IPv6 Subnet Calculator
Enter an IPv6 address with a prefix to see its network, address range, number of /64 subnets, and its full and short forms. You can also split the prefix into smaller subnets.
documentation2001:db8::a400/120
network2001:db8::a400/120
first host2001:db8::a400
last host2001:db8::a4ff
addresses2⁸ = 256
short form2001:db8::a400
ipcalc 2001:db8::a400/120
address2001:0db8:0000:0000:0000:0000:0000:a400
network2001:0db8:0000:0000:0000:0000:0000:a400
last host2001:0db8:0000:0000:0000:0000:0000:a4ff
green = network digits, amber = digit split by the prefix
full form2001:0db8:0000:0000:0000:0000:0000:a400
reverse dns0.0.4.a.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa
/120 split into /128 · 256 subnets
close ×01 / table
IPv6 prefix table.
Click a prefix longer than your network to split it into subnets.
| prefix | addresses | /64 subnets | in your /120 |
|---|---|---|---|
| /8 | 2¹²⁰ | 2⁵⁶ | - |
| /12 | 2¹¹⁶ | 2⁵² | - |
| /16 | 2¹¹² | 2⁴⁸ | - |
| /20 | 2¹⁰⁸ | 2⁴⁴ | - |
| /24 | 2¹⁰⁴ | 2⁴⁰ | - |
| /28 | 2¹⁰⁰ | 2³⁶ | - |
| /32 | 2⁹⁶ | 4,294,967,296 | - |
| /36 | 2⁹² | 268,435,456 | - |
| /40 | 2⁸⁸ | 16,777,216 | - |
| /44 | 2⁸⁴ | 1,048,576 | - |
| /48 | 2⁸⁰ | 65,536 | - |
| /52 | 2⁷⁶ | 4,096 | - |
| /56 | 2⁷² | 256 | - |
| /60 | 2⁶⁸ | 16 | - |
| /64 | 2⁶⁴ | 1 | - |
| /72 | 2⁵⁶ | - | - |
| /80 | 2⁴⁸ | - | - |
| /96 | 4,294,967,296 | - | - |
| /112 | 65,536 | - | - |
| /120 | 256 | - | 1 |
| /124 | 16 | - | 16 split → |
| /126 | 4 | - | 64 split → |
| /127 | 2 | - | 128 split → |
| /128 | 1 | - | 256 split → |
02 / faq
About this calculator.
How do I use this IPv6 calculator?
▼
Type an IPv6 address followed by a prefix, like 2001:db8:abcd::1/48. Without a prefix it uses /64. The address can be written in full or shortened with ::.
Why does IPv6 have no broadcast address?
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IPv6 replaced broadcast with multicast, so no address is set aside for it. That is why this calculator shows the whole range, from the network address to the last address.
What prefix do ISPs usually hand out?
▼
A single LAN is almost always a /64. Home customers usually get a /56 or /60, and an organization or site usually gets a /48. One /48 holds 65,536 /64 subnets.