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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
2130::/12
First address
2130::
Last address
213f: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
2130:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
3.1.2.ip6.arpa
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2130::/12 makes 256 subnets of /20.

Subnets
#SubnetLast address
12130::/202130:fff:ffff:ffff:ffff:ffff:ffff:ffff
22130:1000::/202130:1fff:ffff:ffff:ffff:ffff:ffff:ffff
32130:2000::/202130:2fff:ffff:ffff:ffff:ffff:ffff:ffff
42130:3000::/202130:3fff:ffff:ffff:ffff:ffff:ffff:ffff
52130:4000::/202130:4fff:ffff:ffff:ffff:ffff:ffff:ffff
62130:5000::/202130:5fff:ffff:ffff:ffff:ffff:ffff:ffff
72130:6000::/202130:6fff:ffff:ffff:ffff:ffff:ffff:ffff
82130:7000::/202130:7fff:ffff:ffff:ffff:ffff:ffff:ffff
92130:8000::/202130:8fff:ffff:ffff:ffff:ffff:ffff:ffff
102130:9000::/202130:9fff:ffff:ffff:ffff:ffff:ffff:ffff
112130:a000::/202130:afff:ffff:ffff:ffff:ffff:ffff:ffff
122130:b000::/202130:bfff:ffff:ffff:ffff:ffff:ffff:ffff
132130:c000::/202130:cfff:ffff:ffff:ffff:ffff:ffff:ffff
142130:d000::/202130:dfff:ffff:ffff:ffff:ffff:ffff:ffff
152130:e000::/202130:efff:ffff:ffff:ffff:ffff:ffff:ffff
162130:f000::/202130:ffff:ffff:ffff:ffff:ffff:ffff:ffff
172131::/202131:fff:ffff:ffff:ffff:ffff:ffff:ffff
182131:1000::/202131:1fff:ffff:ffff:ffff:ffff:ffff:ffff
192131:2000::/202131:2fff:ffff:ffff:ffff:ffff:ffff:ffff
202131:3000::/202131:3fff:ffff:ffff:ffff:ffff:ffff:ffff
212131:4000::/202131:4fff:ffff:ffff:ffff:ffff:ffff:ffff
222131:5000::/202131:5fff:ffff:ffff:ffff:ffff:ffff:ffff
232131:6000::/202131:6fff:ffff:ffff:ffff:ffff:ffff:ffff
242131:7000::/202131:7fff:ffff:ffff:ffff:ffff:ffff:ffff
252131:8000::/202131:8fff:ffff:ffff:ffff:ffff:ffff:ffff
262131:9000::/202131:9fff:ffff:ffff:ffff:ffff:ffff:ffff
272131:a000::/202131:afff:ffff:ffff:ffff:ffff:ffff:ffff
282131:b000::/202131:bfff:ffff:ffff:ffff:ffff:ffff:ffff
292131:c000::/202131:cfff:ffff:ffff:ffff:ffff:ffff:ffff
302131:d000::/202131:dfff:ffff:ffff:ffff:ffff:ffff:ffff
312131:e000::/202131:efff:ffff:ffff:ffff:ffff:ffff:ffff
322131:f000::/202131:ffff:ffff:ffff:ffff:ffff:ffff:ffff
332132::/202132:fff:ffff:ffff:ffff:ffff:ffff:ffff
342132:1000::/202132:1fff:ffff:ffff:ffff:ffff:ffff:ffff
352132:2000::/202132:2fff:ffff:ffff:ffff:ffff:ffff:ffff
362132:3000::/202132:3fff:ffff:ffff:ffff:ffff:ffff:ffff
372132:4000::/202132:4fff:ffff:ffff:ffff:ffff:ffff:ffff
382132:5000::/202132:5fff:ffff:ffff:ffff:ffff:ffff:ffff
392132:6000::/202132:6fff:ffff:ffff:ffff:ffff:ffff:ffff
402132:7000::/202132:7fff:ffff:ffff:ffff:ffff:ffff:ffff
412132:8000::/202132:8fff:ffff:ffff:ffff:ffff:ffff:ffff
422132:9000::/202132:9fff:ffff:ffff:ffff:ffff:ffff:ffff
432132:a000::/202132:afff:ffff:ffff:ffff:ffff:ffff:ffff
442132:b000::/202132:bfff:ffff:ffff:ffff:ffff:ffff:ffff
452132:c000::/202132:cfff:ffff:ffff:ffff:ffff:ffff:ffff
462132:d000::/202132:dfff:ffff:ffff:ffff:ffff:ffff:ffff
472132:e000::/202132:efff:ffff:ffff:ffff:ffff:ffff:ffff
482132:f000::/202132:ffff:ffff:ffff:ffff:ffff:ffff:ffff
492133::/202133:fff:ffff:ffff:ffff:ffff:ffff:ffff
502133:1000::/202133:1fff:ffff:ffff:ffff:ffff:ffff:ffff
512133:2000::/202133:2fff:ffff:ffff:ffff:ffff:ffff:ffff
522133:3000::/202133:3fff:ffff:ffff:ffff:ffff:ffff:ffff
532133:4000::/202133:4fff:ffff:ffff:ffff:ffff:ffff:ffff
542133:5000::/202133:5fff:ffff:ffff:ffff:ffff:ffff:ffff
552133:6000::/202133:6fff:ffff:ffff:ffff:ffff:ffff:ffff
562133:7000::/202133:7fff:ffff:ffff:ffff:ffff:ffff:ffff
572133:8000::/202133:8fff:ffff:ffff:ffff:ffff:ffff:ffff
582133:9000::/202133:9fff:ffff:ffff:ffff:ffff:ffff:ffff
592133:a000::/202133:afff:ffff:ffff:ffff:ffff:ffff:ffff
602133:b000::/202133:bfff:ffff:ffff:ffff:ffff:ffff:ffff
612133:c000::/202133:cfff:ffff:ffff:ffff:ffff:ffff:ffff
622133:d000::/202133:dfff:ffff:ffff:ffff:ffff:ffff:ffff
632133:e000::/202133:efff:ffff:ffff:ffff:ffff:ffff:ffff
642133:f000::/202133:ffff:ffff:ffff:ffff:ffff:ffff:ffff
652134::/202134:fff:ffff:ffff:ffff:ffff:ffff:ffff
662134:1000::/202134:1fff:ffff:ffff:ffff:ffff:ffff:ffff
672134:2000::/202134:2fff:ffff:ffff:ffff:ffff:ffff:ffff
682134:3000::/202134:3fff:ffff:ffff:ffff:ffff:ffff:ffff
692134:4000::/202134:4fff:ffff:ffff:ffff:ffff:ffff:ffff
702134:5000::/202134:5fff:ffff:ffff:ffff:ffff:ffff:ffff
712134:6000::/202134:6fff:ffff:ffff:ffff:ffff:ffff:ffff
722134:7000::/202134:7fff:ffff:ffff:ffff:ffff:ffff:ffff
732134:8000::/202134:8fff:ffff:ffff:ffff:ffff:ffff:ffff
742134:9000::/202134:9fff:ffff:ffff:ffff:ffff:ffff:ffff
752134:a000::/202134:afff:ffff:ffff:ffff:ffff:ffff:ffff
762134:b000::/202134:bfff:ffff:ffff:ffff:ffff:ffff:ffff
772134:c000::/202134:cfff:ffff:ffff:ffff:ffff:ffff:ffff
782134:d000::/202134:dfff:ffff:ffff:ffff:ffff:ffff:ffff
792134:e000::/202134:efff:ffff:ffff:ffff:ffff:ffff:ffff
802134:f000::/202134:ffff:ffff:ffff:ffff:ffff:ffff:ffff
812135::/202135:fff:ffff:ffff:ffff:ffff:ffff:ffff
822135:1000::/202135:1fff:ffff:ffff:ffff:ffff:ffff:ffff
832135:2000::/202135:2fff:ffff:ffff:ffff:ffff:ffff:ffff
842135:3000::/202135:3fff:ffff:ffff:ffff:ffff:ffff:ffff
852135:4000::/202135:4fff:ffff:ffff:ffff:ffff:ffff:ffff
862135:5000::/202135:5fff:ffff:ffff:ffff:ffff:ffff:ffff
872135:6000::/202135:6fff:ffff:ffff:ffff:ffff:ffff:ffff
882135:7000::/202135:7fff:ffff:ffff:ffff:ffff:ffff:ffff
892135:8000::/202135:8fff:ffff:ffff:ffff:ffff:ffff:ffff
902135:9000::/202135:9fff:ffff:ffff:ffff:ffff:ffff:ffff
912135:a000::/202135:afff:ffff:ffff:ffff:ffff:ffff:ffff
922135:b000::/202135:bfff:ffff:ffff:ffff:ffff:ffff:ffff
932135:c000::/202135:cfff:ffff:ffff:ffff:ffff:ffff:ffff
942135:d000::/202135:dfff:ffff:ffff:ffff:ffff:ffff:ffff
952135:e000::/202135:efff:ffff:ffff:ffff:ffff:ffff:ffff
962135:f000::/202135:ffff:ffff:ffff:ffff:ffff:ffff:ffff
972136::/202136:fff:ffff:ffff:ffff:ffff:ffff:ffff
982136:1000::/202136:1fff:ffff:ffff:ffff:ffff:ffff:ffff
992136:2000::/202136:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1002136:3000::/202136:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1012136:4000::/202136:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1022136:5000::/202136:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1032136:6000::/202136:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1042136:7000::/202136:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1052136:8000::/202136:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1062136:9000::/202136:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1072136:a000::/202136:afff:ffff:ffff:ffff:ffff:ffff:ffff
1082136:b000::/202136:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1092136:c000::/202136:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1102136:d000::/202136:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1112136:e000::/202136:efff:ffff:ffff:ffff:ffff:ffff:ffff
1122136:f000::/202136:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1132137::/202137:fff:ffff:ffff:ffff:ffff:ffff:ffff
1142137:1000::/202137:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1152137:2000::/202137:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1162137:3000::/202137:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1172137:4000::/202137:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1182137:5000::/202137:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1192137:6000::/202137:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1202137:7000::/202137:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1212137:8000::/202137:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1222137:9000::/202137:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1232137:a000::/202137:afff:ffff:ffff:ffff:ffff:ffff:ffff
1242137:b000::/202137:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1252137:c000::/202137:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1262137:d000::/202137:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1272137:e000::/202137:efff:ffff:ffff:ffff:ffff:ffff:ffff
1282137:f000::/202137:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1292138::/202138:fff:ffff:ffff:ffff:ffff:ffff:ffff
1302138:1000::/202138:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1312138:2000::/202138:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1322138:3000::/202138:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1332138:4000::/202138:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1342138:5000::/202138:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1352138:6000::/202138:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1362138:7000::/202138:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1372138:8000::/202138:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1382138:9000::/202138:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1392138:a000::/202138:afff:ffff:ffff:ffff:ffff:ffff:ffff
1402138:b000::/202138:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1412138:c000::/202138:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1422138:d000::/202138:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1432138:e000::/202138:efff:ffff:ffff:ffff:ffff:ffff:ffff
1442138:f000::/202138:ffff:ffff:ffff:ffff:ffff:ffff:ffff
1452139::/202139:fff:ffff:ffff:ffff:ffff:ffff:ffff
1462139:1000::/202139:1fff:ffff:ffff:ffff:ffff:ffff:ffff
1472139:2000::/202139:2fff:ffff:ffff:ffff:ffff:ffff:ffff
1482139:3000::/202139:3fff:ffff:ffff:ffff:ffff:ffff:ffff
1492139:4000::/202139:4fff:ffff:ffff:ffff:ffff:ffff:ffff
1502139:5000::/202139:5fff:ffff:ffff:ffff:ffff:ffff:ffff
1512139:6000::/202139:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1522139:7000::/202139:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1532139:8000::/202139:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1542139:9000::/202139:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1552139:a000::/202139:afff:ffff:ffff:ffff:ffff:ffff:ffff
1562139:b000::/202139:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1572139:c000::/202139:cfff:ffff:ffff:ffff:ffff:ffff:ffff
1582139:d000::/202139:dfff:ffff:ffff:ffff:ffff:ffff:ffff
1592139:e000::/202139:efff:ffff:ffff:ffff:ffff:ffff:ffff
1602139:f000::/202139:ffff:ffff:ffff:ffff:ffff:ffff:ffff
161213a::/20213a:fff:ffff:ffff:ffff:ffff:ffff:ffff
162213a:1000::/20213a:1fff:ffff:ffff:ffff:ffff:ffff:ffff
163213a:2000::/20213a:2fff:ffff:ffff:ffff:ffff:ffff:ffff
164213a:3000::/20213a:3fff:ffff:ffff:ffff:ffff:ffff:ffff
165213a:4000::/20213a:4fff:ffff:ffff:ffff:ffff:ffff:ffff
166213a:5000::/20213a:5fff:ffff:ffff:ffff:ffff:ffff:ffff
167213a:6000::/20213a:6fff:ffff:ffff:ffff:ffff:ffff:ffff
168213a:7000::/20213a:7fff:ffff:ffff:ffff:ffff:ffff:ffff
169213a:8000::/20213a:8fff:ffff:ffff:ffff:ffff:ffff:ffff
170213a:9000::/20213a:9fff:ffff:ffff:ffff:ffff:ffff:ffff
171213a:a000::/20213a:afff:ffff:ffff:ffff:ffff:ffff:ffff
172213a:b000::/20213a:bfff:ffff:ffff:ffff:ffff:ffff:ffff
173213a:c000::/20213a:cfff:ffff:ffff:ffff:ffff:ffff:ffff
174213a:d000::/20213a:dfff:ffff:ffff:ffff:ffff:ffff:ffff
175213a:e000::/20213a:efff:ffff:ffff:ffff:ffff:ffff:ffff
176213a:f000::/20213a:ffff:ffff:ffff:ffff:ffff:ffff:ffff
177213b::/20213b:fff:ffff:ffff:ffff:ffff:ffff:ffff
178213b:1000::/20213b:1fff:ffff:ffff:ffff:ffff:ffff:ffff
179213b:2000::/20213b:2fff:ffff:ffff:ffff:ffff:ffff:ffff
180213b:3000::/20213b:3fff:ffff:ffff:ffff:ffff:ffff:ffff
181213b:4000::/20213b:4fff:ffff:ffff:ffff:ffff:ffff:ffff
182213b:5000::/20213b:5fff:ffff:ffff:ffff:ffff:ffff:ffff
183213b:6000::/20213b:6fff:ffff:ffff:ffff:ffff:ffff:ffff
184213b:7000::/20213b:7fff:ffff:ffff:ffff:ffff:ffff:ffff
185213b:8000::/20213b:8fff:ffff:ffff:ffff:ffff:ffff:ffff
186213b:9000::/20213b:9fff:ffff:ffff:ffff:ffff:ffff:ffff
187213b:a000::/20213b:afff:ffff:ffff:ffff:ffff:ffff:ffff
188213b:b000::/20213b:bfff:ffff:ffff:ffff:ffff:ffff:ffff
189213b:c000::/20213b:cfff:ffff:ffff:ffff:ffff:ffff:ffff
190213b:d000::/20213b:dfff:ffff:ffff:ffff:ffff:ffff:ffff
191213b:e000::/20213b:efff:ffff:ffff:ffff:ffff:ffff:ffff
192213b:f000::/20213b:ffff:ffff:ffff:ffff:ffff:ffff:ffff
193213c::/20213c:fff:ffff:ffff:ffff:ffff:ffff:ffff
194213c:1000::/20213c:1fff:ffff:ffff:ffff:ffff:ffff:ffff
195213c:2000::/20213c:2fff:ffff:ffff:ffff:ffff:ffff:ffff
196213c:3000::/20213c:3fff:ffff:ffff:ffff:ffff:ffff:ffff
197213c:4000::/20213c:4fff:ffff:ffff:ffff:ffff:ffff:ffff
198213c:5000::/20213c:5fff:ffff:ffff:ffff:ffff:ffff:ffff
199213c:6000::/20213c:6fff:ffff:ffff:ffff:ffff:ffff:ffff
200213c:7000::/20213c:7fff:ffff:ffff:ffff:ffff:ffff:ffff
201213c:8000::/20213c:8fff:ffff:ffff:ffff:ffff:ffff:ffff
202213c:9000::/20213c:9fff:ffff:ffff:ffff:ffff:ffff:ffff
203213c:a000::/20213c:afff:ffff:ffff:ffff:ffff:ffff:ffff
204213c:b000::/20213c:bfff:ffff:ffff:ffff:ffff:ffff:ffff
205213c:c000::/20213c:cfff:ffff:ffff:ffff:ffff:ffff:ffff
206213c:d000::/20213c:dfff:ffff:ffff:ffff:ffff:ffff:ffff
207213c:e000::/20213c:efff:ffff:ffff:ffff:ffff:ffff:ffff
208213c:f000::/20213c:ffff:ffff:ffff:ffff:ffff:ffff:ffff
209213d::/20213d:fff:ffff:ffff:ffff:ffff:ffff:ffff
210213d:1000::/20213d:1fff:ffff:ffff:ffff:ffff:ffff:ffff
211213d:2000::/20213d:2fff:ffff:ffff:ffff:ffff:ffff:ffff
212213d:3000::/20213d:3fff:ffff:ffff:ffff:ffff:ffff:ffff
213213d:4000::/20213d:4fff:ffff:ffff:ffff:ffff:ffff:ffff
214213d:5000::/20213d:5fff:ffff:ffff:ffff:ffff:ffff:ffff
215213d:6000::/20213d:6fff:ffff:ffff:ffff:ffff:ffff:ffff
216213d:7000::/20213d:7fff:ffff:ffff:ffff:ffff:ffff:ffff
217213d:8000::/20213d:8fff:ffff:ffff:ffff:ffff:ffff:ffff
218213d:9000::/20213d:9fff:ffff:ffff:ffff:ffff:ffff:ffff
219213d:a000::/20213d:afff:ffff:ffff:ffff:ffff:ffff:ffff
220213d:b000::/20213d:bfff:ffff:ffff:ffff:ffff:ffff:ffff
221213d:c000::/20213d:cfff:ffff:ffff:ffff:ffff:ffff:ffff
222213d:d000::/20213d:dfff:ffff:ffff:ffff:ffff:ffff:ffff
223213d:e000::/20213d:efff:ffff:ffff:ffff:ffff:ffff:ffff
224213d:f000::/20213d:ffff:ffff:ffff:ffff:ffff:ffff:ffff
225213e::/20213e:fff:ffff:ffff:ffff:ffff:ffff:ffff
226213e:1000::/20213e:1fff:ffff:ffff:ffff:ffff:ffff:ffff
227213e:2000::/20213e:2fff:ffff:ffff:ffff:ffff:ffff:ffff
228213e:3000::/20213e:3fff:ffff:ffff:ffff:ffff:ffff:ffff
229213e:4000::/20213e:4fff:ffff:ffff:ffff:ffff:ffff:ffff
230213e:5000::/20213e:5fff:ffff:ffff:ffff:ffff:ffff:ffff
231213e:6000::/20213e:6fff:ffff:ffff:ffff:ffff:ffff:ffff
232213e:7000::/20213e:7fff:ffff:ffff:ffff:ffff:ffff:ffff
233213e:8000::/20213e:8fff:ffff:ffff:ffff:ffff:ffff:ffff
234213e:9000::/20213e:9fff:ffff:ffff:ffff:ffff:ffff:ffff
235213e:a000::/20213e:afff:ffff:ffff:ffff:ffff:ffff:ffff
236213e:b000::/20213e:bfff:ffff:ffff:ffff:ffff:ffff:ffff
237213e:c000::/20213e:cfff:ffff:ffff:ffff:ffff:ffff:ffff
238213e:d000::/20213e:dfff:ffff:ffff:ffff:ffff:ffff:ffff
239213e:e000::/20213e:efff:ffff:ffff:ffff:ffff:ffff:ffff
240213e:f000::/20213e:ffff:ffff:ffff:ffff:ffff:ffff:ffff
241213f::/20213f:fff:ffff:ffff:ffff:ffff:ffff:ffff
242213f:1000::/20213f:1fff:ffff:ffff:ffff:ffff:ffff:ffff
243213f:2000::/20213f:2fff:ffff:ffff:ffff:ffff:ffff:ffff
244213f:3000::/20213f:3fff:ffff:ffff:ffff:ffff:ffff:ffff
245213f:4000::/20213f:4fff:ffff:ffff:ffff:ffff:ffff:ffff
246213f:5000::/20213f:5fff:ffff:ffff:ffff:ffff:ffff:ffff
247213f:6000::/20213f:6fff:ffff:ffff:ffff:ffff:ffff:ffff
248213f:7000::/20213f:7fff:ffff:ffff:ffff:ffff:ffff:ffff
249213f:8000::/20213f:8fff:ffff:ffff:ffff:ffff:ffff:ffff
250213f:9000::/20213f:9fff:ffff:ffff:ffff:ffff:ffff:ffff
251213f:a000::/20213f:afff:ffff:ffff:ffff:ffff:ffff:ffff
252213f:b000::/20213f:bfff:ffff:ffff:ffff:ffff:ffff:ffff
253213f:c000::/20213f:cfff:ffff:ffff:ffff:ffff:ffff:ffff
254213f:d000::/20213f:dfff:ffff:ffff:ffff:ffff:ffff:ffff
255213f:e000::/20213f:efff:ffff:ffff:ffff:ffff:ffff:ffff
256213f:f000::/20213f: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.