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Online Subnet Calculator

Analyze • Size • Aggregate • VLSM • Splitter • Batch

📋 History

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 Supernet Copy Load Sample

Result

VLSM Planner (start at fixed IP)

Start at (network IP)

Container (optional)

Requirements

Plan VLSM Copy Load 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

Find Smallest CIDR

IP Address 1

IP Address 2

Compute CIDR Copy Load Sample

Result

Batch Process

CSV File Upload

Upload CSV with IP addresses or CIDR notations (one per line)

Or Paste IPs/CIDRs

Process All Clear Load Sample Export CSV

Results