Subnify
Practical subnet planning tool

Subnet your networks with precision

Subnify helps you plan VLSM subnetting with clear calculations and visual network structure so you can allocate IP space with confidence.

No signup
Quick start
Browser-based
Works instantly
CIDR + VLSM
Built for planning
Clear output
Easy to share

Features

Everything you need for subnet planning

Professional-grade tools designed for network engineers, IT administrators, and students learning IP subnetting.

VLSM Calculator
Input your base network and required subnets. Get subnet masks and allocations based on host requirements.
Network Visualization
Interactive visual representation of your network topology. See how subnets relate to each other at a glance.
Instant Results
Results update directly in the interface as you work, without extra page reloads.
RFC Compliant
Designed around RFC 1918 private addressing and CIDR subnetting conventions.
Export Options
Export your subnet calculations as CSV, JSON, or PDF. Share with your team or import into documentation.
Subnet Hierarchy
Visualize parent-child subnet relationships. Understand how your address space is divided hierarchically.

Calculator

Try it yourself

Enter your base network and define your subnet requirements. Our calculator handles the rest.

Network Configuration
Define your base network and subnet requirements
/
Calculation Results
Optimized subnet allocation based on your requirements

Results will appear here after calculation

Visualizer

See your network structure

Interactive visualization helps you understand how your IP address space is divided across subnets.

Network Topology
Visual representation of subnet allocation within 192.168.1.0/24

Address Space Utilization

/26
/27
/28
/28
Unallocated

Subnet Hierarchy

192.168.1.0/24

Main Network - 254 usable hosts

192.168.1.0/26

LAN A - 62 usable hosts

192.168.1.64/27

LAN B - 30 usable hosts

192.168.1.96/28

LAN C - 14 usable hosts

192.168.1.112/28

LAN D - 14 usable hosts

LAN A
LAN B
LAN C
LAN D
Unallocated

Ready to simplify your network planning?

Use Subnify to plan your next subnet layout with a clean workflow for calculation and visualization.