IPv6 Subnet Calculator
Calculate by prefix, required subnet count, or required addresses per subnet. View an abbreviated or complete subnet list.
Open calculatorIPv6 engineering toolkit
Plan IPv6 networks with precision.
A focused engineering toolkit for subnet calculation, address analysis, allocation planning, and reusable exports—developed by Advanced Network Design and Engineering, Inc.
Verified arithmetic/65–/128 calculatorCSV, TXT & JSON exports
Built for network engineers
The information you need, without unnecessary complexity.
The toolkit keeps permanent IPv6 information central while leaving room for future site, building, VLAN, and operational planning workflows.
Reusable Exports
Export calculated ranges as CSV, plain text, or JSON with memory-efficient row-by-row streaming.
Generate an exportAllocation Planning
Separate organizational allocation planning from subnet calculation so each workflow remains clear and technically correct.
View planning servicesIntentional scope
Subnet calculation below the /64 boundary.
The calculator supports prefixes from /65 through /128. Prefixes /0 through /64 belong to organizational allocation and address-planning workflows, which are intentionally treated separately.
Start a calculation →Engineering assistance
Need more than a calculation?
Advanced Network Design and Engineering, Inc. can help structure IPv6 allocations, document deployment standards, and translate network requirements into practical designs.