IPv6 subnet calculator

IPv6 CIDR range for fc00:dead:beef:cac0::/58

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 fc00:dead:beef:cac0::/58

The prefix identifies a network with 70 host bits. Every address from the first address through the last address belongs to this range.

CIDR prefix

fc00:dead:beef:cac0::/58

Network mask

ffff:ffff:ffff:ffc0::

Prefix length

/58

Host bits

70

First address

fc00:dead:beef:cac0::

Last address

fc00:dead:beef:caff:ffff:ffff:ffff:ffff

Total addresses

1180591620717411303424

Total addresses (human readable)

2^70 addresses (1,180,591,620,717,411,303,424; about 1.18 sextillion)

How this range is calculated

  1. 1The /58 prefix keeps the first 58 network bits fixed.
  2. 2Setting all 70 host bits to zero produces fc00:dead:beef:cac0::.
  3. 3Setting those host bits to one produces fc00:dead:beef:caff:ffff:ffff: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

fc00:dead:beef:cac0:0000:0000:0000:0000

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