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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.

Network9.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
9.0.0.0
Broadcast address
9.63.255.255
First usable
9.0.0.1
Last usable
9.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 09000000 · Integer 150994944 to 155189247
Reverse DNS zones
0.9.in-addr.arpa
1.9.in-addr.arpa
2.9.in-addr.arpa
3.9.in-addr.arpa
4.9.in-addr.arpa
5.9.in-addr.arpa
6.9.in-addr.arpa
7.9.in-addr.arpa
8.9.in-addr.arpa
9.9.in-addr.arpa
10.9.in-addr.arpa
11.9.in-addr.arpa
12.9.in-addr.arpa
13.9.in-addr.arpa
14.9.in-addr.arpa
15.9.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00001001.00000000.00000000.000000009.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00001001.00000000.00000000.000000009.0.0.0
Broadcast00001001.00111111.11111111.111111119.63.255.255
Split into smaller subnets/19
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

9.0.0.0/10 makes 512 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
19.0.0.0/199.0.0.1 to 9.0.31.2549.0.31.2558,190
29.0.32.0/199.0.32.1 to 9.0.63.2549.0.63.2558,190
39.0.64.0/199.0.64.1 to 9.0.95.2549.0.95.2558,190
49.0.96.0/199.0.96.1 to 9.0.127.2549.0.127.2558,190
59.0.128.0/199.0.128.1 to 9.0.159.2549.0.159.2558,190
69.0.160.0/199.0.160.1 to 9.0.191.2549.0.191.2558,190
79.0.192.0/199.0.192.1 to 9.0.223.2549.0.223.2558,190
89.0.224.0/199.0.224.1 to 9.0.255.2549.0.255.2558,190
99.1.0.0/199.1.0.1 to 9.1.31.2549.1.31.2558,190
109.1.32.0/199.1.32.1 to 9.1.63.2549.1.63.2558,190
119.1.64.0/199.1.64.1 to 9.1.95.2549.1.95.2558,190
129.1.96.0/199.1.96.1 to 9.1.127.2549.1.127.2558,190
139.1.128.0/199.1.128.1 to 9.1.159.2549.1.159.2558,190
149.1.160.0/199.1.160.1 to 9.1.191.2549.1.191.2558,190
159.1.192.0/199.1.192.1 to 9.1.223.2549.1.223.2558,190
169.1.224.0/199.1.224.1 to 9.1.255.2549.1.255.2558,190
179.2.0.0/199.2.0.1 to 9.2.31.2549.2.31.2558,190
189.2.32.0/199.2.32.1 to 9.2.63.2549.2.63.2558,190
199.2.64.0/199.2.64.1 to 9.2.95.2549.2.95.2558,190
209.2.96.0/199.2.96.1 to 9.2.127.2549.2.127.2558,190
219.2.128.0/199.2.128.1 to 9.2.159.2549.2.159.2558,190
229.2.160.0/199.2.160.1 to 9.2.191.2549.2.191.2558,190
239.2.192.0/199.2.192.1 to 9.2.223.2549.2.223.2558,190
249.2.224.0/199.2.224.1 to 9.2.255.2549.2.255.2558,190
259.3.0.0/199.3.0.1 to 9.3.31.2549.3.31.2558,190
269.3.32.0/199.3.32.1 to 9.3.63.2549.3.63.2558,190
279.3.64.0/199.3.64.1 to 9.3.95.2549.3.95.2558,190
289.3.96.0/199.3.96.1 to 9.3.127.2549.3.127.2558,190
299.3.128.0/199.3.128.1 to 9.3.159.2549.3.159.2558,190
309.3.160.0/199.3.160.1 to 9.3.191.2549.3.191.2558,190
319.3.192.0/199.3.192.1 to 9.3.223.2549.3.223.2558,190
329.3.224.0/199.3.224.1 to 9.3.255.2549.3.255.2558,190
339.4.0.0/199.4.0.1 to 9.4.31.2549.4.31.2558,190
349.4.32.0/199.4.32.1 to 9.4.63.2549.4.63.2558,190
359.4.64.0/199.4.64.1 to 9.4.95.2549.4.95.2558,190
369.4.96.0/199.4.96.1 to 9.4.127.2549.4.127.2558,190
379.4.128.0/199.4.128.1 to 9.4.159.2549.4.159.2558,190
389.4.160.0/199.4.160.1 to 9.4.191.2549.4.191.2558,190
399.4.192.0/199.4.192.1 to 9.4.223.2549.4.223.2558,190
409.4.224.0/199.4.224.1 to 9.4.255.2549.4.255.2558,190
419.5.0.0/199.5.0.1 to 9.5.31.2549.5.31.2558,190
429.5.32.0/199.5.32.1 to 9.5.63.2549.5.63.2558,190
439.5.64.0/199.5.64.1 to 9.5.95.2549.5.95.2558,190
449.5.96.0/199.5.96.1 to 9.5.127.2549.5.127.2558,190
459.5.128.0/199.5.128.1 to 9.5.159.2549.5.159.2558,190
469.5.160.0/199.5.160.1 to 9.5.191.2549.5.191.2558,190
479.5.192.0/199.5.192.1 to 9.5.223.2549.5.223.2558,190
489.5.224.0/199.5.224.1 to 9.5.255.2549.5.255.2558,190
499.6.0.0/199.6.0.1 to 9.6.31.2549.6.31.2558,190
509.6.32.0/199.6.32.1 to 9.6.63.2549.6.63.2558,190
519.6.64.0/199.6.64.1 to 9.6.95.2549.6.95.2558,190
529.6.96.0/199.6.96.1 to 9.6.127.2549.6.127.2558,190
539.6.128.0/199.6.128.1 to 9.6.159.2549.6.159.2558,190
549.6.160.0/199.6.160.1 to 9.6.191.2549.6.191.2558,190
559.6.192.0/199.6.192.1 to 9.6.223.2549.6.223.2558,190
569.6.224.0/199.6.224.1 to 9.6.255.2549.6.255.2558,190
579.7.0.0/199.7.0.1 to 9.7.31.2549.7.31.2558,190
589.7.32.0/199.7.32.1 to 9.7.63.2549.7.63.2558,190
599.7.64.0/199.7.64.1 to 9.7.95.2549.7.95.2558,190
609.7.96.0/199.7.96.1 to 9.7.127.2549.7.127.2558,190
619.7.128.0/199.7.128.1 to 9.7.159.2549.7.159.2558,190
629.7.160.0/199.7.160.1 to 9.7.191.2549.7.191.2558,190
639.7.192.0/199.7.192.1 to 9.7.223.2549.7.223.2558,190
649.7.224.0/199.7.224.1 to 9.7.255.2549.7.255.2558,190
659.8.0.0/199.8.0.1 to 9.8.31.2549.8.31.2558,190
669.8.32.0/199.8.32.1 to 9.8.63.2549.8.63.2558,190
679.8.64.0/199.8.64.1 to 9.8.95.2549.8.95.2558,190
689.8.96.0/199.8.96.1 to 9.8.127.2549.8.127.2558,190
699.8.128.0/199.8.128.1 to 9.8.159.2549.8.159.2558,190
709.8.160.0/199.8.160.1 to 9.8.191.2549.8.191.2558,190
719.8.192.0/199.8.192.1 to 9.8.223.2549.8.223.2558,190
729.8.224.0/199.8.224.1 to 9.8.255.2549.8.255.2558,190
739.9.0.0/199.9.0.1 to 9.9.31.2549.9.31.2558,190
749.9.32.0/199.9.32.1 to 9.9.63.2549.9.63.2558,190
759.9.64.0/199.9.64.1 to 9.9.95.2549.9.95.2558,190
769.9.96.0/199.9.96.1 to 9.9.127.2549.9.127.2558,190
779.9.128.0/199.9.128.1 to 9.9.159.2549.9.159.2558,190
789.9.160.0/199.9.160.1 to 9.9.191.2549.9.191.2558,190
799.9.192.0/199.9.192.1 to 9.9.223.2549.9.223.2558,190
809.9.224.0/199.9.224.1 to 9.9.255.2549.9.255.2558,190
819.10.0.0/199.10.0.1 to 9.10.31.2549.10.31.2558,190
829.10.32.0/199.10.32.1 to 9.10.63.2549.10.63.2558,190
839.10.64.0/199.10.64.1 to 9.10.95.2549.10.95.2558,190
849.10.96.0/199.10.96.1 to 9.10.127.2549.10.127.2558,190
859.10.128.0/199.10.128.1 to 9.10.159.2549.10.159.2558,190
869.10.160.0/199.10.160.1 to 9.10.191.2549.10.191.2558,190
879.10.192.0/199.10.192.1 to 9.10.223.2549.10.223.2558,190
889.10.224.0/199.10.224.1 to 9.10.255.2549.10.255.2558,190
899.11.0.0/199.11.0.1 to 9.11.31.2549.11.31.2558,190
909.11.32.0/199.11.32.1 to 9.11.63.2549.11.63.2558,190
919.11.64.0/199.11.64.1 to 9.11.95.2549.11.95.2558,190
929.11.96.0/199.11.96.1 to 9.11.127.2549.11.127.2558,190
939.11.128.0/199.11.128.1 to 9.11.159.2549.11.159.2558,190
949.11.160.0/199.11.160.1 to 9.11.191.2549.11.191.2558,190
959.11.192.0/199.11.192.1 to 9.11.223.2549.11.223.2558,190
969.11.224.0/199.11.224.1 to 9.11.255.2549.11.255.2558,190
979.12.0.0/199.12.0.1 to 9.12.31.2549.12.31.2558,190
989.12.32.0/199.12.32.1 to 9.12.63.2549.12.63.2558,190
999.12.64.0/199.12.64.1 to 9.12.95.2549.12.95.2558,190
1009.12.96.0/199.12.96.1 to 9.12.127.2549.12.127.2558,190
1019.12.128.0/199.12.128.1 to 9.12.159.2549.12.159.2558,190
1029.12.160.0/199.12.160.1 to 9.12.191.2549.12.191.2558,190
1039.12.192.0/199.12.192.1 to 9.12.223.2549.12.223.2558,190
1049.12.224.0/199.12.224.1 to 9.12.255.2549.12.255.2558,190
1059.13.0.0/199.13.0.1 to 9.13.31.2549.13.31.2558,190
1069.13.32.0/199.13.32.1 to 9.13.63.2549.13.63.2558,190
1079.13.64.0/199.13.64.1 to 9.13.95.2549.13.95.2558,190
1089.13.96.0/199.13.96.1 to 9.13.127.2549.13.127.2558,190
1099.13.128.0/199.13.128.1 to 9.13.159.2549.13.159.2558,190
1109.13.160.0/199.13.160.1 to 9.13.191.2549.13.191.2558,190
1119.13.192.0/199.13.192.1 to 9.13.223.2549.13.223.2558,190
1129.13.224.0/199.13.224.1 to 9.13.255.2549.13.255.2558,190
1139.14.0.0/199.14.0.1 to 9.14.31.2549.14.31.2558,190
1149.14.32.0/199.14.32.1 to 9.14.63.2549.14.63.2558,190
1159.14.64.0/199.14.64.1 to 9.14.95.2549.14.95.2558,190
1169.14.96.0/199.14.96.1 to 9.14.127.2549.14.127.2558,190
1179.14.128.0/199.14.128.1 to 9.14.159.2549.14.159.2558,190
1189.14.160.0/199.14.160.1 to 9.14.191.2549.14.191.2558,190
1199.14.192.0/199.14.192.1 to 9.14.223.2549.14.223.2558,190
1209.14.224.0/199.14.224.1 to 9.14.255.2549.14.255.2558,190
1219.15.0.0/199.15.0.1 to 9.15.31.2549.15.31.2558,190
1229.15.32.0/199.15.32.1 to 9.15.63.2549.15.63.2558,190
1239.15.64.0/199.15.64.1 to 9.15.95.2549.15.95.2558,190
1249.15.96.0/199.15.96.1 to 9.15.127.2549.15.127.2558,190
1259.15.128.0/199.15.128.1 to 9.15.159.2549.15.159.2558,190
1269.15.160.0/199.15.160.1 to 9.15.191.2549.15.191.2558,190
1279.15.192.0/199.15.192.1 to 9.15.223.2549.15.223.2558,190
1289.15.224.0/199.15.224.1 to 9.15.255.2549.15.255.2558,190
1299.16.0.0/199.16.0.1 to 9.16.31.2549.16.31.2558,190
1309.16.32.0/199.16.32.1 to 9.16.63.2549.16.63.2558,190
1319.16.64.0/199.16.64.1 to 9.16.95.2549.16.95.2558,190
1329.16.96.0/199.16.96.1 to 9.16.127.2549.16.127.2558,190
1339.16.128.0/199.16.128.1 to 9.16.159.2549.16.159.2558,190
1349.16.160.0/199.16.160.1 to 9.16.191.2549.16.191.2558,190
1359.16.192.0/199.16.192.1 to 9.16.223.2549.16.223.2558,190
1369.16.224.0/199.16.224.1 to 9.16.255.2549.16.255.2558,190
1379.17.0.0/199.17.0.1 to 9.17.31.2549.17.31.2558,190
1389.17.32.0/199.17.32.1 to 9.17.63.2549.17.63.2558,190
1399.17.64.0/199.17.64.1 to 9.17.95.2549.17.95.2558,190
1409.17.96.0/199.17.96.1 to 9.17.127.2549.17.127.2558,190
1419.17.128.0/199.17.128.1 to 9.17.159.2549.17.159.2558,190
1429.17.160.0/199.17.160.1 to 9.17.191.2549.17.191.2558,190
1439.17.192.0/199.17.192.1 to 9.17.223.2549.17.223.2558,190
1449.17.224.0/199.17.224.1 to 9.17.255.2549.17.255.2558,190
1459.18.0.0/199.18.0.1 to 9.18.31.2549.18.31.2558,190
1469.18.32.0/199.18.32.1 to 9.18.63.2549.18.63.2558,190
1479.18.64.0/199.18.64.1 to 9.18.95.2549.18.95.2558,190
1489.18.96.0/199.18.96.1 to 9.18.127.2549.18.127.2558,190
1499.18.128.0/199.18.128.1 to 9.18.159.2549.18.159.2558,190
1509.18.160.0/199.18.160.1 to 9.18.191.2549.18.191.2558,190
1519.18.192.0/199.18.192.1 to 9.18.223.2549.18.223.2558,190
1529.18.224.0/199.18.224.1 to 9.18.255.2549.18.255.2558,190
1539.19.0.0/199.19.0.1 to 9.19.31.2549.19.31.2558,190
1549.19.32.0/199.19.32.1 to 9.19.63.2549.19.63.2558,190
1559.19.64.0/199.19.64.1 to 9.19.95.2549.19.95.2558,190
1569.19.96.0/199.19.96.1 to 9.19.127.2549.19.127.2558,190
1579.19.128.0/199.19.128.1 to 9.19.159.2549.19.159.2558,190
1589.19.160.0/199.19.160.1 to 9.19.191.2549.19.191.2558,190
1599.19.192.0/199.19.192.1 to 9.19.223.2549.19.223.2558,190
1609.19.224.0/199.19.224.1 to 9.19.255.2549.19.255.2558,190
1619.20.0.0/199.20.0.1 to 9.20.31.2549.20.31.2558,190
1629.20.32.0/199.20.32.1 to 9.20.63.2549.20.63.2558,190
1639.20.64.0/199.20.64.1 to 9.20.95.2549.20.95.2558,190
1649.20.96.0/199.20.96.1 to 9.20.127.2549.20.127.2558,190
1659.20.128.0/199.20.128.1 to 9.20.159.2549.20.159.2558,190
1669.20.160.0/199.20.160.1 to 9.20.191.2549.20.191.2558,190
1679.20.192.0/199.20.192.1 to 9.20.223.2549.20.223.2558,190
1689.20.224.0/199.20.224.1 to 9.20.255.2549.20.255.2558,190
1699.21.0.0/199.21.0.1 to 9.21.31.2549.21.31.2558,190
1709.21.32.0/199.21.32.1 to 9.21.63.2549.21.63.2558,190
1719.21.64.0/199.21.64.1 to 9.21.95.2549.21.95.2558,190
1729.21.96.0/199.21.96.1 to 9.21.127.2549.21.127.2558,190
1739.21.128.0/199.21.128.1 to 9.21.159.2549.21.159.2558,190
1749.21.160.0/199.21.160.1 to 9.21.191.2549.21.191.2558,190
1759.21.192.0/199.21.192.1 to 9.21.223.2549.21.223.2558,190
1769.21.224.0/199.21.224.1 to 9.21.255.2549.21.255.2558,190
1779.22.0.0/199.22.0.1 to 9.22.31.2549.22.31.2558,190
1789.22.32.0/199.22.32.1 to 9.22.63.2549.22.63.2558,190
1799.22.64.0/199.22.64.1 to 9.22.95.2549.22.95.2558,190
1809.22.96.0/199.22.96.1 to 9.22.127.2549.22.127.2558,190
1819.22.128.0/199.22.128.1 to 9.22.159.2549.22.159.2558,190
1829.22.160.0/199.22.160.1 to 9.22.191.2549.22.191.2558,190
1839.22.192.0/199.22.192.1 to 9.22.223.2549.22.223.2558,190
1849.22.224.0/199.22.224.1 to 9.22.255.2549.22.255.2558,190
1859.23.0.0/199.23.0.1 to 9.23.31.2549.23.31.2558,190
1869.23.32.0/199.23.32.1 to 9.23.63.2549.23.63.2558,190
1879.23.64.0/199.23.64.1 to 9.23.95.2549.23.95.2558,190
1889.23.96.0/199.23.96.1 to 9.23.127.2549.23.127.2558,190
1899.23.128.0/199.23.128.1 to 9.23.159.2549.23.159.2558,190
1909.23.160.0/199.23.160.1 to 9.23.191.2549.23.191.2558,190
1919.23.192.0/199.23.192.1 to 9.23.223.2549.23.223.2558,190
1929.23.224.0/199.23.224.1 to 9.23.255.2549.23.255.2558,190
1939.24.0.0/199.24.0.1 to 9.24.31.2549.24.31.2558,190
1949.24.32.0/199.24.32.1 to 9.24.63.2549.24.63.2558,190
1959.24.64.0/199.24.64.1 to 9.24.95.2549.24.95.2558,190
1969.24.96.0/199.24.96.1 to 9.24.127.2549.24.127.2558,190
1979.24.128.0/199.24.128.1 to 9.24.159.2549.24.159.2558,190
1989.24.160.0/199.24.160.1 to 9.24.191.2549.24.191.2558,190
1999.24.192.0/199.24.192.1 to 9.24.223.2549.24.223.2558,190
2009.24.224.0/199.24.224.1 to 9.24.255.2549.24.255.2558,190
2019.25.0.0/199.25.0.1 to 9.25.31.2549.25.31.2558,190
2029.25.32.0/199.25.32.1 to 9.25.63.2549.25.63.2558,190
2039.25.64.0/199.25.64.1 to 9.25.95.2549.25.95.2558,190
2049.25.96.0/199.25.96.1 to 9.25.127.2549.25.127.2558,190
2059.25.128.0/199.25.128.1 to 9.25.159.2549.25.159.2558,190
2069.25.160.0/199.25.160.1 to 9.25.191.2549.25.191.2558,190
2079.25.192.0/199.25.192.1 to 9.25.223.2549.25.223.2558,190
2089.25.224.0/199.25.224.1 to 9.25.255.2549.25.255.2558,190
2099.26.0.0/199.26.0.1 to 9.26.31.2549.26.31.2558,190
2109.26.32.0/199.26.32.1 to 9.26.63.2549.26.63.2558,190
2119.26.64.0/199.26.64.1 to 9.26.95.2549.26.95.2558,190
2129.26.96.0/199.26.96.1 to 9.26.127.2549.26.127.2558,190
2139.26.128.0/199.26.128.1 to 9.26.159.2549.26.159.2558,190
2149.26.160.0/199.26.160.1 to 9.26.191.2549.26.191.2558,190
2159.26.192.0/199.26.192.1 to 9.26.223.2549.26.223.2558,190
2169.26.224.0/199.26.224.1 to 9.26.255.2549.26.255.2558,190
2179.27.0.0/199.27.0.1 to 9.27.31.2549.27.31.2558,190
2189.27.32.0/199.27.32.1 to 9.27.63.2549.27.63.2558,190
2199.27.64.0/199.27.64.1 to 9.27.95.2549.27.95.2558,190
2209.27.96.0/199.27.96.1 to 9.27.127.2549.27.127.2558,190
2219.27.128.0/199.27.128.1 to 9.27.159.2549.27.159.2558,190
2229.27.160.0/199.27.160.1 to 9.27.191.2549.27.191.2558,190
2239.27.192.0/199.27.192.1 to 9.27.223.2549.27.223.2558,190
2249.27.224.0/199.27.224.1 to 9.27.255.2549.27.255.2558,190
2259.28.0.0/199.28.0.1 to 9.28.31.2549.28.31.2558,190
2269.28.32.0/199.28.32.1 to 9.28.63.2549.28.63.2558,190
2279.28.64.0/199.28.64.1 to 9.28.95.2549.28.95.2558,190
2289.28.96.0/199.28.96.1 to 9.28.127.2549.28.127.2558,190
2299.28.128.0/199.28.128.1 to 9.28.159.2549.28.159.2558,190
2309.28.160.0/199.28.160.1 to 9.28.191.2549.28.191.2558,190
2319.28.192.0/199.28.192.1 to 9.28.223.2549.28.223.2558,190
2329.28.224.0/199.28.224.1 to 9.28.255.2549.28.255.2558,190
2339.29.0.0/199.29.0.1 to 9.29.31.2549.29.31.2558,190
2349.29.32.0/199.29.32.1 to 9.29.63.2549.29.63.2558,190
2359.29.64.0/199.29.64.1 to 9.29.95.2549.29.95.2558,190
2369.29.96.0/199.29.96.1 to 9.29.127.2549.29.127.2558,190
2379.29.128.0/199.29.128.1 to 9.29.159.2549.29.159.2558,190
2389.29.160.0/199.29.160.1 to 9.29.191.2549.29.191.2558,190
2399.29.192.0/199.29.192.1 to 9.29.223.2549.29.223.2558,190
2409.29.224.0/199.29.224.1 to 9.29.255.2549.29.255.2558,190
2419.30.0.0/199.30.0.1 to 9.30.31.2549.30.31.2558,190
2429.30.32.0/199.30.32.1 to 9.30.63.2549.30.63.2558,190
2439.30.64.0/199.30.64.1 to 9.30.95.2549.30.95.2558,190
2449.30.96.0/199.30.96.1 to 9.30.127.2549.30.127.2558,190
2459.30.128.0/199.30.128.1 to 9.30.159.2549.30.159.2558,190
2469.30.160.0/199.30.160.1 to 9.30.191.2549.30.191.2558,190
2479.30.192.0/199.30.192.1 to 9.30.223.2549.30.223.2558,190
2489.30.224.0/199.30.224.1 to 9.30.255.2549.30.255.2558,190
2499.31.0.0/199.31.0.1 to 9.31.31.2549.31.31.2558,190
2509.31.32.0/199.31.32.1 to 9.31.63.2549.31.63.2558,190
2519.31.64.0/199.31.64.1 to 9.31.95.2549.31.95.2558,190
2529.31.96.0/199.31.96.1 to 9.31.127.2549.31.127.2558,190
2539.31.128.0/199.31.128.1 to 9.31.159.2549.31.159.2558,190
2549.31.160.0/199.31.160.1 to 9.31.191.2549.31.191.2558,190
2559.31.192.0/199.31.192.1 to 9.31.223.2549.31.223.2558,190
2569.31.224.0/199.31.224.1 to 9.31.255.2549.31.255.2558,190

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.