IPv6 subnet calculator

IPv6 CIDR range for fd00::/85

Calculate the network address, final address, mask, and exact address capacity of any IPv6 CIDR prefix.

Example: 2606:4700::/32

Host bits are normalized to the network address before the range is calculated.

CIDR calculation

Network details for fd00::/85

The prefix identifies a network with 43 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fd00::/85

Network mask

ffff:ffff:ffff:ffff:ffff:f800::

Prefix length

/85

Host bits

43

First address

fd00::

Last address

fd00::7ff:ffff:ffff

Total addresses

8796093022208

Total addresses (human readable)

2^43 addresses (8,796,093,022,208; about 8.79 trillion)

How this range is calculated

  1. 1The /85 prefix keeps the first 85 network bits fixed.
  2. 2Setting all 43 host bits to zero produces fd00::.
  3. 3Setting those host bits to one produces fd00::7ff:ffff:ffff.

Network address

The normalized prefix base

CIDR notation describes a network, not a single host. If an address with host bits set is entered, this calculator normalizes it to the network base before calculating the range.

Expanded network address

fd00:0000:0000:0000:0000:0000:0000:0000

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