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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/7
Addresses2^121
/64 networks2^57
Network
3000::/7
First address
3000::
Last address
31ff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
2,658,455,991,569,831,745,807,614,120,560,689,152 (2^121)
/64 networks (LANs)
144,115,188,075,855,872 (2^57)
Full form
3000:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zones
0.3.ip6.arpa
1.3.ip6.arpa
/7 is not on a 4-bit boundary, so it takes 2 /8 zones.
Split into smaller subnets/20
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/16 (512)/20 (8,192)

3000::/7 makes 8,192 subnets of /20; the first 256 are listed.

Subnets
#SubnetLast address
13000::/203000:fff:ffff:ffff:ffff:ffff:ffff:ffff
23000:1000::/203000:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33000:2000::/203000:2fff:ffff:ffff:ffff:ffff:ffff:ffff
43000:3000::/203000:3fff:ffff:ffff:ffff:ffff:ffff:ffff
53000:4000::/203000:4fff:ffff:ffff:ffff:ffff:ffff:ffff
63000:5000::/203000:5fff:ffff:ffff:ffff:ffff:ffff:ffff
73000:6000::/203000:6fff:ffff:ffff:ffff:ffff:ffff:ffff
83000:7000::/203000:7fff:ffff:ffff:ffff:ffff:ffff:ffff
93000:8000::/203000:8fff:ffff:ffff:ffff:ffff:ffff:ffff
103000:9000::/203000:9fff:ffff:ffff:ffff:ffff:ffff:ffff
113000:a000::/203000:afff:ffff:ffff:ffff:ffff:ffff:ffff
123000:b000::/203000:bfff:ffff:ffff:ffff:ffff:ffff:ffff
133000:c000::/203000:cfff:ffff:ffff:ffff:ffff:ffff:ffff
143000:d000::/203000:dfff:ffff:ffff:ffff:ffff:ffff:ffff
153000:e000::/203000:efff:ffff:ffff:ffff:ffff:ffff:ffff
163000:f000::/203000:ffff:ffff:ffff:ffff:ffff:ffff:ffff
173001::/203001:fff:ffff:ffff:ffff:ffff:ffff:ffff
183001:1000::/203001:1fff:ffff:ffff:ffff:ffff:ffff:ffff
193001:2000::/203001:2fff:ffff:ffff:ffff:ffff:ffff:ffff
203001:3000::/203001:3fff:ffff:ffff:ffff:ffff:ffff:ffff
213001:4000::/203001:4fff:ffff:ffff:ffff:ffff:ffff:ffff
223001:5000::/203001:5fff:ffff:ffff:ffff:ffff:ffff:ffff
233001:6000::/203001:6fff:ffff:ffff:ffff:ffff:ffff:ffff
243001:7000::/203001:7fff:ffff:ffff:ffff:ffff:ffff:ffff
253001:8000::/203001:8fff:ffff:ffff:ffff:ffff:ffff:ffff
263001:9000::/203001:9fff:ffff:ffff:ffff:ffff:ffff:ffff
273001:a000::/203001:afff:ffff:ffff:ffff:ffff:ffff:ffff
283001:b000::/203001:bfff:ffff:ffff:ffff:ffff:ffff:ffff
293001:c000::/203001:cfff:ffff:ffff:ffff:ffff:ffff:ffff
303001:d000::/203001:dfff:ffff:ffff:ffff:ffff:ffff:ffff
313001:e000::/203001:efff:ffff:ffff:ffff:ffff:ffff:ffff
323001:f000::/203001:ffff:ffff:ffff:ffff:ffff:ffff:ffff
333002::/203002:fff:ffff:ffff:ffff:ffff:ffff:ffff
343002:1000::/203002:1fff:ffff:ffff:ffff:ffff:ffff:ffff
353002:2000::/203002:2fff:ffff:ffff:ffff:ffff:ffff:ffff
363002:3000::/203002:3fff:ffff:ffff:ffff:ffff:ffff:ffff
373002:4000::/203002:4fff:ffff:ffff:ffff:ffff:ffff:ffff
383002:5000::/203002:5fff:ffff:ffff:ffff:ffff:ffff:ffff
393002:6000::/203002:6fff:ffff:ffff:ffff:ffff:ffff:ffff
403002:7000::/203002:7fff:ffff:ffff:ffff:ffff:ffff:ffff
413002:8000::/203002:8fff:ffff:ffff:ffff:ffff:ffff:ffff
423002:9000::/203002:9fff:ffff:ffff:ffff:ffff:ffff:ffff
433002:a000::/203002:afff:ffff:ffff:ffff:ffff:ffff:ffff
443002:b000::/203002:bfff:ffff:ffff:ffff:ffff:ffff:ffff
453002:c000::/203002:cfff:ffff:ffff:ffff:ffff:ffff:ffff
463002:d000::/203002:dfff:ffff:ffff:ffff:ffff:ffff:ffff
473002:e000::/203002:efff:ffff:ffff:ffff:ffff:ffff:ffff
483002:f000::/203002:ffff:ffff:ffff:ffff:ffff:ffff:ffff
493003::/203003:fff:ffff:ffff:ffff:ffff:ffff:ffff
503003:1000::/203003:1fff:ffff:ffff:ffff:ffff:ffff:ffff
513003:2000::/203003:2fff:ffff:ffff:ffff:ffff:ffff:ffff
523003:3000::/203003:3fff:ffff:ffff:ffff:ffff:ffff:ffff
533003:4000::/203003:4fff:ffff:ffff:ffff:ffff:ffff:ffff
543003:5000::/203003:5fff:ffff:ffff:ffff:ffff:ffff:ffff
553003:6000::/203003:6fff:ffff:ffff:ffff:ffff:ffff:ffff
563003:7000::/203003:7fff:ffff:ffff:ffff:ffff:ffff:ffff
573003:8000::/203003:8fff:ffff:ffff:ffff:ffff:ffff:ffff
583003:9000::/203003:9fff:ffff:ffff:ffff:ffff:ffff:ffff
593003:a000::/203003:afff:ffff:ffff:ffff:ffff:ffff:ffff
603003:b000::/203003:bfff:ffff:ffff:ffff:ffff:ffff:ffff
613003:c000::/203003:cfff:ffff:ffff:ffff:ffff:ffff:ffff
623003:d000::/203003:dfff:ffff:ffff:ffff:ffff:ffff:ffff
633003:e000::/203003:efff:ffff:ffff:ffff:ffff:ffff:ffff
643003:f000::/203003:ffff:ffff:ffff:ffff:ffff:ffff:ffff
653004::/203004:fff:ffff:ffff:ffff:ffff:ffff:ffff
663004:1000::/203004:1fff:ffff:ffff:ffff:ffff:ffff:ffff
673004:2000::/203004:2fff:ffff:ffff:ffff:ffff:ffff:ffff
683004:3000::/203004:3fff:ffff:ffff:ffff:ffff:ffff:ffff
693004:4000::/203004:4fff:ffff:ffff:ffff:ffff:ffff:ffff
703004:5000::/203004:5fff:ffff:ffff:ffff:ffff:ffff:ffff
713004:6000::/203004:6fff:ffff:ffff:ffff:ffff:ffff:ffff
723004:7000::/203004:7fff:ffff:ffff:ffff:ffff:ffff:ffff
733004:8000::/203004:8fff:ffff:ffff:ffff:ffff:ffff:ffff
743004:9000::/203004:9fff:ffff:ffff:ffff:ffff:ffff:ffff
753004:a000::/203004:afff:ffff:ffff:ffff:ffff:ffff:ffff
763004:b000::/203004:bfff:ffff:ffff:ffff:ffff:ffff:ffff
773004:c000::/203004:cfff:ffff:ffff:ffff:ffff:ffff:ffff
783004:d000::/203004:dfff:ffff:ffff:ffff:ffff:ffff:ffff
793004:e000::/203004:efff:ffff:ffff:ffff:ffff:ffff:ffff
803004:f000::/203004:ffff:ffff:ffff:ffff:ffff:ffff:ffff
813005::/203005:fff:ffff:ffff:ffff:ffff:ffff:ffff
823005:1000::/203005:1fff:ffff:ffff:ffff:ffff:ffff:ffff
833005:2000::/203005:2fff:ffff:ffff:ffff:ffff:ffff:ffff
843005:3000::/203005:3fff:ffff:ffff:ffff:ffff:ffff:ffff
853005:4000::/203005:4fff:ffff:ffff:ffff:ffff:ffff:ffff
863005:5000::/203005:5fff:ffff:ffff:ffff:ffff:ffff:ffff
873005:6000::/203005:6fff:ffff:ffff:ffff:ffff:ffff:ffff
883005:7000::/203005:7fff:ffff:ffff:ffff:ffff:ffff:ffff
893005:8000::/203005:8fff:ffff:ffff:ffff:ffff:ffff:ffff
903005:9000::/203005:9fff:ffff:ffff:ffff:ffff:ffff:ffff
913005:a000::/203005:afff:ffff:ffff:ffff:ffff:ffff:ffff
923005:b000::/203005:bfff:ffff:ffff:ffff:ffff:ffff:ffff
933005:c000::/203005:cfff:ffff:ffff:ffff:ffff:ffff:ffff
943005:d000::/203005:dfff:ffff:ffff:ffff:ffff:ffff:ffff
953005:e000::/203005:efff:ffff:ffff:ffff:ffff:ffff:ffff
963005:f000::/203005:ffff:ffff:ffff:ffff:ffff:ffff:ffff
973006::/203006:fff:ffff:ffff:ffff:ffff:ffff:ffff
983006:1000::/203006:1fff:ffff:ffff:ffff:ffff:ffff:ffff
993006:2000::/203006:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1003006:3000::/203006:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1013006:4000::/203006:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1023006:5000::/203006:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1033006:6000::/203006:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1043006:7000::/203006:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1053006:8000::/203006:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1063006:9000::/203006:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1073006:a000::/203006:afff:ffff:ffff:ffff:ffff:ffff:ffff
1083006:b000::/203006:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1093006:c000::/203006:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1103006:d000::/203006:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1113006:e000::/203006:efff:ffff:ffff:ffff:ffff:ffff:ffff
1123006:f000::/203006:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1133007::/203007:fff:ffff:ffff:ffff:ffff:ffff:ffff
1143007:1000::/203007:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1153007:2000::/203007:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1163007:3000::/203007:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1173007:4000::/203007:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1183007:5000::/203007:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1193007:6000::/203007:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1203007:7000::/203007:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1213007:8000::/203007:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1223007:9000::/203007:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1233007:a000::/203007:afff:ffff:ffff:ffff:ffff:ffff:ffff
1243007:b000::/203007:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1253007:c000::/203007:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1263007:d000::/203007:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1273007:e000::/203007:efff:ffff:ffff:ffff:ffff:ffff:ffff
1283007:f000::/203007:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1293008::/203008:fff:ffff:ffff:ffff:ffff:ffff:ffff
1303008:1000::/203008:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1313008:2000::/203008:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1323008:3000::/203008:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1333008:4000::/203008:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1343008:5000::/203008:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1353008:6000::/203008:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1363008:7000::/203008:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1373008:8000::/203008:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1383008:9000::/203008:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1393008:a000::/203008:afff:ffff:ffff:ffff:ffff:ffff:ffff
1403008:b000::/203008:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1413008:c000::/203008:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1423008:d000::/203008:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1433008:e000::/203008:efff:ffff:ffff:ffff:ffff:ffff:ffff
1443008:f000::/203008:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1453009::/203009:fff:ffff:ffff:ffff:ffff:ffff:ffff
1463009:1000::/203009:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1473009:2000::/203009:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1483009:3000::/203009:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1493009:4000::/203009:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1503009:5000::/203009:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1513009:6000::/203009:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1523009:7000::/203009:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1533009:8000::/203009:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1543009:9000::/203009:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1553009:a000::/203009:afff:ffff:ffff:ffff:ffff:ffff:ffff
1563009:b000::/203009:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1573009:c000::/203009:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1583009:d000::/203009:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1593009:e000::/203009:efff:ffff:ffff:ffff:ffff:ffff:ffff
1603009:f000::/203009:ffff:ffff:ffff:ffff:ffff:ffff:ffff
161300a::/20300a:fff:ffff:ffff:ffff:ffff:ffff:ffff
162300a:1000::/20300a:1fff:ffff:ffff:ffff:ffff:ffff:ffff
163300a:2000::/20300a:2fff:ffff:ffff:ffff:ffff:ffff:ffff
164300a:3000::/20300a:3fff:ffff:ffff:ffff:ffff:ffff:ffff
165300a:4000::/20300a:4fff:ffff:ffff:ffff:ffff:ffff:ffff
166300a:5000::/20300a:5fff:ffff:ffff:ffff:ffff:ffff:ffff
167300a:6000::/20300a:6fff:ffff:ffff:ffff:ffff:ffff:ffff
168300a:7000::/20300a:7fff:ffff:ffff:ffff:ffff:ffff:ffff
169300a:8000::/20300a:8fff:ffff:ffff:ffff:ffff:ffff:ffff
170300a:9000::/20300a:9fff:ffff:ffff:ffff:ffff:ffff:ffff
171300a:a000::/20300a:afff:ffff:ffff:ffff:ffff:ffff:ffff
172300a:b000::/20300a:bfff:ffff:ffff:ffff:ffff:ffff:ffff
173300a:c000::/20300a:cfff:ffff:ffff:ffff:ffff:ffff:ffff
174300a:d000::/20300a:dfff:ffff:ffff:ffff:ffff:ffff:ffff
175300a:e000::/20300a:efff:ffff:ffff:ffff:ffff:ffff:ffff
176300a:f000::/20300a:ffff:ffff:ffff:ffff:ffff:ffff:ffff
177300b::/20300b:fff:ffff:ffff:ffff:ffff:ffff:ffff
178300b:1000::/20300b:1fff:ffff:ffff:ffff:ffff:ffff:ffff
179300b:2000::/20300b:2fff:ffff:ffff:ffff:ffff:ffff:ffff
180300b:3000::/20300b:3fff:ffff:ffff:ffff:ffff:ffff:ffff
181300b:4000::/20300b:4fff:ffff:ffff:ffff:ffff:ffff:ffff
182300b:5000::/20300b:5fff:ffff:ffff:ffff:ffff:ffff:ffff
183300b:6000::/20300b:6fff:ffff:ffff:ffff:ffff:ffff:ffff
184300b:7000::/20300b:7fff:ffff:ffff:ffff:ffff:ffff:ffff
185300b:8000::/20300b:8fff:ffff:ffff:ffff:ffff:ffff:ffff
186300b:9000::/20300b:9fff:ffff:ffff:ffff:ffff:ffff:ffff
187300b:a000::/20300b:afff:ffff:ffff:ffff:ffff:ffff:ffff
188300b:b000::/20300b:bfff:ffff:ffff:ffff:ffff:ffff:ffff
189300b:c000::/20300b:cfff:ffff:ffff:ffff:ffff:ffff:ffff
190300b:d000::/20300b:dfff:ffff:ffff:ffff:ffff:ffff:ffff
191300b:e000::/20300b:efff:ffff:ffff:ffff:ffff:ffff:ffff
192300b:f000::/20300b:ffff:ffff:ffff:ffff:ffff:ffff:ffff
193300c::/20300c:fff:ffff:ffff:ffff:ffff:ffff:ffff
194300c:1000::/20300c:1fff:ffff:ffff:ffff:ffff:ffff:ffff
195300c:2000::/20300c:2fff:ffff:ffff:ffff:ffff:ffff:ffff
196300c:3000::/20300c:3fff:ffff:ffff:ffff:ffff:ffff:ffff
197300c:4000::/20300c:4fff:ffff:ffff:ffff:ffff:ffff:ffff
198300c:5000::/20300c:5fff:ffff:ffff:ffff:ffff:ffff:ffff
199300c:6000::/20300c:6fff:ffff:ffff:ffff:ffff:ffff:ffff
200300c:7000::/20300c:7fff:ffff:ffff:ffff:ffff:ffff:ffff
201300c:8000::/20300c:8fff:ffff:ffff:ffff:ffff:ffff:ffff
202300c:9000::/20300c:9fff:ffff:ffff:ffff:ffff:ffff:ffff
203300c:a000::/20300c:afff:ffff:ffff:ffff:ffff:ffff:ffff
204300c:b000::/20300c:bfff:ffff:ffff:ffff:ffff:ffff:ffff
205300c:c000::/20300c:cfff:ffff:ffff:ffff:ffff:ffff:ffff
206300c:d000::/20300c:dfff:ffff:ffff:ffff:ffff:ffff:ffff
207300c:e000::/20300c:efff:ffff:ffff:ffff:ffff:ffff:ffff
208300c:f000::/20300c:ffff:ffff:ffff:ffff:ffff:ffff:ffff
209300d::/20300d:fff:ffff:ffff:ffff:ffff:ffff:ffff
210300d:1000::/20300d:1fff:ffff:ffff:ffff:ffff:ffff:ffff
211300d:2000::/20300d:2fff:ffff:ffff:ffff:ffff:ffff:ffff
212300d:3000::/20300d:3fff:ffff:ffff:ffff:ffff:ffff:ffff
213300d:4000::/20300d:4fff:ffff:ffff:ffff:ffff:ffff:ffff
214300d:5000::/20300d:5fff:ffff:ffff:ffff:ffff:ffff:ffff
215300d:6000::/20300d:6fff:ffff:ffff:ffff:ffff:ffff:ffff
216300d:7000::/20300d:7fff:ffff:ffff:ffff:ffff:ffff:ffff
217300d:8000::/20300d:8fff:ffff:ffff:ffff:ffff:ffff:ffff
218300d:9000::/20300d:9fff:ffff:ffff:ffff:ffff:ffff:ffff
219300d:a000::/20300d:afff:ffff:ffff:ffff:ffff:ffff:ffff
220300d:b000::/20300d:bfff:ffff:ffff:ffff:ffff:ffff:ffff
221300d:c000::/20300d:cfff:ffff:ffff:ffff:ffff:ffff:ffff
222300d:d000::/20300d:dfff:ffff:ffff:ffff:ffff:ffff:ffff
223300d:e000::/20300d:efff:ffff:ffff:ffff:ffff:ffff:ffff
224300d:f000::/20300d:ffff:ffff:ffff:ffff:ffff:ffff:ffff
225300e::/20300e:fff:ffff:ffff:ffff:ffff:ffff:ffff
226300e:1000::/20300e:1fff:ffff:ffff:ffff:ffff:ffff:ffff
227300e:2000::/20300e:2fff:ffff:ffff:ffff:ffff:ffff:ffff
228300e:3000::/20300e:3fff:ffff:ffff:ffff:ffff:ffff:ffff
229300e:4000::/20300e:4fff:ffff:ffff:ffff:ffff:ffff:ffff
230300e:5000::/20300e:5fff:ffff:ffff:ffff:ffff:ffff:ffff
231300e:6000::/20300e:6fff:ffff:ffff:ffff:ffff:ffff:ffff
232300e:7000::/20300e:7fff:ffff:ffff:ffff:ffff:ffff:ffff
233300e:8000::/20300e:8fff:ffff:ffff:ffff:ffff:ffff:ffff
234300e:9000::/20300e:9fff:ffff:ffff:ffff:ffff:ffff:ffff
235300e:a000::/20300e:afff:ffff:ffff:ffff:ffff:ffff:ffff
236300e:b000::/20300e:bfff:ffff:ffff:ffff:ffff:ffff:ffff
237300e:c000::/20300e:cfff:ffff:ffff:ffff:ffff:ffff:ffff
238300e:d000::/20300e:dfff:ffff:ffff:ffff:ffff:ffff:ffff
239300e:e000::/20300e:efff:ffff:ffff:ffff:ffff:ffff:ffff
240300e:f000::/20300e:ffff:ffff:ffff:ffff:ffff:ffff:ffff
241300f::/20300f:fff:ffff:ffff:ffff:ffff:ffff:ffff
242300f:1000::/20300f:1fff:ffff:ffff:ffff:ffff:ffff:ffff
243300f:2000::/20300f:2fff:ffff:ffff:ffff:ffff:ffff:ffff
244300f:3000::/20300f:3fff:ffff:ffff:ffff:ffff:ffff:ffff
245300f:4000::/20300f:4fff:ffff:ffff:ffff:ffff:ffff:ffff
246300f:5000::/20300f:5fff:ffff:ffff:ffff:ffff:ffff:ffff
247300f:6000::/20300f:6fff:ffff:ffff:ffff:ffff:ffff:ffff
248300f:7000::/20300f:7fff:ffff:ffff:ffff:ffff:ffff:ffff
249300f:8000::/20300f:8fff:ffff:ffff:ffff:ffff:ffff:ffff
250300f:9000::/20300f:9fff:ffff:ffff:ffff:ffff:ffff:ffff
251300f:a000::/20300f:afff:ffff:ffff:ffff:ffff:ffff:ffff
252300f:b000::/20300f:bfff:ffff:ffff:ffff:ffff:ffff:ffff
253300f:c000::/20300f:cfff:ffff:ffff:ffff:ffff:ffff:ffff
254300f:d000::/20300f:dfff:ffff:ffff:ffff:ffff:ffff:ffff
255300f:e000::/20300f:efff:ffff:ffff:ffff:ffff:ffff:ffff
256300f:f000::/20300f: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.