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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.

Network5.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
5.0.0.0
Broadcast address
5.255.255.255
First usable
5.0.0.1
Last usable
5.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 05000000 · Integer 83886080 to 100663295
Reverse DNS zone
5.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00000101..00000000.00000000.000000005.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00000101..00000000.00000000.000000005.0.0.0
Broadcast00000101..11111111.11111111.111111115.255.255.255
Split into smaller subnets/16
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

5.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
15.0.0.0/165.0.0.1 to 5.0.255.2545.0.255.25565,534
25.1.0.0/165.1.0.1 to 5.1.255.2545.1.255.25565,534
35.2.0.0/165.2.0.1 to 5.2.255.2545.2.255.25565,534
45.3.0.0/165.3.0.1 to 5.3.255.2545.3.255.25565,534
55.4.0.0/165.4.0.1 to 5.4.255.2545.4.255.25565,534
65.5.0.0/165.5.0.1 to 5.5.255.2545.5.255.25565,534
75.6.0.0/165.6.0.1 to 5.6.255.2545.6.255.25565,534
85.7.0.0/165.7.0.1 to 5.7.255.2545.7.255.25565,534
95.8.0.0/165.8.0.1 to 5.8.255.2545.8.255.25565,534
105.9.0.0/165.9.0.1 to 5.9.255.2545.9.255.25565,534
115.10.0.0/165.10.0.1 to 5.10.255.2545.10.255.25565,534
125.11.0.0/165.11.0.1 to 5.11.255.2545.11.255.25565,534
135.12.0.0/165.12.0.1 to 5.12.255.2545.12.255.25565,534
145.13.0.0/165.13.0.1 to 5.13.255.2545.13.255.25565,534
155.14.0.0/165.14.0.1 to 5.14.255.2545.14.255.25565,534
165.15.0.0/165.15.0.1 to 5.15.255.2545.15.255.25565,534
175.16.0.0/165.16.0.1 to 5.16.255.2545.16.255.25565,534
185.17.0.0/165.17.0.1 to 5.17.255.2545.17.255.25565,534
195.18.0.0/165.18.0.1 to 5.18.255.2545.18.255.25565,534
205.19.0.0/165.19.0.1 to 5.19.255.2545.19.255.25565,534
215.20.0.0/165.20.0.1 to 5.20.255.2545.20.255.25565,534
225.21.0.0/165.21.0.1 to 5.21.255.2545.21.255.25565,534
235.22.0.0/165.22.0.1 to 5.22.255.2545.22.255.25565,534
245.23.0.0/165.23.0.1 to 5.23.255.2545.23.255.25565,534
255.24.0.0/165.24.0.1 to 5.24.255.2545.24.255.25565,534
265.25.0.0/165.25.0.1 to 5.25.255.2545.25.255.25565,534
275.26.0.0/165.26.0.1 to 5.26.255.2545.26.255.25565,534
285.27.0.0/165.27.0.1 to 5.27.255.2545.27.255.25565,534
295.28.0.0/165.28.0.1 to 5.28.255.2545.28.255.25565,534
305.29.0.0/165.29.0.1 to 5.29.255.2545.29.255.25565,534
315.30.0.0/165.30.0.1 to 5.30.255.2545.30.255.25565,534
325.31.0.0/165.31.0.1 to 5.31.255.2545.31.255.25565,534
335.32.0.0/165.32.0.1 to 5.32.255.2545.32.255.25565,534
345.33.0.0/165.33.0.1 to 5.33.255.2545.33.255.25565,534
355.34.0.0/165.34.0.1 to 5.34.255.2545.34.255.25565,534
365.35.0.0/165.35.0.1 to 5.35.255.2545.35.255.25565,534
375.36.0.0/165.36.0.1 to 5.36.255.2545.36.255.25565,534
385.37.0.0/165.37.0.1 to 5.37.255.2545.37.255.25565,534
395.38.0.0/165.38.0.1 to 5.38.255.2545.38.255.25565,534
405.39.0.0/165.39.0.1 to 5.39.255.2545.39.255.25565,534
415.40.0.0/165.40.0.1 to 5.40.255.2545.40.255.25565,534
425.41.0.0/165.41.0.1 to 5.41.255.2545.41.255.25565,534
435.42.0.0/165.42.0.1 to 5.42.255.2545.42.255.25565,534
445.43.0.0/165.43.0.1 to 5.43.255.2545.43.255.25565,534
455.44.0.0/165.44.0.1 to 5.44.255.2545.44.255.25565,534
465.45.0.0/165.45.0.1 to 5.45.255.2545.45.255.25565,534
475.46.0.0/165.46.0.1 to 5.46.255.2545.46.255.25565,534
485.47.0.0/165.47.0.1 to 5.47.255.2545.47.255.25565,534
495.48.0.0/165.48.0.1 to 5.48.255.2545.48.255.25565,534
505.49.0.0/165.49.0.1 to 5.49.255.2545.49.255.25565,534
515.50.0.0/165.50.0.1 to 5.50.255.2545.50.255.25565,534
525.51.0.0/165.51.0.1 to 5.51.255.2545.51.255.25565,534
535.52.0.0/165.52.0.1 to 5.52.255.2545.52.255.25565,534
545.53.0.0/165.53.0.1 to 5.53.255.2545.53.255.25565,534
555.54.0.0/165.54.0.1 to 5.54.255.2545.54.255.25565,534
565.55.0.0/165.55.0.1 to 5.55.255.2545.55.255.25565,534
575.56.0.0/165.56.0.1 to 5.56.255.2545.56.255.25565,534
585.57.0.0/165.57.0.1 to 5.57.255.2545.57.255.25565,534
595.58.0.0/165.58.0.1 to 5.58.255.2545.58.255.25565,534
605.59.0.0/165.59.0.1 to 5.59.255.2545.59.255.25565,534
615.60.0.0/165.60.0.1 to 5.60.255.2545.60.255.25565,534
625.61.0.0/165.61.0.1 to 5.61.255.2545.61.255.25565,534
635.62.0.0/165.62.0.1 to 5.62.255.2545.62.255.25565,534
645.63.0.0/165.63.0.1 to 5.63.255.2545.63.255.25565,534
655.64.0.0/165.64.0.1 to 5.64.255.2545.64.255.25565,534
665.65.0.0/165.65.0.1 to 5.65.255.2545.65.255.25565,534
675.66.0.0/165.66.0.1 to 5.66.255.2545.66.255.25565,534
685.67.0.0/165.67.0.1 to 5.67.255.2545.67.255.25565,534
695.68.0.0/165.68.0.1 to 5.68.255.2545.68.255.25565,534
705.69.0.0/165.69.0.1 to 5.69.255.2545.69.255.25565,534
715.70.0.0/165.70.0.1 to 5.70.255.2545.70.255.25565,534
725.71.0.0/165.71.0.1 to 5.71.255.2545.71.255.25565,534
735.72.0.0/165.72.0.1 to 5.72.255.2545.72.255.25565,534
745.73.0.0/165.73.0.1 to 5.73.255.2545.73.255.25565,534
755.74.0.0/165.74.0.1 to 5.74.255.2545.74.255.25565,534
765.75.0.0/165.75.0.1 to 5.75.255.2545.75.255.25565,534
775.76.0.0/165.76.0.1 to 5.76.255.2545.76.255.25565,534
785.77.0.0/165.77.0.1 to 5.77.255.2545.77.255.25565,534
795.78.0.0/165.78.0.1 to 5.78.255.2545.78.255.25565,534
805.79.0.0/165.79.0.1 to 5.79.255.2545.79.255.25565,534
815.80.0.0/165.80.0.1 to 5.80.255.2545.80.255.25565,534
825.81.0.0/165.81.0.1 to 5.81.255.2545.81.255.25565,534
835.82.0.0/165.82.0.1 to 5.82.255.2545.82.255.25565,534
845.83.0.0/165.83.0.1 to 5.83.255.2545.83.255.25565,534
855.84.0.0/165.84.0.1 to 5.84.255.2545.84.255.25565,534
865.85.0.0/165.85.0.1 to 5.85.255.2545.85.255.25565,534
875.86.0.0/165.86.0.1 to 5.86.255.2545.86.255.25565,534
885.87.0.0/165.87.0.1 to 5.87.255.2545.87.255.25565,534
895.88.0.0/165.88.0.1 to 5.88.255.2545.88.255.25565,534
905.89.0.0/165.89.0.1 to 5.89.255.2545.89.255.25565,534
915.90.0.0/165.90.0.1 to 5.90.255.2545.90.255.25565,534
925.91.0.0/165.91.0.1 to 5.91.255.2545.91.255.25565,534
935.92.0.0/165.92.0.1 to 5.92.255.2545.92.255.25565,534
945.93.0.0/165.93.0.1 to 5.93.255.2545.93.255.25565,534
955.94.0.0/165.94.0.1 to 5.94.255.2545.94.255.25565,534
965.95.0.0/165.95.0.1 to 5.95.255.2545.95.255.25565,534
975.96.0.0/165.96.0.1 to 5.96.255.2545.96.255.25565,534
985.97.0.0/165.97.0.1 to 5.97.255.2545.97.255.25565,534
995.98.0.0/165.98.0.1 to 5.98.255.2545.98.255.25565,534
1005.99.0.0/165.99.0.1 to 5.99.255.2545.99.255.25565,534
1015.100.0.0/165.100.0.1 to 5.100.255.2545.100.255.25565,534
1025.101.0.0/165.101.0.1 to 5.101.255.2545.101.255.25565,534
1035.102.0.0/165.102.0.1 to 5.102.255.2545.102.255.25565,534
1045.103.0.0/165.103.0.1 to 5.103.255.2545.103.255.25565,534
1055.104.0.0/165.104.0.1 to 5.104.255.2545.104.255.25565,534
1065.105.0.0/165.105.0.1 to 5.105.255.2545.105.255.25565,534
1075.106.0.0/165.106.0.1 to 5.106.255.2545.106.255.25565,534
1085.107.0.0/165.107.0.1 to 5.107.255.2545.107.255.25565,534
1095.108.0.0/165.108.0.1 to 5.108.255.2545.108.255.25565,534
1105.109.0.0/165.109.0.1 to 5.109.255.2545.109.255.25565,534
1115.110.0.0/165.110.0.1 to 5.110.255.2545.110.255.25565,534
1125.111.0.0/165.111.0.1 to 5.111.255.2545.111.255.25565,534
1135.112.0.0/165.112.0.1 to 5.112.255.2545.112.255.25565,534
1145.113.0.0/165.113.0.1 to 5.113.255.2545.113.255.25565,534
1155.114.0.0/165.114.0.1 to 5.114.255.2545.114.255.25565,534
1165.115.0.0/165.115.0.1 to 5.115.255.2545.115.255.25565,534
1175.116.0.0/165.116.0.1 to 5.116.255.2545.116.255.25565,534
1185.117.0.0/165.117.0.1 to 5.117.255.2545.117.255.25565,534
1195.118.0.0/165.118.0.1 to 5.118.255.2545.118.255.25565,534
1205.119.0.0/165.119.0.1 to 5.119.255.2545.119.255.25565,534
1215.120.0.0/165.120.0.1 to 5.120.255.2545.120.255.25565,534
1225.121.0.0/165.121.0.1 to 5.121.255.2545.121.255.25565,534
1235.122.0.0/165.122.0.1 to 5.122.255.2545.122.255.25565,534
1245.123.0.0/165.123.0.1 to 5.123.255.2545.123.255.25565,534
1255.124.0.0/165.124.0.1 to 5.124.255.2545.124.255.25565,534
1265.125.0.0/165.125.0.1 to 5.125.255.2545.125.255.25565,534
1275.126.0.0/165.126.0.1 to 5.126.255.2545.126.255.25565,534
1285.127.0.0/165.127.0.1 to 5.127.255.2545.127.255.25565,534
1295.128.0.0/165.128.0.1 to 5.128.255.2545.128.255.25565,534
1305.129.0.0/165.129.0.1 to 5.129.255.2545.129.255.25565,534
1315.130.0.0/165.130.0.1 to 5.130.255.2545.130.255.25565,534
1325.131.0.0/165.131.0.1 to 5.131.255.2545.131.255.25565,534
1335.132.0.0/165.132.0.1 to 5.132.255.2545.132.255.25565,534
1345.133.0.0/165.133.0.1 to 5.133.255.2545.133.255.25565,534
1355.134.0.0/165.134.0.1 to 5.134.255.2545.134.255.25565,534
1365.135.0.0/165.135.0.1 to 5.135.255.2545.135.255.25565,534
1375.136.0.0/165.136.0.1 to 5.136.255.2545.136.255.25565,534
1385.137.0.0/165.137.0.1 to 5.137.255.2545.137.255.25565,534
1395.138.0.0/165.138.0.1 to 5.138.255.2545.138.255.25565,534
1405.139.0.0/165.139.0.1 to 5.139.255.2545.139.255.25565,534
1415.140.0.0/165.140.0.1 to 5.140.255.2545.140.255.25565,534
1425.141.0.0/165.141.0.1 to 5.141.255.2545.141.255.25565,534
1435.142.0.0/165.142.0.1 to 5.142.255.2545.142.255.25565,534
1445.143.0.0/165.143.0.1 to 5.143.255.2545.143.255.25565,534
1455.144.0.0/165.144.0.1 to 5.144.255.2545.144.255.25565,534
1465.145.0.0/165.145.0.1 to 5.145.255.2545.145.255.25565,534
1475.146.0.0/165.146.0.1 to 5.146.255.2545.146.255.25565,534
1485.147.0.0/165.147.0.1 to 5.147.255.2545.147.255.25565,534
1495.148.0.0/165.148.0.1 to 5.148.255.2545.148.255.25565,534
1505.149.0.0/165.149.0.1 to 5.149.255.2545.149.255.25565,534
1515.150.0.0/165.150.0.1 to 5.150.255.2545.150.255.25565,534
1525.151.0.0/165.151.0.1 to 5.151.255.2545.151.255.25565,534
1535.152.0.0/165.152.0.1 to 5.152.255.2545.152.255.25565,534
1545.153.0.0/165.153.0.1 to 5.153.255.2545.153.255.25565,534
1555.154.0.0/165.154.0.1 to 5.154.255.2545.154.255.25565,534
1565.155.0.0/165.155.0.1 to 5.155.255.2545.155.255.25565,534
1575.156.0.0/165.156.0.1 to 5.156.255.2545.156.255.25565,534
1585.157.0.0/165.157.0.1 to 5.157.255.2545.157.255.25565,534
1595.158.0.0/165.158.0.1 to 5.158.255.2545.158.255.25565,534
1605.159.0.0/165.159.0.1 to 5.159.255.2545.159.255.25565,534
1615.160.0.0/165.160.0.1 to 5.160.255.2545.160.255.25565,534
1625.161.0.0/165.161.0.1 to 5.161.255.2545.161.255.25565,534
1635.162.0.0/165.162.0.1 to 5.162.255.2545.162.255.25565,534
1645.163.0.0/165.163.0.1 to 5.163.255.2545.163.255.25565,534
1655.164.0.0/165.164.0.1 to 5.164.255.2545.164.255.25565,534
1665.165.0.0/165.165.0.1 to 5.165.255.2545.165.255.25565,534
1675.166.0.0/165.166.0.1 to 5.166.255.2545.166.255.25565,534
1685.167.0.0/165.167.0.1 to 5.167.255.2545.167.255.25565,534
1695.168.0.0/165.168.0.1 to 5.168.255.2545.168.255.25565,534
1705.169.0.0/165.169.0.1 to 5.169.255.2545.169.255.25565,534
1715.170.0.0/165.170.0.1 to 5.170.255.2545.170.255.25565,534
1725.171.0.0/165.171.0.1 to 5.171.255.2545.171.255.25565,534
1735.172.0.0/165.172.0.1 to 5.172.255.2545.172.255.25565,534
1745.173.0.0/165.173.0.1 to 5.173.255.2545.173.255.25565,534
1755.174.0.0/165.174.0.1 to 5.174.255.2545.174.255.25565,534
1765.175.0.0/165.175.0.1 to 5.175.255.2545.175.255.25565,534
1775.176.0.0/165.176.0.1 to 5.176.255.2545.176.255.25565,534
1785.177.0.0/165.177.0.1 to 5.177.255.2545.177.255.25565,534
1795.178.0.0/165.178.0.1 to 5.178.255.2545.178.255.25565,534
1805.179.0.0/165.179.0.1 to 5.179.255.2545.179.255.25565,534
1815.180.0.0/165.180.0.1 to 5.180.255.2545.180.255.25565,534
1825.181.0.0/165.181.0.1 to 5.181.255.2545.181.255.25565,534
1835.182.0.0/165.182.0.1 to 5.182.255.2545.182.255.25565,534
1845.183.0.0/165.183.0.1 to 5.183.255.2545.183.255.25565,534
1855.184.0.0/165.184.0.1 to 5.184.255.2545.184.255.25565,534
1865.185.0.0/165.185.0.1 to 5.185.255.2545.185.255.25565,534
1875.186.0.0/165.186.0.1 to 5.186.255.2545.186.255.25565,534
1885.187.0.0/165.187.0.1 to 5.187.255.2545.187.255.25565,534
1895.188.0.0/165.188.0.1 to 5.188.255.2545.188.255.25565,534
1905.189.0.0/165.189.0.1 to 5.189.255.2545.189.255.25565,534
1915.190.0.0/165.190.0.1 to 5.190.255.2545.190.255.25565,534
1925.191.0.0/165.191.0.1 to 5.191.255.2545.191.255.25565,534
1935.192.0.0/165.192.0.1 to 5.192.255.2545.192.255.25565,534
1945.193.0.0/165.193.0.1 to 5.193.255.2545.193.255.25565,534
1955.194.0.0/165.194.0.1 to 5.194.255.2545.194.255.25565,534
1965.195.0.0/165.195.0.1 to 5.195.255.2545.195.255.25565,534
1975.196.0.0/165.196.0.1 to 5.196.255.2545.196.255.25565,534
1985.197.0.0/165.197.0.1 to 5.197.255.2545.197.255.25565,534
1995.198.0.0/165.198.0.1 to 5.198.255.2545.198.255.25565,534
2005.199.0.0/165.199.0.1 to 5.199.255.2545.199.255.25565,534
2015.200.0.0/165.200.0.1 to 5.200.255.2545.200.255.25565,534
2025.201.0.0/165.201.0.1 to 5.201.255.2545.201.255.25565,534
2035.202.0.0/165.202.0.1 to 5.202.255.2545.202.255.25565,534
2045.203.0.0/165.203.0.1 to 5.203.255.2545.203.255.25565,534
2055.204.0.0/165.204.0.1 to 5.204.255.2545.204.255.25565,534
2065.205.0.0/165.205.0.1 to 5.205.255.2545.205.255.25565,534
2075.206.0.0/165.206.0.1 to 5.206.255.2545.206.255.25565,534
2085.207.0.0/165.207.0.1 to 5.207.255.2545.207.255.25565,534
2095.208.0.0/165.208.0.1 to 5.208.255.2545.208.255.25565,534
2105.209.0.0/165.209.0.1 to 5.209.255.2545.209.255.25565,534
2115.210.0.0/165.210.0.1 to 5.210.255.2545.210.255.25565,534
2125.211.0.0/165.211.0.1 to 5.211.255.2545.211.255.25565,534
2135.212.0.0/165.212.0.1 to 5.212.255.2545.212.255.25565,534
2145.213.0.0/165.213.0.1 to 5.213.255.2545.213.255.25565,534
2155.214.0.0/165.214.0.1 to 5.214.255.2545.214.255.25565,534
2165.215.0.0/165.215.0.1 to 5.215.255.2545.215.255.25565,534
2175.216.0.0/165.216.0.1 to 5.216.255.2545.216.255.25565,534
2185.217.0.0/165.217.0.1 to 5.217.255.2545.217.255.25565,534
2195.218.0.0/165.218.0.1 to 5.218.255.2545.218.255.25565,534
2205.219.0.0/165.219.0.1 to 5.219.255.2545.219.255.25565,534
2215.220.0.0/165.220.0.1 to 5.220.255.2545.220.255.25565,534
2225.221.0.0/165.221.0.1 to 5.221.255.2545.221.255.25565,534
2235.222.0.0/165.222.0.1 to 5.222.255.2545.222.255.25565,534
2245.223.0.0/165.223.0.1 to 5.223.255.2545.223.255.25565,534
2255.224.0.0/165.224.0.1 to 5.224.255.2545.224.255.25565,534
2265.225.0.0/165.225.0.1 to 5.225.255.2545.225.255.25565,534
2275.226.0.0/165.226.0.1 to 5.226.255.2545.226.255.25565,534
2285.227.0.0/165.227.0.1 to 5.227.255.2545.227.255.25565,534
2295.228.0.0/165.228.0.1 to 5.228.255.2545.228.255.25565,534
2305.229.0.0/165.229.0.1 to 5.229.255.2545.229.255.25565,534
2315.230.0.0/165.230.0.1 to 5.230.255.2545.230.255.25565,534
2325.231.0.0/165.231.0.1 to 5.231.255.2545.231.255.25565,534
2335.232.0.0/165.232.0.1 to 5.232.255.2545.232.255.25565,534
2345.233.0.0/165.233.0.1 to 5.233.255.2545.233.255.25565,534
2355.234.0.0/165.234.0.1 to 5.234.255.2545.234.255.25565,534
2365.235.0.0/165.235.0.1 to 5.235.255.2545.235.255.25565,534
2375.236.0.0/165.236.0.1 to 5.236.255.2545.236.255.25565,534
2385.237.0.0/165.237.0.1 to 5.237.255.2545.237.255.25565,534
2395.238.0.0/165.238.0.1 to 5.238.255.2545.238.255.25565,534
2405.239.0.0/165.239.0.1 to 5.239.255.2545.239.255.25565,534
2415.240.0.0/165.240.0.1 to 5.240.255.2545.240.255.25565,534
2425.241.0.0/165.241.0.1 to 5.241.255.2545.241.255.25565,534
2435.242.0.0/165.242.0.1 to 5.242.255.2545.242.255.25565,534
2445.243.0.0/165.243.0.1 to 5.243.255.2545.243.255.25565,534
2455.244.0.0/165.244.0.1 to 5.244.255.2545.244.255.25565,534
2465.245.0.0/165.245.0.1 to 5.245.255.2545.245.255.25565,534
2475.246.0.0/165.246.0.1 to 5.246.255.2545.246.255.25565,534
2485.247.0.0/165.247.0.1 to 5.247.255.2545.247.255.25565,534
2495.248.0.0/165.248.0.1 to 5.248.255.2545.248.255.25565,534
2505.249.0.0/165.249.0.1 to 5.249.255.2545.249.255.25565,534
2515.250.0.0/165.250.0.1 to 5.250.255.2545.250.255.25565,534
2525.251.0.0/165.251.0.1 to 5.251.255.2545.251.255.25565,534
2535.252.0.0/165.252.0.1 to 5.252.255.2545.252.255.25565,534
2545.253.0.0/165.253.0.1 to 5.253.255.2545.253.255.25565,534
2555.254.0.0/165.254.0.1 to 5.254.255.2545.254.255.25565,534
2565.255.0.0/165.255.0.1 to 5.255.255.2545.255.255.25565,534

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.