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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.

Network54.3.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
54.3.64.0
Broadcast address
54.3.95.255
First usable
54.3.64.1
Last usable
54.3.95.254
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 36034000 · Integer 906182656 to 906190847
Reverse DNS zones
64.3.54.in-addr.arpa
65.3.54.in-addr.arpa
66.3.54.in-addr.arpa
67.3.54.in-addr.arpa
68.3.54.in-addr.arpa
69.3.54.in-addr.arpa
70.3.54.in-addr.arpa
71.3.54.in-addr.arpa
72.3.54.in-addr.arpa
73.3.54.in-addr.arpa
74.3.54.in-addr.arpa
75.3.54.in-addr.arpa
76.3.54.in-addr.arpa
77.3.54.in-addr.arpa
78.3.54.in-addr.arpa
79.3.54.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
Address00110110.00000011.01000000.0000000054.3.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network00110110.00000011.01000000.0000000054.3.64.0
Broadcast00110110.00000011.01011111.1111111154.3.95.255
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)

54.3.64.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
154.3.64.0/2954.3.64.1 to 54.3.64.654.3.64.76
254.3.64.8/2954.3.64.9 to 54.3.64.1454.3.64.156
354.3.64.16/2954.3.64.17 to 54.3.64.2254.3.64.236
454.3.64.24/2954.3.64.25 to 54.3.64.3054.3.64.316
554.3.64.32/2954.3.64.33 to 54.3.64.3854.3.64.396
654.3.64.40/2954.3.64.41 to 54.3.64.4654.3.64.476
754.3.64.48/2954.3.64.49 to 54.3.64.5454.3.64.556
854.3.64.56/2954.3.64.57 to 54.3.64.6254.3.64.636
954.3.64.64/2954.3.64.65 to 54.3.64.7054.3.64.716
1054.3.64.72/2954.3.64.73 to 54.3.64.7854.3.64.796
1154.3.64.80/2954.3.64.81 to 54.3.64.8654.3.64.876
1254.3.64.88/2954.3.64.89 to 54.3.64.9454.3.64.956
1354.3.64.96/2954.3.64.97 to 54.3.64.10254.3.64.1036
1454.3.64.104/2954.3.64.105 to 54.3.64.11054.3.64.1116
1554.3.64.112/2954.3.64.113 to 54.3.64.11854.3.64.1196
1654.3.64.120/2954.3.64.121 to 54.3.64.12654.3.64.1276
1754.3.64.128/2954.3.64.129 to 54.3.64.13454.3.64.1356
1854.3.64.136/2954.3.64.137 to 54.3.64.14254.3.64.1436
1954.3.64.144/2954.3.64.145 to 54.3.64.15054.3.64.1516
2054.3.64.152/2954.3.64.153 to 54.3.64.15854.3.64.1596
2154.3.64.160/2954.3.64.161 to 54.3.64.16654.3.64.1676
2254.3.64.168/2954.3.64.169 to 54.3.64.17454.3.64.1756
2354.3.64.176/2954.3.64.177 to 54.3.64.18254.3.64.1836
2454.3.64.184/2954.3.64.185 to 54.3.64.19054.3.64.1916
2554.3.64.192/2954.3.64.193 to 54.3.64.19854.3.64.1996
2654.3.64.200/2954.3.64.201 to 54.3.64.20654.3.64.2076
2754.3.64.208/2954.3.64.209 to 54.3.64.21454.3.64.2156
2854.3.64.216/2954.3.64.217 to 54.3.64.22254.3.64.2236
2954.3.64.224/2954.3.64.225 to 54.3.64.23054.3.64.2316
3054.3.64.232/2954.3.64.233 to 54.3.64.23854.3.64.2396
3154.3.64.240/2954.3.64.241 to 54.3.64.24654.3.64.2476
3254.3.64.248/2954.3.64.249 to 54.3.64.25454.3.64.2556
3354.3.65.0/2954.3.65.1 to 54.3.65.654.3.65.76
3454.3.65.8/2954.3.65.9 to 54.3.65.1454.3.65.156
3554.3.65.16/2954.3.65.17 to 54.3.65.2254.3.65.236
3654.3.65.24/2954.3.65.25 to 54.3.65.3054.3.65.316
3754.3.65.32/2954.3.65.33 to 54.3.65.3854.3.65.396
3854.3.65.40/2954.3.65.41 to 54.3.65.4654.3.65.476
3954.3.65.48/2954.3.65.49 to 54.3.65.5454.3.65.556
4054.3.65.56/2954.3.65.57 to 54.3.65.6254.3.65.636
4154.3.65.64/2954.3.65.65 to 54.3.65.7054.3.65.716
4254.3.65.72/2954.3.65.73 to 54.3.65.7854.3.65.796
4354.3.65.80/2954.3.65.81 to 54.3.65.8654.3.65.876
4454.3.65.88/2954.3.65.89 to 54.3.65.9454.3.65.956
4554.3.65.96/2954.3.65.97 to 54.3.65.10254.3.65.1036
4654.3.65.104/2954.3.65.105 to 54.3.65.11054.3.65.1116
4754.3.65.112/2954.3.65.113 to 54.3.65.11854.3.65.1196
4854.3.65.120/2954.3.65.121 to 54.3.65.12654.3.65.1276
4954.3.65.128/2954.3.65.129 to 54.3.65.13454.3.65.1356
5054.3.65.136/2954.3.65.137 to 54.3.65.14254.3.65.1436
5154.3.65.144/2954.3.65.145 to 54.3.65.15054.3.65.1516
5254.3.65.152/2954.3.65.153 to 54.3.65.15854.3.65.1596
5354.3.65.160/2954.3.65.161 to 54.3.65.16654.3.65.1676
5454.3.65.168/2954.3.65.169 to 54.3.65.17454.3.65.1756
5554.3.65.176/2954.3.65.177 to 54.3.65.18254.3.65.1836
5654.3.65.184/2954.3.65.185 to 54.3.65.19054.3.65.1916
5754.3.65.192/2954.3.65.193 to 54.3.65.19854.3.65.1996
5854.3.65.200/2954.3.65.201 to 54.3.65.20654.3.65.2076
5954.3.65.208/2954.3.65.209 to 54.3.65.21454.3.65.2156
6054.3.65.216/2954.3.65.217 to 54.3.65.22254.3.65.2236
6154.3.65.224/2954.3.65.225 to 54.3.65.23054.3.65.2316
6254.3.65.232/2954.3.65.233 to 54.3.65.23854.3.65.2396
6354.3.65.240/2954.3.65.241 to 54.3.65.24654.3.65.2476
6454.3.65.248/2954.3.65.249 to 54.3.65.25454.3.65.2556
6554.3.66.0/2954.3.66.1 to 54.3.66.654.3.66.76
6654.3.66.8/2954.3.66.9 to 54.3.66.1454.3.66.156
6754.3.66.16/2954.3.66.17 to 54.3.66.2254.3.66.236
6854.3.66.24/2954.3.66.25 to 54.3.66.3054.3.66.316
6954.3.66.32/2954.3.66.33 to 54.3.66.3854.3.66.396
7054.3.66.40/2954.3.66.41 to 54.3.66.4654.3.66.476
7154.3.66.48/2954.3.66.49 to 54.3.66.5454.3.66.556
7254.3.66.56/2954.3.66.57 to 54.3.66.6254.3.66.636
7354.3.66.64/2954.3.66.65 to 54.3.66.7054.3.66.716
7454.3.66.72/2954.3.66.73 to 54.3.66.7854.3.66.796
7554.3.66.80/2954.3.66.81 to 54.3.66.8654.3.66.876
7654.3.66.88/2954.3.66.89 to 54.3.66.9454.3.66.956
7754.3.66.96/2954.3.66.97 to 54.3.66.10254.3.66.1036
7854.3.66.104/2954.3.66.105 to 54.3.66.11054.3.66.1116
7954.3.66.112/2954.3.66.113 to 54.3.66.11854.3.66.1196
8054.3.66.120/2954.3.66.121 to 54.3.66.12654.3.66.1276
8154.3.66.128/2954.3.66.129 to 54.3.66.13454.3.66.1356
8254.3.66.136/2954.3.66.137 to 54.3.66.14254.3.66.1436
8354.3.66.144/2954.3.66.145 to 54.3.66.15054.3.66.1516
8454.3.66.152/2954.3.66.153 to 54.3.66.15854.3.66.1596
8554.3.66.160/2954.3.66.161 to 54.3.66.16654.3.66.1676
8654.3.66.168/2954.3.66.169 to 54.3.66.17454.3.66.1756
8754.3.66.176/2954.3.66.177 to 54.3.66.18254.3.66.1836
8854.3.66.184/2954.3.66.185 to 54.3.66.19054.3.66.1916
8954.3.66.192/2954.3.66.193 to 54.3.66.19854.3.66.1996
9054.3.66.200/2954.3.66.201 to 54.3.66.20654.3.66.2076
9154.3.66.208/2954.3.66.209 to 54.3.66.21454.3.66.2156
9254.3.66.216/2954.3.66.217 to 54.3.66.22254.3.66.2236
9354.3.66.224/2954.3.66.225 to 54.3.66.23054.3.66.2316
9454.3.66.232/2954.3.66.233 to 54.3.66.23854.3.66.2396
9554.3.66.240/2954.3.66.241 to 54.3.66.24654.3.66.2476
9654.3.66.248/2954.3.66.249 to 54.3.66.25454.3.66.2556
9754.3.67.0/2954.3.67.1 to 54.3.67.654.3.67.76
9854.3.67.8/2954.3.67.9 to 54.3.67.1454.3.67.156
9954.3.67.16/2954.3.67.17 to 54.3.67.2254.3.67.236
10054.3.67.24/2954.3.67.25 to 54.3.67.3054.3.67.316
10154.3.67.32/2954.3.67.33 to 54.3.67.3854.3.67.396
10254.3.67.40/2954.3.67.41 to 54.3.67.4654.3.67.476
10354.3.67.48/2954.3.67.49 to 54.3.67.5454.3.67.556
10454.3.67.56/2954.3.67.57 to 54.3.67.6254.3.67.636
10554.3.67.64/2954.3.67.65 to 54.3.67.7054.3.67.716
10654.3.67.72/2954.3.67.73 to 54.3.67.7854.3.67.796
10754.3.67.80/2954.3.67.81 to 54.3.67.8654.3.67.876
10854.3.67.88/2954.3.67.89 to 54.3.67.9454.3.67.956
10954.3.67.96/2954.3.67.97 to 54.3.67.10254.3.67.1036
11054.3.67.104/2954.3.67.105 to 54.3.67.11054.3.67.1116
11154.3.67.112/2954.3.67.113 to 54.3.67.11854.3.67.1196
11254.3.67.120/2954.3.67.121 to 54.3.67.12654.3.67.1276
11354.3.67.128/2954.3.67.129 to 54.3.67.13454.3.67.1356
11454.3.67.136/2954.3.67.137 to 54.3.67.14254.3.67.1436
11554.3.67.144/2954.3.67.145 to 54.3.67.15054.3.67.1516
11654.3.67.152/2954.3.67.153 to 54.3.67.15854.3.67.1596
11754.3.67.160/2954.3.67.161 to 54.3.67.16654.3.67.1676
11854.3.67.168/2954.3.67.169 to 54.3.67.17454.3.67.1756
11954.3.67.176/2954.3.67.177 to 54.3.67.18254.3.67.1836
12054.3.67.184/2954.3.67.185 to 54.3.67.19054.3.67.1916
12154.3.67.192/2954.3.67.193 to 54.3.67.19854.3.67.1996
12254.3.67.200/2954.3.67.201 to 54.3.67.20654.3.67.2076
12354.3.67.208/2954.3.67.209 to 54.3.67.21454.3.67.2156
12454.3.67.216/2954.3.67.217 to 54.3.67.22254.3.67.2236
12554.3.67.224/2954.3.67.225 to 54.3.67.23054.3.67.2316
12654.3.67.232/2954.3.67.233 to 54.3.67.23854.3.67.2396
12754.3.67.240/2954.3.67.241 to 54.3.67.24654.3.67.2476
12854.3.67.248/2954.3.67.249 to 54.3.67.25454.3.67.2556
12954.3.68.0/2954.3.68.1 to 54.3.68.654.3.68.76
13054.3.68.8/2954.3.68.9 to 54.3.68.1454.3.68.156
13154.3.68.16/2954.3.68.17 to 54.3.68.2254.3.68.236
13254.3.68.24/2954.3.68.25 to 54.3.68.3054.3.68.316
13354.3.68.32/2954.3.68.33 to 54.3.68.3854.3.68.396
13454.3.68.40/2954.3.68.41 to 54.3.68.4654.3.68.476
13554.3.68.48/2954.3.68.49 to 54.3.68.5454.3.68.556
13654.3.68.56/2954.3.68.57 to 54.3.68.6254.3.68.636
13754.3.68.64/2954.3.68.65 to 54.3.68.7054.3.68.716
13854.3.68.72/2954.3.68.73 to 54.3.68.7854.3.68.796
13954.3.68.80/2954.3.68.81 to 54.3.68.8654.3.68.876
14054.3.68.88/2954.3.68.89 to 54.3.68.9454.3.68.956
14154.3.68.96/2954.3.68.97 to 54.3.68.10254.3.68.1036
14254.3.68.104/2954.3.68.105 to 54.3.68.11054.3.68.1116
14354.3.68.112/2954.3.68.113 to 54.3.68.11854.3.68.1196
14454.3.68.120/2954.3.68.121 to 54.3.68.12654.3.68.1276
14554.3.68.128/2954.3.68.129 to 54.3.68.13454.3.68.1356
14654.3.68.136/2954.3.68.137 to 54.3.68.14254.3.68.1436
14754.3.68.144/2954.3.68.145 to 54.3.68.15054.3.68.1516
14854.3.68.152/2954.3.68.153 to 54.3.68.15854.3.68.1596
14954.3.68.160/2954.3.68.161 to 54.3.68.16654.3.68.1676
15054.3.68.168/2954.3.68.169 to 54.3.68.17454.3.68.1756
15154.3.68.176/2954.3.68.177 to 54.3.68.18254.3.68.1836
15254.3.68.184/2954.3.68.185 to 54.3.68.19054.3.68.1916
15354.3.68.192/2954.3.68.193 to 54.3.68.19854.3.68.1996
15454.3.68.200/2954.3.68.201 to 54.3.68.20654.3.68.2076
15554.3.68.208/2954.3.68.209 to 54.3.68.21454.3.68.2156
15654.3.68.216/2954.3.68.217 to 54.3.68.22254.3.68.2236
15754.3.68.224/2954.3.68.225 to 54.3.68.23054.3.68.2316
15854.3.68.232/2954.3.68.233 to 54.3.68.23854.3.68.2396
15954.3.68.240/2954.3.68.241 to 54.3.68.24654.3.68.2476
16054.3.68.248/2954.3.68.249 to 54.3.68.25454.3.68.2556
16154.3.69.0/2954.3.69.1 to 54.3.69.654.3.69.76
16254.3.69.8/2954.3.69.9 to 54.3.69.1454.3.69.156
16354.3.69.16/2954.3.69.17 to 54.3.69.2254.3.69.236
16454.3.69.24/2954.3.69.25 to 54.3.69.3054.3.69.316
16554.3.69.32/2954.3.69.33 to 54.3.69.3854.3.69.396
16654.3.69.40/2954.3.69.41 to 54.3.69.4654.3.69.476
16754.3.69.48/2954.3.69.49 to 54.3.69.5454.3.69.556
16854.3.69.56/2954.3.69.57 to 54.3.69.6254.3.69.636
16954.3.69.64/2954.3.69.65 to 54.3.69.7054.3.69.716
17054.3.69.72/2954.3.69.73 to 54.3.69.7854.3.69.796
17154.3.69.80/2954.3.69.81 to 54.3.69.8654.3.69.876
17254.3.69.88/2954.3.69.89 to 54.3.69.9454.3.69.956
17354.3.69.96/2954.3.69.97 to 54.3.69.10254.3.69.1036
17454.3.69.104/2954.3.69.105 to 54.3.69.11054.3.69.1116
17554.3.69.112/2954.3.69.113 to 54.3.69.11854.3.69.1196
17654.3.69.120/2954.3.69.121 to 54.3.69.12654.3.69.1276
17754.3.69.128/2954.3.69.129 to 54.3.69.13454.3.69.1356
17854.3.69.136/2954.3.69.137 to 54.3.69.14254.3.69.1436
17954.3.69.144/2954.3.69.145 to 54.3.69.15054.3.69.1516
18054.3.69.152/2954.3.69.153 to 54.3.69.15854.3.69.1596
18154.3.69.160/2954.3.69.161 to 54.3.69.16654.3.69.1676
18254.3.69.168/2954.3.69.169 to 54.3.69.17454.3.69.1756
18354.3.69.176/2954.3.69.177 to 54.3.69.18254.3.69.1836
18454.3.69.184/2954.3.69.185 to 54.3.69.19054.3.69.1916
18554.3.69.192/2954.3.69.193 to 54.3.69.19854.3.69.1996
18654.3.69.200/2954.3.69.201 to 54.3.69.20654.3.69.2076
18754.3.69.208/2954.3.69.209 to 54.3.69.21454.3.69.2156
18854.3.69.216/2954.3.69.217 to 54.3.69.22254.3.69.2236
18954.3.69.224/2954.3.69.225 to 54.3.69.23054.3.69.2316
19054.3.69.232/2954.3.69.233 to 54.3.69.23854.3.69.2396
19154.3.69.240/2954.3.69.241 to 54.3.69.24654.3.69.2476
19254.3.69.248/2954.3.69.249 to 54.3.69.25454.3.69.2556
19354.3.70.0/2954.3.70.1 to 54.3.70.654.3.70.76
19454.3.70.8/2954.3.70.9 to 54.3.70.1454.3.70.156
19554.3.70.16/2954.3.70.17 to 54.3.70.2254.3.70.236
19654.3.70.24/2954.3.70.25 to 54.3.70.3054.3.70.316
19754.3.70.32/2954.3.70.33 to 54.3.70.3854.3.70.396
19854.3.70.40/2954.3.70.41 to 54.3.70.4654.3.70.476
19954.3.70.48/2954.3.70.49 to 54.3.70.5454.3.70.556
20054.3.70.56/2954.3.70.57 to 54.3.70.6254.3.70.636
20154.3.70.64/2954.3.70.65 to 54.3.70.7054.3.70.716
20254.3.70.72/2954.3.70.73 to 54.3.70.7854.3.70.796
20354.3.70.80/2954.3.70.81 to 54.3.70.8654.3.70.876
20454.3.70.88/2954.3.70.89 to 54.3.70.9454.3.70.956
20554.3.70.96/2954.3.70.97 to 54.3.70.10254.3.70.1036
20654.3.70.104/2954.3.70.105 to 54.3.70.11054.3.70.1116
20754.3.70.112/2954.3.70.113 to 54.3.70.11854.3.70.1196
20854.3.70.120/2954.3.70.121 to 54.3.70.12654.3.70.1276
20954.3.70.128/2954.3.70.129 to 54.3.70.13454.3.70.1356
21054.3.70.136/2954.3.70.137 to 54.3.70.14254.3.70.1436
21154.3.70.144/2954.3.70.145 to 54.3.70.15054.3.70.1516
21254.3.70.152/2954.3.70.153 to 54.3.70.15854.3.70.1596
21354.3.70.160/2954.3.70.161 to 54.3.70.16654.3.70.1676
21454.3.70.168/2954.3.70.169 to 54.3.70.17454.3.70.1756
21554.3.70.176/2954.3.70.177 to 54.3.70.18254.3.70.1836
21654.3.70.184/2954.3.70.185 to 54.3.70.19054.3.70.1916
21754.3.70.192/2954.3.70.193 to 54.3.70.19854.3.70.1996
21854.3.70.200/2954.3.70.201 to 54.3.70.20654.3.70.2076
21954.3.70.208/2954.3.70.209 to 54.3.70.21454.3.70.2156
22054.3.70.216/2954.3.70.217 to 54.3.70.22254.3.70.2236
22154.3.70.224/2954.3.70.225 to 54.3.70.23054.3.70.2316
22254.3.70.232/2954.3.70.233 to 54.3.70.23854.3.70.2396
22354.3.70.240/2954.3.70.241 to 54.3.70.24654.3.70.2476
22454.3.70.248/2954.3.70.249 to 54.3.70.25454.3.70.2556
22554.3.71.0/2954.3.71.1 to 54.3.71.654.3.71.76
22654.3.71.8/2954.3.71.9 to 54.3.71.1454.3.71.156
22754.3.71.16/2954.3.71.17 to 54.3.71.2254.3.71.236
22854.3.71.24/2954.3.71.25 to 54.3.71.3054.3.71.316
22954.3.71.32/2954.3.71.33 to 54.3.71.3854.3.71.396
23054.3.71.40/2954.3.71.41 to 54.3.71.4654.3.71.476
23154.3.71.48/2954.3.71.49 to 54.3.71.5454.3.71.556
23254.3.71.56/2954.3.71.57 to 54.3.71.6254.3.71.636
23354.3.71.64/2954.3.71.65 to 54.3.71.7054.3.71.716
23454.3.71.72/2954.3.71.73 to 54.3.71.7854.3.71.796
23554.3.71.80/2954.3.71.81 to 54.3.71.8654.3.71.876
23654.3.71.88/2954.3.71.89 to 54.3.71.9454.3.71.956
23754.3.71.96/2954.3.71.97 to 54.3.71.10254.3.71.1036
23854.3.71.104/2954.3.71.105 to 54.3.71.11054.3.71.1116
23954.3.71.112/2954.3.71.113 to 54.3.71.11854.3.71.1196
24054.3.71.120/2954.3.71.121 to 54.3.71.12654.3.71.1276
24154.3.71.128/2954.3.71.129 to 54.3.71.13454.3.71.1356
24254.3.71.136/2954.3.71.137 to 54.3.71.14254.3.71.1436
24354.3.71.144/2954.3.71.145 to 54.3.71.15054.3.71.1516
24454.3.71.152/2954.3.71.153 to 54.3.71.15854.3.71.1596
24554.3.71.160/2954.3.71.161 to 54.3.71.16654.3.71.1676
24654.3.71.168/2954.3.71.169 to 54.3.71.17454.3.71.1756
24754.3.71.176/2954.3.71.177 to 54.3.71.18254.3.71.1836
24854.3.71.184/2954.3.71.185 to 54.3.71.19054.3.71.1916
24954.3.71.192/2954.3.71.193 to 54.3.71.19854.3.71.1996
25054.3.71.200/2954.3.71.201 to 54.3.71.20654.3.71.2076
25154.3.71.208/2954.3.71.209 to 54.3.71.21454.3.71.2156
25254.3.71.216/2954.3.71.217 to 54.3.71.22254.3.71.2236
25354.3.71.224/2954.3.71.225 to 54.3.71.23054.3.71.2316
25454.3.71.232/2954.3.71.233 to 54.3.71.23854.3.71.2396
25554.3.71.240/2954.3.71.241 to 54.3.71.24654.3.71.2476
25654.3.71.248/2954.3.71.249 to 54.3.71.25454.3.71.2556

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.