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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.

Network136.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
136.0.0.0
Broadcast address
136.255.255.255
First usable
136.0.0.1
Last usable
136.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
B (default /16)
As numbers
Hex 88000000 · Integer 2281701376 to 2298478591
Reverse DNS zone
136.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001000..00000000.00000000.00000000136.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10001000..00000000.00000000.00000000136.0.0.0
Broadcast10001000..11111111.11111111.11111111136.255.255.255
Split into smaller subnets/18
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

136.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1136.0.0.0/18136.0.0.1 to 136.0.63.254136.0.63.25516,382
2136.0.64.0/18136.0.64.1 to 136.0.127.254136.0.127.25516,382
3136.0.128.0/18136.0.128.1 to 136.0.191.254136.0.191.25516,382
4136.0.192.0/18136.0.192.1 to 136.0.255.254136.0.255.25516,382
5136.1.0.0/18136.1.0.1 to 136.1.63.254136.1.63.25516,382
6136.1.64.0/18136.1.64.1 to 136.1.127.254136.1.127.25516,382
7136.1.128.0/18136.1.128.1 to 136.1.191.254136.1.191.25516,382
8136.1.192.0/18136.1.192.1 to 136.1.255.254136.1.255.25516,382
9136.2.0.0/18136.2.0.1 to 136.2.63.254136.2.63.25516,382
10136.2.64.0/18136.2.64.1 to 136.2.127.254136.2.127.25516,382
11136.2.128.0/18136.2.128.1 to 136.2.191.254136.2.191.25516,382
12136.2.192.0/18136.2.192.1 to 136.2.255.254136.2.255.25516,382
13136.3.0.0/18136.3.0.1 to 136.3.63.254136.3.63.25516,382
14136.3.64.0/18136.3.64.1 to 136.3.127.254136.3.127.25516,382
15136.3.128.0/18136.3.128.1 to 136.3.191.254136.3.191.25516,382
16136.3.192.0/18136.3.192.1 to 136.3.255.254136.3.255.25516,382
17136.4.0.0/18136.4.0.1 to 136.4.63.254136.4.63.25516,382
18136.4.64.0/18136.4.64.1 to 136.4.127.254136.4.127.25516,382
19136.4.128.0/18136.4.128.1 to 136.4.191.254136.4.191.25516,382
20136.4.192.0/18136.4.192.1 to 136.4.255.254136.4.255.25516,382
21136.5.0.0/18136.5.0.1 to 136.5.63.254136.5.63.25516,382
22136.5.64.0/18136.5.64.1 to 136.5.127.254136.5.127.25516,382
23136.5.128.0/18136.5.128.1 to 136.5.191.254136.5.191.25516,382
24136.5.192.0/18136.5.192.1 to 136.5.255.254136.5.255.25516,382
25136.6.0.0/18136.6.0.1 to 136.6.63.254136.6.63.25516,382
26136.6.64.0/18136.6.64.1 to 136.6.127.254136.6.127.25516,382
27136.6.128.0/18136.6.128.1 to 136.6.191.254136.6.191.25516,382
28136.6.192.0/18136.6.192.1 to 136.6.255.254136.6.255.25516,382
29136.7.0.0/18136.7.0.1 to 136.7.63.254136.7.63.25516,382
30136.7.64.0/18136.7.64.1 to 136.7.127.254136.7.127.25516,382
31136.7.128.0/18136.7.128.1 to 136.7.191.254136.7.191.25516,382
32136.7.192.0/18136.7.192.1 to 136.7.255.254136.7.255.25516,382
33136.8.0.0/18136.8.0.1 to 136.8.63.254136.8.63.25516,382
34136.8.64.0/18136.8.64.1 to 136.8.127.254136.8.127.25516,382
35136.8.128.0/18136.8.128.1 to 136.8.191.254136.8.191.25516,382
36136.8.192.0/18136.8.192.1 to 136.8.255.254136.8.255.25516,382
37136.9.0.0/18136.9.0.1 to 136.9.63.254136.9.63.25516,382
38136.9.64.0/18136.9.64.1 to 136.9.127.254136.9.127.25516,382
39136.9.128.0/18136.9.128.1 to 136.9.191.254136.9.191.25516,382
40136.9.192.0/18136.9.192.1 to 136.9.255.254136.9.255.25516,382
41136.10.0.0/18136.10.0.1 to 136.10.63.254136.10.63.25516,382
42136.10.64.0/18136.10.64.1 to 136.10.127.254136.10.127.25516,382
43136.10.128.0/18136.10.128.1 to 136.10.191.254136.10.191.25516,382
44136.10.192.0/18136.10.192.1 to 136.10.255.254136.10.255.25516,382
45136.11.0.0/18136.11.0.1 to 136.11.63.254136.11.63.25516,382
46136.11.64.0/18136.11.64.1 to 136.11.127.254136.11.127.25516,382
47136.11.128.0/18136.11.128.1 to 136.11.191.254136.11.191.25516,382
48136.11.192.0/18136.11.192.1 to 136.11.255.254136.11.255.25516,382
49136.12.0.0/18136.12.0.1 to 136.12.63.254136.12.63.25516,382
50136.12.64.0/18136.12.64.1 to 136.12.127.254136.12.127.25516,382
51136.12.128.0/18136.12.128.1 to 136.12.191.254136.12.191.25516,382
52136.12.192.0/18136.12.192.1 to 136.12.255.254136.12.255.25516,382
53136.13.0.0/18136.13.0.1 to 136.13.63.254136.13.63.25516,382
54136.13.64.0/18136.13.64.1 to 136.13.127.254136.13.127.25516,382
55136.13.128.0/18136.13.128.1 to 136.13.191.254136.13.191.25516,382
56136.13.192.0/18136.13.192.1 to 136.13.255.254136.13.255.25516,382
57136.14.0.0/18136.14.0.1 to 136.14.63.254136.14.63.25516,382
58136.14.64.0/18136.14.64.1 to 136.14.127.254136.14.127.25516,382
59136.14.128.0/18136.14.128.1 to 136.14.191.254136.14.191.25516,382
60136.14.192.0/18136.14.192.1 to 136.14.255.254136.14.255.25516,382
61136.15.0.0/18136.15.0.1 to 136.15.63.254136.15.63.25516,382
62136.15.64.0/18136.15.64.1 to 136.15.127.254136.15.127.25516,382
63136.15.128.0/18136.15.128.1 to 136.15.191.254136.15.191.25516,382
64136.15.192.0/18136.15.192.1 to 136.15.255.254136.15.255.25516,382
65136.16.0.0/18136.16.0.1 to 136.16.63.254136.16.63.25516,382
66136.16.64.0/18136.16.64.1 to 136.16.127.254136.16.127.25516,382
67136.16.128.0/18136.16.128.1 to 136.16.191.254136.16.191.25516,382
68136.16.192.0/18136.16.192.1 to 136.16.255.254136.16.255.25516,382
69136.17.0.0/18136.17.0.1 to 136.17.63.254136.17.63.25516,382
70136.17.64.0/18136.17.64.1 to 136.17.127.254136.17.127.25516,382
71136.17.128.0/18136.17.128.1 to 136.17.191.254136.17.191.25516,382
72136.17.192.0/18136.17.192.1 to 136.17.255.254136.17.255.25516,382
73136.18.0.0/18136.18.0.1 to 136.18.63.254136.18.63.25516,382
74136.18.64.0/18136.18.64.1 to 136.18.127.254136.18.127.25516,382
75136.18.128.0/18136.18.128.1 to 136.18.191.254136.18.191.25516,382
76136.18.192.0/18136.18.192.1 to 136.18.255.254136.18.255.25516,382
77136.19.0.0/18136.19.0.1 to 136.19.63.254136.19.63.25516,382
78136.19.64.0/18136.19.64.1 to 136.19.127.254136.19.127.25516,382
79136.19.128.0/18136.19.128.1 to 136.19.191.254136.19.191.25516,382
80136.19.192.0/18136.19.192.1 to 136.19.255.254136.19.255.25516,382
81136.20.0.0/18136.20.0.1 to 136.20.63.254136.20.63.25516,382
82136.20.64.0/18136.20.64.1 to 136.20.127.254136.20.127.25516,382
83136.20.128.0/18136.20.128.1 to 136.20.191.254136.20.191.25516,382
84136.20.192.0/18136.20.192.1 to 136.20.255.254136.20.255.25516,382
85136.21.0.0/18136.21.0.1 to 136.21.63.254136.21.63.25516,382
86136.21.64.0/18136.21.64.1 to 136.21.127.254136.21.127.25516,382
87136.21.128.0/18136.21.128.1 to 136.21.191.254136.21.191.25516,382
88136.21.192.0/18136.21.192.1 to 136.21.255.254136.21.255.25516,382
89136.22.0.0/18136.22.0.1 to 136.22.63.254136.22.63.25516,382
90136.22.64.0/18136.22.64.1 to 136.22.127.254136.22.127.25516,382
91136.22.128.0/18136.22.128.1 to 136.22.191.254136.22.191.25516,382
92136.22.192.0/18136.22.192.1 to 136.22.255.254136.22.255.25516,382
93136.23.0.0/18136.23.0.1 to 136.23.63.254136.23.63.25516,382
94136.23.64.0/18136.23.64.1 to 136.23.127.254136.23.127.25516,382
95136.23.128.0/18136.23.128.1 to 136.23.191.254136.23.191.25516,382
96136.23.192.0/18136.23.192.1 to 136.23.255.254136.23.255.25516,382
97136.24.0.0/18136.24.0.1 to 136.24.63.254136.24.63.25516,382
98136.24.64.0/18136.24.64.1 to 136.24.127.254136.24.127.25516,382
99136.24.128.0/18136.24.128.1 to 136.24.191.254136.24.191.25516,382
100136.24.192.0/18136.24.192.1 to 136.24.255.254136.24.255.25516,382
101136.25.0.0/18136.25.0.1 to 136.25.63.254136.25.63.25516,382
102136.25.64.0/18136.25.64.1 to 136.25.127.254136.25.127.25516,382
103136.25.128.0/18136.25.128.1 to 136.25.191.254136.25.191.25516,382
104136.25.192.0/18136.25.192.1 to 136.25.255.254136.25.255.25516,382
105136.26.0.0/18136.26.0.1 to 136.26.63.254136.26.63.25516,382
106136.26.64.0/18136.26.64.1 to 136.26.127.254136.26.127.25516,382
107136.26.128.0/18136.26.128.1 to 136.26.191.254136.26.191.25516,382
108136.26.192.0/18136.26.192.1 to 136.26.255.254136.26.255.25516,382
109136.27.0.0/18136.27.0.1 to 136.27.63.254136.27.63.25516,382
110136.27.64.0/18136.27.64.1 to 136.27.127.254136.27.127.25516,382
111136.27.128.0/18136.27.128.1 to 136.27.191.254136.27.191.25516,382
112136.27.192.0/18136.27.192.1 to 136.27.255.254136.27.255.25516,382
113136.28.0.0/18136.28.0.1 to 136.28.63.254136.28.63.25516,382
114136.28.64.0/18136.28.64.1 to 136.28.127.254136.28.127.25516,382
115136.28.128.0/18136.28.128.1 to 136.28.191.254136.28.191.25516,382
116136.28.192.0/18136.28.192.1 to 136.28.255.254136.28.255.25516,382
117136.29.0.0/18136.29.0.1 to 136.29.63.254136.29.63.25516,382
118136.29.64.0/18136.29.64.1 to 136.29.127.254136.29.127.25516,382
119136.29.128.0/18136.29.128.1 to 136.29.191.254136.29.191.25516,382
120136.29.192.0/18136.29.192.1 to 136.29.255.254136.29.255.25516,382
121136.30.0.0/18136.30.0.1 to 136.30.63.254136.30.63.25516,382
122136.30.64.0/18136.30.64.1 to 136.30.127.254136.30.127.25516,382
123136.30.128.0/18136.30.128.1 to 136.30.191.254136.30.191.25516,382
124136.30.192.0/18136.30.192.1 to 136.30.255.254136.30.255.25516,382
125136.31.0.0/18136.31.0.1 to 136.31.63.254136.31.63.25516,382
126136.31.64.0/18136.31.64.1 to 136.31.127.254136.31.127.25516,382
127136.31.128.0/18136.31.128.1 to 136.31.191.254136.31.191.25516,382
128136.31.192.0/18136.31.192.1 to 136.31.255.254136.31.255.25516,382
129136.32.0.0/18136.32.0.1 to 136.32.63.254136.32.63.25516,382
130136.32.64.0/18136.32.64.1 to 136.32.127.254136.32.127.25516,382
131136.32.128.0/18136.32.128.1 to 136.32.191.254136.32.191.25516,382
132136.32.192.0/18136.32.192.1 to 136.32.255.254136.32.255.25516,382
133136.33.0.0/18136.33.0.1 to 136.33.63.254136.33.63.25516,382
134136.33.64.0/18136.33.64.1 to 136.33.127.254136.33.127.25516,382
135136.33.128.0/18136.33.128.1 to 136.33.191.254136.33.191.25516,382
136136.33.192.0/18136.33.192.1 to 136.33.255.254136.33.255.25516,382
137136.34.0.0/18136.34.0.1 to 136.34.63.254136.34.63.25516,382
138136.34.64.0/18136.34.64.1 to 136.34.127.254136.34.127.25516,382
139136.34.128.0/18136.34.128.1 to 136.34.191.254136.34.191.25516,382
140136.34.192.0/18136.34.192.1 to 136.34.255.254136.34.255.25516,382
141136.35.0.0/18136.35.0.1 to 136.35.63.254136.35.63.25516,382
142136.35.64.0/18136.35.64.1 to 136.35.127.254136.35.127.25516,382
143136.35.128.0/18136.35.128.1 to 136.35.191.254136.35.191.25516,382
144136.35.192.0/18136.35.192.1 to 136.35.255.254136.35.255.25516,382
145136.36.0.0/18136.36.0.1 to 136.36.63.254136.36.63.25516,382
146136.36.64.0/18136.36.64.1 to 136.36.127.254136.36.127.25516,382
147136.36.128.0/18136.36.128.1 to 136.36.191.254136.36.191.25516,382
148136.36.192.0/18136.36.192.1 to 136.36.255.254136.36.255.25516,382
149136.37.0.0/18136.37.0.1 to 136.37.63.254136.37.63.25516,382
150136.37.64.0/18136.37.64.1 to 136.37.127.254136.37.127.25516,382
151136.37.128.0/18136.37.128.1 to 136.37.191.254136.37.191.25516,382
152136.37.192.0/18136.37.192.1 to 136.37.255.254136.37.255.25516,382
153136.38.0.0/18136.38.0.1 to 136.38.63.254136.38.63.25516,382
154136.38.64.0/18136.38.64.1 to 136.38.127.254136.38.127.25516,382
155136.38.128.0/18136.38.128.1 to 136.38.191.254136.38.191.25516,382
156136.38.192.0/18136.38.192.1 to 136.38.255.254136.38.255.25516,382
157136.39.0.0/18136.39.0.1 to 136.39.63.254136.39.63.25516,382
158136.39.64.0/18136.39.64.1 to 136.39.127.254136.39.127.25516,382
159136.39.128.0/18136.39.128.1 to 136.39.191.254136.39.191.25516,382
160136.39.192.0/18136.39.192.1 to 136.39.255.254136.39.255.25516,382
161136.40.0.0/18136.40.0.1 to 136.40.63.254136.40.63.25516,382
162136.40.64.0/18136.40.64.1 to 136.40.127.254136.40.127.25516,382
163136.40.128.0/18136.40.128.1 to 136.40.191.254136.40.191.25516,382
164136.40.192.0/18136.40.192.1 to 136.40.255.254136.40.255.25516,382
165136.41.0.0/18136.41.0.1 to 136.41.63.254136.41.63.25516,382
166136.41.64.0/18136.41.64.1 to 136.41.127.254136.41.127.25516,382
167136.41.128.0/18136.41.128.1 to 136.41.191.254136.41.191.25516,382
168136.41.192.0/18136.41.192.1 to 136.41.255.254136.41.255.25516,382
169136.42.0.0/18136.42.0.1 to 136.42.63.254136.42.63.25516,382
170136.42.64.0/18136.42.64.1 to 136.42.127.254136.42.127.25516,382
171136.42.128.0/18136.42.128.1 to 136.42.191.254136.42.191.25516,382
172136.42.192.0/18136.42.192.1 to 136.42.255.254136.42.255.25516,382
173136.43.0.0/18136.43.0.1 to 136.43.63.254136.43.63.25516,382
174136.43.64.0/18136.43.64.1 to 136.43.127.254136.43.127.25516,382
175136.43.128.0/18136.43.128.1 to 136.43.191.254136.43.191.25516,382
176136.43.192.0/18136.43.192.1 to 136.43.255.254136.43.255.25516,382
177136.44.0.0/18136.44.0.1 to 136.44.63.254136.44.63.25516,382
178136.44.64.0/18136.44.64.1 to 136.44.127.254136.44.127.25516,382
179136.44.128.0/18136.44.128.1 to 136.44.191.254136.44.191.25516,382
180136.44.192.0/18136.44.192.1 to 136.44.255.254136.44.255.25516,382
181136.45.0.0/18136.45.0.1 to 136.45.63.254136.45.63.25516,382
182136.45.64.0/18136.45.64.1 to 136.45.127.254136.45.127.25516,382
183136.45.128.0/18136.45.128.1 to 136.45.191.254136.45.191.25516,382
184136.45.192.0/18136.45.192.1 to 136.45.255.254136.45.255.25516,382
185136.46.0.0/18136.46.0.1 to 136.46.63.254136.46.63.25516,382
186136.46.64.0/18136.46.64.1 to 136.46.127.254136.46.127.25516,382
187136.46.128.0/18136.46.128.1 to 136.46.191.254136.46.191.25516,382
188136.46.192.0/18136.46.192.1 to 136.46.255.254136.46.255.25516,382
189136.47.0.0/18136.47.0.1 to 136.47.63.254136.47.63.25516,382
190136.47.64.0/18136.47.64.1 to 136.47.127.254136.47.127.25516,382
191136.47.128.0/18136.47.128.1 to 136.47.191.254136.47.191.25516,382
192136.47.192.0/18136.47.192.1 to 136.47.255.254136.47.255.25516,382
193136.48.0.0/18136.48.0.1 to 136.48.63.254136.48.63.25516,382
194136.48.64.0/18136.48.64.1 to 136.48.127.254136.48.127.25516,382
195136.48.128.0/18136.48.128.1 to 136.48.191.254136.48.191.25516,382
196136.48.192.0/18136.48.192.1 to 136.48.255.254136.48.255.25516,382
197136.49.0.0/18136.49.0.1 to 136.49.63.254136.49.63.25516,382
198136.49.64.0/18136.49.64.1 to 136.49.127.254136.49.127.25516,382
199136.49.128.0/18136.49.128.1 to 136.49.191.254136.49.191.25516,382
200136.49.192.0/18136.49.192.1 to 136.49.255.254136.49.255.25516,382
201136.50.0.0/18136.50.0.1 to 136.50.63.254136.50.63.25516,382
202136.50.64.0/18136.50.64.1 to 136.50.127.254136.50.127.25516,382
203136.50.128.0/18136.50.128.1 to 136.50.191.254136.50.191.25516,382
204136.50.192.0/18136.50.192.1 to 136.50.255.254136.50.255.25516,382
205136.51.0.0/18136.51.0.1 to 136.51.63.254136.51.63.25516,382
206136.51.64.0/18136.51.64.1 to 136.51.127.254136.51.127.25516,382
207136.51.128.0/18136.51.128.1 to 136.51.191.254136.51.191.25516,382
208136.51.192.0/18136.51.192.1 to 136.51.255.254136.51.255.25516,382
209136.52.0.0/18136.52.0.1 to 136.52.63.254136.52.63.25516,382
210136.52.64.0/18136.52.64.1 to 136.52.127.254136.52.127.25516,382
211136.52.128.0/18136.52.128.1 to 136.52.191.254136.52.191.25516,382
212136.52.192.0/18136.52.192.1 to 136.52.255.254136.52.255.25516,382
213136.53.0.0/18136.53.0.1 to 136.53.63.254136.53.63.25516,382
214136.53.64.0/18136.53.64.1 to 136.53.127.254136.53.127.25516,382
215136.53.128.0/18136.53.128.1 to 136.53.191.254136.53.191.25516,382
216136.53.192.0/18136.53.192.1 to 136.53.255.254136.53.255.25516,382
217136.54.0.0/18136.54.0.1 to 136.54.63.254136.54.63.25516,382
218136.54.64.0/18136.54.64.1 to 136.54.127.254136.54.127.25516,382
219136.54.128.0/18136.54.128.1 to 136.54.191.254136.54.191.25516,382
220136.54.192.0/18136.54.192.1 to 136.54.255.254136.54.255.25516,382
221136.55.0.0/18136.55.0.1 to 136.55.63.254136.55.63.25516,382
222136.55.64.0/18136.55.64.1 to 136.55.127.254136.55.127.25516,382
223136.55.128.0/18136.55.128.1 to 136.55.191.254136.55.191.25516,382
224136.55.192.0/18136.55.192.1 to 136.55.255.254136.55.255.25516,382
225136.56.0.0/18136.56.0.1 to 136.56.63.254136.56.63.25516,382
226136.56.64.0/18136.56.64.1 to 136.56.127.254136.56.127.25516,382
227136.56.128.0/18136.56.128.1 to 136.56.191.254136.56.191.25516,382
228136.56.192.0/18136.56.192.1 to 136.56.255.254136.56.255.25516,382
229136.57.0.0/18136.57.0.1 to 136.57.63.254136.57.63.25516,382
230136.57.64.0/18136.57.64.1 to 136.57.127.254136.57.127.25516,382
231136.57.128.0/18136.57.128.1 to 136.57.191.254136.57.191.25516,382
232136.57.192.0/18136.57.192.1 to 136.57.255.254136.57.255.25516,382
233136.58.0.0/18136.58.0.1 to 136.58.63.254136.58.63.25516,382
234136.58.64.0/18136.58.64.1 to 136.58.127.254136.58.127.25516,382
235136.58.128.0/18136.58.128.1 to 136.58.191.254136.58.191.25516,382
236136.58.192.0/18136.58.192.1 to 136.58.255.254136.58.255.25516,382
237136.59.0.0/18136.59.0.1 to 136.59.63.254136.59.63.25516,382
238136.59.64.0/18136.59.64.1 to 136.59.127.254136.59.127.25516,382
239136.59.128.0/18136.59.128.1 to 136.59.191.254136.59.191.25516,382
240136.59.192.0/18136.59.192.1 to 136.59.255.254136.59.255.25516,382
241136.60.0.0/18136.60.0.1 to 136.60.63.254136.60.63.25516,382
242136.60.64.0/18136.60.64.1 to 136.60.127.254136.60.127.25516,382
243136.60.128.0/18136.60.128.1 to 136.60.191.254136.60.191.25516,382
244136.60.192.0/18136.60.192.1 to 136.60.255.254136.60.255.25516,382
245136.61.0.0/18136.61.0.1 to 136.61.63.254136.61.63.25516,382
246136.61.64.0/18136.61.64.1 to 136.61.127.254136.61.127.25516,382
247136.61.128.0/18136.61.128.1 to 136.61.191.254136.61.191.25516,382
248136.61.192.0/18136.61.192.1 to 136.61.255.254136.61.255.25516,382
249136.62.0.0/18136.62.0.1 to 136.62.63.254136.62.63.25516,382
250136.62.64.0/18136.62.64.1 to 136.62.127.254136.62.127.25516,382
251136.62.128.0/18136.62.128.1 to 136.62.191.254136.62.191.25516,382
252136.62.192.0/18136.62.192.1 to 136.62.255.254136.62.255.25516,382
253136.63.0.0/18136.63.0.1 to 136.63.63.254136.63.63.25516,382
254136.63.64.0/18136.63.64.1 to 136.63.127.254136.63.127.25516,382
255136.63.128.0/18136.63.128.1 to 136.63.191.254136.63.191.25516,382
256136.63.192.0/18136.63.192.1 to 136.63.255.254136.63.255.25516,382

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.