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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/12
Addresses2^116
/64 networks2^52
Network
2940::/12
First address
2940::
Last address
294f:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
83,076,749,736,557,242,056,487,941,267,521,536 (2^116)
/64 networks (LANs)
4,503,599,627,370,496 (2^52)
Full form
2940:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
4.9.2.ip6.arpa
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2940::/12 makes 256 subnets of /20.

Subnets
#SubnetLast address
12940::/202940:fff:ffff:ffff:ffff:ffff:ffff:ffff
22940:1000::/202940:1fff:ffff:ffff:ffff:ffff:ffff:ffff
32940:2000::/202940:2fff:ffff:ffff:ffff:ffff:ffff:ffff
42940:3000::/202940:3fff:ffff:ffff:ffff:ffff:ffff:ffff
52940:4000::/202940:4fff:ffff:ffff:ffff:ffff:ffff:ffff
62940:5000::/202940:5fff:ffff:ffff:ffff:ffff:ffff:ffff
72940:6000::/202940:6fff:ffff:ffff:ffff:ffff:ffff:ffff
82940:7000::/202940:7fff:ffff:ffff:ffff:ffff:ffff:ffff
92940:8000::/202940:8fff:ffff:ffff:ffff:ffff:ffff:ffff
102940:9000::/202940:9fff:ffff:ffff:ffff:ffff:ffff:ffff
112940:a000::/202940:afff:ffff:ffff:ffff:ffff:ffff:ffff
122940:b000::/202940:bfff:ffff:ffff:ffff:ffff:ffff:ffff
132940:c000::/202940:cfff:ffff:ffff:ffff:ffff:ffff:ffff
142940:d000::/202940:dfff:ffff:ffff:ffff:ffff:ffff:ffff
152940:e000::/202940:efff:ffff:ffff:ffff:ffff:ffff:ffff
162940:f000::/202940:ffff:ffff:ffff:ffff:ffff:ffff:ffff
172941::/202941:fff:ffff:ffff:ffff:ffff:ffff:ffff
182941:1000::/202941:1fff:ffff:ffff:ffff:ffff:ffff:ffff
192941:2000::/202941:2fff:ffff:ffff:ffff:ffff:ffff:ffff
202941:3000::/202941:3fff:ffff:ffff:ffff:ffff:ffff:ffff
212941:4000::/202941:4fff:ffff:ffff:ffff:ffff:ffff:ffff
222941:5000::/202941:5fff:ffff:ffff:ffff:ffff:ffff:ffff
232941:6000::/202941:6fff:ffff:ffff:ffff:ffff:ffff:ffff
242941:7000::/202941:7fff:ffff:ffff:ffff:ffff:ffff:ffff
252941:8000::/202941:8fff:ffff:ffff:ffff:ffff:ffff:ffff
262941:9000::/202941:9fff:ffff:ffff:ffff:ffff:ffff:ffff
272941:a000::/202941:afff:ffff:ffff:ffff:ffff:ffff:ffff
282941:b000::/202941:bfff:ffff:ffff:ffff:ffff:ffff:ffff
292941:c000::/202941:cfff:ffff:ffff:ffff:ffff:ffff:ffff
302941:d000::/202941:dfff:ffff:ffff:ffff:ffff:ffff:ffff
312941:e000::/202941:efff:ffff:ffff:ffff:ffff:ffff:ffff
322941:f000::/202941:ffff:ffff:ffff:ffff:ffff:ffff:ffff
332942::/202942:fff:ffff:ffff:ffff:ffff:ffff:ffff
342942:1000::/202942:1fff:ffff:ffff:ffff:ffff:ffff:ffff
352942:2000::/202942:2fff:ffff:ffff:ffff:ffff:ffff:ffff
362942:3000::/202942:3fff:ffff:ffff:ffff:ffff:ffff:ffff
372942:4000::/202942:4fff:ffff:ffff:ffff:ffff:ffff:ffff
382942:5000::/202942:5fff:ffff:ffff:ffff:ffff:ffff:ffff
392942:6000::/202942:6fff:ffff:ffff:ffff:ffff:ffff:ffff
402942:7000::/202942:7fff:ffff:ffff:ffff:ffff:ffff:ffff
412942:8000::/202942:8fff:ffff:ffff:ffff:ffff:ffff:ffff
422942:9000::/202942:9fff:ffff:ffff:ffff:ffff:ffff:ffff
432942:a000::/202942:afff:ffff:ffff:ffff:ffff:ffff:ffff
442942:b000::/202942:bfff:ffff:ffff:ffff:ffff:ffff:ffff
452942:c000::/202942:cfff:ffff:ffff:ffff:ffff:ffff:ffff
462942:d000::/202942:dfff:ffff:ffff:ffff:ffff:ffff:ffff
472942:e000::/202942:efff:ffff:ffff:ffff:ffff:ffff:ffff
482942:f000::/202942:ffff:ffff:ffff:ffff:ffff:ffff:ffff
492943::/202943:fff:ffff:ffff:ffff:ffff:ffff:ffff
502943:1000::/202943:1fff:ffff:ffff:ffff:ffff:ffff:ffff
512943:2000::/202943:2fff:ffff:ffff:ffff:ffff:ffff:ffff
522943:3000::/202943:3fff:ffff:ffff:ffff:ffff:ffff:ffff
532943:4000::/202943:4fff:ffff:ffff:ffff:ffff:ffff:ffff
542943:5000::/202943:5fff:ffff:ffff:ffff:ffff:ffff:ffff
552943:6000::/202943:6fff:ffff:ffff:ffff:ffff:ffff:ffff
562943:7000::/202943:7fff:ffff:ffff:ffff:ffff:ffff:ffff
572943:8000::/202943:8fff:ffff:ffff:ffff:ffff:ffff:ffff
582943:9000::/202943:9fff:ffff:ffff:ffff:ffff:ffff:ffff
592943:a000::/202943:afff:ffff:ffff:ffff:ffff:ffff:ffff
602943:b000::/202943:bfff:ffff:ffff:ffff:ffff:ffff:ffff
612943:c000::/202943:cfff:ffff:ffff:ffff:ffff:ffff:ffff
622943:d000::/202943:dfff:ffff:ffff:ffff:ffff:ffff:ffff
632943:e000::/202943:efff:ffff:ffff:ffff:ffff:ffff:ffff
642943:f000::/202943:ffff:ffff:ffff:ffff:ffff:ffff:ffff
652944::/202944:fff:ffff:ffff:ffff:ffff:ffff:ffff
662944:1000::/202944:1fff:ffff:ffff:ffff:ffff:ffff:ffff
672944:2000::/202944:2fff:ffff:ffff:ffff:ffff:ffff:ffff
682944:3000::/202944:3fff:ffff:ffff:ffff:ffff:ffff:ffff
692944:4000::/202944:4fff:ffff:ffff:ffff:ffff:ffff:ffff
702944:5000::/202944:5fff:ffff:ffff:ffff:ffff:ffff:ffff
712944:6000::/202944:6fff:ffff:ffff:ffff:ffff:ffff:ffff
722944:7000::/202944:7fff:ffff:ffff:ffff:ffff:ffff:ffff
732944:8000::/202944:8fff:ffff:ffff:ffff:ffff:ffff:ffff
742944:9000::/202944:9fff:ffff:ffff:ffff:ffff:ffff:ffff
752944:a000::/202944:afff:ffff:ffff:ffff:ffff:ffff:ffff
762944:b000::/202944:bfff:ffff:ffff:ffff:ffff:ffff:ffff
772944:c000::/202944:cfff:ffff:ffff:ffff:ffff:ffff:ffff
782944:d000::/202944:dfff:ffff:ffff:ffff:ffff:ffff:ffff
792944:e000::/202944:efff:ffff:ffff:ffff:ffff:ffff:ffff
802944:f000::/202944:ffff:ffff:ffff:ffff:ffff:ffff:ffff
812945::/202945:fff:ffff:ffff:ffff:ffff:ffff:ffff
822945:1000::/202945:1fff:ffff:ffff:ffff:ffff:ffff:ffff
832945:2000::/202945:2fff:ffff:ffff:ffff:ffff:ffff:ffff
842945:3000::/202945:3fff:ffff:ffff:ffff:ffff:ffff:ffff
852945:4000::/202945:4fff:ffff:ffff:ffff:ffff:ffff:ffff
862945:5000::/202945:5fff:ffff:ffff:ffff:ffff:ffff:ffff
872945:6000::/202945:6fff:ffff:ffff:ffff:ffff:ffff:ffff
882945:7000::/202945:7fff:ffff:ffff:ffff:ffff:ffff:ffff
892945:8000::/202945:8fff:ffff:ffff:ffff:ffff:ffff:ffff
902945:9000::/202945:9fff:ffff:ffff:ffff:ffff:ffff:ffff
912945:a000::/202945:afff:ffff:ffff:ffff:ffff:ffff:ffff
922945:b000::/202945:bfff:ffff:ffff:ffff:ffff:ffff:ffff
932945:c000::/202945:cfff:ffff:ffff:ffff:ffff:ffff:ffff
942945:d000::/202945:dfff:ffff:ffff:ffff:ffff:ffff:ffff
952945:e000::/202945:efff:ffff:ffff:ffff:ffff:ffff:ffff
962945:f000::/202945:ffff:ffff:ffff:ffff:ffff:ffff:ffff
972946::/202946:fff:ffff:ffff:ffff:ffff:ffff:ffff
982946:1000::/202946:1fff:ffff:ffff:ffff:ffff:ffff:ffff
992946:2000::/202946:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1002946:3000::/202946:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1012946:4000::/202946:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1022946:5000::/202946:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1032946:6000::/202946:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1042946:7000::/202946:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1052946:8000::/202946:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1062946:9000::/202946:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1072946:a000::/202946:afff:ffff:ffff:ffff:ffff:ffff:ffff
1082946:b000::/202946:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1092946:c000::/202946:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1102946:d000::/202946:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1112946:e000::/202946:efff:ffff:ffff:ffff:ffff:ffff:ffff
1122946:f000::/202946:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1132947::/202947:fff:ffff:ffff:ffff:ffff:ffff:ffff
1142947:1000::/202947:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1152947:2000::/202947:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1162947:3000::/202947:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1172947:4000::/202947:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1182947:5000::/202947:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1192947:6000::/202947:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1202947:7000::/202947:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1212947:8000::/202947:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1222947:9000::/202947:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1232947:a000::/202947:afff:ffff:ffff:ffff:ffff:ffff:ffff
1242947:b000::/202947:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1252947:c000::/202947:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1262947:d000::/202947:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1272947:e000::/202947:efff:ffff:ffff:ffff:ffff:ffff:ffff
1282947:f000::/202947:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1292948::/202948:fff:ffff:ffff:ffff:ffff:ffff:ffff
1302948:1000::/202948:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1312948:2000::/202948:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1322948:3000::/202948:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1332948:4000::/202948:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1342948:5000::/202948:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1352948:6000::/202948:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1362948:7000::/202948:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1372948:8000::/202948:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1382948:9000::/202948:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1392948:a000::/202948:afff:ffff:ffff:ffff:ffff:ffff:ffff
1402948:b000::/202948:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1412948:c000::/202948:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1422948:d000::/202948:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1432948:e000::/202948:efff:ffff:ffff:ffff:ffff:ffff:ffff
1442948:f000::/202948:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1452949::/202949:fff:ffff:ffff:ffff:ffff:ffff:ffff
1462949:1000::/202949:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1472949:2000::/202949:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1482949:3000::/202949:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1492949:4000::/202949:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1502949:5000::/202949:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1512949:6000::/202949:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1522949:7000::/202949:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1532949:8000::/202949:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1542949:9000::/202949:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1552949:a000::/202949:afff:ffff:ffff:ffff:ffff:ffff:ffff
1562949:b000::/202949:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1572949:c000::/202949:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1582949:d000::/202949:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1592949:e000::/202949:efff:ffff:ffff:ffff:ffff:ffff:ffff
1602949:f000::/202949:ffff:ffff:ffff:ffff:ffff:ffff:ffff
161294a::/20294a:fff:ffff:ffff:ffff:ffff:ffff:ffff
162294a:1000::/20294a:1fff:ffff:ffff:ffff:ffff:ffff:ffff
163294a:2000::/20294a:2fff:ffff:ffff:ffff:ffff:ffff:ffff
164294a:3000::/20294a:3fff:ffff:ffff:ffff:ffff:ffff:ffff
165294a:4000::/20294a:4fff:ffff:ffff:ffff:ffff:ffff:ffff
166294a:5000::/20294a:5fff:ffff:ffff:ffff:ffff:ffff:ffff
167294a:6000::/20294a:6fff:ffff:ffff:ffff:ffff:ffff:ffff
168294a:7000::/20294a:7fff:ffff:ffff:ffff:ffff:ffff:ffff
169294a:8000::/20294a:8fff:ffff:ffff:ffff:ffff:ffff:ffff
170294a:9000::/20294a:9fff:ffff:ffff:ffff:ffff:ffff:ffff
171294a:a000::/20294a:afff:ffff:ffff:ffff:ffff:ffff:ffff
172294a:b000::/20294a:bfff:ffff:ffff:ffff:ffff:ffff:ffff
173294a:c000::/20294a:cfff:ffff:ffff:ffff:ffff:ffff:ffff
174294a:d000::/20294a:dfff:ffff:ffff:ffff:ffff:ffff:ffff
175294a:e000::/20294a:efff:ffff:ffff:ffff:ffff:ffff:ffff
176294a:f000::/20294a:ffff:ffff:ffff:ffff:ffff:ffff:ffff
177294b::/20294b:fff:ffff:ffff:ffff:ffff:ffff:ffff
178294b:1000::/20294b:1fff:ffff:ffff:ffff:ffff:ffff:ffff
179294b:2000::/20294b:2fff:ffff:ffff:ffff:ffff:ffff:ffff
180294b:3000::/20294b:3fff:ffff:ffff:ffff:ffff:ffff:ffff
181294b:4000::/20294b:4fff:ffff:ffff:ffff:ffff:ffff:ffff
182294b:5000::/20294b:5fff:ffff:ffff:ffff:ffff:ffff:ffff
183294b:6000::/20294b:6fff:ffff:ffff:ffff:ffff:ffff:ffff
184294b:7000::/20294b:7fff:ffff:ffff:ffff:ffff:ffff:ffff
185294b:8000::/20294b:8fff:ffff:ffff:ffff:ffff:ffff:ffff
186294b:9000::/20294b:9fff:ffff:ffff:ffff:ffff:ffff:ffff
187294b:a000::/20294b:afff:ffff:ffff:ffff:ffff:ffff:ffff
188294b:b000::/20294b:bfff:ffff:ffff:ffff:ffff:ffff:ffff
189294b:c000::/20294b:cfff:ffff:ffff:ffff:ffff:ffff:ffff
190294b:d000::/20294b:dfff:ffff:ffff:ffff:ffff:ffff:ffff
191294b:e000::/20294b:efff:ffff:ffff:ffff:ffff:ffff:ffff
192294b:f000::/20294b:ffff:ffff:ffff:ffff:ffff:ffff:ffff
193294c::/20294c:fff:ffff:ffff:ffff:ffff:ffff:ffff
194294c:1000::/20294c:1fff:ffff:ffff:ffff:ffff:ffff:ffff
195294c:2000::/20294c:2fff:ffff:ffff:ffff:ffff:ffff:ffff
196294c:3000::/20294c:3fff:ffff:ffff:ffff:ffff:ffff:ffff
197294c:4000::/20294c:4fff:ffff:ffff:ffff:ffff:ffff:ffff
198294c:5000::/20294c:5fff:ffff:ffff:ffff:ffff:ffff:ffff
199294c:6000::/20294c:6fff:ffff:ffff:ffff:ffff:ffff:ffff
200294c:7000::/20294c:7fff:ffff:ffff:ffff:ffff:ffff:ffff
201294c:8000::/20294c:8fff:ffff:ffff:ffff:ffff:ffff:ffff
202294c:9000::/20294c:9fff:ffff:ffff:ffff:ffff:ffff:ffff
203294c:a000::/20294c:afff:ffff:ffff:ffff:ffff:ffff:ffff
204294c:b000::/20294c:bfff:ffff:ffff:ffff:ffff:ffff:ffff
205294c:c000::/20294c:cfff:ffff:ffff:ffff:ffff:ffff:ffff
206294c:d000::/20294c:dfff:ffff:ffff:ffff:ffff:ffff:ffff
207294c:e000::/20294c:efff:ffff:ffff:ffff:ffff:ffff:ffff
208294c:f000::/20294c:ffff:ffff:ffff:ffff:ffff:ffff:ffff
209294d::/20294d:fff:ffff:ffff:ffff:ffff:ffff:ffff
210294d:1000::/20294d:1fff:ffff:ffff:ffff:ffff:ffff:ffff
211294d:2000::/20294d:2fff:ffff:ffff:ffff:ffff:ffff:ffff
212294d:3000::/20294d:3fff:ffff:ffff:ffff:ffff:ffff:ffff
213294d:4000::/20294d:4fff:ffff:ffff:ffff:ffff:ffff:ffff
214294d:5000::/20294d:5fff:ffff:ffff:ffff:ffff:ffff:ffff
215294d:6000::/20294d:6fff:ffff:ffff:ffff:ffff:ffff:ffff
216294d:7000::/20294d:7fff:ffff:ffff:ffff:ffff:ffff:ffff
217294d:8000::/20294d:8fff:ffff:ffff:ffff:ffff:ffff:ffff
218294d:9000::/20294d:9fff:ffff:ffff:ffff:ffff:ffff:ffff
219294d:a000::/20294d:afff:ffff:ffff:ffff:ffff:ffff:ffff
220294d:b000::/20294d:bfff:ffff:ffff:ffff:ffff:ffff:ffff
221294d:c000::/20294d:cfff:ffff:ffff:ffff:ffff:ffff:ffff
222294d:d000::/20294d:dfff:ffff:ffff:ffff:ffff:ffff:ffff
223294d:e000::/20294d:efff:ffff:ffff:ffff:ffff:ffff:ffff
224294d:f000::/20294d:ffff:ffff:ffff:ffff:ffff:ffff:ffff
225294e::/20294e:fff:ffff:ffff:ffff:ffff:ffff:ffff
226294e:1000::/20294e:1fff:ffff:ffff:ffff:ffff:ffff:ffff
227294e:2000::/20294e:2fff:ffff:ffff:ffff:ffff:ffff:ffff
228294e:3000::/20294e:3fff:ffff:ffff:ffff:ffff:ffff:ffff
229294e:4000::/20294e:4fff:ffff:ffff:ffff:ffff:ffff:ffff
230294e:5000::/20294e:5fff:ffff:ffff:ffff:ffff:ffff:ffff
231294e:6000::/20294e:6fff:ffff:ffff:ffff:ffff:ffff:ffff
232294e:7000::/20294e:7fff:ffff:ffff:ffff:ffff:ffff:ffff
233294e:8000::/20294e:8fff:ffff:ffff:ffff:ffff:ffff:ffff
234294e:9000::/20294e:9fff:ffff:ffff:ffff:ffff:ffff:ffff
235294e:a000::/20294e:afff:ffff:ffff:ffff:ffff:ffff:ffff
236294e:b000::/20294e:bfff:ffff:ffff:ffff:ffff:ffff:ffff
237294e:c000::/20294e:cfff:ffff:ffff:ffff:ffff:ffff:ffff
238294e:d000::/20294e:dfff:ffff:ffff:ffff:ffff:ffff:ffff
239294e:e000::/20294e:efff:ffff:ffff:ffff:ffff:ffff:ffff
240294e:f000::/20294e:ffff:ffff:ffff:ffff:ffff:ffff:ffff
241294f::/20294f:fff:ffff:ffff:ffff:ffff:ffff:ffff
242294f:1000::/20294f:1fff:ffff:ffff:ffff:ffff:ffff:ffff
243294f:2000::/20294f:2fff:ffff:ffff:ffff:ffff:ffff:ffff
244294f:3000::/20294f:3fff:ffff:ffff:ffff:ffff:ffff:ffff
245294f:4000::/20294f:4fff:ffff:ffff:ffff:ffff:ffff:ffff
246294f:5000::/20294f:5fff:ffff:ffff:ffff:ffff:ffff:ffff
247294f:6000::/20294f:6fff:ffff:ffff:ffff:ffff:ffff:ffff
248294f:7000::/20294f:7fff:ffff:ffff:ffff:ffff:ffff:ffff
249294f:8000::/20294f:8fff:ffff:ffff:ffff:ffff:ffff:ffff
250294f:9000::/20294f:9fff:ffff:ffff:ffff:ffff:ffff:ffff
251294f:a000::/20294f:afff:ffff:ffff:ffff:ffff:ffff:ffff
252294f:b000::/20294f:bfff:ffff:ffff:ffff:ffff:ffff:ffff
253294f:c000::/20294f:cfff:ffff:ffff:ffff:ffff:ffff:ffff
254294f:d000::/20294f:dfff:ffff:ffff:ffff:ffff:ffff:ffff
255294f:e000::/20294f:efff:ffff:ffff:ffff:ffff:ffff:ffff
256294f:f000::/20294f:ffff: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.