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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
fc09:e000::/20
First address
fc09:e000::
Last address
fc09:efff: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
fc09:e000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
e.9.0.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)

fc09:e000::/20 makes 256 subnets of /28.

Subnets
#SubnetLast address
1fc09:e000::/28fc09:e00f:ffff:ffff:ffff:ffff:ffff:ffff
2fc09:e010::/28fc09:e01f:ffff:ffff:ffff:ffff:ffff:ffff
3fc09:e020::/28fc09:e02f:ffff:ffff:ffff:ffff:ffff:ffff
4fc09:e030::/28fc09:e03f:ffff:ffff:ffff:ffff:ffff:ffff
5fc09:e040::/28fc09:e04f:ffff:ffff:ffff:ffff:ffff:ffff
6fc09:e050::/28fc09:e05f:ffff:ffff:ffff:ffff:ffff:ffff
7fc09:e060::/28fc09:e06f:ffff:ffff:ffff:ffff:ffff:ffff
8fc09:e070::/28fc09:e07f:ffff:ffff:ffff:ffff:ffff:ffff
9fc09:e080::/28fc09:e08f:ffff:ffff:ffff:ffff:ffff:ffff
10fc09:e090::/28fc09:e09f:ffff:ffff:ffff:ffff:ffff:ffff
11fc09:e0a0::/28fc09:e0af:ffff:ffff:ffff:ffff:ffff:ffff
12fc09:e0b0::/28fc09:e0bf:ffff:ffff:ffff:ffff:ffff:ffff
13fc09:e0c0::/28fc09:e0cf:ffff:ffff:ffff:ffff:ffff:ffff
14fc09:e0d0::/28fc09:e0df:ffff:ffff:ffff:ffff:ffff:ffff
15fc09:e0e0::/28fc09:e0ef:ffff:ffff:ffff:ffff:ffff:ffff
16fc09:e0f0::/28fc09:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
17fc09:e100::/28fc09:e10f:ffff:ffff:ffff:ffff:ffff:ffff
18fc09:e110::/28fc09:e11f:ffff:ffff:ffff:ffff:ffff:ffff
19fc09:e120::/28fc09:e12f:ffff:ffff:ffff:ffff:ffff:ffff
20fc09:e130::/28fc09:e13f:ffff:ffff:ffff:ffff:ffff:ffff
21fc09:e140::/28fc09:e14f:ffff:ffff:ffff:ffff:ffff:ffff
22fc09:e150::/28fc09:e15f:ffff:ffff:ffff:ffff:ffff:ffff
23fc09:e160::/28fc09:e16f:ffff:ffff:ffff:ffff:ffff:ffff
24fc09:e170::/28fc09:e17f:ffff:ffff:ffff:ffff:ffff:ffff
25fc09:e180::/28fc09:e18f:ffff:ffff:ffff:ffff:ffff:ffff
26fc09:e190::/28fc09:e19f:ffff:ffff:ffff:ffff:ffff:ffff
27fc09:e1a0::/28fc09:e1af:ffff:ffff:ffff:ffff:ffff:ffff
28fc09:e1b0::/28fc09:e1bf:ffff:ffff:ffff:ffff:ffff:ffff
29fc09:e1c0::/28fc09:e1cf:ffff:ffff:ffff:ffff:ffff:ffff
30fc09:e1d0::/28fc09:e1df:ffff:ffff:ffff:ffff:ffff:ffff
31fc09:e1e0::/28fc09:e1ef:ffff:ffff:ffff:ffff:ffff:ffff
32fc09:e1f0::/28fc09:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
33fc09:e200::/28fc09:e20f:ffff:ffff:ffff:ffff:ffff:ffff
34fc09:e210::/28fc09:e21f:ffff:ffff:ffff:ffff:ffff:ffff
35fc09:e220::/28fc09:e22f:ffff:ffff:ffff:ffff:ffff:ffff
36fc09:e230::/28fc09:e23f:ffff:ffff:ffff:ffff:ffff:ffff
37fc09:e240::/28fc09:e24f:ffff:ffff:ffff:ffff:ffff:ffff
38fc09:e250::/28fc09:e25f:ffff:ffff:ffff:ffff:ffff:ffff
39fc09:e260::/28fc09:e26f:ffff:ffff:ffff:ffff:ffff:ffff
40fc09:e270::/28fc09:e27f:ffff:ffff:ffff:ffff:ffff:ffff
41fc09:e280::/28fc09:e28f:ffff:ffff:ffff:ffff:ffff:ffff
42fc09:e290::/28fc09:e29f:ffff:ffff:ffff:ffff:ffff:ffff
43fc09:e2a0::/28fc09:e2af:ffff:ffff:ffff:ffff:ffff:ffff
44fc09:e2b0::/28fc09:e2bf:ffff:ffff:ffff:ffff:ffff:ffff
45fc09:e2c0::/28fc09:e2cf:ffff:ffff:ffff:ffff:ffff:ffff
46fc09:e2d0::/28fc09:e2df:ffff:ffff:ffff:ffff:ffff:ffff
47fc09:e2e0::/28fc09:e2ef:ffff:ffff:ffff:ffff:ffff:ffff
48fc09:e2f0::/28fc09:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
49fc09:e300::/28fc09:e30f:ffff:ffff:ffff:ffff:ffff:ffff
50fc09:e310::/28fc09:e31f:ffff:ffff:ffff:ffff:ffff:ffff
51fc09:e320::/28fc09:e32f:ffff:ffff:ffff:ffff:ffff:ffff
52fc09:e330::/28fc09:e33f:ffff:ffff:ffff:ffff:ffff:ffff
53fc09:e340::/28fc09:e34f:ffff:ffff:ffff:ffff:ffff:ffff
54fc09:e350::/28fc09:e35f:ffff:ffff:ffff:ffff:ffff:ffff
55fc09:e360::/28fc09:e36f:ffff:ffff:ffff:ffff:ffff:ffff
56fc09:e370::/28fc09:e37f:ffff:ffff:ffff:ffff:ffff:ffff
57fc09:e380::/28fc09:e38f:ffff:ffff:ffff:ffff:ffff:ffff
58fc09:e390::/28fc09:e39f:ffff:ffff:ffff:ffff:ffff:ffff
59fc09:e3a0::/28fc09:e3af:ffff:ffff:ffff:ffff:ffff:ffff
60fc09:e3b0::/28fc09:e3bf:ffff:ffff:ffff:ffff:ffff:ffff
61fc09:e3c0::/28fc09:e3cf:ffff:ffff:ffff:ffff:ffff:ffff
62fc09:e3d0::/28fc09:e3df:ffff:ffff:ffff:ffff:ffff:ffff
63fc09:e3e0::/28fc09:e3ef:ffff:ffff:ffff:ffff:ffff:ffff
64fc09:e3f0::/28fc09:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
65fc09:e400::/28fc09:e40f:ffff:ffff:ffff:ffff:ffff:ffff
66fc09:e410::/28fc09:e41f:ffff:ffff:ffff:ffff:ffff:ffff
67fc09:e420::/28fc09:e42f:ffff:ffff:ffff:ffff:ffff:ffff
68fc09:e430::/28fc09:e43f:ffff:ffff:ffff:ffff:ffff:ffff
69fc09:e440::/28fc09:e44f:ffff:ffff:ffff:ffff:ffff:ffff
70fc09:e450::/28fc09:e45f:ffff:ffff:ffff:ffff:ffff:ffff
71fc09:e460::/28fc09:e46f:ffff:ffff:ffff:ffff:ffff:ffff
72fc09:e470::/28fc09:e47f:ffff:ffff:ffff:ffff:ffff:ffff
73fc09:e480::/28fc09:e48f:ffff:ffff:ffff:ffff:ffff:ffff
74fc09:e490::/28fc09:e49f:ffff:ffff:ffff:ffff:ffff:ffff
75fc09:e4a0::/28fc09:e4af:ffff:ffff:ffff:ffff:ffff:ffff
76fc09:e4b0::/28fc09:e4bf:ffff:ffff:ffff:ffff:ffff:ffff
77fc09:e4c0::/28fc09:e4cf:ffff:ffff:ffff:ffff:ffff:ffff
78fc09:e4d0::/28fc09:e4df:ffff:ffff:ffff:ffff:ffff:ffff
79fc09:e4e0::/28fc09:e4ef:ffff:ffff:ffff:ffff:ffff:ffff
80fc09:e4f0::/28fc09:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
81fc09:e500::/28fc09:e50f:ffff:ffff:ffff:ffff:ffff:ffff
82fc09:e510::/28fc09:e51f:ffff:ffff:ffff:ffff:ffff:ffff
83fc09:e520::/28fc09:e52f:ffff:ffff:ffff:ffff:ffff:ffff
84fc09:e530::/28fc09:e53f:ffff:ffff:ffff:ffff:ffff:ffff
85fc09:e540::/28fc09:e54f:ffff:ffff:ffff:ffff:ffff:ffff
86fc09:e550::/28fc09:e55f:ffff:ffff:ffff:ffff:ffff:ffff
87fc09:e560::/28fc09:e56f:ffff:ffff:ffff:ffff:ffff:ffff
88fc09:e570::/28fc09:e57f:ffff:ffff:ffff:ffff:ffff:ffff
89fc09:e580::/28fc09:e58f:ffff:ffff:ffff:ffff:ffff:ffff
90fc09:e590::/28fc09:e59f:ffff:ffff:ffff:ffff:ffff:ffff
91fc09:e5a0::/28fc09:e5af:ffff:ffff:ffff:ffff:ffff:ffff
92fc09:e5b0::/28fc09:e5bf:ffff:ffff:ffff:ffff:ffff:ffff
93fc09:e5c0::/28fc09:e5cf:ffff:ffff:ffff:ffff:ffff:ffff
94fc09:e5d0::/28fc09:e5df:ffff:ffff:ffff:ffff:ffff:ffff
95fc09:e5e0::/28fc09:e5ef:ffff:ffff:ffff:ffff:ffff:ffff
96fc09:e5f0::/28fc09:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
97fc09:e600::/28fc09:e60f:ffff:ffff:ffff:ffff:ffff:ffff
98fc09:e610::/28fc09:e61f:ffff:ffff:ffff:ffff:ffff:ffff
99fc09:e620::/28fc09:e62f:ffff:ffff:ffff:ffff:ffff:ffff
100fc09:e630::/28fc09:e63f:ffff:ffff:ffff:ffff:ffff:ffff
101fc09:e640::/28fc09:e64f:ffff:ffff:ffff:ffff:ffff:ffff
102fc09:e650::/28fc09:e65f:ffff:ffff:ffff:ffff:ffff:ffff
103fc09:e660::/28fc09:e66f:ffff:ffff:ffff:ffff:ffff:ffff
104fc09:e670::/28fc09:e67f:ffff:ffff:ffff:ffff:ffff:ffff
105fc09:e680::/28fc09:e68f:ffff:ffff:ffff:ffff:ffff:ffff
106fc09:e690::/28fc09:e69f:ffff:ffff:ffff:ffff:ffff:ffff
107fc09:e6a0::/28fc09:e6af:ffff:ffff:ffff:ffff:ffff:ffff
108fc09:e6b0::/28fc09:e6bf:ffff:ffff:ffff:ffff:ffff:ffff
109fc09:e6c0::/28fc09:e6cf:ffff:ffff:ffff:ffff:ffff:ffff
110fc09:e6d0::/28fc09:e6df:ffff:ffff:ffff:ffff:ffff:ffff
111fc09:e6e0::/28fc09:e6ef:ffff:ffff:ffff:ffff:ffff:ffff
112fc09:e6f0::/28fc09:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
113fc09:e700::/28fc09:e70f:ffff:ffff:ffff:ffff:ffff:ffff
114fc09:e710::/28fc09:e71f:ffff:ffff:ffff:ffff:ffff:ffff
115fc09:e720::/28fc09:e72f:ffff:ffff:ffff:ffff:ffff:ffff
116fc09:e730::/28fc09:e73f:ffff:ffff:ffff:ffff:ffff:ffff
117fc09:e740::/28fc09:e74f:ffff:ffff:ffff:ffff:ffff:ffff
118fc09:e750::/28fc09:e75f:ffff:ffff:ffff:ffff:ffff:ffff
119fc09:e760::/28fc09:e76f:ffff:ffff:ffff:ffff:ffff:ffff
120fc09:e770::/28fc09:e77f:ffff:ffff:ffff:ffff:ffff:ffff
121fc09:e780::/28fc09:e78f:ffff:ffff:ffff:ffff:ffff:ffff
122fc09:e790::/28fc09:e79f:ffff:ffff:ffff:ffff:ffff:ffff
123fc09:e7a0::/28fc09:e7af:ffff:ffff:ffff:ffff:ffff:ffff
124fc09:e7b0::/28fc09:e7bf:ffff:ffff:ffff:ffff:ffff:ffff
125fc09:e7c0::/28fc09:e7cf:ffff:ffff:ffff:ffff:ffff:ffff
126fc09:e7d0::/28fc09:e7df:ffff:ffff:ffff:ffff:ffff:ffff
127fc09:e7e0::/28fc09:e7ef:ffff:ffff:ffff:ffff:ffff:ffff
128fc09:e7f0::/28fc09:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
129fc09:e800::/28fc09:e80f:ffff:ffff:ffff:ffff:ffff:ffff
130fc09:e810::/28fc09:e81f:ffff:ffff:ffff:ffff:ffff:ffff
131fc09:e820::/28fc09:e82f:ffff:ffff:ffff:ffff:ffff:ffff
132fc09:e830::/28fc09:e83f:ffff:ffff:ffff:ffff:ffff:ffff
133fc09:e840::/28fc09:e84f:ffff:ffff:ffff:ffff:ffff:ffff
134fc09:e850::/28fc09:e85f:ffff:ffff:ffff:ffff:ffff:ffff
135fc09:e860::/28fc09:e86f:ffff:ffff:ffff:ffff:ffff:ffff
136fc09:e870::/28fc09:e87f:ffff:ffff:ffff:ffff:ffff:ffff
137fc09:e880::/28fc09:e88f:ffff:ffff:ffff:ffff:ffff:ffff
138fc09:e890::/28fc09:e89f:ffff:ffff:ffff:ffff:ffff:ffff
139fc09:e8a0::/28fc09:e8af:ffff:ffff:ffff:ffff:ffff:ffff
140fc09:e8b0::/28fc09:e8bf:ffff:ffff:ffff:ffff:ffff:ffff
141fc09:e8c0::/28fc09:e8cf:ffff:ffff:ffff:ffff:ffff:ffff
142fc09:e8d0::/28fc09:e8df:ffff:ffff:ffff:ffff:ffff:ffff
143fc09:e8e0::/28fc09:e8ef:ffff:ffff:ffff:ffff:ffff:ffff
144fc09:e8f0::/28fc09:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
145fc09:e900::/28fc09:e90f:ffff:ffff:ffff:ffff:ffff:ffff
146fc09:e910::/28fc09:e91f:ffff:ffff:ffff:ffff:ffff:ffff
147fc09:e920::/28fc09:e92f:ffff:ffff:ffff:ffff:ffff:ffff
148fc09:e930::/28fc09:e93f:ffff:ffff:ffff:ffff:ffff:ffff
149fc09:e940::/28fc09:e94f:ffff:ffff:ffff:ffff:ffff:ffff
150fc09:e950::/28fc09:e95f:ffff:ffff:ffff:ffff:ffff:ffff
151fc09:e960::/28fc09:e96f:ffff:ffff:ffff:ffff:ffff:ffff
152fc09:e970::/28fc09:e97f:ffff:ffff:ffff:ffff:ffff:ffff
153fc09:e980::/28fc09:e98f:ffff:ffff:ffff:ffff:ffff:ffff
154fc09:e990::/28fc09:e99f:ffff:ffff:ffff:ffff:ffff:ffff
155fc09:e9a0::/28fc09:e9af:ffff:ffff:ffff:ffff:ffff:ffff
156fc09:e9b0::/28fc09:e9bf:ffff:ffff:ffff:ffff:ffff:ffff
157fc09:e9c0::/28fc09:e9cf:ffff:ffff:ffff:ffff:ffff:ffff
158fc09:e9d0::/28fc09:e9df:ffff:ffff:ffff:ffff:ffff:ffff
159fc09:e9e0::/28fc09:e9ef:ffff:ffff:ffff:ffff:ffff:ffff
160fc09:e9f0::/28fc09:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
161fc09:ea00::/28fc09:ea0f:ffff:ffff:ffff:ffff:ffff:ffff
162fc09:ea10::/28fc09:ea1f:ffff:ffff:ffff:ffff:ffff:ffff
163fc09:ea20::/28fc09:ea2f:ffff:ffff:ffff:ffff:ffff:ffff
164fc09:ea30::/28fc09:ea3f:ffff:ffff:ffff:ffff:ffff:ffff
165fc09:ea40::/28fc09:ea4f:ffff:ffff:ffff:ffff:ffff:ffff
166fc09:ea50::/28fc09:ea5f:ffff:ffff:ffff:ffff:ffff:ffff
167fc09:ea60::/28fc09:ea6f:ffff:ffff:ffff:ffff:ffff:ffff
168fc09:ea70::/28fc09:ea7f:ffff:ffff:ffff:ffff:ffff:ffff
169fc09:ea80::/28fc09:ea8f:ffff:ffff:ffff:ffff:ffff:ffff
170fc09:ea90::/28fc09:ea9f:ffff:ffff:ffff:ffff:ffff:ffff
171fc09:eaa0::/28fc09:eaaf:ffff:ffff:ffff:ffff:ffff:ffff
172fc09:eab0::/28fc09:eabf:ffff:ffff:ffff:ffff:ffff:ffff
173fc09:eac0::/28fc09:eacf:ffff:ffff:ffff:ffff:ffff:ffff
174fc09:ead0::/28fc09:eadf:ffff:ffff:ffff:ffff:ffff:ffff
175fc09:eae0::/28fc09:eaef:ffff:ffff:ffff:ffff:ffff:ffff
176fc09:eaf0::/28fc09:eaff:ffff:ffff:ffff:ffff:ffff:ffff
177fc09:eb00::/28fc09:eb0f:ffff:ffff:ffff:ffff:ffff:ffff
178fc09:eb10::/28fc09:eb1f:ffff:ffff:ffff:ffff:ffff:ffff
179fc09:eb20::/28fc09:eb2f:ffff:ffff:ffff:ffff:ffff:ffff
180fc09:eb30::/28fc09:eb3f:ffff:ffff:ffff:ffff:ffff:ffff
181fc09:eb40::/28fc09:eb4f:ffff:ffff:ffff:ffff:ffff:ffff
182fc09:eb50::/28fc09:eb5f:ffff:ffff:ffff:ffff:ffff:ffff
183fc09:eb60::/28fc09:eb6f:ffff:ffff:ffff:ffff:ffff:ffff
184fc09:eb70::/28fc09:eb7f:ffff:ffff:ffff:ffff:ffff:ffff
185fc09:eb80::/28fc09:eb8f:ffff:ffff:ffff:ffff:ffff:ffff
186fc09:eb90::/28fc09:eb9f:ffff:ffff:ffff:ffff:ffff:ffff
187fc09:eba0::/28fc09:ebaf:ffff:ffff:ffff:ffff:ffff:ffff
188fc09:ebb0::/28fc09:ebbf:ffff:ffff:ffff:ffff:ffff:ffff
189fc09:ebc0::/28fc09:ebcf:ffff:ffff:ffff:ffff:ffff:ffff
190fc09:ebd0::/28fc09:ebdf:ffff:ffff:ffff:ffff:ffff:ffff
191fc09:ebe0::/28fc09:ebef:ffff:ffff:ffff:ffff:ffff:ffff
192fc09:ebf0::/28fc09:ebff:ffff:ffff:ffff:ffff:ffff:ffff
193fc09:ec00::/28fc09:ec0f:ffff:ffff:ffff:ffff:ffff:ffff
194fc09:ec10::/28fc09:ec1f:ffff:ffff:ffff:ffff:ffff:ffff
195fc09:ec20::/28fc09:ec2f:ffff:ffff:ffff:ffff:ffff:ffff
196fc09:ec30::/28fc09:ec3f:ffff:ffff:ffff:ffff:ffff:ffff
197fc09:ec40::/28fc09:ec4f:ffff:ffff:ffff:ffff:ffff:ffff
198fc09:ec50::/28fc09:ec5f:ffff:ffff:ffff:ffff:ffff:ffff
199fc09:ec60::/28fc09:ec6f:ffff:ffff:ffff:ffff:ffff:ffff
200fc09:ec70::/28fc09:ec7f:ffff:ffff:ffff:ffff:ffff:ffff
201fc09:ec80::/28fc09:ec8f:ffff:ffff:ffff:ffff:ffff:ffff
202fc09:ec90::/28fc09:ec9f:ffff:ffff:ffff:ffff:ffff:ffff
203fc09:eca0::/28fc09:ecaf:ffff:ffff:ffff:ffff:ffff:ffff
204fc09:ecb0::/28fc09:ecbf:ffff:ffff:ffff:ffff:ffff:ffff
205fc09:ecc0::/28fc09:eccf:ffff:ffff:ffff:ffff:ffff:ffff
206fc09:ecd0::/28fc09:ecdf:ffff:ffff:ffff:ffff:ffff:ffff
207fc09:ece0::/28fc09:ecef:ffff:ffff:ffff:ffff:ffff:ffff
208fc09:ecf0::/28fc09:ecff:ffff:ffff:ffff:ffff:ffff:ffff
209fc09:ed00::/28fc09:ed0f:ffff:ffff:ffff:ffff:ffff:ffff
210fc09:ed10::/28fc09:ed1f:ffff:ffff:ffff:ffff:ffff:ffff
211fc09:ed20::/28fc09:ed2f:ffff:ffff:ffff:ffff:ffff:ffff
212fc09:ed30::/28fc09:ed3f:ffff:ffff:ffff:ffff:ffff:ffff
213fc09:ed40::/28fc09:ed4f:ffff:ffff:ffff:ffff:ffff:ffff
214fc09:ed50::/28fc09:ed5f:ffff:ffff:ffff:ffff:ffff:ffff
215fc09:ed60::/28fc09:ed6f:ffff:ffff:ffff:ffff:ffff:ffff
216fc09:ed70::/28fc09:ed7f:ffff:ffff:ffff:ffff:ffff:ffff
217fc09:ed80::/28fc09:ed8f:ffff:ffff:ffff:ffff:ffff:ffff
218fc09:ed90::/28fc09:ed9f:ffff:ffff:ffff:ffff:ffff:ffff
219fc09:eda0::/28fc09:edaf:ffff:ffff:ffff:ffff:ffff:ffff
220fc09:edb0::/28fc09:edbf:ffff:ffff:ffff:ffff:ffff:ffff
221fc09:edc0::/28fc09:edcf:ffff:ffff:ffff:ffff:ffff:ffff
222fc09:edd0::/28fc09:eddf:ffff:ffff:ffff:ffff:ffff:ffff
223fc09:ede0::/28fc09:edef:ffff:ffff:ffff:ffff:ffff:ffff
224fc09:edf0::/28fc09:edff:ffff:ffff:ffff:ffff:ffff:ffff
225fc09:ee00::/28fc09:ee0f:ffff:ffff:ffff:ffff:ffff:ffff
226fc09:ee10::/28fc09:ee1f:ffff:ffff:ffff:ffff:ffff:ffff
227fc09:ee20::/28fc09:ee2f:ffff:ffff:ffff:ffff:ffff:ffff
228fc09:ee30::/28fc09:ee3f:ffff:ffff:ffff:ffff:ffff:ffff
229fc09:ee40::/28fc09:ee4f:ffff:ffff:ffff:ffff:ffff:ffff
230fc09:ee50::/28fc09:ee5f:ffff:ffff:ffff:ffff:ffff:ffff
231fc09:ee60::/28fc09:ee6f:ffff:ffff:ffff:ffff:ffff:ffff
232fc09:ee70::/28fc09:ee7f:ffff:ffff:ffff:ffff:ffff:ffff
233fc09:ee80::/28fc09:ee8f:ffff:ffff:ffff:ffff:ffff:ffff
234fc09:ee90::/28fc09:ee9f:ffff:ffff:ffff:ffff:ffff:ffff
235fc09:eea0::/28fc09:eeaf:ffff:ffff:ffff:ffff:ffff:ffff
236fc09:eeb0::/28fc09:eebf:ffff:ffff:ffff:ffff:ffff:ffff
237fc09:eec0::/28fc09:eecf:ffff:ffff:ffff:ffff:ffff:ffff
238fc09:eed0::/28fc09:eedf:ffff:ffff:ffff:ffff:ffff:ffff
239fc09:eee0::/28fc09:eeef:ffff:ffff:ffff:ffff:ffff:ffff
240fc09:eef0::/28fc09:eeff:ffff:ffff:ffff:ffff:ffff:ffff
241fc09:ef00::/28fc09:ef0f:ffff:ffff:ffff:ffff:ffff:ffff
242fc09:ef10::/28fc09:ef1f:ffff:ffff:ffff:ffff:ffff:ffff
243fc09:ef20::/28fc09:ef2f:ffff:ffff:ffff:ffff:ffff:ffff
244fc09:ef30::/28fc09:ef3f:ffff:ffff:ffff:ffff:ffff:ffff
245fc09:ef40::/28fc09:ef4f:ffff:ffff:ffff:ffff:ffff:ffff
246fc09:ef50::/28fc09:ef5f:ffff:ffff:ffff:ffff:ffff:ffff
247fc09:ef60::/28fc09:ef6f:ffff:ffff:ffff:ffff:ffff:ffff
248fc09:ef70::/28fc09:ef7f:ffff:ffff:ffff:ffff:ffff:ffff
249fc09:ef80::/28fc09:ef8f:ffff:ffff:ffff:ffff:ffff:ffff
250fc09:ef90::/28fc09:ef9f:ffff:ffff:ffff:ffff:ffff:ffff
251fc09:efa0::/28fc09:efaf:ffff:ffff:ffff:ffff:ffff:ffff
252fc09:efb0::/28fc09:efbf:ffff:ffff:ffff:ffff:ffff:ffff
253fc09:efc0::/28fc09:efcf:ffff:ffff:ffff:ffff:ffff:ffff
254fc09:efd0::/28fc09:efdf:ffff:ffff:ffff:ffff:ffff:ffff
255fc09:efe0::/28fc09:efef:ffff:ffff:ffff:ffff:ffff:ffff
256fc09:eff0::/28fc09:efff: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.