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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.

Network35.45.64.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
35.45.64.0
Broadcast address
35.45.127.255
First usable
35.45.64.1
Last usable
35.45.127.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 232D4000 · Integer 590168064 to 590184447
Reverse DNS zones
64.45.35.in-addr.arpa
65.45.35.in-addr.arpa
66.45.35.in-addr.arpa
67.45.35.in-addr.arpa
68.45.35.in-addr.arpa
69.45.35.in-addr.arpa
70.45.35.in-addr.arpa
71.45.35.in-addr.arpa
72.45.35.in-addr.arpa
73.45.35.in-addr.arpa
74.45.35.in-addr.arpa
75.45.35.in-addr.arpa
76.45.35.in-addr.arpa
77.45.35.in-addr.arpa
78.45.35.in-addr.arpa
79.45.35.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00100011.00101101.01000000.0000000035.45.64.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network00100011.00101101.01000000.0000000035.45.64.0
Broadcast00100011.00101101.01111111.1111111135.45.127.255
Split into smaller subnets/29
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

35.45.64.0/18 makes 2,048 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
135.45.64.0/2935.45.64.1 to 35.45.64.635.45.64.76
235.45.64.8/2935.45.64.9 to 35.45.64.1435.45.64.156
335.45.64.16/2935.45.64.17 to 35.45.64.2235.45.64.236
435.45.64.24/2935.45.64.25 to 35.45.64.3035.45.64.316
535.45.64.32/2935.45.64.33 to 35.45.64.3835.45.64.396
635.45.64.40/2935.45.64.41 to 35.45.64.4635.45.64.476
735.45.64.48/2935.45.64.49 to 35.45.64.5435.45.64.556
835.45.64.56/2935.45.64.57 to 35.45.64.6235.45.64.636
935.45.64.64/2935.45.64.65 to 35.45.64.7035.45.64.716
1035.45.64.72/2935.45.64.73 to 35.45.64.7835.45.64.796
1135.45.64.80/2935.45.64.81 to 35.45.64.8635.45.64.876
1235.45.64.88/2935.45.64.89 to 35.45.64.9435.45.64.956
1335.45.64.96/2935.45.64.97 to 35.45.64.10235.45.64.1036
1435.45.64.104/2935.45.64.105 to 35.45.64.11035.45.64.1116
1535.45.64.112/2935.45.64.113 to 35.45.64.11835.45.64.1196
1635.45.64.120/2935.45.64.121 to 35.45.64.12635.45.64.1276
1735.45.64.128/2935.45.64.129 to 35.45.64.13435.45.64.1356
1835.45.64.136/2935.45.64.137 to 35.45.64.14235.45.64.1436
1935.45.64.144/2935.45.64.145 to 35.45.64.15035.45.64.1516
2035.45.64.152/2935.45.64.153 to 35.45.64.15835.45.64.1596
2135.45.64.160/2935.45.64.161 to 35.45.64.16635.45.64.1676
2235.45.64.168/2935.45.64.169 to 35.45.64.17435.45.64.1756
2335.45.64.176/2935.45.64.177 to 35.45.64.18235.45.64.1836
2435.45.64.184/2935.45.64.185 to 35.45.64.19035.45.64.1916
2535.45.64.192/2935.45.64.193 to 35.45.64.19835.45.64.1996
2635.45.64.200/2935.45.64.201 to 35.45.64.20635.45.64.2076
2735.45.64.208/2935.45.64.209 to 35.45.64.21435.45.64.2156
2835.45.64.216/2935.45.64.217 to 35.45.64.22235.45.64.2236
2935.45.64.224/2935.45.64.225 to 35.45.64.23035.45.64.2316
3035.45.64.232/2935.45.64.233 to 35.45.64.23835.45.64.2396
3135.45.64.240/2935.45.64.241 to 35.45.64.24635.45.64.2476
3235.45.64.248/2935.45.64.249 to 35.45.64.25435.45.64.2556
3335.45.65.0/2935.45.65.1 to 35.45.65.635.45.65.76
3435.45.65.8/2935.45.65.9 to 35.45.65.1435.45.65.156
3535.45.65.16/2935.45.65.17 to 35.45.65.2235.45.65.236
3635.45.65.24/2935.45.65.25 to 35.45.65.3035.45.65.316
3735.45.65.32/2935.45.65.33 to 35.45.65.3835.45.65.396
3835.45.65.40/2935.45.65.41 to 35.45.65.4635.45.65.476
3935.45.65.48/2935.45.65.49 to 35.45.65.5435.45.65.556
4035.45.65.56/2935.45.65.57 to 35.45.65.6235.45.65.636
4135.45.65.64/2935.45.65.65 to 35.45.65.7035.45.65.716
4235.45.65.72/2935.45.65.73 to 35.45.65.7835.45.65.796
4335.45.65.80/2935.45.65.81 to 35.45.65.8635.45.65.876
4435.45.65.88/2935.45.65.89 to 35.45.65.9435.45.65.956
4535.45.65.96/2935.45.65.97 to 35.45.65.10235.45.65.1036
4635.45.65.104/2935.45.65.105 to 35.45.65.11035.45.65.1116
4735.45.65.112/2935.45.65.113 to 35.45.65.11835.45.65.1196
4835.45.65.120/2935.45.65.121 to 35.45.65.12635.45.65.1276
4935.45.65.128/2935.45.65.129 to 35.45.65.13435.45.65.1356
5035.45.65.136/2935.45.65.137 to 35.45.65.14235.45.65.1436
5135.45.65.144/2935.45.65.145 to 35.45.65.15035.45.65.1516
5235.45.65.152/2935.45.65.153 to 35.45.65.15835.45.65.1596
5335.45.65.160/2935.45.65.161 to 35.45.65.16635.45.65.1676
5435.45.65.168/2935.45.65.169 to 35.45.65.17435.45.65.1756
5535.45.65.176/2935.45.65.177 to 35.45.65.18235.45.65.1836
5635.45.65.184/2935.45.65.185 to 35.45.65.19035.45.65.1916
5735.45.65.192/2935.45.65.193 to 35.45.65.19835.45.65.1996
5835.45.65.200/2935.45.65.201 to 35.45.65.20635.45.65.2076
5935.45.65.208/2935.45.65.209 to 35.45.65.21435.45.65.2156
6035.45.65.216/2935.45.65.217 to 35.45.65.22235.45.65.2236
6135.45.65.224/2935.45.65.225 to 35.45.65.23035.45.65.2316
6235.45.65.232/2935.45.65.233 to 35.45.65.23835.45.65.2396
6335.45.65.240/2935.45.65.241 to 35.45.65.24635.45.65.2476
6435.45.65.248/2935.45.65.249 to 35.45.65.25435.45.65.2556
6535.45.66.0/2935.45.66.1 to 35.45.66.635.45.66.76
6635.45.66.8/2935.45.66.9 to 35.45.66.1435.45.66.156
6735.45.66.16/2935.45.66.17 to 35.45.66.2235.45.66.236
6835.45.66.24/2935.45.66.25 to 35.45.66.3035.45.66.316
6935.45.66.32/2935.45.66.33 to 35.45.66.3835.45.66.396
7035.45.66.40/2935.45.66.41 to 35.45.66.4635.45.66.476
7135.45.66.48/2935.45.66.49 to 35.45.66.5435.45.66.556
7235.45.66.56/2935.45.66.57 to 35.45.66.6235.45.66.636
7335.45.66.64/2935.45.66.65 to 35.45.66.7035.45.66.716
7435.45.66.72/2935.45.66.73 to 35.45.66.7835.45.66.796
7535.45.66.80/2935.45.66.81 to 35.45.66.8635.45.66.876
7635.45.66.88/2935.45.66.89 to 35.45.66.9435.45.66.956
7735.45.66.96/2935.45.66.97 to 35.45.66.10235.45.66.1036
7835.45.66.104/2935.45.66.105 to 35.45.66.11035.45.66.1116
7935.45.66.112/2935.45.66.113 to 35.45.66.11835.45.66.1196
8035.45.66.120/2935.45.66.121 to 35.45.66.12635.45.66.1276
8135.45.66.128/2935.45.66.129 to 35.45.66.13435.45.66.1356
8235.45.66.136/2935.45.66.137 to 35.45.66.14235.45.66.1436
8335.45.66.144/2935.45.66.145 to 35.45.66.15035.45.66.1516
8435.45.66.152/2935.45.66.153 to 35.45.66.15835.45.66.1596
8535.45.66.160/2935.45.66.161 to 35.45.66.16635.45.66.1676
8635.45.66.168/2935.45.66.169 to 35.45.66.17435.45.66.1756
8735.45.66.176/2935.45.66.177 to 35.45.66.18235.45.66.1836
8835.45.66.184/2935.45.66.185 to 35.45.66.19035.45.66.1916
8935.45.66.192/2935.45.66.193 to 35.45.66.19835.45.66.1996
9035.45.66.200/2935.45.66.201 to 35.45.66.20635.45.66.2076
9135.45.66.208/2935.45.66.209 to 35.45.66.21435.45.66.2156
9235.45.66.216/2935.45.66.217 to 35.45.66.22235.45.66.2236
9335.45.66.224/2935.45.66.225 to 35.45.66.23035.45.66.2316
9435.45.66.232/2935.45.66.233 to 35.45.66.23835.45.66.2396
9535.45.66.240/2935.45.66.241 to 35.45.66.24635.45.66.2476
9635.45.66.248/2935.45.66.249 to 35.45.66.25435.45.66.2556
9735.45.67.0/2935.45.67.1 to 35.45.67.635.45.67.76
9835.45.67.8/2935.45.67.9 to 35.45.67.1435.45.67.156
9935.45.67.16/2935.45.67.17 to 35.45.67.2235.45.67.236
10035.45.67.24/2935.45.67.25 to 35.45.67.3035.45.67.316
10135.45.67.32/2935.45.67.33 to 35.45.67.3835.45.67.396
10235.45.67.40/2935.45.67.41 to 35.45.67.4635.45.67.476
10335.45.67.48/2935.45.67.49 to 35.45.67.5435.45.67.556
10435.45.67.56/2935.45.67.57 to 35.45.67.6235.45.67.636
10535.45.67.64/2935.45.67.65 to 35.45.67.7035.45.67.716
10635.45.67.72/2935.45.67.73 to 35.45.67.7835.45.67.796
10735.45.67.80/2935.45.67.81 to 35.45.67.8635.45.67.876
10835.45.67.88/2935.45.67.89 to 35.45.67.9435.45.67.956
10935.45.67.96/2935.45.67.97 to 35.45.67.10235.45.67.1036
11035.45.67.104/2935.45.67.105 to 35.45.67.11035.45.67.1116
11135.45.67.112/2935.45.67.113 to 35.45.67.11835.45.67.1196
11235.45.67.120/2935.45.67.121 to 35.45.67.12635.45.67.1276
11335.45.67.128/2935.45.67.129 to 35.45.67.13435.45.67.1356
11435.45.67.136/2935.45.67.137 to 35.45.67.14235.45.67.1436
11535.45.67.144/2935.45.67.145 to 35.45.67.15035.45.67.1516
11635.45.67.152/2935.45.67.153 to 35.45.67.15835.45.67.1596
11735.45.67.160/2935.45.67.161 to 35.45.67.16635.45.67.1676
11835.45.67.168/2935.45.67.169 to 35.45.67.17435.45.67.1756
11935.45.67.176/2935.45.67.177 to 35.45.67.18235.45.67.1836
12035.45.67.184/2935.45.67.185 to 35.45.67.19035.45.67.1916
12135.45.67.192/2935.45.67.193 to 35.45.67.19835.45.67.1996
12235.45.67.200/2935.45.67.201 to 35.45.67.20635.45.67.2076
12335.45.67.208/2935.45.67.209 to 35.45.67.21435.45.67.2156
12435.45.67.216/2935.45.67.217 to 35.45.67.22235.45.67.2236
12535.45.67.224/2935.45.67.225 to 35.45.67.23035.45.67.2316
12635.45.67.232/2935.45.67.233 to 35.45.67.23835.45.67.2396
12735.45.67.240/2935.45.67.241 to 35.45.67.24635.45.67.2476
12835.45.67.248/2935.45.67.249 to 35.45.67.25435.45.67.2556
12935.45.68.0/2935.45.68.1 to 35.45.68.635.45.68.76
13035.45.68.8/2935.45.68.9 to 35.45.68.1435.45.68.156
13135.45.68.16/2935.45.68.17 to 35.45.68.2235.45.68.236
13235.45.68.24/2935.45.68.25 to 35.45.68.3035.45.68.316
13335.45.68.32/2935.45.68.33 to 35.45.68.3835.45.68.396
13435.45.68.40/2935.45.68.41 to 35.45.68.4635.45.68.476
13535.45.68.48/2935.45.68.49 to 35.45.68.5435.45.68.556
13635.45.68.56/2935.45.68.57 to 35.45.68.6235.45.68.636
13735.45.68.64/2935.45.68.65 to 35.45.68.7035.45.68.716
13835.45.68.72/2935.45.68.73 to 35.45.68.7835.45.68.796
13935.45.68.80/2935.45.68.81 to 35.45.68.8635.45.68.876
14035.45.68.88/2935.45.68.89 to 35.45.68.9435.45.68.956
14135.45.68.96/2935.45.68.97 to 35.45.68.10235.45.68.1036
14235.45.68.104/2935.45.68.105 to 35.45.68.11035.45.68.1116
14335.45.68.112/2935.45.68.113 to 35.45.68.11835.45.68.1196
14435.45.68.120/2935.45.68.121 to 35.45.68.12635.45.68.1276
14535.45.68.128/2935.45.68.129 to 35.45.68.13435.45.68.1356
14635.45.68.136/2935.45.68.137 to 35.45.68.14235.45.68.1436
14735.45.68.144/2935.45.68.145 to 35.45.68.15035.45.68.1516
14835.45.68.152/2935.45.68.153 to 35.45.68.15835.45.68.1596
14935.45.68.160/2935.45.68.161 to 35.45.68.16635.45.68.1676
15035.45.68.168/2935.45.68.169 to 35.45.68.17435.45.68.1756
15135.45.68.176/2935.45.68.177 to 35.45.68.18235.45.68.1836
15235.45.68.184/2935.45.68.185 to 35.45.68.19035.45.68.1916
15335.45.68.192/2935.45.68.193 to 35.45.68.19835.45.68.1996
15435.45.68.200/2935.45.68.201 to 35.45.68.20635.45.68.2076
15535.45.68.208/2935.45.68.209 to 35.45.68.21435.45.68.2156
15635.45.68.216/2935.45.68.217 to 35.45.68.22235.45.68.2236
15735.45.68.224/2935.45.68.225 to 35.45.68.23035.45.68.2316
15835.45.68.232/2935.45.68.233 to 35.45.68.23835.45.68.2396
15935.45.68.240/2935.45.68.241 to 35.45.68.24635.45.68.2476
16035.45.68.248/2935.45.68.249 to 35.45.68.25435.45.68.2556
16135.45.69.0/2935.45.69.1 to 35.45.69.635.45.69.76
16235.45.69.8/2935.45.69.9 to 35.45.69.1435.45.69.156
16335.45.69.16/2935.45.69.17 to 35.45.69.2235.45.69.236
16435.45.69.24/2935.45.69.25 to 35.45.69.3035.45.69.316
16535.45.69.32/2935.45.69.33 to 35.45.69.3835.45.69.396
16635.45.69.40/2935.45.69.41 to 35.45.69.4635.45.69.476
16735.45.69.48/2935.45.69.49 to 35.45.69.5435.45.69.556
16835.45.69.56/2935.45.69.57 to 35.45.69.6235.45.69.636
16935.45.69.64/2935.45.69.65 to 35.45.69.7035.45.69.716
17035.45.69.72/2935.45.69.73 to 35.45.69.7835.45.69.796
17135.45.69.80/2935.45.69.81 to 35.45.69.8635.45.69.876
17235.45.69.88/2935.45.69.89 to 35.45.69.9435.45.69.956
17335.45.69.96/2935.45.69.97 to 35.45.69.10235.45.69.1036
17435.45.69.104/2935.45.69.105 to 35.45.69.11035.45.69.1116
17535.45.69.112/2935.45.69.113 to 35.45.69.11835.45.69.1196
17635.45.69.120/2935.45.69.121 to 35.45.69.12635.45.69.1276
17735.45.69.128/2935.45.69.129 to 35.45.69.13435.45.69.1356
17835.45.69.136/2935.45.69.137 to 35.45.69.14235.45.69.1436
17935.45.69.144/2935.45.69.145 to 35.45.69.15035.45.69.1516
18035.45.69.152/2935.45.69.153 to 35.45.69.15835.45.69.1596
18135.45.69.160/2935.45.69.161 to 35.45.69.16635.45.69.1676
18235.45.69.168/2935.45.69.169 to 35.45.69.17435.45.69.1756
18335.45.69.176/2935.45.69.177 to 35.45.69.18235.45.69.1836
18435.45.69.184/2935.45.69.185 to 35.45.69.19035.45.69.1916
18535.45.69.192/2935.45.69.193 to 35.45.69.19835.45.69.1996
18635.45.69.200/2935.45.69.201 to 35.45.69.20635.45.69.2076
18735.45.69.208/2935.45.69.209 to 35.45.69.21435.45.69.2156
18835.45.69.216/2935.45.69.217 to 35.45.69.22235.45.69.2236
18935.45.69.224/2935.45.69.225 to 35.45.69.23035.45.69.2316
19035.45.69.232/2935.45.69.233 to 35.45.69.23835.45.69.2396
19135.45.69.240/2935.45.69.241 to 35.45.69.24635.45.69.2476
19235.45.69.248/2935.45.69.249 to 35.45.69.25435.45.69.2556
19335.45.70.0/2935.45.70.1 to 35.45.70.635.45.70.76
19435.45.70.8/2935.45.70.9 to 35.45.70.1435.45.70.156
19535.45.70.16/2935.45.70.17 to 35.45.70.2235.45.70.236
19635.45.70.24/2935.45.70.25 to 35.45.70.3035.45.70.316
19735.45.70.32/2935.45.70.33 to 35.45.70.3835.45.70.396
19835.45.70.40/2935.45.70.41 to 35.45.70.4635.45.70.476
19935.45.70.48/2935.45.70.49 to 35.45.70.5435.45.70.556
20035.45.70.56/2935.45.70.57 to 35.45.70.6235.45.70.636
20135.45.70.64/2935.45.70.65 to 35.45.70.7035.45.70.716
20235.45.70.72/2935.45.70.73 to 35.45.70.7835.45.70.796
20335.45.70.80/2935.45.70.81 to 35.45.70.8635.45.70.876
20435.45.70.88/2935.45.70.89 to 35.45.70.9435.45.70.956
20535.45.70.96/2935.45.70.97 to 35.45.70.10235.45.70.1036
20635.45.70.104/2935.45.70.105 to 35.45.70.11035.45.70.1116
20735.45.70.112/2935.45.70.113 to 35.45.70.11835.45.70.1196
20835.45.70.120/2935.45.70.121 to 35.45.70.12635.45.70.1276
20935.45.70.128/2935.45.70.129 to 35.45.70.13435.45.70.1356
21035.45.70.136/2935.45.70.137 to 35.45.70.14235.45.70.1436
21135.45.70.144/2935.45.70.145 to 35.45.70.15035.45.70.1516
21235.45.70.152/2935.45.70.153 to 35.45.70.15835.45.70.1596
21335.45.70.160/2935.45.70.161 to 35.45.70.16635.45.70.1676
21435.45.70.168/2935.45.70.169 to 35.45.70.17435.45.70.1756
21535.45.70.176/2935.45.70.177 to 35.45.70.18235.45.70.1836
21635.45.70.184/2935.45.70.185 to 35.45.70.19035.45.70.1916
21735.45.70.192/2935.45.70.193 to 35.45.70.19835.45.70.1996
21835.45.70.200/2935.45.70.201 to 35.45.70.20635.45.70.2076
21935.45.70.208/2935.45.70.209 to 35.45.70.21435.45.70.2156
22035.45.70.216/2935.45.70.217 to 35.45.70.22235.45.70.2236
22135.45.70.224/2935.45.70.225 to 35.45.70.23035.45.70.2316
22235.45.70.232/2935.45.70.233 to 35.45.70.23835.45.70.2396
22335.45.70.240/2935.45.70.241 to 35.45.70.24635.45.70.2476
22435.45.70.248/2935.45.70.249 to 35.45.70.25435.45.70.2556
22535.45.71.0/2935.45.71.1 to 35.45.71.635.45.71.76
22635.45.71.8/2935.45.71.9 to 35.45.71.1435.45.71.156
22735.45.71.16/2935.45.71.17 to 35.45.71.2235.45.71.236
22835.45.71.24/2935.45.71.25 to 35.45.71.3035.45.71.316
22935.45.71.32/2935.45.71.33 to 35.45.71.3835.45.71.396
23035.45.71.40/2935.45.71.41 to 35.45.71.4635.45.71.476
23135.45.71.48/2935.45.71.49 to 35.45.71.5435.45.71.556
23235.45.71.56/2935.45.71.57 to 35.45.71.6235.45.71.636
23335.45.71.64/2935.45.71.65 to 35.45.71.7035.45.71.716
23435.45.71.72/2935.45.71.73 to 35.45.71.7835.45.71.796
23535.45.71.80/2935.45.71.81 to 35.45.71.8635.45.71.876
23635.45.71.88/2935.45.71.89 to 35.45.71.9435.45.71.956
23735.45.71.96/2935.45.71.97 to 35.45.71.10235.45.71.1036
23835.45.71.104/2935.45.71.105 to 35.45.71.11035.45.71.1116
23935.45.71.112/2935.45.71.113 to 35.45.71.11835.45.71.1196
24035.45.71.120/2935.45.71.121 to 35.45.71.12635.45.71.1276
24135.45.71.128/2935.45.71.129 to 35.45.71.13435.45.71.1356
24235.45.71.136/2935.45.71.137 to 35.45.71.14235.45.71.1436
24335.45.71.144/2935.45.71.145 to 35.45.71.15035.45.71.1516
24435.45.71.152/2935.45.71.153 to 35.45.71.15835.45.71.1596
24535.45.71.160/2935.45.71.161 to 35.45.71.16635.45.71.1676
24635.45.71.168/2935.45.71.169 to 35.45.71.17435.45.71.1756
24735.45.71.176/2935.45.71.177 to 35.45.71.18235.45.71.1836
24835.45.71.184/2935.45.71.185 to 35.45.71.19035.45.71.1916
24935.45.71.192/2935.45.71.193 to 35.45.71.19835.45.71.1996
25035.45.71.200/2935.45.71.201 to 35.45.71.20635.45.71.2076
25135.45.71.208/2935.45.71.209 to 35.45.71.21435.45.71.2156
25235.45.71.216/2935.45.71.217 to 35.45.71.22235.45.71.2236
25335.45.71.224/2935.45.71.225 to 35.45.71.23035.45.71.2316
25435.45.71.232/2935.45.71.233 to 35.45.71.23835.45.71.2396
25535.45.71.240/2935.45.71.241 to 35.45.71.24635.45.71.2476
25635.45.71.248/2935.45.71.249 to 35.45.71.25435.45.71.2556

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.