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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.

Network136.97.128.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
136.97.128.0
Broadcast address
136.97.255.255
First usable
136.97.128.1
Last usable
136.97.255.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
B (default /16)
As numbers
Hex 88618000 · Integer 2288091136 to 2288123903
Reverse DNS zones
128.97.136.in-addr.arpa
129.97.136.in-addr.arpa
130.97.136.in-addr.arpa
131.97.136.in-addr.arpa
132.97.136.in-addr.arpa
133.97.136.in-addr.arpa
134.97.136.in-addr.arpa
135.97.136.in-addr.arpa
136.97.136.in-addr.arpa
137.97.136.in-addr.arpa
138.97.136.in-addr.arpa
139.97.136.in-addr.arpa
140.97.136.in-addr.arpa
141.97.136.in-addr.arpa
142.97.136.in-addr.arpa
143.97.136.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001000.01100001.10000000.00000000136.97.128.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network10001000.01100001.10000000.00000000136.97.128.0
Broadcast10001000.01100001.11111111.11111111136.97.255.255
Split into smaller subnets/28
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

136.97.128.0/17 makes 2,048 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1136.97.128.0/28136.97.128.1 to 136.97.128.14136.97.128.1514
2136.97.128.16/28136.97.128.17 to 136.97.128.30136.97.128.3114
3136.97.128.32/28136.97.128.33 to 136.97.128.46136.97.128.4714
4136.97.128.48/28136.97.128.49 to 136.97.128.62136.97.128.6314
5136.97.128.64/28136.97.128.65 to 136.97.128.78136.97.128.7914
6136.97.128.80/28136.97.128.81 to 136.97.128.94136.97.128.9514
7136.97.128.96/28136.97.128.97 to 136.97.128.110136.97.128.11114
8136.97.128.112/28136.97.128.113 to 136.97.128.126136.97.128.12714
9136.97.128.128/28136.97.128.129 to 136.97.128.142136.97.128.14314
10136.97.128.144/28136.97.128.145 to 136.97.128.158136.97.128.15914
11136.97.128.160/28136.97.128.161 to 136.97.128.174136.97.128.17514
12136.97.128.176/28136.97.128.177 to 136.97.128.190136.97.128.19114
13136.97.128.192/28136.97.128.193 to 136.97.128.206136.97.128.20714
14136.97.128.208/28136.97.128.209 to 136.97.128.222136.97.128.22314
15136.97.128.224/28136.97.128.225 to 136.97.128.238136.97.128.23914
16136.97.128.240/28136.97.128.241 to 136.97.128.254136.97.128.25514
17136.97.129.0/28136.97.129.1 to 136.97.129.14136.97.129.1514
18136.97.129.16/28136.97.129.17 to 136.97.129.30136.97.129.3114
19136.97.129.32/28136.97.129.33 to 136.97.129.46136.97.129.4714
20136.97.129.48/28136.97.129.49 to 136.97.129.62136.97.129.6314
21136.97.129.64/28136.97.129.65 to 136.97.129.78136.97.129.7914
22136.97.129.80/28136.97.129.81 to 136.97.129.94136.97.129.9514
23136.97.129.96/28136.97.129.97 to 136.97.129.110136.97.129.11114
24136.97.129.112/28136.97.129.113 to 136.97.129.126136.97.129.12714
25136.97.129.128/28136.97.129.129 to 136.97.129.142136.97.129.14314
26136.97.129.144/28136.97.129.145 to 136.97.129.158136.97.129.15914
27136.97.129.160/28136.97.129.161 to 136.97.129.174136.97.129.17514
28136.97.129.176/28136.97.129.177 to 136.97.129.190136.97.129.19114
29136.97.129.192/28136.97.129.193 to 136.97.129.206136.97.129.20714
30136.97.129.208/28136.97.129.209 to 136.97.129.222136.97.129.22314
31136.97.129.224/28136.97.129.225 to 136.97.129.238136.97.129.23914
32136.97.129.240/28136.97.129.241 to 136.97.129.254136.97.129.25514
33136.97.130.0/28136.97.130.1 to 136.97.130.14136.97.130.1514
34136.97.130.16/28136.97.130.17 to 136.97.130.30136.97.130.3114
35136.97.130.32/28136.97.130.33 to 136.97.130.46136.97.130.4714
36136.97.130.48/28136.97.130.49 to 136.97.130.62136.97.130.6314
37136.97.130.64/28136.97.130.65 to 136.97.130.78136.97.130.7914
38136.97.130.80/28136.97.130.81 to 136.97.130.94136.97.130.9514
39136.97.130.96/28136.97.130.97 to 136.97.130.110136.97.130.11114
40136.97.130.112/28136.97.130.113 to 136.97.130.126136.97.130.12714
41136.97.130.128/28136.97.130.129 to 136.97.130.142136.97.130.14314
42136.97.130.144/28136.97.130.145 to 136.97.130.158136.97.130.15914
43136.97.130.160/28136.97.130.161 to 136.97.130.174136.97.130.17514
44136.97.130.176/28136.97.130.177 to 136.97.130.190136.97.130.19114
45136.97.130.192/28136.97.130.193 to 136.97.130.206136.97.130.20714
46136.97.130.208/28136.97.130.209 to 136.97.130.222136.97.130.22314
47136.97.130.224/28136.97.130.225 to 136.97.130.238136.97.130.23914
48136.97.130.240/28136.97.130.241 to 136.97.130.254136.97.130.25514
49136.97.131.0/28136.97.131.1 to 136.97.131.14136.97.131.1514
50136.97.131.16/28136.97.131.17 to 136.97.131.30136.97.131.3114
51136.97.131.32/28136.97.131.33 to 136.97.131.46136.97.131.4714
52136.97.131.48/28136.97.131.49 to 136.97.131.62136.97.131.6314
53136.97.131.64/28136.97.131.65 to 136.97.131.78136.97.131.7914
54136.97.131.80/28136.97.131.81 to 136.97.131.94136.97.131.9514
55136.97.131.96/28136.97.131.97 to 136.97.131.110136.97.131.11114
56136.97.131.112/28136.97.131.113 to 136.97.131.126136.97.131.12714
57136.97.131.128/28136.97.131.129 to 136.97.131.142136.97.131.14314
58136.97.131.144/28136.97.131.145 to 136.97.131.158136.97.131.15914
59136.97.131.160/28136.97.131.161 to 136.97.131.174136.97.131.17514
60136.97.131.176/28136.97.131.177 to 136.97.131.190136.97.131.19114
61136.97.131.192/28136.97.131.193 to 136.97.131.206136.97.131.20714
62136.97.131.208/28136.97.131.209 to 136.97.131.222136.97.131.22314
63136.97.131.224/28136.97.131.225 to 136.97.131.238136.97.131.23914
64136.97.131.240/28136.97.131.241 to 136.97.131.254136.97.131.25514
65136.97.132.0/28136.97.132.1 to 136.97.132.14136.97.132.1514
66136.97.132.16/28136.97.132.17 to 136.97.132.30136.97.132.3114
67136.97.132.32/28136.97.132.33 to 136.97.132.46136.97.132.4714
68136.97.132.48/28136.97.132.49 to 136.97.132.62136.97.132.6314
69136.97.132.64/28136.97.132.65 to 136.97.132.78136.97.132.7914
70136.97.132.80/28136.97.132.81 to 136.97.132.94136.97.132.9514
71136.97.132.96/28136.97.132.97 to 136.97.132.110136.97.132.11114
72136.97.132.112/28136.97.132.113 to 136.97.132.126136.97.132.12714
73136.97.132.128/28136.97.132.129 to 136.97.132.142136.97.132.14314
74136.97.132.144/28136.97.132.145 to 136.97.132.158136.97.132.15914
75136.97.132.160/28136.97.132.161 to 136.97.132.174136.97.132.17514
76136.97.132.176/28136.97.132.177 to 136.97.132.190136.97.132.19114
77136.97.132.192/28136.97.132.193 to 136.97.132.206136.97.132.20714
78136.97.132.208/28136.97.132.209 to 136.97.132.222136.97.132.22314
79136.97.132.224/28136.97.132.225 to 136.97.132.238136.97.132.23914
80136.97.132.240/28136.97.132.241 to 136.97.132.254136.97.132.25514
81136.97.133.0/28136.97.133.1 to 136.97.133.14136.97.133.1514
82136.97.133.16/28136.97.133.17 to 136.97.133.30136.97.133.3114
83136.97.133.32/28136.97.133.33 to 136.97.133.46136.97.133.4714
84136.97.133.48/28136.97.133.49 to 136.97.133.62136.97.133.6314
85136.97.133.64/28136.97.133.65 to 136.97.133.78136.97.133.7914
86136.97.133.80/28136.97.133.81 to 136.97.133.94136.97.133.9514
87136.97.133.96/28136.97.133.97 to 136.97.133.110136.97.133.11114
88136.97.133.112/28136.97.133.113 to 136.97.133.126136.97.133.12714
89136.97.133.128/28136.97.133.129 to 136.97.133.142136.97.133.14314
90136.97.133.144/28136.97.133.145 to 136.97.133.158136.97.133.15914
91136.97.133.160/28136.97.133.161 to 136.97.133.174136.97.133.17514
92136.97.133.176/28136.97.133.177 to 136.97.133.190136.97.133.19114
93136.97.133.192/28136.97.133.193 to 136.97.133.206136.97.133.20714
94136.97.133.208/28136.97.133.209 to 136.97.133.222136.97.133.22314
95136.97.133.224/28136.97.133.225 to 136.97.133.238136.97.133.23914
96136.97.133.240/28136.97.133.241 to 136.97.133.254136.97.133.25514
97136.97.134.0/28136.97.134.1 to 136.97.134.14136.97.134.1514
98136.97.134.16/28136.97.134.17 to 136.97.134.30136.97.134.3114
99136.97.134.32/28136.97.134.33 to 136.97.134.46136.97.134.4714
100136.97.134.48/28136.97.134.49 to 136.97.134.62136.97.134.6314
101136.97.134.64/28136.97.134.65 to 136.97.134.78136.97.134.7914
102136.97.134.80/28136.97.134.81 to 136.97.134.94136.97.134.9514
103136.97.134.96/28136.97.134.97 to 136.97.134.110136.97.134.11114
104136.97.134.112/28136.97.134.113 to 136.97.134.126136.97.134.12714
105136.97.134.128/28136.97.134.129 to 136.97.134.142136.97.134.14314
106136.97.134.144/28136.97.134.145 to 136.97.134.158136.97.134.15914
107136.97.134.160/28136.97.134.161 to 136.97.134.174136.97.134.17514
108136.97.134.176/28136.97.134.177 to 136.97.134.190136.97.134.19114
109136.97.134.192/28136.97.134.193 to 136.97.134.206136.97.134.20714
110136.97.134.208/28136.97.134.209 to 136.97.134.222136.97.134.22314
111136.97.134.224/28136.97.134.225 to 136.97.134.238136.97.134.23914
112136.97.134.240/28136.97.134.241 to 136.97.134.254136.97.134.25514
113136.97.135.0/28136.97.135.1 to 136.97.135.14136.97.135.1514
114136.97.135.16/28136.97.135.17 to 136.97.135.30136.97.135.3114
115136.97.135.32/28136.97.135.33 to 136.97.135.46136.97.135.4714
116136.97.135.48/28136.97.135.49 to 136.97.135.62136.97.135.6314
117136.97.135.64/28136.97.135.65 to 136.97.135.78136.97.135.7914
118136.97.135.80/28136.97.135.81 to 136.97.135.94136.97.135.9514
119136.97.135.96/28136.97.135.97 to 136.97.135.110136.97.135.11114
120136.97.135.112/28136.97.135.113 to 136.97.135.126136.97.135.12714
121136.97.135.128/28136.97.135.129 to 136.97.135.142136.97.135.14314
122136.97.135.144/28136.97.135.145 to 136.97.135.158136.97.135.15914
123136.97.135.160/28136.97.135.161 to 136.97.135.174136.97.135.17514
124136.97.135.176/28136.97.135.177 to 136.97.135.190136.97.135.19114
125136.97.135.192/28136.97.135.193 to 136.97.135.206136.97.135.20714
126136.97.135.208/28136.97.135.209 to 136.97.135.222136.97.135.22314
127136.97.135.224/28136.97.135.225 to 136.97.135.238136.97.135.23914
128136.97.135.240/28136.97.135.241 to 136.97.135.254136.97.135.25514
129136.97.136.0/28136.97.136.1 to 136.97.136.14136.97.136.1514
130136.97.136.16/28136.97.136.17 to 136.97.136.30136.97.136.3114
131136.97.136.32/28136.97.136.33 to 136.97.136.46136.97.136.4714
132136.97.136.48/28136.97.136.49 to 136.97.136.62136.97.136.6314
133136.97.136.64/28136.97.136.65 to 136.97.136.78136.97.136.7914
134136.97.136.80/28136.97.136.81 to 136.97.136.94136.97.136.9514
135136.97.136.96/28136.97.136.97 to 136.97.136.110136.97.136.11114
136136.97.136.112/28136.97.136.113 to 136.97.136.126136.97.136.12714
137136.97.136.128/28136.97.136.129 to 136.97.136.142136.97.136.14314
138136.97.136.144/28136.97.136.145 to 136.97.136.158136.97.136.15914
139136.97.136.160/28136.97.136.161 to 136.97.136.174136.97.136.17514
140136.97.136.176/28136.97.136.177 to 136.97.136.190136.97.136.19114
141136.97.136.192/28136.97.136.193 to 136.97.136.206136.97.136.20714
142136.97.136.208/28136.97.136.209 to 136.97.136.222136.97.136.22314
143136.97.136.224/28136.97.136.225 to 136.97.136.238136.97.136.23914
144136.97.136.240/28136.97.136.241 to 136.97.136.254136.97.136.25514
145136.97.137.0/28136.97.137.1 to 136.97.137.14136.97.137.1514
146136.97.137.16/28136.97.137.17 to 136.97.137.30136.97.137.3114
147136.97.137.32/28136.97.137.33 to 136.97.137.46136.97.137.4714
148136.97.137.48/28136.97.137.49 to 136.97.137.62136.97.137.6314
149136.97.137.64/28136.97.137.65 to 136.97.137.78136.97.137.7914
150136.97.137.80/28136.97.137.81 to 136.97.137.94136.97.137.9514
151136.97.137.96/28136.97.137.97 to 136.97.137.110136.97.137.11114
152136.97.137.112/28136.97.137.113 to 136.97.137.126136.97.137.12714
153136.97.137.128/28136.97.137.129 to 136.97.137.142136.97.137.14314
154136.97.137.144/28136.97.137.145 to 136.97.137.158136.97.137.15914
155136.97.137.160/28136.97.137.161 to 136.97.137.174136.97.137.17514
156136.97.137.176/28136.97.137.177 to 136.97.137.190136.97.137.19114
157136.97.137.192/28136.97.137.193 to 136.97.137.206136.97.137.20714
158136.97.137.208/28136.97.137.209 to 136.97.137.222136.97.137.22314
159136.97.137.224/28136.97.137.225 to 136.97.137.238136.97.137.23914
160136.97.137.240/28136.97.137.241 to 136.97.137.254136.97.137.25514
161136.97.138.0/28136.97.138.1 to 136.97.138.14136.97.138.1514
162136.97.138.16/28136.97.138.17 to 136.97.138.30136.97.138.3114
163136.97.138.32/28136.97.138.33 to 136.97.138.46136.97.138.4714
164136.97.138.48/28136.97.138.49 to 136.97.138.62136.97.138.6314
165136.97.138.64/28136.97.138.65 to 136.97.138.78136.97.138.7914
166136.97.138.80/28136.97.138.81 to 136.97.138.94136.97.138.9514
167136.97.138.96/28136.97.138.97 to 136.97.138.110136.97.138.11114
168136.97.138.112/28136.97.138.113 to 136.97.138.126136.97.138.12714
169136.97.138.128/28136.97.138.129 to 136.97.138.142136.97.138.14314
170136.97.138.144/28136.97.138.145 to 136.97.138.158136.97.138.15914
171136.97.138.160/28136.97.138.161 to 136.97.138.174136.97.138.17514
172136.97.138.176/28136.97.138.177 to 136.97.138.190136.97.138.19114
173136.97.138.192/28136.97.138.193 to 136.97.138.206136.97.138.20714
174136.97.138.208/28136.97.138.209 to 136.97.138.222136.97.138.22314
175136.97.138.224/28136.97.138.225 to 136.97.138.238136.97.138.23914
176136.97.138.240/28136.97.138.241 to 136.97.138.254136.97.138.25514
177136.97.139.0/28136.97.139.1 to 136.97.139.14136.97.139.1514
178136.97.139.16/28136.97.139.17 to 136.97.139.30136.97.139.3114
179136.97.139.32/28136.97.139.33 to 136.97.139.46136.97.139.4714
180136.97.139.48/28136.97.139.49 to 136.97.139.62136.97.139.6314
181136.97.139.64/28136.97.139.65 to 136.97.139.78136.97.139.7914
182136.97.139.80/28136.97.139.81 to 136.97.139.94136.97.139.9514
183136.97.139.96/28136.97.139.97 to 136.97.139.110136.97.139.11114
184136.97.139.112/28136.97.139.113 to 136.97.139.126136.97.139.12714
185136.97.139.128/28136.97.139.129 to 136.97.139.142136.97.139.14314
186136.97.139.144/28136.97.139.145 to 136.97.139.158136.97.139.15914
187136.97.139.160/28136.97.139.161 to 136.97.139.174136.97.139.17514
188136.97.139.176/28136.97.139.177 to 136.97.139.190136.97.139.19114
189136.97.139.192/28136.97.139.193 to 136.97.139.206136.97.139.20714
190136.97.139.208/28136.97.139.209 to 136.97.139.222136.97.139.22314
191136.97.139.224/28136.97.139.225 to 136.97.139.238136.97.139.23914
192136.97.139.240/28136.97.139.241 to 136.97.139.254136.97.139.25514
193136.97.140.0/28136.97.140.1 to 136.97.140.14136.97.140.1514
194136.97.140.16/28136.97.140.17 to 136.97.140.30136.97.140.3114
195136.97.140.32/28136.97.140.33 to 136.97.140.46136.97.140.4714
196136.97.140.48/28136.97.140.49 to 136.97.140.62136.97.140.6314
197136.97.140.64/28136.97.140.65 to 136.97.140.78136.97.140.7914
198136.97.140.80/28136.97.140.81 to 136.97.140.94136.97.140.9514
199136.97.140.96/28136.97.140.97 to 136.97.140.110136.97.140.11114
200136.97.140.112/28136.97.140.113 to 136.97.140.126136.97.140.12714
201136.97.140.128/28136.97.140.129 to 136.97.140.142136.97.140.14314
202136.97.140.144/28136.97.140.145 to 136.97.140.158136.97.140.15914
203136.97.140.160/28136.97.140.161 to 136.97.140.174136.97.140.17514
204136.97.140.176/28136.97.140.177 to 136.97.140.190136.97.140.19114
205136.97.140.192/28136.97.140.193 to 136.97.140.206136.97.140.20714
206136.97.140.208/28136.97.140.209 to 136.97.140.222136.97.140.22314
207136.97.140.224/28136.97.140.225 to 136.97.140.238136.97.140.23914
208136.97.140.240/28136.97.140.241 to 136.97.140.254136.97.140.25514
209136.97.141.0/28136.97.141.1 to 136.97.141.14136.97.141.1514
210136.97.141.16/28136.97.141.17 to 136.97.141.30136.97.141.3114
211136.97.141.32/28136.97.141.33 to 136.97.141.46136.97.141.4714
212136.97.141.48/28136.97.141.49 to 136.97.141.62136.97.141.6314
213136.97.141.64/28136.97.141.65 to 136.97.141.78136.97.141.7914
214136.97.141.80/28136.97.141.81 to 136.97.141.94136.97.141.9514
215136.97.141.96/28136.97.141.97 to 136.97.141.110136.97.141.11114
216136.97.141.112/28136.97.141.113 to 136.97.141.126136.97.141.12714
217136.97.141.128/28136.97.141.129 to 136.97.141.142136.97.141.14314
218136.97.141.144/28136.97.141.145 to 136.97.141.158136.97.141.15914
219136.97.141.160/28136.97.141.161 to 136.97.141.174136.97.141.17514
220136.97.141.176/28136.97.141.177 to 136.97.141.190136.97.141.19114
221136.97.141.192/28136.97.141.193 to 136.97.141.206136.97.141.20714
222136.97.141.208/28136.97.141.209 to 136.97.141.222136.97.141.22314
223136.97.141.224/28136.97.141.225 to 136.97.141.238136.97.141.23914
224136.97.141.240/28136.97.141.241 to 136.97.141.254136.97.141.25514
225136.97.142.0/28136.97.142.1 to 136.97.142.14136.97.142.1514
226136.97.142.16/28136.97.142.17 to 136.97.142.30136.97.142.3114
227136.97.142.32/28136.97.142.33 to 136.97.142.46136.97.142.4714
228136.97.142.48/28136.97.142.49 to 136.97.142.62136.97.142.6314
229136.97.142.64/28136.97.142.65 to 136.97.142.78136.97.142.7914
230136.97.142.80/28136.97.142.81 to 136.97.142.94136.97.142.9514
231136.97.142.96/28136.97.142.97 to 136.97.142.110136.97.142.11114
232136.97.142.112/28136.97.142.113 to 136.97.142.126136.97.142.12714
233136.97.142.128/28136.97.142.129 to 136.97.142.142136.97.142.14314
234136.97.142.144/28136.97.142.145 to 136.97.142.158136.97.142.15914
235136.97.142.160/28136.97.142.161 to 136.97.142.174136.97.142.17514
236136.97.142.176/28136.97.142.177 to 136.97.142.190136.97.142.19114
237136.97.142.192/28136.97.142.193 to 136.97.142.206136.97.142.20714
238136.97.142.208/28136.97.142.209 to 136.97.142.222136.97.142.22314
239136.97.142.224/28136.97.142.225 to 136.97.142.238136.97.142.23914
240136.97.142.240/28136.97.142.241 to 136.97.142.254136.97.142.25514
241136.97.143.0/28136.97.143.1 to 136.97.143.14136.97.143.1514
242136.97.143.16/28136.97.143.17 to 136.97.143.30136.97.143.3114
243136.97.143.32/28136.97.143.33 to 136.97.143.46136.97.143.4714
244136.97.143.48/28136.97.143.49 to 136.97.143.62136.97.143.6314
245136.97.143.64/28136.97.143.65 to 136.97.143.78136.97.143.7914
246136.97.143.80/28136.97.143.81 to 136.97.143.94136.97.143.9514
247136.97.143.96/28136.97.143.97 to 136.97.143.110136.97.143.11114
248136.97.143.112/28136.97.143.113 to 136.97.143.126136.97.143.12714
249136.97.143.128/28136.97.143.129 to 136.97.143.142136.97.143.14314
250136.97.143.144/28136.97.143.145 to 136.97.143.158136.97.143.15914
251136.97.143.160/28136.97.143.161 to 136.97.143.174136.97.143.17514
252136.97.143.176/28136.97.143.177 to 136.97.143.190136.97.143.19114
253136.97.143.192/28136.97.143.193 to 136.97.143.206136.97.143.20714
254136.97.143.208/28136.97.143.209 to 136.97.143.222136.97.143.22314
255136.97.143.224/28136.97.143.225 to 136.97.143.238136.97.143.23914
256136.97.143.240/28136.97.143.241 to 136.97.143.254136.97.143.25514

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.