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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.

Network8.0.0.0/5
Usable hosts134,217,726
Subnet mask248.0.0.0
Addresses134,217,728
Network address
8.0.0.0
Broadcast address
15.255.255.255
First usable
8.0.0.1
Last usable
15.255.255.254
Usable hosts
134,217,726 (134,217,728 less the network and broadcast addresses)
Subnet mask
248.0.0.0
Wildcard mask
7.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/5
Type
Public public
Old class
A (default /8)
As numbers
Hex 08000000 · Integer 134217728 to 268435455
Reverse DNS zones
8.in-addr.arpa
9.in-addr.arpa
10.in-addr.arpa
11.in-addr.arpa
12.in-addr.arpa
13.in-addr.arpa
14.in-addr.arpa
15.in-addr.arpa
/5 is not on a 8-bit boundary, so it takes 8 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00001000.00000000.00000000.000000008.0.0.0
Subnet mask11111000.00000000.00000000.00000000248.0.0.0
Network00001000.00000000.00000000.000000008.0.0.0
Broadcast00001111.11111111.11111111.1111111115.255.255.255
Split into smaller subnets/13
/6 (2)/7 (4)/8 (8)/9 (16)/10 (32)/11 (64)/12 (128)/13 (256)/14 (512)/15 (1,024)/16 (2,048)/17 (4,096)

8.0.0.0/5 makes 256 subnets of /13.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
18.0.0.0/138.0.0.1 to 8.7.255.2548.7.255.255524,286
28.8.0.0/138.8.0.1 to 8.15.255.2548.15.255.255524,286
38.16.0.0/138.16.0.1 to 8.23.255.2548.23.255.255524,286
48.24.0.0/138.24.0.1 to 8.31.255.2548.31.255.255524,286
58.32.0.0/138.32.0.1 to 8.39.255.2548.39.255.255524,286
68.40.0.0/138.40.0.1 to 8.47.255.2548.47.255.255524,286
78.48.0.0/138.48.0.1 to 8.55.255.2548.55.255.255524,286
88.56.0.0/138.56.0.1 to 8.63.255.2548.63.255.255524,286
98.64.0.0/138.64.0.1 to 8.71.255.2548.71.255.255524,286
108.72.0.0/138.72.0.1 to 8.79.255.2548.79.255.255524,286
118.80.0.0/138.80.0.1 to 8.87.255.2548.87.255.255524,286
128.88.0.0/138.88.0.1 to 8.95.255.2548.95.255.255524,286
138.96.0.0/138.96.0.1 to 8.103.255.2548.103.255.255524,286
148.104.0.0/138.104.0.1 to 8.111.255.2548.111.255.255524,286
158.112.0.0/138.112.0.1 to 8.119.255.2548.119.255.255524,286
168.120.0.0/138.120.0.1 to 8.127.255.2548.127.255.255524,286
178.128.0.0/138.128.0.1 to 8.135.255.2548.135.255.255524,286
188.136.0.0/138.136.0.1 to 8.143.255.2548.143.255.255524,286
198.144.0.0/138.144.0.1 to 8.151.255.2548.151.255.255524,286
208.152.0.0/138.152.0.1 to 8.159.255.2548.159.255.255524,286
218.160.0.0/138.160.0.1 to 8.167.255.2548.167.255.255524,286
228.168.0.0/138.168.0.1 to 8.175.255.2548.175.255.255524,286
238.176.0.0/138.176.0.1 to 8.183.255.2548.183.255.255524,286
248.184.0.0/138.184.0.1 to 8.191.255.2548.191.255.255524,286
258.192.0.0/138.192.0.1 to 8.199.255.2548.199.255.255524,286
268.200.0.0/138.200.0.1 to 8.207.255.2548.207.255.255524,286
278.208.0.0/138.208.0.1 to 8.215.255.2548.215.255.255524,286
288.216.0.0/138.216.0.1 to 8.223.255.2548.223.255.255524,286
298.224.0.0/138.224.0.1 to 8.231.255.2548.231.255.255524,286
308.232.0.0/138.232.0.1 to 8.239.255.2548.239.255.255524,286
318.240.0.0/138.240.0.1 to 8.247.255.2548.247.255.255524,286
328.248.0.0/138.248.0.1 to 8.255.255.2548.255.255.255524,286
339.0.0.0/139.0.0.1 to 9.7.255.2549.7.255.255524,286
349.8.0.0/139.8.0.1 to 9.15.255.2549.15.255.255524,286
359.16.0.0/139.16.0.1 to 9.23.255.2549.23.255.255524,286
369.24.0.0/139.24.0.1 to 9.31.255.2549.31.255.255524,286
379.32.0.0/139.32.0.1 to 9.39.255.2549.39.255.255524,286
389.40.0.0/139.40.0.1 to 9.47.255.2549.47.255.255524,286
399.48.0.0/139.48.0.1 to 9.55.255.2549.55.255.255524,286
409.56.0.0/139.56.0.1 to 9.63.255.2549.63.255.255524,286
419.64.0.0/139.64.0.1 to 9.71.255.2549.71.255.255524,286
429.72.0.0/139.72.0.1 to 9.79.255.2549.79.255.255524,286
439.80.0.0/139.80.0.1 to 9.87.255.2549.87.255.255524,286
449.88.0.0/139.88.0.1 to 9.95.255.2549.95.255.255524,286
459.96.0.0/139.96.0.1 to 9.103.255.2549.103.255.255524,286
469.104.0.0/139.104.0.1 to 9.111.255.2549.111.255.255524,286
479.112.0.0/139.112.0.1 to 9.119.255.2549.119.255.255524,286
489.120.0.0/139.120.0.1 to 9.127.255.2549.127.255.255524,286
499.128.0.0/139.128.0.1 to 9.135.255.2549.135.255.255524,286
509.136.0.0/139.136.0.1 to 9.143.255.2549.143.255.255524,286
519.144.0.0/139.144.0.1 to 9.151.255.2549.151.255.255524,286
529.152.0.0/139.152.0.1 to 9.159.255.2549.159.255.255524,286
539.160.0.0/139.160.0.1 to 9.167.255.2549.167.255.255524,286
549.168.0.0/139.168.0.1 to 9.175.255.2549.175.255.255524,286
559.176.0.0/139.176.0.1 to 9.183.255.2549.183.255.255524,286
569.184.0.0/139.184.0.1 to 9.191.255.2549.191.255.255524,286
579.192.0.0/139.192.0.1 to 9.199.255.2549.199.255.255524,286
589.200.0.0/139.200.0.1 to 9.207.255.2549.207.255.255524,286
599.208.0.0/139.208.0.1 to 9.215.255.2549.215.255.255524,286
609.216.0.0/139.216.0.1 to 9.223.255.2549.223.255.255524,286
619.224.0.0/139.224.0.1 to 9.231.255.2549.231.255.255524,286
629.232.0.0/139.232.0.1 to 9.239.255.2549.239.255.255524,286
639.240.0.0/139.240.0.1 to 9.247.255.2549.247.255.255524,286
649.248.0.0/139.248.0.1 to 9.255.255.2549.255.255.255524,286
6510.0.0.0/1310.0.0.1 to 10.7.255.25410.7.255.255524,286
6610.8.0.0/1310.8.0.1 to 10.15.255.25410.15.255.255524,286
6710.16.0.0/1310.16.0.1 to 10.23.255.25410.23.255.255524,286
6810.24.0.0/1310.24.0.1 to 10.31.255.25410.31.255.255524,286
6910.32.0.0/1310.32.0.1 to 10.39.255.25410.39.255.255524,286
7010.40.0.0/1310.40.0.1 to 10.47.255.25410.47.255.255524,286
7110.48.0.0/1310.48.0.1 to 10.55.255.25410.55.255.255524,286
7210.56.0.0/1310.56.0.1 to 10.63.255.25410.63.255.255524,286
7310.64.0.0/1310.64.0.1 to 10.71.255.25410.71.255.255524,286
7410.72.0.0/1310.72.0.1 to 10.79.255.25410.79.255.255524,286
7510.80.0.0/1310.80.0.1 to 10.87.255.25410.87.255.255524,286
7610.88.0.0/1310.88.0.1 to 10.95.255.25410.95.255.255524,286
7710.96.0.0/1310.96.0.1 to 10.103.255.25410.103.255.255524,286
7810.104.0.0/1310.104.0.1 to 10.111.255.25410.111.255.255524,286
7910.112.0.0/1310.112.0.1 to 10.119.255.25410.119.255.255524,286
8010.120.0.0/1310.120.0.1 to 10.127.255.25410.127.255.255524,286
8110.128.0.0/1310.128.0.1 to 10.135.255.25410.135.255.255524,286
8210.136.0.0/1310.136.0.1 to 10.143.255.25410.143.255.255524,286
8310.144.0.0/1310.144.0.1 to 10.151.255.25410.151.255.255524,286
8410.152.0.0/1310.152.0.1 to 10.159.255.25410.159.255.255524,286
8510.160.0.0/1310.160.0.1 to 10.167.255.25410.167.255.255524,286
8610.168.0.0/1310.168.0.1 to 10.175.255.25410.175.255.255524,286
8710.176.0.0/1310.176.0.1 to 10.183.255.25410.183.255.255524,286
8810.184.0.0/1310.184.0.1 to 10.191.255.25410.191.255.255524,286
8910.192.0.0/1310.192.0.1 to 10.199.255.25410.199.255.255524,286
9010.200.0.0/1310.200.0.1 to 10.207.255.25410.207.255.255524,286
9110.208.0.0/1310.208.0.1 to 10.215.255.25410.215.255.255524,286
9210.216.0.0/1310.216.0.1 to 10.223.255.25410.223.255.255524,286
9310.224.0.0/1310.224.0.1 to 10.231.255.25410.231.255.255524,286
9410.232.0.0/1310.232.0.1 to 10.239.255.25410.239.255.255524,286
9510.240.0.0/1310.240.0.1 to 10.247.255.25410.247.255.255524,286
9610.248.0.0/1310.248.0.1 to 10.255.255.25410.255.255.255524,286
9711.0.0.0/1311.0.0.1 to 11.7.255.25411.7.255.255524,286
9811.8.0.0/1311.8.0.1 to 11.15.255.25411.15.255.255524,286
9911.16.0.0/1311.16.0.1 to 11.23.255.25411.23.255.255524,286
10011.24.0.0/1311.24.0.1 to 11.31.255.25411.31.255.255524,286
10111.32.0.0/1311.32.0.1 to 11.39.255.25411.39.255.255524,286
10211.40.0.0/1311.40.0.1 to 11.47.255.25411.47.255.255524,286
10311.48.0.0/1311.48.0.1 to 11.55.255.25411.55.255.255524,286
10411.56.0.0/1311.56.0.1 to 11.63.255.25411.63.255.255524,286
10511.64.0.0/1311.64.0.1 to 11.71.255.25411.71.255.255524,286
10611.72.0.0/1311.72.0.1 to 11.79.255.25411.79.255.255524,286
10711.80.0.0/1311.80.0.1 to 11.87.255.25411.87.255.255524,286
10811.88.0.0/1311.88.0.1 to 11.95.255.25411.95.255.255524,286
10911.96.0.0/1311.96.0.1 to 11.103.255.25411.103.255.255524,286
11011.104.0.0/1311.104.0.1 to 11.111.255.25411.111.255.255524,286
11111.112.0.0/1311.112.0.1 to 11.119.255.25411.119.255.255524,286
11211.120.0.0/1311.120.0.1 to 11.127.255.25411.127.255.255524,286
11311.128.0.0/1311.128.0.1 to 11.135.255.25411.135.255.255524,286
11411.136.0.0/1311.136.0.1 to 11.143.255.25411.143.255.255524,286
11511.144.0.0/1311.144.0.1 to 11.151.255.25411.151.255.255524,286
11611.152.0.0/1311.152.0.1 to 11.159.255.25411.159.255.255524,286
11711.160.0.0/1311.160.0.1 to 11.167.255.25411.167.255.255524,286
11811.168.0.0/1311.168.0.1 to 11.175.255.25411.175.255.255524,286
11911.176.0.0/1311.176.0.1 to 11.183.255.25411.183.255.255524,286
12011.184.0.0/1311.184.0.1 to 11.191.255.25411.191.255.255524,286
12111.192.0.0/1311.192.0.1 to 11.199.255.25411.199.255.255524,286
12211.200.0.0/1311.200.0.1 to 11.207.255.25411.207.255.255524,286
12311.208.0.0/1311.208.0.1 to 11.215.255.25411.215.255.255524,286
12411.216.0.0/1311.216.0.1 to 11.223.255.25411.223.255.255524,286
12511.224.0.0/1311.224.0.1 to 11.231.255.25411.231.255.255524,286
12611.232.0.0/1311.232.0.1 to 11.239.255.25411.239.255.255524,286
12711.240.0.0/1311.240.0.1 to 11.247.255.25411.247.255.255524,286
12811.248.0.0/1311.248.0.1 to 11.255.255.25411.255.255.255524,286
12912.0.0.0/1312.0.0.1 to 12.7.255.25412.7.255.255524,286
13012.8.0.0/1312.8.0.1 to 12.15.255.25412.15.255.255524,286
13112.16.0.0/1312.16.0.1 to 12.23.255.25412.23.255.255524,286
13212.24.0.0/1312.24.0.1 to 12.31.255.25412.31.255.255524,286
13312.32.0.0/1312.32.0.1 to 12.39.255.25412.39.255.255524,286
13412.40.0.0/1312.40.0.1 to 12.47.255.25412.47.255.255524,286
13512.48.0.0/1312.48.0.1 to 12.55.255.25412.55.255.255524,286
13612.56.0.0/1312.56.0.1 to 12.63.255.25412.63.255.255524,286
13712.64.0.0/1312.64.0.1 to 12.71.255.25412.71.255.255524,286
13812.72.0.0/1312.72.0.1 to 12.79.255.25412.79.255.255524,286
13912.80.0.0/1312.80.0.1 to 12.87.255.25412.87.255.255524,286
14012.88.0.0/1312.88.0.1 to 12.95.255.25412.95.255.255524,286
14112.96.0.0/1312.96.0.1 to 12.103.255.25412.103.255.255524,286
14212.104.0.0/1312.104.0.1 to 12.111.255.25412.111.255.255524,286
14312.112.0.0/1312.112.0.1 to 12.119.255.25412.119.255.255524,286
14412.120.0.0/1312.120.0.1 to 12.127.255.25412.127.255.255524,286
14512.128.0.0/1312.128.0.1 to 12.135.255.25412.135.255.255524,286
14612.136.0.0/1312.136.0.1 to 12.143.255.25412.143.255.255524,286
14712.144.0.0/1312.144.0.1 to 12.151.255.25412.151.255.255524,286
14812.152.0.0/1312.152.0.1 to 12.159.255.25412.159.255.255524,286
14912.160.0.0/1312.160.0.1 to 12.167.255.25412.167.255.255524,286
15012.168.0.0/1312.168.0.1 to 12.175.255.25412.175.255.255524,286
15112.176.0.0/1312.176.0.1 to 12.183.255.25412.183.255.255524,286
15212.184.0.0/1312.184.0.1 to 12.191.255.25412.191.255.255524,286
15312.192.0.0/1312.192.0.1 to 12.199.255.25412.199.255.255524,286
15412.200.0.0/1312.200.0.1 to 12.207.255.25412.207.255.255524,286
15512.208.0.0/1312.208.0.1 to 12.215.255.25412.215.255.255524,286
15612.216.0.0/1312.216.0.1 to 12.223.255.25412.223.255.255524,286
15712.224.0.0/1312.224.0.1 to 12.231.255.25412.231.255.255524,286
15812.232.0.0/1312.232.0.1 to 12.239.255.25412.239.255.255524,286
15912.240.0.0/1312.240.0.1 to 12.247.255.25412.247.255.255524,286
16012.248.0.0/1312.248.0.1 to 12.255.255.25412.255.255.255524,286
16113.0.0.0/1313.0.0.1 to 13.7.255.25413.7.255.255524,286
16213.8.0.0/1313.8.0.1 to 13.15.255.25413.15.255.255524,286
16313.16.0.0/1313.16.0.1 to 13.23.255.25413.23.255.255524,286
16413.24.0.0/1313.24.0.1 to 13.31.255.25413.31.255.255524,286
16513.32.0.0/1313.32.0.1 to 13.39.255.25413.39.255.255524,286
16613.40.0.0/1313.40.0.1 to 13.47.255.25413.47.255.255524,286
16713.48.0.0/1313.48.0.1 to 13.55.255.25413.55.255.255524,286
16813.56.0.0/1313.56.0.1 to 13.63.255.25413.63.255.255524,286
16913.64.0.0/1313.64.0.1 to 13.71.255.25413.71.255.255524,286
17013.72.0.0/1313.72.0.1 to 13.79.255.25413.79.255.255524,286
17113.80.0.0/1313.80.0.1 to 13.87.255.25413.87.255.255524,286
17213.88.0.0/1313.88.0.1 to 13.95.255.25413.95.255.255524,286
17313.96.0.0/1313.96.0.1 to 13.103.255.25413.103.255.255524,286
17413.104.0.0/1313.104.0.1 to 13.111.255.25413.111.255.255524,286
17513.112.0.0/1313.112.0.1 to 13.119.255.25413.119.255.255524,286
17613.120.0.0/1313.120.0.1 to 13.127.255.25413.127.255.255524,286
17713.128.0.0/1313.128.0.1 to 13.135.255.25413.135.255.255524,286
17813.136.0.0/1313.136.0.1 to 13.143.255.25413.143.255.255524,286
17913.144.0.0/1313.144.0.1 to 13.151.255.25413.151.255.255524,286
18013.152.0.0/1313.152.0.1 to 13.159.255.25413.159.255.255524,286
18113.160.0.0/1313.160.0.1 to 13.167.255.25413.167.255.255524,286
18213.168.0.0/1313.168.0.1 to 13.175.255.25413.175.255.255524,286
18313.176.0.0/1313.176.0.1 to 13.183.255.25413.183.255.255524,286
18413.184.0.0/1313.184.0.1 to 13.191.255.25413.191.255.255524,286
18513.192.0.0/1313.192.0.1 to 13.199.255.25413.199.255.255524,286
18613.200.0.0/1313.200.0.1 to 13.207.255.25413.207.255.255524,286
18713.208.0.0/1313.208.0.1 to 13.215.255.25413.215.255.255524,286
18813.216.0.0/1313.216.0.1 to 13.223.255.25413.223.255.255524,286
18913.224.0.0/1313.224.0.1 to 13.231.255.25413.231.255.255524,286
19013.232.0.0/1313.232.0.1 to 13.239.255.25413.239.255.255524,286
19113.240.0.0/1313.240.0.1 to 13.247.255.25413.247.255.255524,286
19213.248.0.0/1313.248.0.1 to 13.255.255.25413.255.255.255524,286
19314.0.0.0/1314.0.0.1 to 14.7.255.25414.7.255.255524,286
19414.8.0.0/1314.8.0.1 to 14.15.255.25414.15.255.255524,286
19514.16.0.0/1314.16.0.1 to 14.23.255.25414.23.255.255524,286
19614.24.0.0/1314.24.0.1 to 14.31.255.25414.31.255.255524,286
19714.32.0.0/1314.32.0.1 to 14.39.255.25414.39.255.255524,286
19814.40.0.0/1314.40.0.1 to 14.47.255.25414.47.255.255524,286
19914.48.0.0/1314.48.0.1 to 14.55.255.25414.55.255.255524,286
20014.56.0.0/1314.56.0.1 to 14.63.255.25414.63.255.255524,286
20114.64.0.0/1314.64.0.1 to 14.71.255.25414.71.255.255524,286
20214.72.0.0/1314.72.0.1 to 14.79.255.25414.79.255.255524,286
20314.80.0.0/1314.80.0.1 to 14.87.255.25414.87.255.255524,286
20414.88.0.0/1314.88.0.1 to 14.95.255.25414.95.255.255524,286
20514.96.0.0/1314.96.0.1 to 14.103.255.25414.103.255.255524,286
20614.104.0.0/1314.104.0.1 to 14.111.255.25414.111.255.255524,286
20714.112.0.0/1314.112.0.1 to 14.119.255.25414.119.255.255524,286
20814.120.0.0/1314.120.0.1 to 14.127.255.25414.127.255.255524,286
20914.128.0.0/1314.128.0.1 to 14.135.255.25414.135.255.255524,286
21014.136.0.0/1314.136.0.1 to 14.143.255.25414.143.255.255524,286
21114.144.0.0/1314.144.0.1 to 14.151.255.25414.151.255.255524,286
21214.152.0.0/1314.152.0.1 to 14.159.255.25414.159.255.255524,286
21314.160.0.0/1314.160.0.1 to 14.167.255.25414.167.255.255524,286
21414.168.0.0/1314.168.0.1 to 14.175.255.25414.175.255.255524,286
21514.176.0.0/1314.176.0.1 to 14.183.255.25414.183.255.255524,286
21614.184.0.0/1314.184.0.1 to 14.191.255.25414.191.255.255524,286
21714.192.0.0/1314.192.0.1 to 14.199.255.25414.199.255.255524,286
21814.200.0.0/1314.200.0.1 to 14.207.255.25414.207.255.255524,286
21914.208.0.0/1314.208.0.1 to 14.215.255.25414.215.255.255524,286
22014.216.0.0/1314.216.0.1 to 14.223.255.25414.223.255.255524,286
22114.224.0.0/1314.224.0.1 to 14.231.255.25414.231.255.255524,286
22214.232.0.0/1314.232.0.1 to 14.239.255.25414.239.255.255524,286
22314.240.0.0/1314.240.0.1 to 14.247.255.25414.247.255.255524,286
22414.248.0.0/1314.248.0.1 to 14.255.255.25414.255.255.255524,286
22515.0.0.0/1315.0.0.1 to 15.7.255.25415.7.255.255524,286
22615.8.0.0/1315.8.0.1 to 15.15.255.25415.15.255.255524,286
22715.16.0.0/1315.16.0.1 to 15.23.255.25415.23.255.255524,286
22815.24.0.0/1315.24.0.1 to 15.31.255.25415.31.255.255524,286
22915.32.0.0/1315.32.0.1 to 15.39.255.25415.39.255.255524,286
23015.40.0.0/1315.40.0.1 to 15.47.255.25415.47.255.255524,286
23115.48.0.0/1315.48.0.1 to 15.55.255.25415.55.255.255524,286
23215.56.0.0/1315.56.0.1 to 15.63.255.25415.63.255.255524,286
23315.64.0.0/1315.64.0.1 to 15.71.255.25415.71.255.255524,286
23415.72.0.0/1315.72.0.1 to 15.79.255.25415.79.255.255524,286
23515.80.0.0/1315.80.0.1 to 15.87.255.25415.87.255.255524,286
23615.88.0.0/1315.88.0.1 to 15.95.255.25415.95.255.255524,286
23715.96.0.0/1315.96.0.1 to 15.103.255.25415.103.255.255524,286
23815.104.0.0/1315.104.0.1 to 15.111.255.25415.111.255.255524,286
23915.112.0.0/1315.112.0.1 to 15.119.255.25415.119.255.255524,286
24015.120.0.0/1315.120.0.1 to 15.127.255.25415.127.255.255524,286
24115.128.0.0/1315.128.0.1 to 15.135.255.25415.135.255.255524,286
24215.136.0.0/1315.136.0.1 to 15.143.255.25415.143.255.255524,286
24315.144.0.0/1315.144.0.1 to 15.151.255.25415.151.255.255524,286
24415.152.0.0/1315.152.0.1 to 15.159.255.25415.159.255.255524,286
24515.160.0.0/1315.160.0.1 to 15.167.255.25415.167.255.255524,286
24615.168.0.0/1315.168.0.1 to 15.175.255.25415.175.255.255524,286
24715.176.0.0/1315.176.0.1 to 15.183.255.25415.183.255.255524,286
24815.184.0.0/1315.184.0.1 to 15.191.255.25415.191.255.255524,286
24915.192.0.0/1315.192.0.1 to 15.199.255.25415.199.255.255524,286
25015.200.0.0/1315.200.0.1 to 15.207.255.25415.207.255.255524,286
25115.208.0.0/1315.208.0.1 to 15.215.255.25415.215.255.255524,286
25215.216.0.0/1315.216.0.1 to 15.223.255.25415.223.255.255524,286
25315.224.0.0/1315.224.0.1 to 15.231.255.25415.231.255.255524,286
25415.232.0.0/1315.232.0.1 to 15.239.255.25415.239.255.255524,286
25515.240.0.0/1315.240.0.1 to 15.247.255.25415.247.255.255524,286
25615.248.0.0/1315.248.0.1 to 15.255.255.25415.255.255.255524,286

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.