SubnetBuddy

CIDR & Subnet Calculator

Free · Designed for iPad

SubnetBuddy is a fast, offline subnet calculator and network planning tool built for IT professionals, network engineers, students, and anyone studying for their CCNA, CompTIA Network+, or just needs to crunch CIDR notation on the fly. No internet required. No ads. No account needed. Just open the app and start calculating. SUBNET CALCULATOR • Enter any IP address and CIDR prefix (e.g. 192.168.1.0/24) • Instantly see network address, broadcast address, first and last usable host • View total hosts, usable hosts, and wildcard mask • Get the next sequential subnet with one tap • Supports all prefix lengths from /0 to /32 MASK CONVERTER • Convert between CIDR notation, dotted decimal, and binary • Enter a prefix length and see all three formats instantly • Quick-reference for common subnet masks • Perfect for exam prep and on-the-job lookups VLAN PLANNER • Plan multiple VLANs with custom names and sizes • Set a base network and SubnetBuddy calculates non-overlapping subnets for each VLAN • See network range, gateway, CIDR, and host count per VLAN • Great for designing office networks, lab environments, and homework assignments IP VISUALIZER • Enter a CIDR block and see a visual map of the IP address space • Color-coded grid shows used vs. available addresses • Instantly understand how big (or small) your subnet really is • Tap any cell to see the full IP address TERMINAL-STYLE DESIGN • Dark theme with VibeCMD's signature hacker-green aesthetic • Monospace fonts and command-line inspired interface • Clean, distraction-free layout built for speed • Easy on the eyes during late-night study sessions WORKS COMPLETELY OFFLINE • Zero network calls — all calculations happen on-device • No account required — open and use immediately • No data collection — your network plans stay on your phone • Lightning fast — results appear as you type BUILT FOR REAL PEOPLE • IT professionals doing quick subnet math on-site • Students studying for CCNA, Network+, or any networking exam • Homelab enthusiasts planning their network segments • DevOps engineers carving up VPC address spaces • Anyone who's tired of Googling "what is /22 in dotted decimal" SubnetBuddy is a utility tool for network address calculations. It does not connect to or scan any networks.

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v1.2.0 • Every screen now loads with live example results — no more blank screens on launch. • Subnet Calculator auto-recalculates as you type. • New app icon and splash screen with refreshed dark terminal branding. • Cleaner screen headers with more vertical space. • Result rows now show a copy icon so you know they're tappable. • CIDR/Mask converter highlights the active reference row. • VLAN Planner stability improvements.

Version 1.2

The developer, VibeCMD, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    • Seller
      • VibeCMD LLC
    • Size
      • 24.7 MB
    • Category
      • Utilities
    • Compatibility
      Requires iOS 15.1 or later.
      • iPhone
        Requires iOS 15.1 or later.
      • iPad
        Requires iPadOS 15.1 or later.
      • iPod touch
        Requires iOS 15.1 or later.
      • Mac
        Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
    • Languages
      • English
    • Age Rating
      4+
    • Copyright
      • © 2026 VibeCMD LLC
  • Developer Website
  • Privacy Policy

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