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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.

Network19.26.0.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
19.26.0.0
Broadcast address
19.26.31.255
First usable
19.26.0.1
Last usable
19.26.31.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
A (default /8)
As numbers
Hex 131A0000 · Integer 320471040 to 320479231
Reverse DNS zones
0.26.19.in-addr.arpa
1.26.19.in-addr.arpa
2.26.19.in-addr.arpa
3.26.19.in-addr.arpa
4.26.19.in-addr.arpa
5.26.19.in-addr.arpa
6.26.19.in-addr.arpa
7.26.19.in-addr.arpa
8.26.19.in-addr.arpa
9.26.19.in-addr.arpa
10.26.19.in-addr.arpa
11.26.19.in-addr.arpa
12.26.19.in-addr.arpa
13.26.19.in-addr.arpa
14.26.19.in-addr.arpa
15.26.19.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00010011.00011010.00000000.0000000019.26.0.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network00010011.00011010.00000000.0000000019.26.0.0
Broadcast00010011.00011010.00011111.1111111119.26.31.255
Split into smaller subnets/29
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

19.26.0.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
119.26.0.0/2919.26.0.1 to 19.26.0.619.26.0.76
219.26.0.8/2919.26.0.9 to 19.26.0.1419.26.0.156
319.26.0.16/2919.26.0.17 to 19.26.0.2219.26.0.236
419.26.0.24/2919.26.0.25 to 19.26.0.3019.26.0.316
519.26.0.32/2919.26.0.33 to 19.26.0.3819.26.0.396
619.26.0.40/2919.26.0.41 to 19.26.0.4619.26.0.476
719.26.0.48/2919.26.0.49 to 19.26.0.5419.26.0.556
819.26.0.56/2919.26.0.57 to 19.26.0.6219.26.0.636
919.26.0.64/2919.26.0.65 to 19.26.0.7019.26.0.716
1019.26.0.72/2919.26.0.73 to 19.26.0.7819.26.0.796
1119.26.0.80/2919.26.0.81 to 19.26.0.8619.26.0.876
1219.26.0.88/2919.26.0.89 to 19.26.0.9419.26.0.956
1319.26.0.96/2919.26.0.97 to 19.26.0.10219.26.0.1036
1419.26.0.104/2919.26.0.105 to 19.26.0.11019.26.0.1116
1519.26.0.112/2919.26.0.113 to 19.26.0.11819.26.0.1196
1619.26.0.120/2919.26.0.121 to 19.26.0.12619.26.0.1276
1719.26.0.128/2919.26.0.129 to 19.26.0.13419.26.0.1356
1819.26.0.136/2919.26.0.137 to 19.26.0.14219.26.0.1436
1919.26.0.144/2919.26.0.145 to 19.26.0.15019.26.0.1516
2019.26.0.152/2919.26.0.153 to 19.26.0.15819.26.0.1596
2119.26.0.160/2919.26.0.161 to 19.26.0.16619.26.0.1676
2219.26.0.168/2919.26.0.169 to 19.26.0.17419.26.0.1756
2319.26.0.176/2919.26.0.177 to 19.26.0.18219.26.0.1836
2419.26.0.184/2919.26.0.185 to 19.26.0.19019.26.0.1916
2519.26.0.192/2919.26.0.193 to 19.26.0.19819.26.0.1996
2619.26.0.200/2919.26.0.201 to 19.26.0.20619.26.0.2076
2719.26.0.208/2919.26.0.209 to 19.26.0.21419.26.0.2156
2819.26.0.216/2919.26.0.217 to 19.26.0.22219.26.0.2236
2919.26.0.224/2919.26.0.225 to 19.26.0.23019.26.0.2316
3019.26.0.232/2919.26.0.233 to 19.26.0.23819.26.0.2396
3119.26.0.240/2919.26.0.241 to 19.26.0.24619.26.0.2476
3219.26.0.248/2919.26.0.249 to 19.26.0.25419.26.0.2556
3319.26.1.0/2919.26.1.1 to 19.26.1.619.26.1.76
3419.26.1.8/2919.26.1.9 to 19.26.1.1419.26.1.156
3519.26.1.16/2919.26.1.17 to 19.26.1.2219.26.1.236
3619.26.1.24/2919.26.1.25 to 19.26.1.3019.26.1.316
3719.26.1.32/2919.26.1.33 to 19.26.1.3819.26.1.396
3819.26.1.40/2919.26.1.41 to 19.26.1.4619.26.1.476
3919.26.1.48/2919.26.1.49 to 19.26.1.5419.26.1.556
4019.26.1.56/2919.26.1.57 to 19.26.1.6219.26.1.636
4119.26.1.64/2919.26.1.65 to 19.26.1.7019.26.1.716
4219.26.1.72/2919.26.1.73 to 19.26.1.7819.26.1.796
4319.26.1.80/2919.26.1.81 to 19.26.1.8619.26.1.876
4419.26.1.88/2919.26.1.89 to 19.26.1.9419.26.1.956
4519.26.1.96/2919.26.1.97 to 19.26.1.10219.26.1.1036
4619.26.1.104/2919.26.1.105 to 19.26.1.11019.26.1.1116
4719.26.1.112/2919.26.1.113 to 19.26.1.11819.26.1.1196
4819.26.1.120/2919.26.1.121 to 19.26.1.12619.26.1.1276
4919.26.1.128/2919.26.1.129 to 19.26.1.13419.26.1.1356
5019.26.1.136/2919.26.1.137 to 19.26.1.14219.26.1.1436
5119.26.1.144/2919.26.1.145 to 19.26.1.15019.26.1.1516
5219.26.1.152/2919.26.1.153 to 19.26.1.15819.26.1.1596
5319.26.1.160/2919.26.1.161 to 19.26.1.16619.26.1.1676
5419.26.1.168/2919.26.1.169 to 19.26.1.17419.26.1.1756
5519.26.1.176/2919.26.1.177 to 19.26.1.18219.26.1.1836
5619.26.1.184/2919.26.1.185 to 19.26.1.19019.26.1.1916
5719.26.1.192/2919.26.1.193 to 19.26.1.19819.26.1.1996
5819.26.1.200/2919.26.1.201 to 19.26.1.20619.26.1.2076
5919.26.1.208/2919.26.1.209 to 19.26.1.21419.26.1.2156
6019.26.1.216/2919.26.1.217 to 19.26.1.22219.26.1.2236
6119.26.1.224/2919.26.1.225 to 19.26.1.23019.26.1.2316
6219.26.1.232/2919.26.1.233 to 19.26.1.23819.26.1.2396
6319.26.1.240/2919.26.1.241 to 19.26.1.24619.26.1.2476
6419.26.1.248/2919.26.1.249 to 19.26.1.25419.26.1.2556
6519.26.2.0/2919.26.2.1 to 19.26.2.619.26.2.76
6619.26.2.8/2919.26.2.9 to 19.26.2.1419.26.2.156
6719.26.2.16/2919.26.2.17 to 19.26.2.2219.26.2.236
6819.26.2.24/2919.26.2.25 to 19.26.2.3019.26.2.316
6919.26.2.32/2919.26.2.33 to 19.26.2.3819.26.2.396
7019.26.2.40/2919.26.2.41 to 19.26.2.4619.26.2.476
7119.26.2.48/2919.26.2.49 to 19.26.2.5419.26.2.556
7219.26.2.56/2919.26.2.57 to 19.26.2.6219.26.2.636
7319.26.2.64/2919.26.2.65 to 19.26.2.7019.26.2.716
7419.26.2.72/2919.26.2.73 to 19.26.2.7819.26.2.796
7519.26.2.80/2919.26.2.81 to 19.26.2.8619.26.2.876
7619.26.2.88/2919.26.2.89 to 19.26.2.9419.26.2.956
7719.26.2.96/2919.26.2.97 to 19.26.2.10219.26.2.1036
7819.26.2.104/2919.26.2.105 to 19.26.2.11019.26.2.1116
7919.26.2.112/2919.26.2.113 to 19.26.2.11819.26.2.1196
8019.26.2.120/2919.26.2.121 to 19.26.2.12619.26.2.1276
8119.26.2.128/2919.26.2.129 to 19.26.2.13419.26.2.1356
8219.26.2.136/2919.26.2.137 to 19.26.2.14219.26.2.1436
8319.26.2.144/2919.26.2.145 to 19.26.2.15019.26.2.1516
8419.26.2.152/2919.26.2.153 to 19.26.2.15819.26.2.1596
8519.26.2.160/2919.26.2.161 to 19.26.2.16619.26.2.1676
8619.26.2.168/2919.26.2.169 to 19.26.2.17419.26.2.1756
8719.26.2.176/2919.26.2.177 to 19.26.2.18219.26.2.1836
8819.26.2.184/2919.26.2.185 to 19.26.2.19019.26.2.1916
8919.26.2.192/2919.26.2.193 to 19.26.2.19819.26.2.1996
9019.26.2.200/2919.26.2.201 to 19.26.2.20619.26.2.2076
9119.26.2.208/2919.26.2.209 to 19.26.2.21419.26.2.2156
9219.26.2.216/2919.26.2.217 to 19.26.2.22219.26.2.2236
9319.26.2.224/2919.26.2.225 to 19.26.2.23019.26.2.2316
9419.26.2.232/2919.26.2.233 to 19.26.2.23819.26.2.2396
9519.26.2.240/2919.26.2.241 to 19.26.2.24619.26.2.2476
9619.26.2.248/2919.26.2.249 to 19.26.2.25419.26.2.2556
9719.26.3.0/2919.26.3.1 to 19.26.3.619.26.3.76
9819.26.3.8/2919.26.3.9 to 19.26.3.1419.26.3.156
9919.26.3.16/2919.26.3.17 to 19.26.3.2219.26.3.236
10019.26.3.24/2919.26.3.25 to 19.26.3.3019.26.3.316
10119.26.3.32/2919.26.3.33 to 19.26.3.3819.26.3.396
10219.26.3.40/2919.26.3.41 to 19.26.3.4619.26.3.476
10319.26.3.48/2919.26.3.49 to 19.26.3.5419.26.3.556
10419.26.3.56/2919.26.3.57 to 19.26.3.6219.26.3.636
10519.26.3.64/2919.26.3.65 to 19.26.3.7019.26.3.716
10619.26.3.72/2919.26.3.73 to 19.26.3.7819.26.3.796
10719.26.3.80/2919.26.3.81 to 19.26.3.8619.26.3.876
10819.26.3.88/2919.26.3.89 to 19.26.3.9419.26.3.956
10919.26.3.96/2919.26.3.97 to 19.26.3.10219.26.3.1036
11019.26.3.104/2919.26.3.105 to 19.26.3.11019.26.3.1116
11119.26.3.112/2919.26.3.113 to 19.26.3.11819.26.3.1196
11219.26.3.120/2919.26.3.121 to 19.26.3.12619.26.3.1276
11319.26.3.128/2919.26.3.129 to 19.26.3.13419.26.3.1356
11419.26.3.136/2919.26.3.137 to 19.26.3.14219.26.3.1436
11519.26.3.144/2919.26.3.145 to 19.26.3.15019.26.3.1516
11619.26.3.152/2919.26.3.153 to 19.26.3.15819.26.3.1596
11719.26.3.160/2919.26.3.161 to 19.26.3.16619.26.3.1676
11819.26.3.168/2919.26.3.169 to 19.26.3.17419.26.3.1756
11919.26.3.176/2919.26.3.177 to 19.26.3.18219.26.3.1836
12019.26.3.184/2919.26.3.185 to 19.26.3.19019.26.3.1916
12119.26.3.192/2919.26.3.193 to 19.26.3.19819.26.3.1996
12219.26.3.200/2919.26.3.201 to 19.26.3.20619.26.3.2076
12319.26.3.208/2919.26.3.209 to 19.26.3.21419.26.3.2156
12419.26.3.216/2919.26.3.217 to 19.26.3.22219.26.3.2236
12519.26.3.224/2919.26.3.225 to 19.26.3.23019.26.3.2316
12619.26.3.232/2919.26.3.233 to 19.26.3.23819.26.3.2396
12719.26.3.240/2919.26.3.241 to 19.26.3.24619.26.3.2476
12819.26.3.248/2919.26.3.249 to 19.26.3.25419.26.3.2556
12919.26.4.0/2919.26.4.1 to 19.26.4.619.26.4.76
13019.26.4.8/2919.26.4.9 to 19.26.4.1419.26.4.156
13119.26.4.16/2919.26.4.17 to 19.26.4.2219.26.4.236
13219.26.4.24/2919.26.4.25 to 19.26.4.3019.26.4.316
13319.26.4.32/2919.26.4.33 to 19.26.4.3819.26.4.396
13419.26.4.40/2919.26.4.41 to 19.26.4.4619.26.4.476
13519.26.4.48/2919.26.4.49 to 19.26.4.5419.26.4.556
13619.26.4.56/2919.26.4.57 to 19.26.4.6219.26.4.636
13719.26.4.64/2919.26.4.65 to 19.26.4.7019.26.4.716
13819.26.4.72/2919.26.4.73 to 19.26.4.7819.26.4.796
13919.26.4.80/2919.26.4.81 to 19.26.4.8619.26.4.876
14019.26.4.88/2919.26.4.89 to 19.26.4.9419.26.4.956
14119.26.4.96/2919.26.4.97 to 19.26.4.10219.26.4.1036
14219.26.4.104/2919.26.4.105 to 19.26.4.11019.26.4.1116
14319.26.4.112/2919.26.4.113 to 19.26.4.11819.26.4.1196
14419.26.4.120/2919.26.4.121 to 19.26.4.12619.26.4.1276
14519.26.4.128/2919.26.4.129 to 19.26.4.13419.26.4.1356
14619.26.4.136/2919.26.4.137 to 19.26.4.14219.26.4.1436
14719.26.4.144/2919.26.4.145 to 19.26.4.15019.26.4.1516
14819.26.4.152/2919.26.4.153 to 19.26.4.15819.26.4.1596
14919.26.4.160/2919.26.4.161 to 19.26.4.16619.26.4.1676
15019.26.4.168/2919.26.4.169 to 19.26.4.17419.26.4.1756
15119.26.4.176/2919.26.4.177 to 19.26.4.18219.26.4.1836
15219.26.4.184/2919.26.4.185 to 19.26.4.19019.26.4.1916
15319.26.4.192/2919.26.4.193 to 19.26.4.19819.26.4.1996
15419.26.4.200/2919.26.4.201 to 19.26.4.20619.26.4.2076
15519.26.4.208/2919.26.4.209 to 19.26.4.21419.26.4.2156
15619.26.4.216/2919.26.4.217 to 19.26.4.22219.26.4.2236
15719.26.4.224/2919.26.4.225 to 19.26.4.23019.26.4.2316
15819.26.4.232/2919.26.4.233 to 19.26.4.23819.26.4.2396
15919.26.4.240/2919.26.4.241 to 19.26.4.24619.26.4.2476
16019.26.4.248/2919.26.4.249 to 19.26.4.25419.26.4.2556
16119.26.5.0/2919.26.5.1 to 19.26.5.619.26.5.76
16219.26.5.8/2919.26.5.9 to 19.26.5.1419.26.5.156
16319.26.5.16/2919.26.5.17 to 19.26.5.2219.26.5.236
16419.26.5.24/2919.26.5.25 to 19.26.5.3019.26.5.316
16519.26.5.32/2919.26.5.33 to 19.26.5.3819.26.5.396
16619.26.5.40/2919.26.5.41 to 19.26.5.4619.26.5.476
16719.26.5.48/2919.26.5.49 to 19.26.5.5419.26.5.556
16819.26.5.56/2919.26.5.57 to 19.26.5.6219.26.5.636
16919.26.5.64/2919.26.5.65 to 19.26.5.7019.26.5.716
17019.26.5.72/2919.26.5.73 to 19.26.5.7819.26.5.796
17119.26.5.80/2919.26.5.81 to 19.26.5.8619.26.5.876
17219.26.5.88/2919.26.5.89 to 19.26.5.9419.26.5.956
17319.26.5.96/2919.26.5.97 to 19.26.5.10219.26.5.1036
17419.26.5.104/2919.26.5.105 to 19.26.5.11019.26.5.1116
17519.26.5.112/2919.26.5.113 to 19.26.5.11819.26.5.1196
17619.26.5.120/2919.26.5.121 to 19.26.5.12619.26.5.1276
17719.26.5.128/2919.26.5.129 to 19.26.5.13419.26.5.1356
17819.26.5.136/2919.26.5.137 to 19.26.5.14219.26.5.1436
17919.26.5.144/2919.26.5.145 to 19.26.5.15019.26.5.1516
18019.26.5.152/2919.26.5.153 to 19.26.5.15819.26.5.1596
18119.26.5.160/2919.26.5.161 to 19.26.5.16619.26.5.1676
18219.26.5.168/2919.26.5.169 to 19.26.5.17419.26.5.1756
18319.26.5.176/2919.26.5.177 to 19.26.5.18219.26.5.1836
18419.26.5.184/2919.26.5.185 to 19.26.5.19019.26.5.1916
18519.26.5.192/2919.26.5.193 to 19.26.5.19819.26.5.1996
18619.26.5.200/2919.26.5.201 to 19.26.5.20619.26.5.2076
18719.26.5.208/2919.26.5.209 to 19.26.5.21419.26.5.2156
18819.26.5.216/2919.26.5.217 to 19.26.5.22219.26.5.2236
18919.26.5.224/2919.26.5.225 to 19.26.5.23019.26.5.2316
19019.26.5.232/2919.26.5.233 to 19.26.5.23819.26.5.2396
19119.26.5.240/2919.26.5.241 to 19.26.5.24619.26.5.2476
19219.26.5.248/2919.26.5.249 to 19.26.5.25419.26.5.2556
19319.26.6.0/2919.26.6.1 to 19.26.6.619.26.6.76
19419.26.6.8/2919.26.6.9 to 19.26.6.1419.26.6.156
19519.26.6.16/2919.26.6.17 to 19.26.6.2219.26.6.236
19619.26.6.24/2919.26.6.25 to 19.26.6.3019.26.6.316
19719.26.6.32/2919.26.6.33 to 19.26.6.3819.26.6.396
19819.26.6.40/2919.26.6.41 to 19.26.6.4619.26.6.476
19919.26.6.48/2919.26.6.49 to 19.26.6.5419.26.6.556
20019.26.6.56/2919.26.6.57 to 19.26.6.6219.26.6.636
20119.26.6.64/2919.26.6.65 to 19.26.6.7019.26.6.716
20219.26.6.72/2919.26.6.73 to 19.26.6.7819.26.6.796
20319.26.6.80/2919.26.6.81 to 19.26.6.8619.26.6.876
20419.26.6.88/2919.26.6.89 to 19.26.6.9419.26.6.956
20519.26.6.96/2919.26.6.97 to 19.26.6.10219.26.6.1036
20619.26.6.104/2919.26.6.105 to 19.26.6.11019.26.6.1116
20719.26.6.112/2919.26.6.113 to 19.26.6.11819.26.6.1196
20819.26.6.120/2919.26.6.121 to 19.26.6.12619.26.6.1276
20919.26.6.128/2919.26.6.129 to 19.26.6.13419.26.6.1356
21019.26.6.136/2919.26.6.137 to 19.26.6.14219.26.6.1436
21119.26.6.144/2919.26.6.145 to 19.26.6.15019.26.6.1516
21219.26.6.152/2919.26.6.153 to 19.26.6.15819.26.6.1596
21319.26.6.160/2919.26.6.161 to 19.26.6.16619.26.6.1676
21419.26.6.168/2919.26.6.169 to 19.26.6.17419.26.6.1756
21519.26.6.176/2919.26.6.177 to 19.26.6.18219.26.6.1836
21619.26.6.184/2919.26.6.185 to 19.26.6.19019.26.6.1916
21719.26.6.192/2919.26.6.193 to 19.26.6.19819.26.6.1996
21819.26.6.200/2919.26.6.201 to 19.26.6.20619.26.6.2076
21919.26.6.208/2919.26.6.209 to 19.26.6.21419.26.6.2156
22019.26.6.216/2919.26.6.217 to 19.26.6.22219.26.6.2236
22119.26.6.224/2919.26.6.225 to 19.26.6.23019.26.6.2316
22219.26.6.232/2919.26.6.233 to 19.26.6.23819.26.6.2396
22319.26.6.240/2919.26.6.241 to 19.26.6.24619.26.6.2476
22419.26.6.248/2919.26.6.249 to 19.26.6.25419.26.6.2556
22519.26.7.0/2919.26.7.1 to 19.26.7.619.26.7.76
22619.26.7.8/2919.26.7.9 to 19.26.7.1419.26.7.156
22719.26.7.16/2919.26.7.17 to 19.26.7.2219.26.7.236
22819.26.7.24/2919.26.7.25 to 19.26.7.3019.26.7.316
22919.26.7.32/2919.26.7.33 to 19.26.7.3819.26.7.396
23019.26.7.40/2919.26.7.41 to 19.26.7.4619.26.7.476
23119.26.7.48/2919.26.7.49 to 19.26.7.5419.26.7.556
23219.26.7.56/2919.26.7.57 to 19.26.7.6219.26.7.636
23319.26.7.64/2919.26.7.65 to 19.26.7.7019.26.7.716
23419.26.7.72/2919.26.7.73 to 19.26.7.7819.26.7.796
23519.26.7.80/2919.26.7.81 to 19.26.7.8619.26.7.876
23619.26.7.88/2919.26.7.89 to 19.26.7.9419.26.7.956
23719.26.7.96/2919.26.7.97 to 19.26.7.10219.26.7.1036
23819.26.7.104/2919.26.7.105 to 19.26.7.11019.26.7.1116
23919.26.7.112/2919.26.7.113 to 19.26.7.11819.26.7.1196
24019.26.7.120/2919.26.7.121 to 19.26.7.12619.26.7.1276
24119.26.7.128/2919.26.7.129 to 19.26.7.13419.26.7.1356
24219.26.7.136/2919.26.7.137 to 19.26.7.14219.26.7.1436
24319.26.7.144/2919.26.7.145 to 19.26.7.15019.26.7.1516
24419.26.7.152/2919.26.7.153 to 19.26.7.15819.26.7.1596
24519.26.7.160/2919.26.7.161 to 19.26.7.16619.26.7.1676
24619.26.7.168/2919.26.7.169 to 19.26.7.17419.26.7.1756
24719.26.7.176/2919.26.7.177 to 19.26.7.18219.26.7.1836
24819.26.7.184/2919.26.7.185 to 19.26.7.19019.26.7.1916
24919.26.7.192/2919.26.7.193 to 19.26.7.19819.26.7.1996
25019.26.7.200/2919.26.7.201 to 19.26.7.20619.26.7.2076
25119.26.7.208/2919.26.7.209 to 19.26.7.21419.26.7.2156
25219.26.7.216/2919.26.7.217 to 19.26.7.22219.26.7.2236
25319.26.7.224/2919.26.7.225 to 19.26.7.23019.26.7.2316
25419.26.7.232/2919.26.7.233 to 19.26.7.23819.26.7.2396
25519.26.7.240/2919.26.7.241 to 19.26.7.24619.26.7.2476
25619.26.7.248/2919.26.7.249 to 19.26.7.25419.26.7.2556

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.