Competition!

Our subnet calculator IMMEDIATELY shows you EVERYTHING you need:

COMPLETE IP address breakdown (decimal AND binary)
PRECISE netmask calculations that are ALWAYS accurate
EXACT network address that forms your subnet's foundation
CRITICAL broadcast address that other calculators get WRONG
NEXT available subnet block for seamless network expansion
FULL range of usable IP addresses - no more guessing!
FIRST usable IP after the network address - perfect for your gateway!
LAST usable IP before broadcast - ideal for DHCP ranges!

SEE Our Subnet Calculator in ACTION!

Let me show you how our subnet calculator CRUSHES a typical small office network calculation:

IP Address: 192.168.1.0 (standard small network block)
Subnet Mask: 255.255.255.0 (or /24 for the PROS!)

INSTANT Results:

Network Address: 192.168.1.0 - The FOUNDATION of your subnet!
Broadcast Address: 192.168.1.255 - CRITICAL for network-wide messages!
First Usable IP: 192.168.1.1 - PERFECT for your gateway router!
Last Usable IP: 192.168.1.254 - The FINAL address before broadcast!
Total Usable Hosts: 254 - PLENTY for most small networks!

INSIDER SECRETS From Network PROS!

ALWAYS plan for EXPLOSIVE growth! Choose subnet sizes that give you ROOM TO BREATHE - your future self will THANK YOU!
DOCUMENT EVERYTHING! Start with a simple Excel sheet to track your subnet assignments, then LEVEL UP to a professional IPAM system when you're ready to DOMINATE!
NEVER TRUST just one calculation for production networks! VERIFY your subnet calculator results with peers - a second set of eyes can SAVE YOU from network DISASTERS!

BURNING QUESTIONS About Our Subnet Calculator - ANSWERED!

WHO Can Benefit from Our Subnet Calculator?

EVERYONE in tech needs this! Developers, DevOps engineers, network engineers, IT pros, Cloud Architects, and software engineers - our subnet calculator is the SECRET WEAPON for ANYONE configuring cloud networks or managing IP addresses! If you work with networks, you NEED this tool!

Why Our Subnet Calculator DESTROYS the Competition!

Created by a Network Cloud Engineer with over 15 YEARS of battle-tested experience! While other calculators cut corners, ours is built on ROCK-SOLID networking fundamentals with SPECIAL OPTIMIZATIONS for AWS, Azure, and other cloud providers that the competition COMPLETELY MISSES!

How Does Our POWERFUL Subnet Calculator Work?

It's DEAD SIMPLE! Just input your network address and subnet mask, then our calculator INSTANTLY delivers EVERYTHING you need: usable IP ranges, subnet counts, host counts per subnet, network address, broadcast address, subnet mask, wildcard mask, and IPv4 APR domain - ALL in ONE PLACE!

Can I Use This for Cloud Network Planning?

ABSOLUTELY YES! Our subnet calculator is SPECIFICALLY OPTIMIZED for cloud environments! While the core networking concepts apply everywhere, we've added SPECIAL FEATURES to handle those CRITICAL reserved IPs in AWS, Azure, and GCP that other calculators COMPLETELY IGNORE!

What's the EXACT Formula Behind Our Subnet Calculator?

We use the PRECISE mathematical formula that powers ALL networking: 2^n - 1, where n is the number of bits in the network portion. For example, with 3 network bits, that's 2^3 - 1 = 7, giving you a subnet mask of 255.255.255.248. Our calculator does this INSTANTLY so you don't have to!

Why Do We Show Binary Values When Others Don't?

Because we're SERIOUS about networking! Subnetting is FUNDAMENTALLY binary at its core. By showing you the binary representation, we help you VISUALIZE exactly how networks are divided - something other calculators HIDE from you! This is how REAL network engineers think!

What EXACTLY Is a Subnet Mask?

A subnet mask is a CRITICAL 32-bit number that DIVIDES IP addresses into two essential parts: network and host addresses. The first part identifies WHICH network a device belongs to, while the second part identifies the SPECIFIC device within that network. Get this wrong and NOTHING works!

Why Are Subnets ABSOLUTELY ESSENTIAL?

Subnets aren't optional - they're MANDATORY for modern networks! They deliver SUPERIOR IP allocation by dividing large networks into manageable chunks, DRAMATICALLY improve network performance by reducing broadcast traffic, and provide BULLETPROOF security by containing potential attacks!

Free Online Subnet Calculator - Calculate IP Ranges, CIDR Notation, and Subnet Masks