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Online Subnet Calculator

Analyze • Size • Aggregate • VLSM Planner • Splitter

☀️ Light

Inputs

IP (ip or ip/prefix)

Mask / CIDR

/24 sample /22 sample ip/prefix

Results

Copy

Inputs

Anchor host

Usable hosts

Allow /31 p2p

Sample/31 p2p

Suggested Subnet

Copy

Aggregate / Supernet

Subnets (one per line)

Compute SupernetCopyLoad Sample

Result

VLSM Planner (start at fixed IP)

Start at (network IP)

Container (optional)

Requirements

Plan VLSMCopyLoad Sample

Plan

Subnet Splitter

Step 1 — Starting Network (CIDR)

Step 2 — How many subnets?

Build rows

Step 3 — Names & Hosts

Allow spill outside starting CIDR (⚠️ will warn & tint rows)

Calculate Copy Export CSV

Results