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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Prefix/20
Addresses2^108
/64 networks2^44
Network
fc02:5000::/20
First address
fc02:5000::
Last address
fc02:5fff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
324,518,553,658,426,726,783,156,020,576,256 (2^108)
/64 networks (LANs)
17,592,186,044,416 (2^44)
Full form
fc02:5000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
5.2.0.c.f.ip6.arpa
Split into smaller subnets/28
/21 (2)/22 (4)/23 (8)/24 (16)/28 (256)/32 (4,096)/36 (65,536)

fc02:5000::/20 makes 256 subnets of /28.

Subnets
#SubnetLast address
1fc02:5000::/28fc02:500f:ffff:ffff:ffff:ffff:ffff:ffff
2fc02:5010::/28fc02:501f:ffff:ffff:ffff:ffff:ffff:ffff
3fc02:5020::/28fc02:502f:ffff:ffff:ffff:ffff:ffff:ffff
4fc02:5030::/28fc02:503f:ffff:ffff:ffff:ffff:ffff:ffff
5fc02:5040::/28fc02:504f:ffff:ffff:ffff:ffff:ffff:ffff
6fc02:5050::/28fc02:505f:ffff:ffff:ffff:ffff:ffff:ffff
7fc02:5060::/28fc02:506f:ffff:ffff:ffff:ffff:ffff:ffff
8fc02:5070::/28fc02:507f:ffff:ffff:ffff:ffff:ffff:ffff
9fc02:5080::/28fc02:508f:ffff:ffff:ffff:ffff:ffff:ffff
10fc02:5090::/28fc02:509f:ffff:ffff:ffff:ffff:ffff:ffff
11fc02:50a0::/28fc02:50af:ffff:ffff:ffff:ffff:ffff:ffff
12fc02:50b0::/28fc02:50bf:ffff:ffff:ffff:ffff:ffff:ffff
13fc02:50c0::/28fc02:50cf:ffff:ffff:ffff:ffff:ffff:ffff
14fc02:50d0::/28fc02:50df:ffff:ffff:ffff:ffff:ffff:ffff
15fc02:50e0::/28fc02:50ef:ffff:ffff:ffff:ffff:ffff:ffff
16fc02:50f0::/28fc02:50ff:ffff:ffff:ffff:ffff:ffff:ffff
17fc02:5100::/28fc02:510f:ffff:ffff:ffff:ffff:ffff:ffff
18fc02:5110::/28fc02:511f:ffff:ffff:ffff:ffff:ffff:ffff
19fc02:5120::/28fc02:512f:ffff:ffff:ffff:ffff:ffff:ffff
20fc02:5130::/28fc02:513f:ffff:ffff:ffff:ffff:ffff:ffff
21fc02:5140::/28fc02:514f:ffff:ffff:ffff:ffff:ffff:ffff
22fc02:5150::/28fc02:515f:ffff:ffff:ffff:ffff:ffff:ffff
23fc02:5160::/28fc02:516f:ffff:ffff:ffff:ffff:ffff:ffff
24fc02:5170::/28fc02:517f:ffff:ffff:ffff:ffff:ffff:ffff
25fc02:5180::/28fc02:518f:ffff:ffff:ffff:ffff:ffff:ffff
26fc02:5190::/28fc02:519f:ffff:ffff:ffff:ffff:ffff:ffff
27fc02:51a0::/28fc02:51af:ffff:ffff:ffff:ffff:ffff:ffff
28fc02:51b0::/28fc02:51bf:ffff:ffff:ffff:ffff:ffff:ffff
29fc02:51c0::/28fc02:51cf:ffff:ffff:ffff:ffff:ffff:ffff
30fc02:51d0::/28fc02:51df:ffff:ffff:ffff:ffff:ffff:ffff
31fc02:51e0::/28fc02:51ef:ffff:ffff:ffff:ffff:ffff:ffff
32fc02:51f0::/28fc02:51ff:ffff:ffff:ffff:ffff:ffff:ffff
33fc02:5200::/28fc02:520f:ffff:ffff:ffff:ffff:ffff:ffff
34fc02:5210::/28fc02:521f:ffff:ffff:ffff:ffff:ffff:ffff
35fc02:5220::/28fc02:522f:ffff:ffff:ffff:ffff:ffff:ffff
36fc02:5230::/28fc02:523f:ffff:ffff:ffff:ffff:ffff:ffff
37fc02:5240::/28fc02:524f:ffff:ffff:ffff:ffff:ffff:ffff
38fc02:5250::/28fc02:525f:ffff:ffff:ffff:ffff:ffff:ffff
39fc02:5260::/28fc02:526f:ffff:ffff:ffff:ffff:ffff:ffff
40fc02:5270::/28fc02:527f:ffff:ffff:ffff:ffff:ffff:ffff
41fc02:5280::/28fc02:528f:ffff:ffff:ffff:ffff:ffff:ffff
42fc02:5290::/28fc02:529f:ffff:ffff:ffff:ffff:ffff:ffff
43fc02:52a0::/28fc02:52af:ffff:ffff:ffff:ffff:ffff:ffff
44fc02:52b0::/28fc02:52bf:ffff:ffff:ffff:ffff:ffff:ffff
45fc02:52c0::/28fc02:52cf:ffff:ffff:ffff:ffff:ffff:ffff
46fc02:52d0::/28fc02:52df:ffff:ffff:ffff:ffff:ffff:ffff
47fc02:52e0::/28fc02:52ef:ffff:ffff:ffff:ffff:ffff:ffff
48fc02:52f0::/28fc02:52ff:ffff:ffff:ffff:ffff:ffff:ffff
49fc02:5300::/28fc02:530f:ffff:ffff:ffff:ffff:ffff:ffff
50fc02:5310::/28fc02:531f:ffff:ffff:ffff:ffff:ffff:ffff
51fc02:5320::/28fc02:532f:ffff:ffff:ffff:ffff:ffff:ffff
52fc02:5330::/28fc02:533f:ffff:ffff:ffff:ffff:ffff:ffff
53fc02:5340::/28fc02:534f:ffff:ffff:ffff:ffff:ffff:ffff
54fc02:5350::/28fc02:535f:ffff:ffff:ffff:ffff:ffff:ffff
55fc02:5360::/28fc02:536f:ffff:ffff:ffff:ffff:ffff:ffff
56fc02:5370::/28fc02:537f:ffff:ffff:ffff:ffff:ffff:ffff
57fc02:5380::/28fc02:538f:ffff:ffff:ffff:ffff:ffff:ffff
58fc02:5390::/28fc02:539f:ffff:ffff:ffff:ffff:ffff:ffff
59fc02:53a0::/28fc02:53af:ffff:ffff:ffff:ffff:ffff:ffff
60fc02:53b0::/28fc02:53bf:ffff:ffff:ffff:ffff:ffff:ffff
61fc02:53c0::/28fc02:53cf:ffff:ffff:ffff:ffff:ffff:ffff
62fc02:53d0::/28fc02:53df:ffff:ffff:ffff:ffff:ffff:ffff
63fc02:53e0::/28fc02:53ef:ffff:ffff:ffff:ffff:ffff:ffff
64fc02:53f0::/28fc02:53ff:ffff:ffff:ffff:ffff:ffff:ffff
65fc02:5400::/28fc02:540f:ffff:ffff:ffff:ffff:ffff:ffff
66fc02:5410::/28fc02:541f:ffff:ffff:ffff:ffff:ffff:ffff
67fc02:5420::/28fc02:542f:ffff:ffff:ffff:ffff:ffff:ffff
68fc02:5430::/28fc02:543f:ffff:ffff:ffff:ffff:ffff:ffff
69fc02:5440::/28fc02:544f:ffff:ffff:ffff:ffff:ffff:ffff
70fc02:5450::/28fc02:545f:ffff:ffff:ffff:ffff:ffff:ffff
71fc02:5460::/28fc02:546f:ffff:ffff:ffff:ffff:ffff:ffff
72fc02:5470::/28fc02:547f:ffff:ffff:ffff:ffff:ffff:ffff
73fc02:5480::/28fc02:548f:ffff:ffff:ffff:ffff:ffff:ffff
74fc02:5490::/28fc02:549f:ffff:ffff:ffff:ffff:ffff:ffff
75fc02:54a0::/28fc02:54af:ffff:ffff:ffff:ffff:ffff:ffff
76fc02:54b0::/28fc02:54bf:ffff:ffff:ffff:ffff:ffff:ffff
77fc02:54c0::/28fc02:54cf:ffff:ffff:ffff:ffff:ffff:ffff
78fc02:54d0::/28fc02:54df:ffff:ffff:ffff:ffff:ffff:ffff
79fc02:54e0::/28fc02:54ef:ffff:ffff:ffff:ffff:ffff:ffff
80fc02:54f0::/28fc02:54ff:ffff:ffff:ffff:ffff:ffff:ffff
81fc02:5500::/28fc02:550f:ffff:ffff:ffff:ffff:ffff:ffff
82fc02:5510::/28fc02:551f:ffff:ffff:ffff:ffff:ffff:ffff
83fc02:5520::/28fc02:552f:ffff:ffff:ffff:ffff:ffff:ffff
84fc02:5530::/28fc02:553f:ffff:ffff:ffff:ffff:ffff:ffff
85fc02:5540::/28fc02:554f:ffff:ffff:ffff:ffff:ffff:ffff
86fc02:5550::/28fc02:555f:ffff:ffff:ffff:ffff:ffff:ffff
87fc02:5560::/28fc02:556f:ffff:ffff:ffff:ffff:ffff:ffff
88fc02:5570::/28fc02:557f:ffff:ffff:ffff:ffff:ffff:ffff
89fc02:5580::/28fc02:558f:ffff:ffff:ffff:ffff:ffff:ffff
90fc02:5590::/28fc02:559f:ffff:ffff:ffff:ffff:ffff:ffff
91fc02:55a0::/28fc02:55af:ffff:ffff:ffff:ffff:ffff:ffff
92fc02:55b0::/28fc02:55bf:ffff:ffff:ffff:ffff:ffff:ffff
93fc02:55c0::/28fc02:55cf:ffff:ffff:ffff:ffff:ffff:ffff
94fc02:55d0::/28fc02:55df:ffff:ffff:ffff:ffff:ffff:ffff
95fc02:55e0::/28fc02:55ef:ffff:ffff:ffff:ffff:ffff:ffff
96fc02:55f0::/28fc02:55ff:ffff:ffff:ffff:ffff:ffff:ffff
97fc02:5600::/28fc02:560f:ffff:ffff:ffff:ffff:ffff:ffff
98fc02:5610::/28fc02:561f:ffff:ffff:ffff:ffff:ffff:ffff
99fc02:5620::/28fc02:562f:ffff:ffff:ffff:ffff:ffff:ffff
100fc02:5630::/28fc02:563f:ffff:ffff:ffff:ffff:ffff:ffff
101fc02:5640::/28fc02:564f:ffff:ffff:ffff:ffff:ffff:ffff
102fc02:5650::/28fc02:565f:ffff:ffff:ffff:ffff:ffff:ffff
103fc02:5660::/28fc02:566f:ffff:ffff:ffff:ffff:ffff:ffff
104fc02:5670::/28fc02:567f:ffff:ffff:ffff:ffff:ffff:ffff
105fc02:5680::/28fc02:568f:ffff:ffff:ffff:ffff:ffff:ffff
106fc02:5690::/28fc02:569f:ffff:ffff:ffff:ffff:ffff:ffff
107fc02:56a0::/28fc02:56af:ffff:ffff:ffff:ffff:ffff:ffff
108fc02:56b0::/28fc02:56bf:ffff:ffff:ffff:ffff:ffff:ffff
109fc02:56c0::/28fc02:56cf:ffff:ffff:ffff:ffff:ffff:ffff
110fc02:56d0::/28fc02:56df:ffff:ffff:ffff:ffff:ffff:ffff
111fc02:56e0::/28fc02:56ef:ffff:ffff:ffff:ffff:ffff:ffff
112fc02:56f0::/28fc02:56ff:ffff:ffff:ffff:ffff:ffff:ffff
113fc02:5700::/28fc02:570f:ffff:ffff:ffff:ffff:ffff:ffff
114fc02:5710::/28fc02:571f:ffff:ffff:ffff:ffff:ffff:ffff
115fc02:5720::/28fc02:572f:ffff:ffff:ffff:ffff:ffff:ffff
116fc02:5730::/28fc02:573f:ffff:ffff:ffff:ffff:ffff:ffff
117fc02:5740::/28fc02:574f:ffff:ffff:ffff:ffff:ffff:ffff
118fc02:5750::/28fc02:575f:ffff:ffff:ffff:ffff:ffff:ffff
119fc02:5760::/28fc02:576f:ffff:ffff:ffff:ffff:ffff:ffff
120fc02:5770::/28fc02:577f:ffff:ffff:ffff:ffff:ffff:ffff
121fc02:5780::/28fc02:578f:ffff:ffff:ffff:ffff:ffff:ffff
122fc02:5790::/28fc02:579f:ffff:ffff:ffff:ffff:ffff:ffff
123fc02:57a0::/28fc02:57af:ffff:ffff:ffff:ffff:ffff:ffff
124fc02:57b0::/28fc02:57bf:ffff:ffff:ffff:ffff:ffff:ffff
125fc02:57c0::/28fc02:57cf:ffff:ffff:ffff:ffff:ffff:ffff
126fc02:57d0::/28fc02:57df:ffff:ffff:ffff:ffff:ffff:ffff
127fc02:57e0::/28fc02:57ef:ffff:ffff:ffff:ffff:ffff:ffff
128fc02:57f0::/28fc02:57ff:ffff:ffff:ffff:ffff:ffff:ffff
129fc02:5800::/28fc02:580f:ffff:ffff:ffff:ffff:ffff:ffff
130fc02:5810::/28fc02:581f:ffff:ffff:ffff:ffff:ffff:ffff
131fc02:5820::/28fc02:582f:ffff:ffff:ffff:ffff:ffff:ffff
132fc02:5830::/28fc02:583f:ffff:ffff:ffff:ffff:ffff:ffff
133fc02:5840::/28fc02:584f:ffff:ffff:ffff:ffff:ffff:ffff
134fc02:5850::/28fc02:585f:ffff:ffff:ffff:ffff:ffff:ffff
135fc02:5860::/28fc02:586f:ffff:ffff:ffff:ffff:ffff:ffff
136fc02:5870::/28fc02:587f:ffff:ffff:ffff:ffff:ffff:ffff
137fc02:5880::/28fc02:588f:ffff:ffff:ffff:ffff:ffff:ffff
138fc02:5890::/28fc02:589f:ffff:ffff:ffff:ffff:ffff:ffff
139fc02:58a0::/28fc02:58af:ffff:ffff:ffff:ffff:ffff:ffff
140fc02:58b0::/28fc02:58bf:ffff:ffff:ffff:ffff:ffff:ffff
141fc02:58c0::/28fc02:58cf:ffff:ffff:ffff:ffff:ffff:ffff
142fc02:58d0::/28fc02:58df:ffff:ffff:ffff:ffff:ffff:ffff
143fc02:58e0::/28fc02:58ef:ffff:ffff:ffff:ffff:ffff:ffff
144fc02:58f0::/28fc02:58ff:ffff:ffff:ffff:ffff:ffff:ffff
145fc02:5900::/28fc02:590f:ffff:ffff:ffff:ffff:ffff:ffff
146fc02:5910::/28fc02:591f:ffff:ffff:ffff:ffff:ffff:ffff
147fc02:5920::/28fc02:592f:ffff:ffff:ffff:ffff:ffff:ffff
148fc02:5930::/28fc02:593f:ffff:ffff:ffff:ffff:ffff:ffff
149fc02:5940::/28fc02:594f:ffff:ffff:ffff:ffff:ffff:ffff
150fc02:5950::/28fc02:595f:ffff:ffff:ffff:ffff:ffff:ffff
151fc02:5960::/28fc02:596f:ffff:ffff:ffff:ffff:ffff:ffff
152fc02:5970::/28fc02:597f:ffff:ffff:ffff:ffff:ffff:ffff
153fc02:5980::/28fc02:598f:ffff:ffff:ffff:ffff:ffff:ffff
154fc02:5990::/28fc02:599f:ffff:ffff:ffff:ffff:ffff:ffff
155fc02:59a0::/28fc02:59af:ffff:ffff:ffff:ffff:ffff:ffff
156fc02:59b0::/28fc02:59bf:ffff:ffff:ffff:ffff:ffff:ffff
157fc02:59c0::/28fc02:59cf:ffff:ffff:ffff:ffff:ffff:ffff
158fc02:59d0::/28fc02:59df:ffff:ffff:ffff:ffff:ffff:ffff
159fc02:59e0::/28fc02:59ef:ffff:ffff:ffff:ffff:ffff:ffff
160fc02:59f0::/28fc02:59ff:ffff:ffff:ffff:ffff:ffff:ffff
161fc02:5a00::/28fc02:5a0f:ffff:ffff:ffff:ffff:ffff:ffff
162fc02:5a10::/28fc02:5a1f:ffff:ffff:ffff:ffff:ffff:ffff
163fc02:5a20::/28fc02:5a2f:ffff:ffff:ffff:ffff:ffff:ffff
164fc02:5a30::/28fc02:5a3f:ffff:ffff:ffff:ffff:ffff:ffff
165fc02:5a40::/28fc02:5a4f:ffff:ffff:ffff:ffff:ffff:ffff
166fc02:5a50::/28fc02:5a5f:ffff:ffff:ffff:ffff:ffff:ffff
167fc02:5a60::/28fc02:5a6f:ffff:ffff:ffff:ffff:ffff:ffff
168fc02:5a70::/28fc02:5a7f:ffff:ffff:ffff:ffff:ffff:ffff
169fc02:5a80::/28fc02:5a8f:ffff:ffff:ffff:ffff:ffff:ffff
170fc02:5a90::/28fc02:5a9f:ffff:ffff:ffff:ffff:ffff:ffff
171fc02:5aa0::/28fc02:5aaf:ffff:ffff:ffff:ffff:ffff:ffff
172fc02:5ab0::/28fc02:5abf:ffff:ffff:ffff:ffff:ffff:ffff
173fc02:5ac0::/28fc02:5acf:ffff:ffff:ffff:ffff:ffff:ffff
174fc02:5ad0::/28fc02:5adf:ffff:ffff:ffff:ffff:ffff:ffff
175fc02:5ae0::/28fc02:5aef:ffff:ffff:ffff:ffff:ffff:ffff
176fc02:5af0::/28fc02:5aff:ffff:ffff:ffff:ffff:ffff:ffff
177fc02:5b00::/28fc02:5b0f:ffff:ffff:ffff:ffff:ffff:ffff
178fc02:5b10::/28fc02:5b1f:ffff:ffff:ffff:ffff:ffff:ffff
179fc02:5b20::/28fc02:5b2f:ffff:ffff:ffff:ffff:ffff:ffff
180fc02:5b30::/28fc02:5b3f:ffff:ffff:ffff:ffff:ffff:ffff
181fc02:5b40::/28fc02:5b4f:ffff:ffff:ffff:ffff:ffff:ffff
182fc02:5b50::/28fc02:5b5f:ffff:ffff:ffff:ffff:ffff:ffff
183fc02:5b60::/28fc02:5b6f:ffff:ffff:ffff:ffff:ffff:ffff
184fc02:5b70::/28fc02:5b7f:ffff:ffff:ffff:ffff:ffff:ffff
185fc02:5b80::/28fc02:5b8f:ffff:ffff:ffff:ffff:ffff:ffff
186fc02:5b90::/28fc02:5b9f:ffff:ffff:ffff:ffff:ffff:ffff
187fc02:5ba0::/28fc02:5baf:ffff:ffff:ffff:ffff:ffff:ffff
188fc02:5bb0::/28fc02:5bbf:ffff:ffff:ffff:ffff:ffff:ffff
189fc02:5bc0::/28fc02:5bcf:ffff:ffff:ffff:ffff:ffff:ffff
190fc02:5bd0::/28fc02:5bdf:ffff:ffff:ffff:ffff:ffff:ffff
191fc02:5be0::/28fc02:5bef:ffff:ffff:ffff:ffff:ffff:ffff
192fc02:5bf0::/28fc02:5bff:ffff:ffff:ffff:ffff:ffff:ffff
193fc02:5c00::/28fc02:5c0f:ffff:ffff:ffff:ffff:ffff:ffff
194fc02:5c10::/28fc02:5c1f:ffff:ffff:ffff:ffff:ffff:ffff
195fc02:5c20::/28fc02:5c2f:ffff:ffff:ffff:ffff:ffff:ffff
196fc02:5c30::/28fc02:5c3f:ffff:ffff:ffff:ffff:ffff:ffff
197fc02:5c40::/28fc02:5c4f:ffff:ffff:ffff:ffff:ffff:ffff
198fc02:5c50::/28fc02:5c5f:ffff:ffff:ffff:ffff:ffff:ffff
199fc02:5c60::/28fc02:5c6f:ffff:ffff:ffff:ffff:ffff:ffff
200fc02:5c70::/28fc02:5c7f:ffff:ffff:ffff:ffff:ffff:ffff
201fc02:5c80::/28fc02:5c8f:ffff:ffff:ffff:ffff:ffff:ffff
202fc02:5c90::/28fc02:5c9f:ffff:ffff:ffff:ffff:ffff:ffff
203fc02:5ca0::/28fc02:5caf:ffff:ffff:ffff:ffff:ffff:ffff
204fc02:5cb0::/28fc02:5cbf:ffff:ffff:ffff:ffff:ffff:ffff
205fc02:5cc0::/28fc02:5ccf:ffff:ffff:ffff:ffff:ffff:ffff
206fc02:5cd0::/28fc02:5cdf:ffff:ffff:ffff:ffff:ffff:ffff
207fc02:5ce0::/28fc02:5cef:ffff:ffff:ffff:ffff:ffff:ffff
208fc02:5cf0::/28fc02:5cff:ffff:ffff:ffff:ffff:ffff:ffff
209fc02:5d00::/28fc02:5d0f:ffff:ffff:ffff:ffff:ffff:ffff
210fc02:5d10::/28fc02:5d1f:ffff:ffff:ffff:ffff:ffff:ffff
211fc02:5d20::/28fc02:5d2f:ffff:ffff:ffff:ffff:ffff:ffff
212fc02:5d30::/28fc02:5d3f:ffff:ffff:ffff:ffff:ffff:ffff
213fc02:5d40::/28fc02:5d4f:ffff:ffff:ffff:ffff:ffff:ffff
214fc02:5d50::/28fc02:5d5f:ffff:ffff:ffff:ffff:ffff:ffff
215fc02:5d60::/28fc02:5d6f:ffff:ffff:ffff:ffff:ffff:ffff
216fc02:5d70::/28fc02:5d7f:ffff:ffff:ffff:ffff:ffff:ffff
217fc02:5d80::/28fc02:5d8f:ffff:ffff:ffff:ffff:ffff:ffff
218fc02:5d90::/28fc02:5d9f:ffff:ffff:ffff:ffff:ffff:ffff
219fc02:5da0::/28fc02:5daf:ffff:ffff:ffff:ffff:ffff:ffff
220fc02:5db0::/28fc02:5dbf:ffff:ffff:ffff:ffff:ffff:ffff
221fc02:5dc0::/28fc02:5dcf:ffff:ffff:ffff:ffff:ffff:ffff
222fc02:5dd0::/28fc02:5ddf:ffff:ffff:ffff:ffff:ffff:ffff
223fc02:5de0::/28fc02:5def:ffff:ffff:ffff:ffff:ffff:ffff
224fc02:5df0::/28fc02:5dff:ffff:ffff:ffff:ffff:ffff:ffff
225fc02:5e00::/28fc02:5e0f:ffff:ffff:ffff:ffff:ffff:ffff
226fc02:5e10::/28fc02:5e1f:ffff:ffff:ffff:ffff:ffff:ffff
227fc02:5e20::/28fc02:5e2f:ffff:ffff:ffff:ffff:ffff:ffff
228fc02:5e30::/28fc02:5e3f:ffff:ffff:ffff:ffff:ffff:ffff
229fc02:5e40::/28fc02:5e4f:ffff:ffff:ffff:ffff:ffff:ffff
230fc02:5e50::/28fc02:5e5f:ffff:ffff:ffff:ffff:ffff:ffff
231fc02:5e60::/28fc02:5e6f:ffff:ffff:ffff:ffff:ffff:ffff
232fc02:5e70::/28fc02:5e7f:ffff:ffff:ffff:ffff:ffff:ffff
233fc02:5e80::/28fc02:5e8f:ffff:ffff:ffff:ffff:ffff:ffff
234fc02:5e90::/28fc02:5e9f:ffff:ffff:ffff:ffff:ffff:ffff
235fc02:5ea0::/28fc02:5eaf:ffff:ffff:ffff:ffff:ffff:ffff
236fc02:5eb0::/28fc02:5ebf:ffff:ffff:ffff:ffff:ffff:ffff
237fc02:5ec0::/28fc02:5ecf:ffff:ffff:ffff:ffff:ffff:ffff
238fc02:5ed0::/28fc02:5edf:ffff:ffff:ffff:ffff:ffff:ffff
239fc02:5ee0::/28fc02:5eef:ffff:ffff:ffff:ffff:ffff:ffff
240fc02:5ef0::/28fc02:5eff:ffff:ffff:ffff:ffff:ffff:ffff
241fc02:5f00::/28fc02:5f0f:ffff:ffff:ffff:ffff:ffff:ffff
242fc02:5f10::/28fc02:5f1f:ffff:ffff:ffff:ffff:ffff:ffff
243fc02:5f20::/28fc02:5f2f:ffff:ffff:ffff:ffff:ffff:ffff
244fc02:5f30::/28fc02:5f3f:ffff:ffff:ffff:ffff:ffff:ffff
245fc02:5f40::/28fc02:5f4f:ffff:ffff:ffff:ffff:ffff:ffff
246fc02:5f50::/28fc02:5f5f:ffff:ffff:ffff:ffff:ffff:ffff
247fc02:5f60::/28fc02:5f6f:ffff:ffff:ffff:ffff:ffff:ffff
248fc02:5f70::/28fc02:5f7f:ffff:ffff:ffff:ffff:ffff:ffff
249fc02:5f80::/28fc02:5f8f:ffff:ffff:ffff:ffff:ffff:ffff
250fc02:5f90::/28fc02:5f9f:ffff:ffff:ffff:ffff:ffff:ffff
251fc02:5fa0::/28fc02:5faf:ffff:ffff:ffff:ffff:ffff:ffff
252fc02:5fb0::/28fc02:5fbf:ffff:ffff:ffff:ffff:ffff:ffff
253fc02:5fc0::/28fc02:5fcf:ffff:ffff:ffff:ffff:ffff:ffff
254fc02:5fd0::/28fc02:5fdf:ffff:ffff:ffff:ffff:ffff:ffff
255fc02:5fe0::/28fc02:5fef:ffff:ffff:ffff:ffff:ffff:ffff
256fc02:5ff0::/28fc02:5fff:ffff:ffff:ffff:ffff:ffff:ffff

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.