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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.

Network6.232.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
6.232.0.0
Broadcast address
6.239.255.255
First usable
6.232.0.1
Last usable
6.239.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
A (default /8)
As numbers
Hex 06E80000 · Integer 115867648 to 116391935
Reverse DNS zones
232.6.in-addr.arpa
233.6.in-addr.arpa
234.6.in-addr.arpa
235.6.in-addr.arpa
236.6.in-addr.arpa
237.6.in-addr.arpa
238.6.in-addr.arpa
239.6.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00000110.11101000.00000000.000000006.232.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network00000110.11101000.00000000.000000006.232.0.0
Broadcast00000110.11101111.11111111.111111116.239.255.255
Split into smaller subnets/25
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

6.232.0.0/13 makes 4,096 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
16.232.0.0/256.232.0.1 to 6.232.0.1266.232.0.127126
26.232.0.128/256.232.0.129 to 6.232.0.2546.232.0.255126
36.232.1.0/256.232.1.1 to 6.232.1.1266.232.1.127126
46.232.1.128/256.232.1.129 to 6.232.1.2546.232.1.255126
56.232.2.0/256.232.2.1 to 6.232.2.1266.232.2.127126
66.232.2.128/256.232.2.129 to 6.232.2.2546.232.2.255126
76.232.3.0/256.232.3.1 to 6.232.3.1266.232.3.127126
86.232.3.128/256.232.3.129 to 6.232.3.2546.232.3.255126
96.232.4.0/256.232.4.1 to 6.232.4.1266.232.4.127126
106.232.4.128/256.232.4.129 to 6.232.4.2546.232.4.255126
116.232.5.0/256.232.5.1 to 6.232.5.1266.232.5.127126
126.232.5.128/256.232.5.129 to 6.232.5.2546.232.5.255126
136.232.6.0/256.232.6.1 to 6.232.6.1266.232.6.127126
146.232.6.128/256.232.6.129 to 6.232.6.2546.232.6.255126
156.232.7.0/256.232.7.1 to 6.232.7.1266.232.7.127126
166.232.7.128/256.232.7.129 to 6.232.7.2546.232.7.255126
176.232.8.0/256.232.8.1 to 6.232.8.1266.232.8.127126
186.232.8.128/256.232.8.129 to 6.232.8.2546.232.8.255126
196.232.9.0/256.232.9.1 to 6.232.9.1266.232.9.127126
206.232.9.128/256.232.9.129 to 6.232.9.2546.232.9.255126
216.232.10.0/256.232.10.1 to 6.232.10.1266.232.10.127126
226.232.10.128/256.232.10.129 to 6.232.10.2546.232.10.255126
236.232.11.0/256.232.11.1 to 6.232.11.1266.232.11.127126
246.232.11.128/256.232.11.129 to 6.232.11.2546.232.11.255126
256.232.12.0/256.232.12.1 to 6.232.12.1266.232.12.127126
266.232.12.128/256.232.12.129 to 6.232.12.2546.232.12.255126
276.232.13.0/256.232.13.1 to 6.232.13.1266.232.13.127126
286.232.13.128/256.232.13.129 to 6.232.13.2546.232.13.255126
296.232.14.0/256.232.14.1 to 6.232.14.1266.232.14.127126
306.232.14.128/256.232.14.129 to 6.232.14.2546.232.14.255126
316.232.15.0/256.232.15.1 to 6.232.15.1266.232.15.127126
326.232.15.128/256.232.15.129 to 6.232.15.2546.232.15.255126
336.232.16.0/256.232.16.1 to 6.232.16.1266.232.16.127126
346.232.16.128/256.232.16.129 to 6.232.16.2546.232.16.255126
356.232.17.0/256.232.17.1 to 6.232.17.1266.232.17.127126
366.232.17.128/256.232.17.129 to 6.232.17.2546.232.17.255126
376.232.18.0/256.232.18.1 to 6.232.18.1266.232.18.127126
386.232.18.128/256.232.18.129 to 6.232.18.2546.232.18.255126
396.232.19.0/256.232.19.1 to 6.232.19.1266.232.19.127126
406.232.19.128/256.232.19.129 to 6.232.19.2546.232.19.255126
416.232.20.0/256.232.20.1 to 6.232.20.1266.232.20.127126
426.232.20.128/256.232.20.129 to 6.232.20.2546.232.20.255126
436.232.21.0/256.232.21.1 to 6.232.21.1266.232.21.127126
446.232.21.128/256.232.21.129 to 6.232.21.2546.232.21.255126
456.232.22.0/256.232.22.1 to 6.232.22.1266.232.22.127126
466.232.22.128/256.232.22.129 to 6.232.22.2546.232.22.255126
476.232.23.0/256.232.23.1 to 6.232.23.1266.232.23.127126
486.232.23.128/256.232.23.129 to 6.232.23.2546.232.23.255126
496.232.24.0/256.232.24.1 to 6.232.24.1266.232.24.127126
506.232.24.128/256.232.24.129 to 6.232.24.2546.232.24.255126
516.232.25.0/256.232.25.1 to 6.232.25.1266.232.25.127126
526.232.25.128/256.232.25.129 to 6.232.25.2546.232.25.255126
536.232.26.0/256.232.26.1 to 6.232.26.1266.232.26.127126
546.232.26.128/256.232.26.129 to 6.232.26.2546.232.26.255126
556.232.27.0/256.232.27.1 to 6.232.27.1266.232.27.127126
566.232.27.128/256.232.27.129 to 6.232.27.2546.232.27.255126
576.232.28.0/256.232.28.1 to 6.232.28.1266.232.28.127126
586.232.28.128/256.232.28.129 to 6.232.28.2546.232.28.255126
596.232.29.0/256.232.29.1 to 6.232.29.1266.232.29.127126
606.232.29.128/256.232.29.129 to 6.232.29.2546.232.29.255126
616.232.30.0/256.232.30.1 to 6.232.30.1266.232.30.127126
626.232.30.128/256.232.30.129 to 6.232.30.2546.232.30.255126
636.232.31.0/256.232.31.1 to 6.232.31.1266.232.31.127126
646.232.31.128/256.232.31.129 to 6.232.31.2546.232.31.255126
656.232.32.0/256.232.32.1 to 6.232.32.1266.232.32.127126
666.232.32.128/256.232.32.129 to 6.232.32.2546.232.32.255126
676.232.33.0/256.232.33.1 to 6.232.33.1266.232.33.127126
686.232.33.128/256.232.33.129 to 6.232.33.2546.232.33.255126
696.232.34.0/256.232.34.1 to 6.232.34.1266.232.34.127126
706.232.34.128/256.232.34.129 to 6.232.34.2546.232.34.255126
716.232.35.0/256.232.35.1 to 6.232.35.1266.232.35.127126
726.232.35.128/256.232.35.129 to 6.232.35.2546.232.35.255126
736.232.36.0/256.232.36.1 to 6.232.36.1266.232.36.127126
746.232.36.128/256.232.36.129 to 6.232.36.2546.232.36.255126
756.232.37.0/256.232.37.1 to 6.232.37.1266.232.37.127126
766.232.37.128/256.232.37.129 to 6.232.37.2546.232.37.255126
776.232.38.0/256.232.38.1 to 6.232.38.1266.232.38.127126
786.232.38.128/256.232.38.129 to 6.232.38.2546.232.38.255126
796.232.39.0/256.232.39.1 to 6.232.39.1266.232.39.127126
806.232.39.128/256.232.39.129 to 6.232.39.2546.232.39.255126
816.232.40.0/256.232.40.1 to 6.232.40.1266.232.40.127126
826.232.40.128/256.232.40.129 to 6.232.40.2546.232.40.255126
836.232.41.0/256.232.41.1 to 6.232.41.1266.232.41.127126
846.232.41.128/256.232.41.129 to 6.232.41.2546.232.41.255126
856.232.42.0/256.232.42.1 to 6.232.42.1266.232.42.127126
866.232.42.128/256.232.42.129 to 6.232.42.2546.232.42.255126
876.232.43.0/256.232.43.1 to 6.232.43.1266.232.43.127126
886.232.43.128/256.232.43.129 to 6.232.43.2546.232.43.255126
896.232.44.0/256.232.44.1 to 6.232.44.1266.232.44.127126
906.232.44.128/256.232.44.129 to 6.232.44.2546.232.44.255126
916.232.45.0/256.232.45.1 to 6.232.45.1266.232.45.127126
926.232.45.128/256.232.45.129 to 6.232.45.2546.232.45.255126
936.232.46.0/256.232.46.1 to 6.232.46.1266.232.46.127126
946.232.46.128/256.232.46.129 to 6.232.46.2546.232.46.255126
956.232.47.0/256.232.47.1 to 6.232.47.1266.232.47.127126
966.232.47.128/256.232.47.129 to 6.232.47.2546.232.47.255126
976.232.48.0/256.232.48.1 to 6.232.48.1266.232.48.127126
986.232.48.128/256.232.48.129 to 6.232.48.2546.232.48.255126
996.232.49.0/256.232.49.1 to 6.232.49.1266.232.49.127126
1006.232.49.128/256.232.49.129 to 6.232.49.2546.232.49.255126
1016.232.50.0/256.232.50.1 to 6.232.50.1266.232.50.127126
1026.232.50.128/256.232.50.129 to 6.232.50.2546.232.50.255126
1036.232.51.0/256.232.51.1 to 6.232.51.1266.232.51.127126
1046.232.51.128/256.232.51.129 to 6.232.51.2546.232.51.255126
1056.232.52.0/256.232.52.1 to 6.232.52.1266.232.52.127126
1066.232.52.128/256.232.52.129 to 6.232.52.2546.232.52.255126
1076.232.53.0/256.232.53.1 to 6.232.53.1266.232.53.127126
1086.232.53.128/256.232.53.129 to 6.232.53.2546.232.53.255126
1096.232.54.0/256.232.54.1 to 6.232.54.1266.232.54.127126
1106.232.54.128/256.232.54.129 to 6.232.54.2546.232.54.255126
1116.232.55.0/256.232.55.1 to 6.232.55.1266.232.55.127126
1126.232.55.128/256.232.55.129 to 6.232.55.2546.232.55.255126
1136.232.56.0/256.232.56.1 to 6.232.56.1266.232.56.127126
1146.232.56.128/256.232.56.129 to 6.232.56.2546.232.56.255126
1156.232.57.0/256.232.57.1 to 6.232.57.1266.232.57.127126
1166.232.57.128/256.232.57.129 to 6.232.57.2546.232.57.255126
1176.232.58.0/256.232.58.1 to 6.232.58.1266.232.58.127126
1186.232.58.128/256.232.58.129 to 6.232.58.2546.232.58.255126
1196.232.59.0/256.232.59.1 to 6.232.59.1266.232.59.127126
1206.232.59.128/256.232.59.129 to 6.232.59.2546.232.59.255126
1216.232.60.0/256.232.60.1 to 6.232.60.1266.232.60.127126
1226.232.60.128/256.232.60.129 to 6.232.60.2546.232.60.255126
1236.232.61.0/256.232.61.1 to 6.232.61.1266.232.61.127126
1246.232.61.128/256.232.61.129 to 6.232.61.2546.232.61.255126
1256.232.62.0/256.232.62.1 to 6.232.62.1266.232.62.127126
1266.232.62.128/256.232.62.129 to 6.232.62.2546.232.62.255126
1276.232.63.0/256.232.63.1 to 6.232.63.1266.232.63.127126
1286.232.63.128/256.232.63.129 to 6.232.63.2546.232.63.255126
1296.232.64.0/256.232.64.1 to 6.232.64.1266.232.64.127126
1306.232.64.128/256.232.64.129 to 6.232.64.2546.232.64.255126
1316.232.65.0/256.232.65.1 to 6.232.65.1266.232.65.127126
1326.232.65.128/256.232.65.129 to 6.232.65.2546.232.65.255126
1336.232.66.0/256.232.66.1 to 6.232.66.1266.232.66.127126
1346.232.66.128/256.232.66.129 to 6.232.66.2546.232.66.255126
1356.232.67.0/256.232.67.1 to 6.232.67.1266.232.67.127126
1366.232.67.128/256.232.67.129 to 6.232.67.2546.232.67.255126
1376.232.68.0/256.232.68.1 to 6.232.68.1266.232.68.127126
1386.232.68.128/256.232.68.129 to 6.232.68.2546.232.68.255126
1396.232.69.0/256.232.69.1 to 6.232.69.1266.232.69.127126
1406.232.69.128/256.232.69.129 to 6.232.69.2546.232.69.255126
1416.232.70.0/256.232.70.1 to 6.232.70.1266.232.70.127126
1426.232.70.128/256.232.70.129 to 6.232.70.2546.232.70.255126
1436.232.71.0/256.232.71.1 to 6.232.71.1266.232.71.127126
1446.232.71.128/256.232.71.129 to 6.232.71.2546.232.71.255126
1456.232.72.0/256.232.72.1 to 6.232.72.1266.232.72.127126
1466.232.72.128/256.232.72.129 to 6.232.72.2546.232.72.255126
1476.232.73.0/256.232.73.1 to 6.232.73.1266.232.73.127126
1486.232.73.128/256.232.73.129 to 6.232.73.2546.232.73.255126
1496.232.74.0/256.232.74.1 to 6.232.74.1266.232.74.127126
1506.232.74.128/256.232.74.129 to 6.232.74.2546.232.74.255126
1516.232.75.0/256.232.75.1 to 6.232.75.1266.232.75.127126
1526.232.75.128/256.232.75.129 to 6.232.75.2546.232.75.255126
1536.232.76.0/256.232.76.1 to 6.232.76.1266.232.76.127126
1546.232.76.128/256.232.76.129 to 6.232.76.2546.232.76.255126
1556.232.77.0/256.232.77.1 to 6.232.77.1266.232.77.127126
1566.232.77.128/256.232.77.129 to 6.232.77.2546.232.77.255126
1576.232.78.0/256.232.78.1 to 6.232.78.1266.232.78.127126
1586.232.78.128/256.232.78.129 to 6.232.78.2546.232.78.255126
1596.232.79.0/256.232.79.1 to 6.232.79.1266.232.79.127126
1606.232.79.128/256.232.79.129 to 6.232.79.2546.232.79.255126
1616.232.80.0/256.232.80.1 to 6.232.80.1266.232.80.127126
1626.232.80.128/256.232.80.129 to 6.232.80.2546.232.80.255126
1636.232.81.0/256.232.81.1 to 6.232.81.1266.232.81.127126
1646.232.81.128/256.232.81.129 to 6.232.81.2546.232.81.255126
1656.232.82.0/256.232.82.1 to 6.232.82.1266.232.82.127126
1666.232.82.128/256.232.82.129 to 6.232.82.2546.232.82.255126
1676.232.83.0/256.232.83.1 to 6.232.83.1266.232.83.127126
1686.232.83.128/256.232.83.129 to 6.232.83.2546.232.83.255126
1696.232.84.0/256.232.84.1 to 6.232.84.1266.232.84.127126
1706.232.84.128/256.232.84.129 to 6.232.84.2546.232.84.255126
1716.232.85.0/256.232.85.1 to 6.232.85.1266.232.85.127126
1726.232.85.128/256.232.85.129 to 6.232.85.2546.232.85.255126
1736.232.86.0/256.232.86.1 to 6.232.86.1266.232.86.127126
1746.232.86.128/256.232.86.129 to 6.232.86.2546.232.86.255126
1756.232.87.0/256.232.87.1 to 6.232.87.1266.232.87.127126
1766.232.87.128/256.232.87.129 to 6.232.87.2546.232.87.255126
1776.232.88.0/256.232.88.1 to 6.232.88.1266.232.88.127126
1786.232.88.128/256.232.88.129 to 6.232.88.2546.232.88.255126
1796.232.89.0/256.232.89.1 to 6.232.89.1266.232.89.127126
1806.232.89.128/256.232.89.129 to 6.232.89.2546.232.89.255126
1816.232.90.0/256.232.90.1 to 6.232.90.1266.232.90.127126
1826.232.90.128/256.232.90.129 to 6.232.90.2546.232.90.255126
1836.232.91.0/256.232.91.1 to 6.232.91.1266.232.91.127126
1846.232.91.128/256.232.91.129 to 6.232.91.2546.232.91.255126
1856.232.92.0/256.232.92.1 to 6.232.92.1266.232.92.127126
1866.232.92.128/256.232.92.129 to 6.232.92.2546.232.92.255126
1876.232.93.0/256.232.93.1 to 6.232.93.1266.232.93.127126
1886.232.93.128/256.232.93.129 to 6.232.93.2546.232.93.255126
1896.232.94.0/256.232.94.1 to 6.232.94.1266.232.94.127126
1906.232.94.128/256.232.94.129 to 6.232.94.2546.232.94.255126
1916.232.95.0/256.232.95.1 to 6.232.95.1266.232.95.127126
1926.232.95.128/256.232.95.129 to 6.232.95.2546.232.95.255126
1936.232.96.0/256.232.96.1 to 6.232.96.1266.232.96.127126
1946.232.96.128/256.232.96.129 to 6.232.96.2546.232.96.255126
1956.232.97.0/256.232.97.1 to 6.232.97.1266.232.97.127126
1966.232.97.128/256.232.97.129 to 6.232.97.2546.232.97.255126
1976.232.98.0/256.232.98.1 to 6.232.98.1266.232.98.127126
1986.232.98.128/256.232.98.129 to 6.232.98.2546.232.98.255126
1996.232.99.0/256.232.99.1 to 6.232.99.1266.232.99.127126
2006.232.99.128/256.232.99.129 to 6.232.99.2546.232.99.255126
2016.232.100.0/256.232.100.1 to 6.232.100.1266.232.100.127126
2026.232.100.128/256.232.100.129 to 6.232.100.2546.232.100.255126
2036.232.101.0/256.232.101.1 to 6.232.101.1266.232.101.127126
2046.232.101.128/256.232.101.129 to 6.232.101.2546.232.101.255126
2056.232.102.0/256.232.102.1 to 6.232.102.1266.232.102.127126
2066.232.102.128/256.232.102.129 to 6.232.102.2546.232.102.255126
2076.232.103.0/256.232.103.1 to 6.232.103.1266.232.103.127126
2086.232.103.128/256.232.103.129 to 6.232.103.2546.232.103.255126
2096.232.104.0/256.232.104.1 to 6.232.104.1266.232.104.127126
2106.232.104.128/256.232.104.129 to 6.232.104.2546.232.104.255126
2116.232.105.0/256.232.105.1 to 6.232.105.1266.232.105.127126
2126.232.105.128/256.232.105.129 to 6.232.105.2546.232.105.255126
2136.232.106.0/256.232.106.1 to 6.232.106.1266.232.106.127126
2146.232.106.128/256.232.106.129 to 6.232.106.2546.232.106.255126
2156.232.107.0/256.232.107.1 to 6.232.107.1266.232.107.127126
2166.232.107.128/256.232.107.129 to 6.232.107.2546.232.107.255126
2176.232.108.0/256.232.108.1 to 6.232.108.1266.232.108.127126
2186.232.108.128/256.232.108.129 to 6.232.108.2546.232.108.255126
2196.232.109.0/256.232.109.1 to 6.232.109.1266.232.109.127126
2206.232.109.128/256.232.109.129 to 6.232.109.2546.232.109.255126
2216.232.110.0/256.232.110.1 to 6.232.110.1266.232.110.127126
2226.232.110.128/256.232.110.129 to 6.232.110.2546.232.110.255126
2236.232.111.0/256.232.111.1 to 6.232.111.1266.232.111.127126
2246.232.111.128/256.232.111.129 to 6.232.111.2546.232.111.255126
2256.232.112.0/256.232.112.1 to 6.232.112.1266.232.112.127126
2266.232.112.128/256.232.112.129 to 6.232.112.2546.232.112.255126
2276.232.113.0/256.232.113.1 to 6.232.113.1266.232.113.127126
2286.232.113.128/256.232.113.129 to 6.232.113.2546.232.113.255126
2296.232.114.0/256.232.114.1 to 6.232.114.1266.232.114.127126
2306.232.114.128/256.232.114.129 to 6.232.114.2546.232.114.255126
2316.232.115.0/256.232.115.1 to 6.232.115.1266.232.115.127126
2326.232.115.128/256.232.115.129 to 6.232.115.2546.232.115.255126
2336.232.116.0/256.232.116.1 to 6.232.116.1266.232.116.127126
2346.232.116.128/256.232.116.129 to 6.232.116.2546.232.116.255126
2356.232.117.0/256.232.117.1 to 6.232.117.1266.232.117.127126
2366.232.117.128/256.232.117.129 to 6.232.117.2546.232.117.255126
2376.232.118.0/256.232.118.1 to 6.232.118.1266.232.118.127126
2386.232.118.128/256.232.118.129 to 6.232.118.2546.232.118.255126
2396.232.119.0/256.232.119.1 to 6.232.119.1266.232.119.127126
2406.232.119.128/256.232.119.129 to 6.232.119.2546.232.119.255126
2416.232.120.0/256.232.120.1 to 6.232.120.1266.232.120.127126
2426.232.120.128/256.232.120.129 to 6.232.120.2546.232.120.255126
2436.232.121.0/256.232.121.1 to 6.232.121.1266.232.121.127126
2446.232.121.128/256.232.121.129 to 6.232.121.2546.232.121.255126
2456.232.122.0/256.232.122.1 to 6.232.122.1266.232.122.127126
2466.232.122.128/256.232.122.129 to 6.232.122.2546.232.122.255126
2476.232.123.0/256.232.123.1 to 6.232.123.1266.232.123.127126
2486.232.123.128/256.232.123.129 to 6.232.123.2546.232.123.255126
2496.232.124.0/256.232.124.1 to 6.232.124.1266.232.124.127126
2506.232.124.128/256.232.124.129 to 6.232.124.2546.232.124.255126
2516.232.125.0/256.232.125.1 to 6.232.125.1266.232.125.127126
2526.232.125.128/256.232.125.129 to 6.232.125.2546.232.125.255126
2536.232.126.0/256.232.126.1 to 6.232.126.1266.232.126.127126
2546.232.126.128/256.232.126.129 to 6.232.126.2546.232.126.255126
2556.232.127.0/256.232.127.1 to 6.232.127.1266.232.127.127126
2566.232.127.128/256.232.127.129 to 6.232.127.2546.232.127.255126

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.