Networking · Free tool

IPv6 Subnet Calculator

Enter any IPv6 address — compressed, expanded, or with an embedded IPv4 like ::ffff:192.168.1.1 — and pick a prefix length from /0 to /128. Get the full subnet breakdown instantly: expanded and compressed forms, network and last address, total address count (as a power of two and a /64 count), address type, ip6.arpa reverse DNS nibble pointer, and a subnet-split helper to list the first several sub-prefixes.

IPv6 Address

Prefix

Subnet for2001:db8::1 / 64

Global Unicast

Expanded address

2001:0db8:0000:0000:0000:0000:0000:0001

Compressed address

2001:db8::1

Network / prefix address

2001:db8::

Last address in prefix

2001:db8::ffff:ffff:ffff:ffff

Address range

2001:db8:: → 2001:db8::ffff:ffff:ffff:ffff

Total addresses

2⁶⁴

/64 subnets contained

Address typeDocumentation (2001:db8::/32)

CIDR notation

2001:db8::/64

Reverse DNS (ip6.arpa)

Nibble-by-nibble pointer for the input address:

Split this prefix

Divide the network into smaller sub-prefixes:

Split into /

Need IPv6 expertise?

From dual-stack design to IPv6 rollout — Peritus Digital can help.

Our Newcastle team designs and manages networks for Hunter Region businesses — IPv6 planning, dual-stack migrations, firewall policy, SD-WAN and structured cabling. If you're calculating prefixes, chances are you're planning infrastructure. Let's talk.

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