Free developer tool
IPv6 Subnet Calculator
IPv6 addresses are 128 bits long and usually written in a shortened form, where leading zeros and one run of zero groups are left out. That makes them hard to compare by eye.
IPv6 Calculator
Convert IPv6 CIDR notation.
Compressed address
2001:db8::1
Expanded address
2001:0db8:0000:0000:0000:0000:0000:0001
Network
2001:db8::/64
First address
2001:db8::
Last address
2001:db8::ffff:ffff:ffff:ffff
Total addresses
18446744073709551616
About this tool
This calculator shows an address in both its compressed and fully expanded forms, and works out the network, the first and last address, and how many addresses the prefix covers.
How to use it
- Type an IPv6 address with a prefix length, for example 2001:db8:abcd::/48.
- Read the results as you type and copy any value you need.
What the results mean
- Compressed and expanded address
- The same address in its shortest form and with all eight groups written out.
- Network
- The first address of the block, with the prefix length.
- First and last address
- The start and end of the block.
- Total addresses
- How many addresses the prefix covers. A /64 holds 18,446,744,073,709,551,616.
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