IP Subnet Calculator - Find Subnet, CIDR, and IP Ranges

Want to create short URLs? Sign up for free to get started.

About IP Subnet Calculator

Why I built this

I got tired of scribbling subnet math on paper, so this calculator shows the network address, broadcast, usable range, and host count as soon as you enter an IPv4 and pick a mask or CIDR.

How it works

Enter an IPv4 address.
Select the subnet mask or CIDR prefix.
See the network address, broadcast, usable IP range, and host totals right away.

Details it shows

Network & broadcast: The exact boundaries of the subnet.
Usable range: First and last IPs you can assign.
Host count: How many usable addresses you get.
CIDR and mask: Clear view of both notations.

Where it helps

Handy for lab builds, quick audits, cloud VPC planning, or study sessions when you just want to check your work without reaching for a calculator.

For related network tasks, also check IP Range Calculator, IP Address Lookup, and What Is My IP Address.

Related Tools

More tools you may find useful.

Clipboard Test Microphone Tester Live Speech Translator Dead Pixel Test Web Video Player Cm To Feet Converter Feet To Cm Converter Typing Speed Test Age Calculator Business Days Calculator What Is My User Agent? Unix Timestamp Converter HTML to PDF Converter Excel to CSV Converter Weight Converter Area Converter Speed Converter Time Converter Find Image Dimensions Duplicate Image

Recent Blog Posts

How to Track Influencer Marketing With Short Links and QR Codes

Influencer marketing is hard to track when everyone shares the same link. One creator posts on TikTok. Another adds a story link. Someone else hands out promo cards at an event. If they all use the sa...

2 MIN READ

Introducing the T.LY iOS App

T.LY now has a native iOS app for iPhone and iPad. It is built for the work people already do in T.LY: create short links, manage campaign links, check clicks, watch QR scans, and make changes when so...

4 MIN READ

A Free QR Code Scanner & Creator App for iPhone

Most QR scanner apps on the App Store do the same frustrating thing: they take a tool that should be free and wall it off behind ads, sign-up screens, or a “pro” subscription. Want to scan from a phot...

2 MIN READ

T.LY Link Shortener Extension Now Supports Safari

The T.LY Link Shortener Extension now supports Safari. If Safari is your daily browser, you can create a T.LY short link for the page you are already viewing without opening another tab. Click the too...

1 MIN READ

Dashboard and Stats Refresh

T.LY analytics recently got a cleaner dashboard and stats page. This update was not just about making the screens look newer. The goal was to make link performance easier to understand when you have a...

8 MIN READ

IPv4 vs IPv6: What Is the Difference?

IPv4 and IPv6 are two versions of IP addresses. Both help devices communicate across networks. The main difference is address space. IPv4 is older and shorter. IPv6 is newer and supports a much larger...

5 MIN READ

How to Track QR Code Campaigns Before You Print

The best time to set up QR code tracking is before you print. Not after the flyers arrive. Not after the menu is laminated. Not after the conference badges are shipped. Before. Once a QR code is print...

8 MIN READ

How to Choose a Short Branded Domain

A short branded domain is the domain you use for your short links. Instead of sending people through a generic short URL, you use something tied to your brand, campaign, product, or organization. For...

9 MIN READ

What Is an ISP and ASN Lookup?

An IP address can tell you more than the number. With the right lookup, you can often see the internet service provider, organization, usage type, and ASN behind the connection. The T.LY What Is My IP...

4 MIN READ

Why Is My IP Location Wrong?

IP location is useful, but it is not exact. If an IP lookup shows the wrong city, wrong region, or even the wrong country, it does not automatically mean your device is hacked or your internet is brok...

5 MIN READ

How to Check If a VPN or Proxy Is Working

When a VPN or proxy is working, websites should see different network details than they see on your normal connection. The fastest check is still the boring one: compare your public IP before and afte...

4 MIN READ

Free T.LY Campaign QA Tools Worth Bookmarking

Most campaign mistakes are boring. That is what makes them expensive. They are small things that get missed before launch: A QR code points through too many redirects A landing page has the wrong soc...

5 MIN READ