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Subnet Plus: Subnet Calculator

Subnet Plus: Subnet Calculator

Network Toolkit

57 ratings
74 reviews
With Ads
📚 Education
🔧 Utilities
Free
In-App PurchasesWith Ads

Details

Released
October 30, 2013
Updated
October 21, 2026

Features

Developer

Ted Trentler
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Subnet Plus: Subnet Calculator screenshot #1 for iPhone
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Subnet Plus: Subnet Calculator screenshot #5 for iPhone
Subnet Plus: Subnet Calculator screenshot #6 for iPhone
Subnet Plus: Subnet Calculator screenshot #7 for iPhone
Subnet Plus: Subnet Calculator screenshot #8 for iPhone
iphone
ipad
🧾$4.99
In-App Purchase↘︎
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Reviews summary↘︎
⭐74
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📝2+ tags
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🔄6+ apps
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❓5 answered
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📦~ in 3 weeks
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About

Calculate IP subnets with ease on your iPhone or iPad. This tool helps visualize binary and hex information for subnets, aiding in network studies and professional calculations. Save your calculated networks for future reference.

✓Subnet calculation
✓Save calculated networks
✓Binary and hex display
✓Network address ranges
✓Broadcast IP addresses
✓Study aid for networking exams
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What users say about Subnet Plus

Reviews of Subnet Plus are mostly positive: the Utilities app is rated 4.7/5 from 57 App Store ratings. What users like most: convenient and simple interface, practical and useful tool. Top complaints: interface needs work, text in subnet netmask field too large. Summarized from real user reviews.

Positive things

  • 👍Convenient and simple interface
  • 👍Practical and useful tool
  • 👍Saves locations and provides needed information
  • 👍Smart layout
  • 👍Great use of sliding octets for real-time effects
  • 👍Well-designed subnet calculator
  • 👍Binary display is togglable
  • 👍Ability to save and recall subnets
  • 👍Useful and professional conversion tool
  • 👍Robust and complete tool
  • 👍Data is accurate
  • 👍Great helper for math stuff
  • 👍Easy calculator, never disappoints
  • 👍Fully satisfies needs
  • 👍Great for sysadmins
  • 👍Helpful for system administrators
  • 👍Simplified subnetting
  • 👍Unusual and unique calculator with perfect interface
  • 👍Works consistently
  • 👍Good for network administrators
  • 👍Fast, good looking, and powerful
  • 👍Normal subnet calculator
  • 👍Handy calculator
  • 👍Trusted, works correctly
  • 👍Easy app for newbies
  • 👍Accurate data and convenient UI
  • 👍No ads (mentioned by one user)
  • 👍Easy to use and informative
  • 👍Calculation for number of subnets is correct (contradicted by another user)
  • 👍Love the binary display
  • 👍Simple UI, easy to use
  • 👍Awesome, fast, and simple
  • 👍Useful and helpful app, performs well
  • 👍Works as stated
  • 👍Great UI and features
  • 👍Helpful for studying CCNA
  • 👍Good for learners
  • 👍Handy for on-the-fly calculations
  • 👍Invaluable tool for Cisco instructors
  • 👍Love this app, use it all the time
  • 👍Simple, does what it's supposed to
  • 👍Nice, very good app
  • 👍No fuss, just works
  • 👍Educative, good for networking students
  • 👍Brilliant, simple and effective
  • 👍Very helpful for studying Cisco CCNA
  • 👍Clean and easy to read iPad interface
  • 👍Toggleable binary and hex output
  • 👍Extremely useful for on-the-go engineers
  • 👍Very necessary app, convenient and helpful
  • 👍Simple way to calculate networks
  • 👍Works fast and perfectly well
  • 👍Convenient and clear interface, easy to use
  • 👍Real help with work and study
  • 👍Cool, like it
  • 👍Saves calculated networks, helps with study
  • 👍Boyfriend is pleased, helps him a lot
  • 👍Handy tool for learning/studying
  • 👍Nice touch being able to save calculations
  • 👍Just what I've been looking for

Negative things

  • 🐛Interface needs work
  • 🐛Text in subnet netmask field too large
  • 🐛Last octet not visible
  • 🐛No apparent way to enlarge field or change text
  • 🐛No landscape mode for iPad Pro
  • 🐛Calculation for number of subnets is not correct (mentioned by one user)
  • 🐛Values are truncated with no apparent way to view full values
  • 🐛Subnet mask truncated, cannot be read
  • 🐛IP addresses truncated
  • 🐛Cannot read all data
  • 🐛No way to type netmask
  • 🐛Numbers truncated on iPhone 5s
  • 🐛Fields populated by app cannot be expanded
  • 🐛Screen cannot fit full mask on iPad
  • 🐛Needs update for iOS 9 screen visualization/adjustment
  • 🐛Ads are present (mentioned by multiple users)
  • 🐛Slow (mentioned by one user)
  • 🐛Visual interface looks really poor (mentioned by one user)
See all reviews

What's New in Subnet Plus

2.5

October 21, 2026

What's new in 2.5: • Designed for iPhone Duo: SubnetPlus fills both the outer and inner displays and adapts instantly as you fold and unfold, with tabs, results and ads laid out for each screen • TLS Certificate: check the certificate on any host and port to see days until expiry, the names it covers, the full chain, and the negotiated TLS version and cipher. Flags expired, self-signed and untrusted certificates, hostname mismatches, missing intermediates, weak keys and legacy TLS. Works on VPN gateways, load balancers, LDAPS and mail servers, not just websites • Certificate watchlist (Pro): tap the bell to watch a certificate. SubnetPlus re-checks it in the background and reminds you 30, 14, 7 and 1 days before it expires, and alerts you if it changes unexpectedly • Certificate Expiry widget (Pro): days left on your watched certificates, on the Home Screen and Lock Screen • Port Scan and Network Scanner now link straight to the certificate on any open TLS port • Siri & Shortcuts: "Check a certificate with SubnetPlus" tells you how many days are left • Calculate: the subnet mask now appears in binary and dotted decimal right under the prefix stepper, with network and host bits color-coded, so you can watch them shift as you step. The address field is larger and easier to read

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Subscriptions & In-App Purchases

$4.99

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User reviews

Most RecentHighest RatedLowest Rated

It’s good

Works good and looks clean. Would like to see an export option to share saved subnets with team members.
Nnetworksandchill

Response from developer

Thanks — glad it looks clean and works well for you! An export option to share saved subnets with your team is a great idea and it's on the list. Appreciate the review. — Ted, Subnet Plus

Interface needs work

The text in the subnet netmask field was so large (bold) that the last octet was not visible. No apparent way to enlarge the field or change the text. Free is fine as long as it still works.
PPBehne

Response from developer

You were right about the oversized text hiding the last octet — the 2026 rebuild (v2.x) fixes the layout so the full netmask is always visible, and it's still free. Thanks for the honest review. — Ted, Subnet Plus

this is what you were looking for

convenient and simple interface
BUBabykiller uuur

Practical and most useful

For iPhone...this is the most useful subnet tool used. Saves locations and gives you all the information you need in one page.
RRogerinMentor

No landscape?

Landscape would be great for iPad Pro use. Even with black bars on the sides like a 90’s TV show....other than that its great.
PPlayinpearls
See 69 more reviews

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User experience

🐞

Reported Bugs

8 issues

Text in subnet netmask field too large, last octet not visible

Bug

Values truncated, cannot view full values

Bug

Subnet mask and IP addresses truncated

Bug

Cannot read all data

Bug

Numbers truncated on iPhone 5s

Bug

Fields populated by app cannot be expanded

Bug

Screen cannot fit full mask on iPad

Bug

Calculation for number of subnets may be incorrect

Bug
✨

Requested Features

5 requests

Export option to share saved subnets

Feature

Pay to remove ads

Feature

Landscape mode for iPad Pro

Feature

Update for visualising or adjusting screen on iOS 9

Feature

Ability to type netmask

Feature

FAQ

What does Subnet Plus do?

Subnet Plus is a free subnet calculator for iPhone and iPad. It allows users to calculate subnet masks, usable IP address ranges, broadcast IP addresses, and network numbers. It also provides options to display complete binary and hex information for calculated subnets and lets you save your networks.

Who is this app for?

This app is designed for network engineers and individuals learning about subnetting. It's particularly useful for those studying for networking certifications like CCNA and Network+, as it helps visualize subnet details and perform essential calculations.

Is Subnet Plus free to use?

Yes, Subnet Plus is a free application. There are no costs associated with downloading or using its core subnet calculation features.

What kind of information can I calculate with this app?

You can calculate essential subnetting information including subnet masks, the range of usable IP addresses within a subnet, the broadcast IP address for each subnet, and the network number. The app also offers detailed binary and hex displays for better understanding.

Can I save my subnet calculations?

Yes, the app allows you to save your calculated networks. This feature is helpful for keeping track of network configurations or for revisiting calculations you've previously performed.