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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
2150::/12
First address
2150::
Last address
215f: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
2150:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
5.1.2.ip6.arpa
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2150::/12 makes 256 subnets of /20.

Subnets
#SubnetLast address
12150::/202150:fff:ffff:ffff:ffff:ffff:ffff:ffff
22150:1000::/202150:1fff:ffff:ffff:ffff:ffff:ffff:ffff
32150:2000::/202150:2fff:ffff:ffff:ffff:ffff:ffff:ffff
42150:3000::/202150:3fff:ffff:ffff:ffff:ffff:ffff:ffff
52150:4000::/202150:4fff:ffff:ffff:ffff:ffff:ffff:ffff
62150:5000::/202150:5fff:ffff:ffff:ffff:ffff:ffff:ffff
72150:6000::/202150:6fff:ffff:ffff:ffff:ffff:ffff:ffff
82150:7000::/202150:7fff:ffff:ffff:ffff:ffff:ffff:ffff
92150:8000::/202150:8fff:ffff:ffff:ffff:ffff:ffff:ffff
102150:9000::/202150:9fff:ffff:ffff:ffff:ffff:ffff:ffff
112150:a000::/202150:afff:ffff:ffff:ffff:ffff:ffff:ffff
122150:b000::/202150:bfff:ffff:ffff:ffff:ffff:ffff:ffff
132150:c000::/202150:cfff:ffff:ffff:ffff:ffff:ffff:ffff
142150:d000::/202150:dfff:ffff:ffff:ffff:ffff:ffff:ffff
152150:e000::/202150:efff:ffff:ffff:ffff:ffff:ffff:ffff
162150:f000::/202150:ffff:ffff:ffff:ffff:ffff:ffff:ffff
172151::/202151:fff:ffff:ffff:ffff:ffff:ffff:ffff
182151:1000::/202151:1fff:ffff:ffff:ffff:ffff:ffff:ffff
192151:2000::/202151:2fff:ffff:ffff:ffff:ffff:ffff:ffff
202151:3000::/202151:3fff:ffff:ffff:ffff:ffff:ffff:ffff
212151:4000::/202151:4fff:ffff:ffff:ffff:ffff:ffff:ffff
222151:5000::/202151:5fff:ffff:ffff:ffff:ffff:ffff:ffff
232151:6000::/202151:6fff:ffff:ffff:ffff:ffff:ffff:ffff
242151:7000::/202151:7fff:ffff:ffff:ffff:ffff:ffff:ffff
252151:8000::/202151:8fff:ffff:ffff:ffff:ffff:ffff:ffff
262151:9000::/202151:9fff:ffff:ffff:ffff:ffff:ffff:ffff
272151:a000::/202151:afff:ffff:ffff:ffff:ffff:ffff:ffff
282151:b000::/202151:bfff:ffff:ffff:ffff:ffff:ffff:ffff
292151:c000::/202151:cfff:ffff:ffff:ffff:ffff:ffff:ffff
302151:d000::/202151:dfff:ffff:ffff:ffff:ffff:ffff:ffff
312151:e000::/202151:efff:ffff:ffff:ffff:ffff:ffff:ffff
322151:f000::/202151:ffff:ffff:ffff:ffff:ffff:ffff:ffff
332152::/202152:fff:ffff:ffff:ffff:ffff:ffff:ffff
342152:1000::/202152:1fff:ffff:ffff:ffff:ffff:ffff:ffff
352152:2000::/202152:2fff:ffff:ffff:ffff:ffff:ffff:ffff
362152:3000::/202152:3fff:ffff:ffff:ffff:ffff:ffff:ffff
372152:4000::/202152:4fff:ffff:ffff:ffff:ffff:ffff:ffff
382152:5000::/202152:5fff:ffff:ffff:ffff:ffff:ffff:ffff
392152:6000::/202152:6fff:ffff:ffff:ffff:ffff:ffff:ffff
402152:7000::/202152:7fff:ffff:ffff:ffff:ffff:ffff:ffff
412152:8000::/202152:8fff:ffff:ffff:ffff:ffff:ffff:ffff
422152:9000::/202152:9fff:ffff:ffff:ffff:ffff:ffff:ffff
432152:a000::/202152:afff:ffff:ffff:ffff:ffff:ffff:ffff
442152:b000::/202152:bfff:ffff:ffff:ffff:ffff:ffff:ffff
452152:c000::/202152:cfff:ffff:ffff:ffff:ffff:ffff:ffff
462152:d000::/202152:dfff:ffff:ffff:ffff:ffff:ffff:ffff
472152:e000::/202152:efff:ffff:ffff:ffff:ffff:ffff:ffff
482152:f000::/202152:ffff:ffff:ffff:ffff:ffff:ffff:ffff
492153::/202153:fff:ffff:ffff:ffff:ffff:ffff:ffff
502153:1000::/202153:1fff:ffff:ffff:ffff:ffff:ffff:ffff
512153:2000::/202153:2fff:ffff:ffff:ffff:ffff:ffff:ffff
522153:3000::/202153:3fff:ffff:ffff:ffff:ffff:ffff:ffff
532153:4000::/202153:4fff:ffff:ffff:ffff:ffff:ffff:ffff
542153:5000::/202153:5fff:ffff:ffff:ffff:ffff:ffff:ffff
552153:6000::/202153:6fff:ffff:ffff:ffff:ffff:ffff:ffff
562153:7000::/202153:7fff:ffff:ffff:ffff:ffff:ffff:ffff
572153:8000::/202153:8fff:ffff:ffff:ffff:ffff:ffff:ffff
582153:9000::/202153:9fff:ffff:ffff:ffff:ffff:ffff:ffff
592153:a000::/202153:afff:ffff:ffff:ffff:ffff:ffff:ffff
602153:b000::/202153:bfff:ffff:ffff:ffff:ffff:ffff:ffff
612153:c000::/202153:cfff:ffff:ffff:ffff:ffff:ffff:ffff
622153:d000::/202153:dfff:ffff:ffff:ffff:ffff:ffff:ffff
632153:e000::/202153:efff:ffff:ffff:ffff:ffff:ffff:ffff
642153:f000::/202153:ffff:ffff:ffff:ffff:ffff:ffff:ffff
652154::/202154:fff:ffff:ffff:ffff:ffff:ffff:ffff
662154:1000::/202154:1fff:ffff:ffff:ffff:ffff:ffff:ffff
672154:2000::/202154:2fff:ffff:ffff:ffff:ffff:ffff:ffff
682154:3000::/202154:3fff:ffff:ffff:ffff:ffff:ffff:ffff
692154:4000::/202154:4fff:ffff:ffff:ffff:ffff:ffff:ffff
702154:5000::/202154:5fff:ffff:ffff:ffff:ffff:ffff:ffff
712154:6000::/202154:6fff:ffff:ffff:ffff:ffff:ffff:ffff
722154:7000::/202154:7fff:ffff:ffff:ffff:ffff:ffff:ffff
732154:8000::/202154:8fff:ffff:ffff:ffff:ffff:ffff:ffff
742154:9000::/202154:9fff:ffff:ffff:ffff:ffff:ffff:ffff
752154:a000::/202154:afff:ffff:ffff:ffff:ffff:ffff:ffff
762154:b000::/202154:bfff:ffff:ffff:ffff:ffff:ffff:ffff
772154:c000::/202154:cfff:ffff:ffff:ffff:ffff:ffff:ffff
782154:d000::/202154:dfff:ffff:ffff:ffff:ffff:ffff:ffff
792154:e000::/202154:efff:ffff:ffff:ffff:ffff:ffff:ffff
802154:f000::/202154:ffff:ffff:ffff:ffff:ffff:ffff:ffff
812155::/202155:fff:ffff:ffff:ffff:ffff:ffff:ffff
822155:1000::/202155:1fff:ffff:ffff:ffff:ffff:ffff:ffff
832155:2000::/202155:2fff:ffff:ffff:ffff:ffff:ffff:ffff
842155:3000::/202155:3fff:ffff:ffff:ffff:ffff:ffff:ffff
852155:4000::/202155:4fff:ffff:ffff:ffff:ffff:ffff:ffff
862155:5000::/202155:5fff:ffff:ffff:ffff:ffff:ffff:ffff
872155:6000::/202155:6fff:ffff:ffff:ffff:ffff:ffff:ffff
882155:7000::/202155:7fff:ffff:ffff:ffff:ffff:ffff:ffff
892155:8000::/202155:8fff:ffff:ffff:ffff:ffff:ffff:ffff
902155:9000::/202155:9fff:ffff:ffff:ffff:ffff:ffff:ffff
912155:a000::/202155:afff:ffff:ffff:ffff:ffff:ffff:ffff
922155:b000::/202155:bfff:ffff:ffff:ffff:ffff:ffff:ffff
932155:c000::/202155:cfff:ffff:ffff:ffff:ffff:ffff:ffff
942155:d000::/202155:dfff:ffff:ffff:ffff:ffff:ffff:ffff
952155:e000::/202155:efff:ffff:ffff:ffff:ffff:ffff:ffff
962155:f000::/202155:ffff:ffff:ffff:ffff:ffff:ffff:ffff
972156::/202156:fff:ffff:ffff:ffff:ffff:ffff:ffff
982156:1000::/202156:1fff:ffff:ffff:ffff:ffff:ffff:ffff
992156:2000::/202156:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1002156:3000::/202156:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1012156:4000::/202156:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1022156:5000::/202156:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1032156:6000::/202156:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1042156:7000::/202156:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1052156:8000::/202156:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1062156:9000::/202156:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1072156:a000::/202156:afff:ffff:ffff:ffff:ffff:ffff:ffff
1082156:b000::/202156:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1092156:c000::/202156:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1102156:d000::/202156:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1112156:e000::/202156:efff:ffff:ffff:ffff:ffff:ffff:ffff
1122156:f000::/202156:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1132157::/202157:fff:ffff:ffff:ffff:ffff:ffff:ffff
1142157:1000::/202157:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1152157:2000::/202157:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1162157:3000::/202157:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1172157:4000::/202157:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1182157:5000::/202157:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1192157:6000::/202157:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1202157:7000::/202157:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1212157:8000::/202157:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1222157:9000::/202157:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1232157:a000::/202157:afff:ffff:ffff:ffff:ffff:ffff:ffff
1242157:b000::/202157:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1252157:c000::/202157:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1262157:d000::/202157:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1272157:e000::/202157:efff:ffff:ffff:ffff:ffff:ffff:ffff
1282157:f000::/202157:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1292158::/202158:fff:ffff:ffff:ffff:ffff:ffff:ffff
1302158:1000::/202158:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1312158:2000::/202158:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1322158:3000::/202158:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1332158:4000::/202158:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1342158:5000::/202158:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1352158:6000::/202158:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1362158:7000::/202158:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1372158:8000::/202158:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1382158:9000::/202158:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1392158:a000::/202158:afff:ffff:ffff:ffff:ffff:ffff:ffff
1402158:b000::/202158:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1412158:c000::/202158:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1422158:d000::/202158:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1432158:e000::/202158:efff:ffff:ffff:ffff:ffff:ffff:ffff
1442158:f000::/202158:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1452159::/202159:fff:ffff:ffff:ffff:ffff:ffff:ffff
1462159:1000::/202159:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1472159:2000::/202159:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1482159:3000::/202159:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1492159:4000::/202159:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1502159:5000::/202159:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1512159:6000::/202159:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1522159:7000::/202159:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1532159:8000::/202159:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1542159:9000::/202159:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1552159:a000::/202159:afff:ffff:ffff:ffff:ffff:ffff:ffff
1562159:b000::/202159:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1572159:c000::/202159:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1582159:d000::/202159:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1592159:e000::/202159:efff:ffff:ffff:ffff:ffff:ffff:ffff
1602159:f000::/202159:ffff:ffff:ffff:ffff:ffff:ffff:ffff
161215a::/20215a:fff:ffff:ffff:ffff:ffff:ffff:ffff
162215a:1000::/20215a:1fff:ffff:ffff:ffff:ffff:ffff:ffff
163215a:2000::/20215a:2fff:ffff:ffff:ffff:ffff:ffff:ffff
164215a:3000::/20215a:3fff:ffff:ffff:ffff:ffff:ffff:ffff
165215a:4000::/20215a:4fff:ffff:ffff:ffff:ffff:ffff:ffff
166215a:5000::/20215a:5fff:ffff:ffff:ffff:ffff:ffff:ffff
167215a:6000::/20215a:6fff:ffff:ffff:ffff:ffff:ffff:ffff
168215a:7000::/20215a:7fff:ffff:ffff:ffff:ffff:ffff:ffff
169215a:8000::/20215a:8fff:ffff:ffff:ffff:ffff:ffff:ffff
170215a:9000::/20215a:9fff:ffff:ffff:ffff:ffff:ffff:ffff
171215a:a000::/20215a:afff:ffff:ffff:ffff:ffff:ffff:ffff
172215a:b000::/20215a:bfff:ffff:ffff:ffff:ffff:ffff:ffff
173215a:c000::/20215a:cfff:ffff:ffff:ffff:ffff:ffff:ffff
174215a:d000::/20215a:dfff:ffff:ffff:ffff:ffff:ffff:ffff
175215a:e000::/20215a:efff:ffff:ffff:ffff:ffff:ffff:ffff
176215a:f000::/20215a:ffff:ffff:ffff:ffff:ffff:ffff:ffff
177215b::/20215b:fff:ffff:ffff:ffff:ffff:ffff:ffff
178215b:1000::/20215b:1fff:ffff:ffff:ffff:ffff:ffff:ffff
179215b:2000::/20215b:2fff:ffff:ffff:ffff:ffff:ffff:ffff
180215b:3000::/20215b:3fff:ffff:ffff:ffff:ffff:ffff:ffff
181215b:4000::/20215b:4fff:ffff:ffff:ffff:ffff:ffff:ffff
182215b:5000::/20215b:5fff:ffff:ffff:ffff:ffff:ffff:ffff
183215b:6000::/20215b:6fff:ffff:ffff:ffff:ffff:ffff:ffff
184215b:7000::/20215b:7fff:ffff:ffff:ffff:ffff:ffff:ffff
185215b:8000::/20215b:8fff:ffff:ffff:ffff:ffff:ffff:ffff
186215b:9000::/20215b:9fff:ffff:ffff:ffff:ffff:ffff:ffff
187215b:a000::/20215b:afff:ffff:ffff:ffff:ffff:ffff:ffff
188215b:b000::/20215b:bfff:ffff:ffff:ffff:ffff:ffff:ffff
189215b:c000::/20215b:cfff:ffff:ffff:ffff:ffff:ffff:ffff
190215b:d000::/20215b:dfff:ffff:ffff:ffff:ffff:ffff:ffff
191215b:e000::/20215b:efff:ffff:ffff:ffff:ffff:ffff:ffff
192215b:f000::/20215b:ffff:ffff:ffff:ffff:ffff:ffff:ffff
193215c::/20215c:fff:ffff:ffff:ffff:ffff:ffff:ffff
194215c:1000::/20215c:1fff:ffff:ffff:ffff:ffff:ffff:ffff
195215c:2000::/20215c:2fff:ffff:ffff:ffff:ffff:ffff:ffff
196215c:3000::/20215c:3fff:ffff:ffff:ffff:ffff:ffff:ffff
197215c:4000::/20215c:4fff:ffff:ffff:ffff:ffff:ffff:ffff
198215c:5000::/20215c:5fff:ffff:ffff:ffff:ffff:ffff:ffff
199215c:6000::/20215c:6fff:ffff:ffff:ffff:ffff:ffff:ffff
200215c:7000::/20215c:7fff:ffff:ffff:ffff:ffff:ffff:ffff
201215c:8000::/20215c:8fff:ffff:ffff:ffff:ffff:ffff:ffff
202215c:9000::/20215c:9fff:ffff:ffff:ffff:ffff:ffff:ffff
203215c:a000::/20215c:afff:ffff:ffff:ffff:ffff:ffff:ffff
204215c:b000::/20215c:bfff:ffff:ffff:ffff:ffff:ffff:ffff
205215c:c000::/20215c:cfff:ffff:ffff:ffff:ffff:ffff:ffff
206215c:d000::/20215c:dfff:ffff:ffff:ffff:ffff:ffff:ffff
207215c:e000::/20215c:efff:ffff:ffff:ffff:ffff:ffff:ffff
208215c:f000::/20215c:ffff:ffff:ffff:ffff:ffff:ffff:ffff
209215d::/20215d:fff:ffff:ffff:ffff:ffff:ffff:ffff
210215d:1000::/20215d:1fff:ffff:ffff:ffff:ffff:ffff:ffff
211215d:2000::/20215d:2fff:ffff:ffff:ffff:ffff:ffff:ffff
212215d:3000::/20215d:3fff:ffff:ffff:ffff:ffff:ffff:ffff
213215d:4000::/20215d:4fff:ffff:ffff:ffff:ffff:ffff:ffff
214215d:5000::/20215d:5fff:ffff:ffff:ffff:ffff:ffff:ffff
215215d:6000::/20215d:6fff:ffff:ffff:ffff:ffff:ffff:ffff
216215d:7000::/20215d:7fff:ffff:ffff:ffff:ffff:ffff:ffff
217215d:8000::/20215d:8fff:ffff:ffff:ffff:ffff:ffff:ffff
218215d:9000::/20215d:9fff:ffff:ffff:ffff:ffff:ffff:ffff
219215d:a000::/20215d:afff:ffff:ffff:ffff:ffff:ffff:ffff
220215d:b000::/20215d:bfff:ffff:ffff:ffff:ffff:ffff:ffff
221215d:c000::/20215d:cfff:ffff:ffff:ffff:ffff:ffff:ffff
222215d:d000::/20215d:dfff:ffff:ffff:ffff:ffff:ffff:ffff
223215d:e000::/20215d:efff:ffff:ffff:ffff:ffff:ffff:ffff
224215d:f000::/20215d:ffff:ffff:ffff:ffff:ffff:ffff:ffff
225215e::/20215e:fff:ffff:ffff:ffff:ffff:ffff:ffff
226215e:1000::/20215e:1fff:ffff:ffff:ffff:ffff:ffff:ffff
227215e:2000::/20215e:2fff:ffff:ffff:ffff:ffff:ffff:ffff
228215e:3000::/20215e:3fff:ffff:ffff:ffff:ffff:ffff:ffff
229215e:4000::/20215e:4fff:ffff:ffff:ffff:ffff:ffff:ffff
230215e:5000::/20215e:5fff:ffff:ffff:ffff:ffff:ffff:ffff
231215e:6000::/20215e:6fff:ffff:ffff:ffff:ffff:ffff:ffff
232215e:7000::/20215e:7fff:ffff:ffff:ffff:ffff:ffff:ffff
233215e:8000::/20215e:8fff:ffff:ffff:ffff:ffff:ffff:ffff
234215e:9000::/20215e:9fff:ffff:ffff:ffff:ffff:ffff:ffff
235215e:a000::/20215e:afff:ffff:ffff:ffff:ffff:ffff:ffff
236215e:b000::/20215e:bfff:ffff:ffff:ffff:ffff:ffff:ffff
237215e:c000::/20215e:cfff:ffff:ffff:ffff:ffff:ffff:ffff
238215e:d000::/20215e:dfff:ffff:ffff:ffff:ffff:ffff:ffff
239215e:e000::/20215e:efff:ffff:ffff:ffff:ffff:ffff:ffff
240215e:f000::/20215e:ffff:ffff:ffff:ffff:ffff:ffff:ffff
241215f::/20215f:fff:ffff:ffff:ffff:ffff:ffff:ffff
242215f:1000::/20215f:1fff:ffff:ffff:ffff:ffff:ffff:ffff
243215f:2000::/20215f:2fff:ffff:ffff:ffff:ffff:ffff:ffff
244215f:3000::/20215f:3fff:ffff:ffff:ffff:ffff:ffff:ffff
245215f:4000::/20215f:4fff:ffff:ffff:ffff:ffff:ffff:ffff
246215f:5000::/20215f:5fff:ffff:ffff:ffff:ffff:ffff:ffff
247215f:6000::/20215f:6fff:ffff:ffff:ffff:ffff:ffff:ffff
248215f:7000::/20215f:7fff:ffff:ffff:ffff:ffff:ffff:ffff
249215f:8000::/20215f:8fff:ffff:ffff:ffff:ffff:ffff:ffff
250215f:9000::/20215f:9fff:ffff:ffff:ffff:ffff:ffff:ffff
251215f:a000::/20215f:afff:ffff:ffff:ffff:ffff:ffff:ffff
252215f:b000::/20215f:bfff:ffff:ffff:ffff:ffff:ffff:ffff
253215f:c000::/20215f:cfff:ffff:ffff:ffff:ffff:ffff:ffff
254215f:d000::/20215f:dfff:ffff:ffff:ffff:ffff:ffff:ffff
255215f:e000::/20215f:efff:ffff:ffff:ffff:ffff:ffff:ffff
256215f:f000::/20215f: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.