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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.

Network134.3.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
134.3.64.0
Broadcast address
134.3.95.255
First usable
134.3.64.1
Last usable
134.3.95.254
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
B (default /16)
As numbers
Hex 86034000 · Integer 2248359936 to 2248368127
Reverse DNS zones
64.3.134.in-addr.arpa
65.3.134.in-addr.arpa
66.3.134.in-addr.arpa
67.3.134.in-addr.arpa
68.3.134.in-addr.arpa
69.3.134.in-addr.arpa
70.3.134.in-addr.arpa
71.3.134.in-addr.arpa
72.3.134.in-addr.arpa
73.3.134.in-addr.arpa
74.3.134.in-addr.arpa
75.3.134.in-addr.arpa
76.3.134.in-addr.arpa
77.3.134.in-addr.arpa
78.3.134.in-addr.arpa
79.3.134.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
Address10000110.00000011.01000000.00000000134.3.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10000110.00000011.01000000.00000000134.3.64.0
Broadcast10000110.00000011.01011111.11111111134.3.95.255
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)

134.3.64.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1134.3.64.0/29134.3.64.1 to 134.3.64.6134.3.64.76
2134.3.64.8/29134.3.64.9 to 134.3.64.14134.3.64.156
3134.3.64.16/29134.3.64.17 to 134.3.64.22134.3.64.236
4134.3.64.24/29134.3.64.25 to 134.3.64.30134.3.64.316
5134.3.64.32/29134.3.64.33 to 134.3.64.38134.3.64.396
6134.3.64.40/29134.3.64.41 to 134.3.64.46134.3.64.476
7134.3.64.48/29134.3.64.49 to 134.3.64.54134.3.64.556
8134.3.64.56/29134.3.64.57 to 134.3.64.62134.3.64.636
9134.3.64.64/29134.3.64.65 to 134.3.64.70134.3.64.716
10134.3.64.72/29134.3.64.73 to 134.3.64.78134.3.64.796
11134.3.64.80/29134.3.64.81 to 134.3.64.86134.3.64.876
12134.3.64.88/29134.3.64.89 to 134.3.64.94134.3.64.956
13134.3.64.96/29134.3.64.97 to 134.3.64.102134.3.64.1036
14134.3.64.104/29134.3.64.105 to 134.3.64.110134.3.64.1116
15134.3.64.112/29134.3.64.113 to 134.3.64.118134.3.64.1196
16134.3.64.120/29134.3.64.121 to 134.3.64.126134.3.64.1276
17134.3.64.128/29134.3.64.129 to 134.3.64.134134.3.64.1356
18134.3.64.136/29134.3.64.137 to 134.3.64.142134.3.64.1436
19134.3.64.144/29134.3.64.145 to 134.3.64.150134.3.64.1516
20134.3.64.152/29134.3.64.153 to 134.3.64.158134.3.64.1596
21134.3.64.160/29134.3.64.161 to 134.3.64.166134.3.64.1676
22134.3.64.168/29134.3.64.169 to 134.3.64.174134.3.64.1756
23134.3.64.176/29134.3.64.177 to 134.3.64.182134.3.64.1836
24134.3.64.184/29134.3.64.185 to 134.3.64.190134.3.64.1916
25134.3.64.192/29134.3.64.193 to 134.3.64.198134.3.64.1996
26134.3.64.200/29134.3.64.201 to 134.3.64.206134.3.64.2076
27134.3.64.208/29134.3.64.209 to 134.3.64.214134.3.64.2156
28134.3.64.216/29134.3.64.217 to 134.3.64.222134.3.64.2236
29134.3.64.224/29134.3.64.225 to 134.3.64.230134.3.64.2316
30134.3.64.232/29134.3.64.233 to 134.3.64.238134.3.64.2396
31134.3.64.240/29134.3.64.241 to 134.3.64.246134.3.64.2476
32134.3.64.248/29134.3.64.249 to 134.3.64.254134.3.64.2556
33134.3.65.0/29134.3.65.1 to 134.3.65.6134.3.65.76
34134.3.65.8/29134.3.65.9 to 134.3.65.14134.3.65.156
35134.3.65.16/29134.3.65.17 to 134.3.65.22134.3.65.236
36134.3.65.24/29134.3.65.25 to 134.3.65.30134.3.65.316
37134.3.65.32/29134.3.65.33 to 134.3.65.38134.3.65.396
38134.3.65.40/29134.3.65.41 to 134.3.65.46134.3.65.476
39134.3.65.48/29134.3.65.49 to 134.3.65.54134.3.65.556
40134.3.65.56/29134.3.65.57 to 134.3.65.62134.3.65.636
41134.3.65.64/29134.3.65.65 to 134.3.65.70134.3.65.716
42134.3.65.72/29134.3.65.73 to 134.3.65.78134.3.65.796
43134.3.65.80/29134.3.65.81 to 134.3.65.86134.3.65.876
44134.3.65.88/29134.3.65.89 to 134.3.65.94134.3.65.956
45134.3.65.96/29134.3.65.97 to 134.3.65.102134.3.65.1036
46134.3.65.104/29134.3.65.105 to 134.3.65.110134.3.65.1116
47134.3.65.112/29134.3.65.113 to 134.3.65.118134.3.65.1196
48134.3.65.120/29134.3.65.121 to 134.3.65.126134.3.65.1276
49134.3.65.128/29134.3.65.129 to 134.3.65.134134.3.65.1356
50134.3.65.136/29134.3.65.137 to 134.3.65.142134.3.65.1436
51134.3.65.144/29134.3.65.145 to 134.3.65.150134.3.65.1516
52134.3.65.152/29134.3.65.153 to 134.3.65.158134.3.65.1596
53134.3.65.160/29134.3.65.161 to 134.3.65.166134.3.65.1676
54134.3.65.168/29134.3.65.169 to 134.3.65.174134.3.65.1756
55134.3.65.176/29134.3.65.177 to 134.3.65.182134.3.65.1836
56134.3.65.184/29134.3.65.185 to 134.3.65.190134.3.65.1916
57134.3.65.192/29134.3.65.193 to 134.3.65.198134.3.65.1996
58134.3.65.200/29134.3.65.201 to 134.3.65.206134.3.65.2076
59134.3.65.208/29134.3.65.209 to 134.3.65.214134.3.65.2156
60134.3.65.216/29134.3.65.217 to 134.3.65.222134.3.65.2236
61134.3.65.224/29134.3.65.225 to 134.3.65.230134.3.65.2316
62134.3.65.232/29134.3.65.233 to 134.3.65.238134.3.65.2396
63134.3.65.240/29134.3.65.241 to 134.3.65.246134.3.65.2476
64134.3.65.248/29134.3.65.249 to 134.3.65.254134.3.65.2556
65134.3.66.0/29134.3.66.1 to 134.3.66.6134.3.66.76
66134.3.66.8/29134.3.66.9 to 134.3.66.14134.3.66.156
67134.3.66.16/29134.3.66.17 to 134.3.66.22134.3.66.236
68134.3.66.24/29134.3.66.25 to 134.3.66.30134.3.66.316
69134.3.66.32/29134.3.66.33 to 134.3.66.38134.3.66.396
70134.3.66.40/29134.3.66.41 to 134.3.66.46134.3.66.476
71134.3.66.48/29134.3.66.49 to 134.3.66.54134.3.66.556
72134.3.66.56/29134.3.66.57 to 134.3.66.62134.3.66.636
73134.3.66.64/29134.3.66.65 to 134.3.66.70134.3.66.716
74134.3.66.72/29134.3.66.73 to 134.3.66.78134.3.66.796
75134.3.66.80/29134.3.66.81 to 134.3.66.86134.3.66.876
76134.3.66.88/29134.3.66.89 to 134.3.66.94134.3.66.956
77134.3.66.96/29134.3.66.97 to 134.3.66.102134.3.66.1036
78134.3.66.104/29134.3.66.105 to 134.3.66.110134.3.66.1116
79134.3.66.112/29134.3.66.113 to 134.3.66.118134.3.66.1196
80134.3.66.120/29134.3.66.121 to 134.3.66.126134.3.66.1276
81134.3.66.128/29134.3.66.129 to 134.3.66.134134.3.66.1356
82134.3.66.136/29134.3.66.137 to 134.3.66.142134.3.66.1436
83134.3.66.144/29134.3.66.145 to 134.3.66.150134.3.66.1516
84134.3.66.152/29134.3.66.153 to 134.3.66.158134.3.66.1596
85134.3.66.160/29134.3.66.161 to 134.3.66.166134.3.66.1676
86134.3.66.168/29134.3.66.169 to 134.3.66.174134.3.66.1756
87134.3.66.176/29134.3.66.177 to 134.3.66.182134.3.66.1836
88134.3.66.184/29134.3.66.185 to 134.3.66.190134.3.66.1916
89134.3.66.192/29134.3.66.193 to 134.3.66.198134.3.66.1996
90134.3.66.200/29134.3.66.201 to 134.3.66.206134.3.66.2076
91134.3.66.208/29134.3.66.209 to 134.3.66.214134.3.66.2156
92134.3.66.216/29134.3.66.217 to 134.3.66.222134.3.66.2236
93134.3.66.224/29134.3.66.225 to 134.3.66.230134.3.66.2316
94134.3.66.232/29134.3.66.233 to 134.3.66.238134.3.66.2396
95134.3.66.240/29134.3.66.241 to 134.3.66.246134.3.66.2476
96134.3.66.248/29134.3.66.249 to 134.3.66.254134.3.66.2556
97134.3.67.0/29134.3.67.1 to 134.3.67.6134.3.67.76
98134.3.67.8/29134.3.67.9 to 134.3.67.14134.3.67.156
99134.3.67.16/29134.3.67.17 to 134.3.67.22134.3.67.236
100134.3.67.24/29134.3.67.25 to 134.3.67.30134.3.67.316
101134.3.67.32/29134.3.67.33 to 134.3.67.38134.3.67.396
102134.3.67.40/29134.3.67.41 to 134.3.67.46134.3.67.476
103134.3.67.48/29134.3.67.49 to 134.3.67.54134.3.67.556
104134.3.67.56/29134.3.67.57 to 134.3.67.62134.3.67.636
105134.3.67.64/29134.3.67.65 to 134.3.67.70134.3.67.716
106134.3.67.72/29134.3.67.73 to 134.3.67.78134.3.67.796
107134.3.67.80/29134.3.67.81 to 134.3.67.86134.3.67.876
108134.3.67.88/29134.3.67.89 to 134.3.67.94134.3.67.956
109134.3.67.96/29134.3.67.97 to 134.3.67.102134.3.67.1036
110134.3.67.104/29134.3.67.105 to 134.3.67.110134.3.67.1116
111134.3.67.112/29134.3.67.113 to 134.3.67.118134.3.67.1196
112134.3.67.120/29134.3.67.121 to 134.3.67.126134.3.67.1276
113134.3.67.128/29134.3.67.129 to 134.3.67.134134.3.67.1356
114134.3.67.136/29134.3.67.137 to 134.3.67.142134.3.67.1436
115134.3.67.144/29134.3.67.145 to 134.3.67.150134.3.67.1516
116134.3.67.152/29134.3.67.153 to 134.3.67.158134.3.67.1596
117134.3.67.160/29134.3.67.161 to 134.3.67.166134.3.67.1676
118134.3.67.168/29134.3.67.169 to 134.3.67.174134.3.67.1756
119134.3.67.176/29134.3.67.177 to 134.3.67.182134.3.67.1836
120134.3.67.184/29134.3.67.185 to 134.3.67.190134.3.67.1916
121134.3.67.192/29134.3.67.193 to 134.3.67.198134.3.67.1996
122134.3.67.200/29134.3.67.201 to 134.3.67.206134.3.67.2076
123134.3.67.208/29134.3.67.209 to 134.3.67.214134.3.67.2156
124134.3.67.216/29134.3.67.217 to 134.3.67.222134.3.67.2236
125134.3.67.224/29134.3.67.225 to 134.3.67.230134.3.67.2316
126134.3.67.232/29134.3.67.233 to 134.3.67.238134.3.67.2396
127134.3.67.240/29134.3.67.241 to 134.3.67.246134.3.67.2476
128134.3.67.248/29134.3.67.249 to 134.3.67.254134.3.67.2556
129134.3.68.0/29134.3.68.1 to 134.3.68.6134.3.68.76
130134.3.68.8/29134.3.68.9 to 134.3.68.14134.3.68.156
131134.3.68.16/29134.3.68.17 to 134.3.68.22134.3.68.236
132134.3.68.24/29134.3.68.25 to 134.3.68.30134.3.68.316
133134.3.68.32/29134.3.68.33 to 134.3.68.38134.3.68.396
134134.3.68.40/29134.3.68.41 to 134.3.68.46134.3.68.476
135134.3.68.48/29134.3.68.49 to 134.3.68.54134.3.68.556
136134.3.68.56/29134.3.68.57 to 134.3.68.62134.3.68.636
137134.3.68.64/29134.3.68.65 to 134.3.68.70134.3.68.716
138134.3.68.72/29134.3.68.73 to 134.3.68.78134.3.68.796
139134.3.68.80/29134.3.68.81 to 134.3.68.86134.3.68.876
140134.3.68.88/29134.3.68.89 to 134.3.68.94134.3.68.956
141134.3.68.96/29134.3.68.97 to 134.3.68.102134.3.68.1036
142134.3.68.104/29134.3.68.105 to 134.3.68.110134.3.68.1116
143134.3.68.112/29134.3.68.113 to 134.3.68.118134.3.68.1196
144134.3.68.120/29134.3.68.121 to 134.3.68.126134.3.68.1276
145134.3.68.128/29134.3.68.129 to 134.3.68.134134.3.68.1356
146134.3.68.136/29134.3.68.137 to 134.3.68.142134.3.68.1436
147134.3.68.144/29134.3.68.145 to 134.3.68.150134.3.68.1516
148134.3.68.152/29134.3.68.153 to 134.3.68.158134.3.68.1596
149134.3.68.160/29134.3.68.161 to 134.3.68.166134.3.68.1676
150134.3.68.168/29134.3.68.169 to 134.3.68.174134.3.68.1756
151134.3.68.176/29134.3.68.177 to 134.3.68.182134.3.68.1836
152134.3.68.184/29134.3.68.185 to 134.3.68.190134.3.68.1916
153134.3.68.192/29134.3.68.193 to 134.3.68.198134.3.68.1996
154134.3.68.200/29134.3.68.201 to 134.3.68.206134.3.68.2076
155134.3.68.208/29134.3.68.209 to 134.3.68.214134.3.68.2156
156134.3.68.216/29134.3.68.217 to 134.3.68.222134.3.68.2236
157134.3.68.224/29134.3.68.225 to 134.3.68.230134.3.68.2316
158134.3.68.232/29134.3.68.233 to 134.3.68.238134.3.68.2396
159134.3.68.240/29134.3.68.241 to 134.3.68.246134.3.68.2476
160134.3.68.248/29134.3.68.249 to 134.3.68.254134.3.68.2556
161134.3.69.0/29134.3.69.1 to 134.3.69.6134.3.69.76
162134.3.69.8/29134.3.69.9 to 134.3.69.14134.3.69.156
163134.3.69.16/29134.3.69.17 to 134.3.69.22134.3.69.236
164134.3.69.24/29134.3.69.25 to 134.3.69.30134.3.69.316
165134.3.69.32/29134.3.69.33 to 134.3.69.38134.3.69.396
166134.3.69.40/29134.3.69.41 to 134.3.69.46134.3.69.476
167134.3.69.48/29134.3.69.49 to 134.3.69.54134.3.69.556
168134.3.69.56/29134.3.69.57 to 134.3.69.62134.3.69.636
169134.3.69.64/29134.3.69.65 to 134.3.69.70134.3.69.716
170134.3.69.72/29134.3.69.73 to 134.3.69.78134.3.69.796
171134.3.69.80/29134.3.69.81 to 134.3.69.86134.3.69.876
172134.3.69.88/29134.3.69.89 to 134.3.69.94134.3.69.956
173134.3.69.96/29134.3.69.97 to 134.3.69.102134.3.69.1036
174134.3.69.104/29134.3.69.105 to 134.3.69.110134.3.69.1116
175134.3.69.112/29134.3.69.113 to 134.3.69.118134.3.69.1196
176134.3.69.120/29134.3.69.121 to 134.3.69.126134.3.69.1276
177134.3.69.128/29134.3.69.129 to 134.3.69.134134.3.69.1356
178134.3.69.136/29134.3.69.137 to 134.3.69.142134.3.69.1436
179134.3.69.144/29134.3.69.145 to 134.3.69.150134.3.69.1516
180134.3.69.152/29134.3.69.153 to 134.3.69.158134.3.69.1596
181134.3.69.160/29134.3.69.161 to 134.3.69.166134.3.69.1676
182134.3.69.168/29134.3.69.169 to 134.3.69.174134.3.69.1756
183134.3.69.176/29134.3.69.177 to 134.3.69.182134.3.69.1836
184134.3.69.184/29134.3.69.185 to 134.3.69.190134.3.69.1916
185134.3.69.192/29134.3.69.193 to 134.3.69.198134.3.69.1996
186134.3.69.200/29134.3.69.201 to 134.3.69.206134.3.69.2076
187134.3.69.208/29134.3.69.209 to 134.3.69.214134.3.69.2156
188134.3.69.216/29134.3.69.217 to 134.3.69.222134.3.69.2236
189134.3.69.224/29134.3.69.225 to 134.3.69.230134.3.69.2316
190134.3.69.232/29134.3.69.233 to 134.3.69.238134.3.69.2396
191134.3.69.240/29134.3.69.241 to 134.3.69.246134.3.69.2476
192134.3.69.248/29134.3.69.249 to 134.3.69.254134.3.69.2556
193134.3.70.0/29134.3.70.1 to 134.3.70.6134.3.70.76
194134.3.70.8/29134.3.70.9 to 134.3.70.14134.3.70.156
195134.3.70.16/29134.3.70.17 to 134.3.70.22134.3.70.236
196134.3.70.24/29134.3.70.25 to 134.3.70.30134.3.70.316
197134.3.70.32/29134.3.70.33 to 134.3.70.38134.3.70.396
198134.3.70.40/29134.3.70.41 to 134.3.70.46134.3.70.476
199134.3.70.48/29134.3.70.49 to 134.3.70.54134.3.70.556
200134.3.70.56/29134.3.70.57 to 134.3.70.62134.3.70.636
201134.3.70.64/29134.3.70.65 to 134.3.70.70134.3.70.716
202134.3.70.72/29134.3.70.73 to 134.3.70.78134.3.70.796
203134.3.70.80/29134.3.70.81 to 134.3.70.86134.3.70.876
204134.3.70.88/29134.3.70.89 to 134.3.70.94134.3.70.956
205134.3.70.96/29134.3.70.97 to 134.3.70.102134.3.70.1036
206134.3.70.104/29134.3.70.105 to 134.3.70.110134.3.70.1116
207134.3.70.112/29134.3.70.113 to 134.3.70.118134.3.70.1196
208134.3.70.120/29134.3.70.121 to 134.3.70.126134.3.70.1276
209134.3.70.128/29134.3.70.129 to 134.3.70.134134.3.70.1356
210134.3.70.136/29134.3.70.137 to 134.3.70.142134.3.70.1436
211134.3.70.144/29134.3.70.145 to 134.3.70.150134.3.70.1516
212134.3.70.152/29134.3.70.153 to 134.3.70.158134.3.70.1596
213134.3.70.160/29134.3.70.161 to 134.3.70.166134.3.70.1676
214134.3.70.168/29134.3.70.169 to 134.3.70.174134.3.70.1756
215134.3.70.176/29134.3.70.177 to 134.3.70.182134.3.70.1836
216134.3.70.184/29134.3.70.185 to 134.3.70.190134.3.70.1916
217134.3.70.192/29134.3.70.193 to 134.3.70.198134.3.70.1996
218134.3.70.200/29134.3.70.201 to 134.3.70.206134.3.70.2076
219134.3.70.208/29134.3.70.209 to 134.3.70.214134.3.70.2156
220134.3.70.216/29134.3.70.217 to 134.3.70.222134.3.70.2236
221134.3.70.224/29134.3.70.225 to 134.3.70.230134.3.70.2316
222134.3.70.232/29134.3.70.233 to 134.3.70.238134.3.70.2396
223134.3.70.240/29134.3.70.241 to 134.3.70.246134.3.70.2476
224134.3.70.248/29134.3.70.249 to 134.3.70.254134.3.70.2556
225134.3.71.0/29134.3.71.1 to 134.3.71.6134.3.71.76
226134.3.71.8/29134.3.71.9 to 134.3.71.14134.3.71.156
227134.3.71.16/29134.3.71.17 to 134.3.71.22134.3.71.236
228134.3.71.24/29134.3.71.25 to 134.3.71.30134.3.71.316
229134.3.71.32/29134.3.71.33 to 134.3.71.38134.3.71.396
230134.3.71.40/29134.3.71.41 to 134.3.71.46134.3.71.476
231134.3.71.48/29134.3.71.49 to 134.3.71.54134.3.71.556
232134.3.71.56/29134.3.71.57 to 134.3.71.62134.3.71.636
233134.3.71.64/29134.3.71.65 to 134.3.71.70134.3.71.716
234134.3.71.72/29134.3.71.73 to 134.3.71.78134.3.71.796
235134.3.71.80/29134.3.71.81 to 134.3.71.86134.3.71.876
236134.3.71.88/29134.3.71.89 to 134.3.71.94134.3.71.956
237134.3.71.96/29134.3.71.97 to 134.3.71.102134.3.71.1036
238134.3.71.104/29134.3.71.105 to 134.3.71.110134.3.71.1116
239134.3.71.112/29134.3.71.113 to 134.3.71.118134.3.71.1196
240134.3.71.120/29134.3.71.121 to 134.3.71.126134.3.71.1276
241134.3.71.128/29134.3.71.129 to 134.3.71.134134.3.71.1356
242134.3.71.136/29134.3.71.137 to 134.3.71.142134.3.71.1436
243134.3.71.144/29134.3.71.145 to 134.3.71.150134.3.71.1516
244134.3.71.152/29134.3.71.153 to 134.3.71.158134.3.71.1596
245134.3.71.160/29134.3.71.161 to 134.3.71.166134.3.71.1676
246134.3.71.168/29134.3.71.169 to 134.3.71.174134.3.71.1756
247134.3.71.176/29134.3.71.177 to 134.3.71.182134.3.71.1836
248134.3.71.184/29134.3.71.185 to 134.3.71.190134.3.71.1916
249134.3.71.192/29134.3.71.193 to 134.3.71.198134.3.71.1996
250134.3.71.200/29134.3.71.201 to 134.3.71.206134.3.71.2076
251134.3.71.208/29134.3.71.209 to 134.3.71.214134.3.71.2156
252134.3.71.216/29134.3.71.217 to 134.3.71.222134.3.71.2236
253134.3.71.224/29134.3.71.225 to 134.3.71.230134.3.71.2316
254134.3.71.232/29134.3.71.233 to 134.3.71.238134.3.71.2396
255134.3.71.240/29134.3.71.241 to 134.3.71.246134.3.71.2476
256134.3.71.248/29134.3.71.249 to 134.3.71.254134.3.71.2556

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.