IPv6 calculator

Subnet details, /127 and /128 planning, splitting, compress/expand, overlap check.

What it is for

Divide a larger prefix into equal smaller ones (e.g. /48 → /56 or /64, /64 → /127).

Why it helps

Know the exact subnet count and first rows — allocate your whole /48 without gaps or guessing.

Subnet splitter

E.g. /48 → /64 = 65536 × /64 · /64 → /127 = 2⁶³ pairs.

Quick templates

/48→/64 /48→/56 /64→/127 /64→/128

Split result

From2001:db8:1::/48
To/64
Subnets65536
#PrefixNetwork
0 2001:db8:1::/64 2001:db8:1::
1 2001:db8:1:1::/64 2001:db8:1:1::
2 2001:db8:1:2::/64 2001:db8:1:2::
3 2001:db8:1:3::/64 2001:db8:1:3::
4 2001:db8:1:4::/64 2001:db8:1:4::
5 2001:db8:1:5::/64 2001:db8:1:5::
6 2001:db8:1:6::/64 2001:db8:1:6::
7 2001:db8:1:7::/64 2001:db8:1:7::
8 2001:db8:1:8::/64 2001:db8:1:8::
9 2001:db8:1:9::/64 2001:db8:1:9::
10 2001:db8:1:a::/64 2001:db8:1:a::
11 2001:db8:1:b::/64 2001:db8:1:b::
12 2001:db8:1:c::/64 2001:db8:1:c::
13 2001:db8:1:d::/64 2001:db8:1:d::
14 2001:db8:1:e::/64 2001:db8:1:e::
15 2001:db8:1:f::/64 2001:db8:1:f::
→