Subnet CIDR Pro Downloads & RevenueSubnet CIDR Pro · App Store

Subnet CIDR Pro is a focused, offline-first network calculator and VLSM planner built for network engineers, sysadmins, homelab users, and IT students.

From quick /30 interface checks to full multi-VLAN allocation plans, get accurate IPv4 subnetting and address tooling directly on your iPhone and iPad—with zero tracking, zero ads, and 100% local calculation.

IPv4 & CIDR CALCULATOR
• Full Range Support: Calculate any prefix from /0 to /32
• Essential Telemetry: Network, broadcast, subnet mask, wildcard mask, and usable host ranges
• Host Capacity: Instant breakdown of total addresses vs. usable host capacity
• Modern Link Handling: Full support for /31 point-to-point links (RFC 3021) and /32 host routes
• Binary Inspection: Visualize network vs. host bits in clear binary layout
• Mask Conversion: Seamless conversion between CIDR prefixes, subnet masks, and wildcard masks
• One-Tap Copy: Copy individual values or complete formatted network summaries

VLSM NETWORK PLANNING
• Requirement-Driven Allocation: Subnet a parent IPv4 block based on exact host requirements
• VLAN & Naming: Assign custom network labels and VLAN IDs per subnet
• Growth Headroom: Configurable growth reserve percentage per allocation
• Gateway Reservation: Optional automatic reservation for default gateway addresses
• Space Optimization: View allocated CIDRs alongside remaining unallocated blocks
• Overflow Warnings: Instant alerts when requirements exceed parent network capacity

ADDRESS TOOLS & IP MATH
• Subnet Compare: Test two subnets for containment, overlap, equality, or isolation
• IP Membership: Verify instantly whether an IPv4 address belongs to a target network
• Range to CIDR: Convert arbitrary start/end IP ranges into minimal exact CIDR blocks
• Subnet Splitting: Break down any network into equal-sized child subnets
• Supernetting: Summarize adjacent or overlapping subnets into clean aggregation blocks

PROJECT WORKSPACE & EXPORT
• Project History: Save named planning projects, reopen, rename, or duplicate anytime
• Auto-Save: Automatically preserves your current planning draft
• Data Export: Export complete subnet plans and available address blocks as CSV
• Clipboard Sharing: One-tap copy for formatted plain-text documentation

CIDR QUICK REFERENCE TABLE
• Interactive reference matrix for all prefixes (/0 to /32)
• Searchable by prefix, dotted-decimal mask, wildcard mask, or usable host count
• Fast reference copying for switch and firewall configuration

DESIGNED FOR iOS & iPadOS
• High-contrast dark interface tailored for server rooms and night operations
• Adaptive iPad workspace: side-by-side inputs, live results, and wide allocation tables
• Localized in 13 languages: English, Simplified & Traditional Chinese, German, French, Japanese, Korean, Italian, Spanish, Brazilian Portuguese, Arabic, Dutch, and Turkish

100% OFFLINE & PRIVATE
• Calculations run purely on your device
• No account required, no telemetry SDKs, no ads, and no in-app purchases

Terms of Use