IPv6 CIDR Calculator

Calculate IPv6 subnet information by entering an address with prefix length (e.g., 2001:db8::/32). Get detailed information about network range and address properties.

About IPv6 Addressing

IPv6 addresses are 128-bit addresses expressed in hexadecimal notation, divided into eight 16-bit blocks separated by colons. The prefix length specifies how many bits are used for the network portion of the address.

  • A /128 represents a single IPv6 address
  • A /64 is typically used for a single subnet (interface identifier bits)
  • A /48 is commonly allocated to end sites
  • A /32 is often allocated to ISPs
  • Double colons (::) can be used once to compress multiple zero blocks
  • Leading zeros in a block can be omitted