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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.

Network134.6.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
134.6.64.0
Broadcast address
134.6.95.255
First usable
134.6.64.1
Last usable
134.6.95.254
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 86064000 · Integer 2248556544 to 2248564735
Reverse DNS zones
64.6.134.in-addr.arpa
65.6.134.in-addr.arpa
66.6.134.in-addr.arpa
67.6.134.in-addr.arpa
68.6.134.in-addr.arpa
69.6.134.in-addr.arpa
70.6.134.in-addr.arpa
71.6.134.in-addr.arpa
72.6.134.in-addr.arpa
73.6.134.in-addr.arpa
74.6.134.in-addr.arpa
75.6.134.in-addr.arpa
76.6.134.in-addr.arpa
77.6.134.in-addr.arpa
78.6.134.in-addr.arpa
79.6.134.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
Address10000110.00000110.01000000.00000000134.6.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10000110.00000110.01000000.00000000134.6.64.0
Broadcast10000110.00000110.01011111.11111111134.6.95.255
Split into smaller subnets/28
/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)

134.6.64.0/19 makes 512 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1134.6.64.0/28134.6.64.1 to 134.6.64.14134.6.64.1514
2134.6.64.16/28134.6.64.17 to 134.6.64.30134.6.64.3114
3134.6.64.32/28134.6.64.33 to 134.6.64.46134.6.64.4714
4134.6.64.48/28134.6.64.49 to 134.6.64.62134.6.64.6314
5134.6.64.64/28134.6.64.65 to 134.6.64.78134.6.64.7914
6134.6.64.80/28134.6.64.81 to 134.6.64.94134.6.64.9514
7134.6.64.96/28134.6.64.97 to 134.6.64.110134.6.64.11114
8134.6.64.112/28134.6.64.113 to 134.6.64.126134.6.64.12714
9134.6.64.128/28134.6.64.129 to 134.6.64.142134.6.64.14314
10134.6.64.144/28134.6.64.145 to 134.6.64.158134.6.64.15914
11134.6.64.160/28134.6.64.161 to 134.6.64.174134.6.64.17514
12134.6.64.176/28134.6.64.177 to 134.6.64.190134.6.64.19114
13134.6.64.192/28134.6.64.193 to 134.6.64.206134.6.64.20714
14134.6.64.208/28134.6.64.209 to 134.6.64.222134.6.64.22314
15134.6.64.224/28134.6.64.225 to 134.6.64.238134.6.64.23914
16134.6.64.240/28134.6.64.241 to 134.6.64.254134.6.64.25514
17134.6.65.0/28134.6.65.1 to 134.6.65.14134.6.65.1514
18134.6.65.16/28134.6.65.17 to 134.6.65.30134.6.65.3114
19134.6.65.32/28134.6.65.33 to 134.6.65.46134.6.65.4714
20134.6.65.48/28134.6.65.49 to 134.6.65.62134.6.65.6314
21134.6.65.64/28134.6.65.65 to 134.6.65.78134.6.65.7914
22134.6.65.80/28134.6.65.81 to 134.6.65.94134.6.65.9514
23134.6.65.96/28134.6.65.97 to 134.6.65.110134.6.65.11114
24134.6.65.112/28134.6.65.113 to 134.6.65.126134.6.65.12714
25134.6.65.128/28134.6.65.129 to 134.6.65.142134.6.65.14314
26134.6.65.144/28134.6.65.145 to 134.6.65.158134.6.65.15914
27134.6.65.160/28134.6.65.161 to 134.6.65.174134.6.65.17514
28134.6.65.176/28134.6.65.177 to 134.6.65.190134.6.65.19114
29134.6.65.192/28134.6.65.193 to 134.6.65.206134.6.65.20714
30134.6.65.208/28134.6.65.209 to 134.6.65.222134.6.65.22314
31134.6.65.224/28134.6.65.225 to 134.6.65.238134.6.65.23914
32134.6.65.240/28134.6.65.241 to 134.6.65.254134.6.65.25514
33134.6.66.0/28134.6.66.1 to 134.6.66.14134.6.66.1514
34134.6.66.16/28134.6.66.17 to 134.6.66.30134.6.66.3114
35134.6.66.32/28134.6.66.33 to 134.6.66.46134.6.66.4714
36134.6.66.48/28134.6.66.49 to 134.6.66.62134.6.66.6314
37134.6.66.64/28134.6.66.65 to 134.6.66.78134.6.66.7914
38134.6.66.80/28134.6.66.81 to 134.6.66.94134.6.66.9514
39134.6.66.96/28134.6.66.97 to 134.6.66.110134.6.66.11114
40134.6.66.112/28134.6.66.113 to 134.6.66.126134.6.66.12714
41134.6.66.128/28134.6.66.129 to 134.6.66.142134.6.66.14314
42134.6.66.144/28134.6.66.145 to 134.6.66.158134.6.66.15914
43134.6.66.160/28134.6.66.161 to 134.6.66.174134.6.66.17514
44134.6.66.176/28134.6.66.177 to 134.6.66.190134.6.66.19114
45134.6.66.192/28134.6.66.193 to 134.6.66.206134.6.66.20714
46134.6.66.208/28134.6.66.209 to 134.6.66.222134.6.66.22314
47134.6.66.224/28134.6.66.225 to 134.6.66.238134.6.66.23914
48134.6.66.240/28134.6.66.241 to 134.6.66.254134.6.66.25514
49134.6.67.0/28134.6.67.1 to 134.6.67.14134.6.67.1514
50134.6.67.16/28134.6.67.17 to 134.6.67.30134.6.67.3114
51134.6.67.32/28134.6.67.33 to 134.6.67.46134.6.67.4714
52134.6.67.48/28134.6.67.49 to 134.6.67.62134.6.67.6314
53134.6.67.64/28134.6.67.65 to 134.6.67.78134.6.67.7914
54134.6.67.80/28134.6.67.81 to 134.6.67.94134.6.67.9514
55134.6.67.96/28134.6.67.97 to 134.6.67.110134.6.67.11114
56134.6.67.112/28134.6.67.113 to 134.6.67.126134.6.67.12714
57134.6.67.128/28134.6.67.129 to 134.6.67.142134.6.67.14314
58134.6.67.144/28134.6.67.145 to 134.6.67.158134.6.67.15914
59134.6.67.160/28134.6.67.161 to 134.6.67.174134.6.67.17514
60134.6.67.176/28134.6.67.177 to 134.6.67.190134.6.67.19114
61134.6.67.192/28134.6.67.193 to 134.6.67.206134.6.67.20714
62134.6.67.208/28134.6.67.209 to 134.6.67.222134.6.67.22314
63134.6.67.224/28134.6.67.225 to 134.6.67.238134.6.67.23914
64134.6.67.240/28134.6.67.241 to 134.6.67.254134.6.67.25514
65134.6.68.0/28134.6.68.1 to 134.6.68.14134.6.68.1514
66134.6.68.16/28134.6.68.17 to 134.6.68.30134.6.68.3114
67134.6.68.32/28134.6.68.33 to 134.6.68.46134.6.68.4714
68134.6.68.48/28134.6.68.49 to 134.6.68.62134.6.68.6314
69134.6.68.64/28134.6.68.65 to 134.6.68.78134.6.68.7914
70134.6.68.80/28134.6.68.81 to 134.6.68.94134.6.68.9514
71134.6.68.96/28134.6.68.97 to 134.6.68.110134.6.68.11114
72134.6.68.112/28134.6.68.113 to 134.6.68.126134.6.68.12714
73134.6.68.128/28134.6.68.129 to 134.6.68.142134.6.68.14314
74134.6.68.144/28134.6.68.145 to 134.6.68.158134.6.68.15914
75134.6.68.160/28134.6.68.161 to 134.6.68.174134.6.68.17514
76134.6.68.176/28134.6.68.177 to 134.6.68.190134.6.68.19114
77134.6.68.192/28134.6.68.193 to 134.6.68.206134.6.68.20714
78134.6.68.208/28134.6.68.209 to 134.6.68.222134.6.68.22314
79134.6.68.224/28134.6.68.225 to 134.6.68.238134.6.68.23914
80134.6.68.240/28134.6.68.241 to 134.6.68.254134.6.68.25514
81134.6.69.0/28134.6.69.1 to 134.6.69.14134.6.69.1514
82134.6.69.16/28134.6.69.17 to 134.6.69.30134.6.69.3114
83134.6.69.32/28134.6.69.33 to 134.6.69.46134.6.69.4714
84134.6.69.48/28134.6.69.49 to 134.6.69.62134.6.69.6314
85134.6.69.64/28134.6.69.65 to 134.6.69.78134.6.69.7914
86134.6.69.80/28134.6.69.81 to 134.6.69.94134.6.69.9514
87134.6.69.96/28134.6.69.97 to 134.6.69.110134.6.69.11114
88134.6.69.112/28134.6.69.113 to 134.6.69.126134.6.69.12714
89134.6.69.128/28134.6.69.129 to 134.6.69.142134.6.69.14314
90134.6.69.144/28134.6.69.145 to 134.6.69.158134.6.69.15914
91134.6.69.160/28134.6.69.161 to 134.6.69.174134.6.69.17514
92134.6.69.176/28134.6.69.177 to 134.6.69.190134.6.69.19114
93134.6.69.192/28134.6.69.193 to 134.6.69.206134.6.69.20714
94134.6.69.208/28134.6.69.209 to 134.6.69.222134.6.69.22314
95134.6.69.224/28134.6.69.225 to 134.6.69.238134.6.69.23914
96134.6.69.240/28134.6.69.241 to 134.6.69.254134.6.69.25514
97134.6.70.0/28134.6.70.1 to 134.6.70.14134.6.70.1514
98134.6.70.16/28134.6.70.17 to 134.6.70.30134.6.70.3114
99134.6.70.32/28134.6.70.33 to 134.6.70.46134.6.70.4714
100134.6.70.48/28134.6.70.49 to 134.6.70.62134.6.70.6314
101134.6.70.64/28134.6.70.65 to 134.6.70.78134.6.70.7914
102134.6.70.80/28134.6.70.81 to 134.6.70.94134.6.70.9514
103134.6.70.96/28134.6.70.97 to 134.6.70.110134.6.70.11114
104134.6.70.112/28134.6.70.113 to 134.6.70.126134.6.70.12714
105134.6.70.128/28134.6.70.129 to 134.6.70.142134.6.70.14314
106134.6.70.144/28134.6.70.145 to 134.6.70.158134.6.70.15914
107134.6.70.160/28134.6.70.161 to 134.6.70.174134.6.70.17514
108134.6.70.176/28134.6.70.177 to 134.6.70.190134.6.70.19114
109134.6.70.192/28134.6.70.193 to 134.6.70.206134.6.70.20714
110134.6.70.208/28134.6.70.209 to 134.6.70.222134.6.70.22314
111134.6.70.224/28134.6.70.225 to 134.6.70.238134.6.70.23914
112134.6.70.240/28134.6.70.241 to 134.6.70.254134.6.70.25514
113134.6.71.0/28134.6.71.1 to 134.6.71.14134.6.71.1514
114134.6.71.16/28134.6.71.17 to 134.6.71.30134.6.71.3114
115134.6.71.32/28134.6.71.33 to 134.6.71.46134.6.71.4714
116134.6.71.48/28134.6.71.49 to 134.6.71.62134.6.71.6314
117134.6.71.64/28134.6.71.65 to 134.6.71.78134.6.71.7914
118134.6.71.80/28134.6.71.81 to 134.6.71.94134.6.71.9514
119134.6.71.96/28134.6.71.97 to 134.6.71.110134.6.71.11114
120134.6.71.112/28134.6.71.113 to 134.6.71.126134.6.71.12714
121134.6.71.128/28134.6.71.129 to 134.6.71.142134.6.71.14314
122134.6.71.144/28134.6.71.145 to 134.6.71.158134.6.71.15914
123134.6.71.160/28134.6.71.161 to 134.6.71.174134.6.71.17514
124134.6.71.176/28134.6.71.177 to 134.6.71.190134.6.71.19114
125134.6.71.192/28134.6.71.193 to 134.6.71.206134.6.71.20714
126134.6.71.208/28134.6.71.209 to 134.6.71.222134.6.71.22314
127134.6.71.224/28134.6.71.225 to 134.6.71.238134.6.71.23914
128134.6.71.240/28134.6.71.241 to 134.6.71.254134.6.71.25514
129134.6.72.0/28134.6.72.1 to 134.6.72.14134.6.72.1514
130134.6.72.16/28134.6.72.17 to 134.6.72.30134.6.72.3114
131134.6.72.32/28134.6.72.33 to 134.6.72.46134.6.72.4714
132134.6.72.48/28134.6.72.49 to 134.6.72.62134.6.72.6314
133134.6.72.64/28134.6.72.65 to 134.6.72.78134.6.72.7914
134134.6.72.80/28134.6.72.81 to 134.6.72.94134.6.72.9514
135134.6.72.96/28134.6.72.97 to 134.6.72.110134.6.72.11114
136134.6.72.112/28134.6.72.113 to 134.6.72.126134.6.72.12714
137134.6.72.128/28134.6.72.129 to 134.6.72.142134.6.72.14314
138134.6.72.144/28134.6.72.145 to 134.6.72.158134.6.72.15914
139134.6.72.160/28134.6.72.161 to 134.6.72.174134.6.72.17514
140134.6.72.176/28134.6.72.177 to 134.6.72.190134.6.72.19114
141134.6.72.192/28134.6.72.193 to 134.6.72.206134.6.72.20714
142134.6.72.208/28134.6.72.209 to 134.6.72.222134.6.72.22314
143134.6.72.224/28134.6.72.225 to 134.6.72.238134.6.72.23914
144134.6.72.240/28134.6.72.241 to 134.6.72.254134.6.72.25514
145134.6.73.0/28134.6.73.1 to 134.6.73.14134.6.73.1514
146134.6.73.16/28134.6.73.17 to 134.6.73.30134.6.73.3114
147134.6.73.32/28134.6.73.33 to 134.6.73.46134.6.73.4714
148134.6.73.48/28134.6.73.49 to 134.6.73.62134.6.73.6314
149134.6.73.64/28134.6.73.65 to 134.6.73.78134.6.73.7914
150134.6.73.80/28134.6.73.81 to 134.6.73.94134.6.73.9514
151134.6.73.96/28134.6.73.97 to 134.6.73.110134.6.73.11114
152134.6.73.112/28134.6.73.113 to 134.6.73.126134.6.73.12714
153134.6.73.128/28134.6.73.129 to 134.6.73.142134.6.73.14314
154134.6.73.144/28134.6.73.145 to 134.6.73.158134.6.73.15914
155134.6.73.160/28134.6.73.161 to 134.6.73.174134.6.73.17514
156134.6.73.176/28134.6.73.177 to 134.6.73.190134.6.73.19114
157134.6.73.192/28134.6.73.193 to 134.6.73.206134.6.73.20714
158134.6.73.208/28134.6.73.209 to 134.6.73.222134.6.73.22314
159134.6.73.224/28134.6.73.225 to 134.6.73.238134.6.73.23914
160134.6.73.240/28134.6.73.241 to 134.6.73.254134.6.73.25514
161134.6.74.0/28134.6.74.1 to 134.6.74.14134.6.74.1514
162134.6.74.16/28134.6.74.17 to 134.6.74.30134.6.74.3114
163134.6.74.32/28134.6.74.33 to 134.6.74.46134.6.74.4714
164134.6.74.48/28134.6.74.49 to 134.6.74.62134.6.74.6314
165134.6.74.64/28134.6.74.65 to 134.6.74.78134.6.74.7914
166134.6.74.80/28134.6.74.81 to 134.6.74.94134.6.74.9514
167134.6.74.96/28134.6.74.97 to 134.6.74.110134.6.74.11114
168134.6.74.112/28134.6.74.113 to 134.6.74.126134.6.74.12714
169134.6.74.128/28134.6.74.129 to 134.6.74.142134.6.74.14314
170134.6.74.144/28134.6.74.145 to 134.6.74.158134.6.74.15914
171134.6.74.160/28134.6.74.161 to 134.6.74.174134.6.74.17514
172134.6.74.176/28134.6.74.177 to 134.6.74.190134.6.74.19114
173134.6.74.192/28134.6.74.193 to 134.6.74.206134.6.74.20714
174134.6.74.208/28134.6.74.209 to 134.6.74.222134.6.74.22314
175134.6.74.224/28134.6.74.225 to 134.6.74.238134.6.74.23914
176134.6.74.240/28134.6.74.241 to 134.6.74.254134.6.74.25514
177134.6.75.0/28134.6.75.1 to 134.6.75.14134.6.75.1514
178134.6.75.16/28134.6.75.17 to 134.6.75.30134.6.75.3114
179134.6.75.32/28134.6.75.33 to 134.6.75.46134.6.75.4714
180134.6.75.48/28134.6.75.49 to 134.6.75.62134.6.75.6314
181134.6.75.64/28134.6.75.65 to 134.6.75.78134.6.75.7914
182134.6.75.80/28134.6.75.81 to 134.6.75.94134.6.75.9514
183134.6.75.96/28134.6.75.97 to 134.6.75.110134.6.75.11114
184134.6.75.112/28134.6.75.113 to 134.6.75.126134.6.75.12714
185134.6.75.128/28134.6.75.129 to 134.6.75.142134.6.75.14314
186134.6.75.144/28134.6.75.145 to 134.6.75.158134.6.75.15914
187134.6.75.160/28134.6.75.161 to 134.6.75.174134.6.75.17514
188134.6.75.176/28134.6.75.177 to 134.6.75.190134.6.75.19114
189134.6.75.192/28134.6.75.193 to 134.6.75.206134.6.75.20714
190134.6.75.208/28134.6.75.209 to 134.6.75.222134.6.75.22314
191134.6.75.224/28134.6.75.225 to 134.6.75.238134.6.75.23914
192134.6.75.240/28134.6.75.241 to 134.6.75.254134.6.75.25514
193134.6.76.0/28134.6.76.1 to 134.6.76.14134.6.76.1514
194134.6.76.16/28134.6.76.17 to 134.6.76.30134.6.76.3114
195134.6.76.32/28134.6.76.33 to 134.6.76.46134.6.76.4714
196134.6.76.48/28134.6.76.49 to 134.6.76.62134.6.76.6314
197134.6.76.64/28134.6.76.65 to 134.6.76.78134.6.76.7914
198134.6.76.80/28134.6.76.81 to 134.6.76.94134.6.76.9514
199134.6.76.96/28134.6.76.97 to 134.6.76.110134.6.76.11114
200134.6.76.112/28134.6.76.113 to 134.6.76.126134.6.76.12714
201134.6.76.128/28134.6.76.129 to 134.6.76.142134.6.76.14314
202134.6.76.144/28134.6.76.145 to 134.6.76.158134.6.76.15914
203134.6.76.160/28134.6.76.161 to 134.6.76.174134.6.76.17514
204134.6.76.176/28134.6.76.177 to 134.6.76.190134.6.76.19114
205134.6.76.192/28134.6.76.193 to 134.6.76.206134.6.76.20714
206134.6.76.208/28134.6.76.209 to 134.6.76.222134.6.76.22314
207134.6.76.224/28134.6.76.225 to 134.6.76.238134.6.76.23914
208134.6.76.240/28134.6.76.241 to 134.6.76.254134.6.76.25514
209134.6.77.0/28134.6.77.1 to 134.6.77.14134.6.77.1514
210134.6.77.16/28134.6.77.17 to 134.6.77.30134.6.77.3114
211134.6.77.32/28134.6.77.33 to 134.6.77.46134.6.77.4714
212134.6.77.48/28134.6.77.49 to 134.6.77.62134.6.77.6314
213134.6.77.64/28134.6.77.65 to 134.6.77.78134.6.77.7914
214134.6.77.80/28134.6.77.81 to 134.6.77.94134.6.77.9514
215134.6.77.96/28134.6.77.97 to 134.6.77.110134.6.77.11114
216134.6.77.112/28134.6.77.113 to 134.6.77.126134.6.77.12714
217134.6.77.128/28134.6.77.129 to 134.6.77.142134.6.77.14314
218134.6.77.144/28134.6.77.145 to 134.6.77.158134.6.77.15914
219134.6.77.160/28134.6.77.161 to 134.6.77.174134.6.77.17514
220134.6.77.176/28134.6.77.177 to 134.6.77.190134.6.77.19114
221134.6.77.192/28134.6.77.193 to 134.6.77.206134.6.77.20714
222134.6.77.208/28134.6.77.209 to 134.6.77.222134.6.77.22314
223134.6.77.224/28134.6.77.225 to 134.6.77.238134.6.77.23914
224134.6.77.240/28134.6.77.241 to 134.6.77.254134.6.77.25514
225134.6.78.0/28134.6.78.1 to 134.6.78.14134.6.78.1514
226134.6.78.16/28134.6.78.17 to 134.6.78.30134.6.78.3114
227134.6.78.32/28134.6.78.33 to 134.6.78.46134.6.78.4714
228134.6.78.48/28134.6.78.49 to 134.6.78.62134.6.78.6314
229134.6.78.64/28134.6.78.65 to 134.6.78.78134.6.78.7914
230134.6.78.80/28134.6.78.81 to 134.6.78.94134.6.78.9514
231134.6.78.96/28134.6.78.97 to 134.6.78.110134.6.78.11114
232134.6.78.112/28134.6.78.113 to 134.6.78.126134.6.78.12714
233134.6.78.128/28134.6.78.129 to 134.6.78.142134.6.78.14314
234134.6.78.144/28134.6.78.145 to 134.6.78.158134.6.78.15914
235134.6.78.160/28134.6.78.161 to 134.6.78.174134.6.78.17514
236134.6.78.176/28134.6.78.177 to 134.6.78.190134.6.78.19114
237134.6.78.192/28134.6.78.193 to 134.6.78.206134.6.78.20714
238134.6.78.208/28134.6.78.209 to 134.6.78.222134.6.78.22314
239134.6.78.224/28134.6.78.225 to 134.6.78.238134.6.78.23914
240134.6.78.240/28134.6.78.241 to 134.6.78.254134.6.78.25514
241134.6.79.0/28134.6.79.1 to 134.6.79.14134.6.79.1514
242134.6.79.16/28134.6.79.17 to 134.6.79.30134.6.79.3114
243134.6.79.32/28134.6.79.33 to 134.6.79.46134.6.79.4714
244134.6.79.48/28134.6.79.49 to 134.6.79.62134.6.79.6314
245134.6.79.64/28134.6.79.65 to 134.6.79.78134.6.79.7914
246134.6.79.80/28134.6.79.81 to 134.6.79.94134.6.79.9514
247134.6.79.96/28134.6.79.97 to 134.6.79.110134.6.79.11114
248134.6.79.112/28134.6.79.113 to 134.6.79.126134.6.79.12714
249134.6.79.128/28134.6.79.129 to 134.6.79.142134.6.79.14314
250134.6.79.144/28134.6.79.145 to 134.6.79.158134.6.79.15914
251134.6.79.160/28134.6.79.161 to 134.6.79.174134.6.79.17514
252134.6.79.176/28134.6.79.177 to 134.6.79.190134.6.79.19114
253134.6.79.192/28134.6.79.193 to 134.6.79.206134.6.79.20714
254134.6.79.208/28134.6.79.209 to 134.6.79.222134.6.79.22314
255134.6.79.224/28134.6.79.225 to 134.6.79.238134.6.79.23914
256134.6.79.240/28134.6.79.241 to 134.6.79.254134.6.79.25514

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.