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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.

Network177.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
177.0.0.0
Broadcast address
177.255.255.255
First usable
177.0.0.1
Last usable
177.255.255.254
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 B1000000 · Integer 2969567232 to 2986344447
Reverse DNS zone
177.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110001..00000000.00000000.00000000177.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10110001..00000000.00000000.00000000177.0.0.0
Broadcast10110001..11111111.11111111.11111111177.255.255.255
Split into smaller subnets/17
/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)

177.0.0.0/8 makes 512 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1177.0.0.0/17177.0.0.1 to 177.0.127.254177.0.127.25532,766
2177.0.128.0/17177.0.128.1 to 177.0.255.254177.0.255.25532,766
3177.1.0.0/17177.1.0.1 to 177.1.127.254177.1.127.25532,766
4177.1.128.0/17177.1.128.1 to 177.1.255.254177.1.255.25532,766
5177.2.0.0/17177.2.0.1 to 177.2.127.254177.2.127.25532,766
6177.2.128.0/17177.2.128.1 to 177.2.255.254177.2.255.25532,766
7177.3.0.0/17177.3.0.1 to 177.3.127.254177.3.127.25532,766
8177.3.128.0/17177.3.128.1 to 177.3.255.254177.3.255.25532,766
9177.4.0.0/17177.4.0.1 to 177.4.127.254177.4.127.25532,766
10177.4.128.0/17177.4.128.1 to 177.4.255.254177.4.255.25532,766
11177.5.0.0/17177.5.0.1 to 177.5.127.254177.5.127.25532,766
12177.5.128.0/17177.5.128.1 to 177.5.255.254177.5.255.25532,766
13177.6.0.0/17177.6.0.1 to 177.6.127.254177.6.127.25532,766
14177.6.128.0/17177.6.128.1 to 177.6.255.254177.6.255.25532,766
15177.7.0.0/17177.7.0.1 to 177.7.127.254177.7.127.25532,766
16177.7.128.0/17177.7.128.1 to 177.7.255.254177.7.255.25532,766
17177.8.0.0/17177.8.0.1 to 177.8.127.254177.8.127.25532,766
18177.8.128.0/17177.8.128.1 to 177.8.255.254177.8.255.25532,766
19177.9.0.0/17177.9.0.1 to 177.9.127.254177.9.127.25532,766
20177.9.128.0/17177.9.128.1 to 177.9.255.254177.9.255.25532,766
21177.10.0.0/17177.10.0.1 to 177.10.127.254177.10.127.25532,766
22177.10.128.0/17177.10.128.1 to 177.10.255.254177.10.255.25532,766
23177.11.0.0/17177.11.0.1 to 177.11.127.254177.11.127.25532,766
24177.11.128.0/17177.11.128.1 to 177.11.255.254177.11.255.25532,766
25177.12.0.0/17177.12.0.1 to 177.12.127.254177.12.127.25532,766
26177.12.128.0/17177.12.128.1 to 177.12.255.254177.12.255.25532,766
27177.13.0.0/17177.13.0.1 to 177.13.127.254177.13.127.25532,766
28177.13.128.0/17177.13.128.1 to 177.13.255.254177.13.255.25532,766
29177.14.0.0/17177.14.0.1 to 177.14.127.254177.14.127.25532,766
30177.14.128.0/17177.14.128.1 to 177.14.255.254177.14.255.25532,766
31177.15.0.0/17177.15.0.1 to 177.15.127.254177.15.127.25532,766
32177.15.128.0/17177.15.128.1 to 177.15.255.254177.15.255.25532,766
33177.16.0.0/17177.16.0.1 to 177.16.127.254177.16.127.25532,766
34177.16.128.0/17177.16.128.1 to 177.16.255.254177.16.255.25532,766
35177.17.0.0/17177.17.0.1 to 177.17.127.254177.17.127.25532,766
36177.17.128.0/17177.17.128.1 to 177.17.255.254177.17.255.25532,766
37177.18.0.0/17177.18.0.1 to 177.18.127.254177.18.127.25532,766
38177.18.128.0/17177.18.128.1 to 177.18.255.254177.18.255.25532,766
39177.19.0.0/17177.19.0.1 to 177.19.127.254177.19.127.25532,766
40177.19.128.0/17177.19.128.1 to 177.19.255.254177.19.255.25532,766
41177.20.0.0/17177.20.0.1 to 177.20.127.254177.20.127.25532,766
42177.20.128.0/17177.20.128.1 to 177.20.255.254177.20.255.25532,766
43177.21.0.0/17177.21.0.1 to 177.21.127.254177.21.127.25532,766
44177.21.128.0/17177.21.128.1 to 177.21.255.254177.21.255.25532,766
45177.22.0.0/17177.22.0.1 to 177.22.127.254177.22.127.25532,766
46177.22.128.0/17177.22.128.1 to 177.22.255.254177.22.255.25532,766
47177.23.0.0/17177.23.0.1 to 177.23.127.254177.23.127.25532,766
48177.23.128.0/17177.23.128.1 to 177.23.255.254177.23.255.25532,766
49177.24.0.0/17177.24.0.1 to 177.24.127.254177.24.127.25532,766
50177.24.128.0/17177.24.128.1 to 177.24.255.254177.24.255.25532,766
51177.25.0.0/17177.25.0.1 to 177.25.127.254177.25.127.25532,766
52177.25.128.0/17177.25.128.1 to 177.25.255.254177.25.255.25532,766
53177.26.0.0/17177.26.0.1 to 177.26.127.254177.26.127.25532,766
54177.26.128.0/17177.26.128.1 to 177.26.255.254177.26.255.25532,766
55177.27.0.0/17177.27.0.1 to 177.27.127.254177.27.127.25532,766
56177.27.128.0/17177.27.128.1 to 177.27.255.254177.27.255.25532,766
57177.28.0.0/17177.28.0.1 to 177.28.127.254177.28.127.25532,766
58177.28.128.0/17177.28.128.1 to 177.28.255.254177.28.255.25532,766
59177.29.0.0/17177.29.0.1 to 177.29.127.254177.29.127.25532,766
60177.29.128.0/17177.29.128.1 to 177.29.255.254177.29.255.25532,766
61177.30.0.0/17177.30.0.1 to 177.30.127.254177.30.127.25532,766
62177.30.128.0/17177.30.128.1 to 177.30.255.254177.30.255.25532,766
63177.31.0.0/17177.31.0.1 to 177.31.127.254177.31.127.25532,766
64177.31.128.0/17177.31.128.1 to 177.31.255.254177.31.255.25532,766
65177.32.0.0/17177.32.0.1 to 177.32.127.254177.32.127.25532,766
66177.32.128.0/17177.32.128.1 to 177.32.255.254177.32.255.25532,766
67177.33.0.0/17177.33.0.1 to 177.33.127.254177.33.127.25532,766
68177.33.128.0/17177.33.128.1 to 177.33.255.254177.33.255.25532,766
69177.34.0.0/17177.34.0.1 to 177.34.127.254177.34.127.25532,766
70177.34.128.0/17177.34.128.1 to 177.34.255.254177.34.255.25532,766
71177.35.0.0/17177.35.0.1 to 177.35.127.254177.35.127.25532,766
72177.35.128.0/17177.35.128.1 to 177.35.255.254177.35.255.25532,766
73177.36.0.0/17177.36.0.1 to 177.36.127.254177.36.127.25532,766
74177.36.128.0/17177.36.128.1 to 177.36.255.254177.36.255.25532,766
75177.37.0.0/17177.37.0.1 to 177.37.127.254177.37.127.25532,766
76177.37.128.0/17177.37.128.1 to 177.37.255.254177.37.255.25532,766
77177.38.0.0/17177.38.0.1 to 177.38.127.254177.38.127.25532,766
78177.38.128.0/17177.38.128.1 to 177.38.255.254177.38.255.25532,766
79177.39.0.0/17177.39.0.1 to 177.39.127.254177.39.127.25532,766
80177.39.128.0/17177.39.128.1 to 177.39.255.254177.39.255.25532,766
81177.40.0.0/17177.40.0.1 to 177.40.127.254177.40.127.25532,766
82177.40.128.0/17177.40.128.1 to 177.40.255.254177.40.255.25532,766
83177.41.0.0/17177.41.0.1 to 177.41.127.254177.41.127.25532,766
84177.41.128.0/17177.41.128.1 to 177.41.255.254177.41.255.25532,766
85177.42.0.0/17177.42.0.1 to 177.42.127.254177.42.127.25532,766
86177.42.128.0/17177.42.128.1 to 177.42.255.254177.42.255.25532,766
87177.43.0.0/17177.43.0.1 to 177.43.127.254177.43.127.25532,766
88177.43.128.0/17177.43.128.1 to 177.43.255.254177.43.255.25532,766
89177.44.0.0/17177.44.0.1 to 177.44.127.254177.44.127.25532,766
90177.44.128.0/17177.44.128.1 to 177.44.255.254177.44.255.25532,766
91177.45.0.0/17177.45.0.1 to 177.45.127.254177.45.127.25532,766
92177.45.128.0/17177.45.128.1 to 177.45.255.254177.45.255.25532,766
93177.46.0.0/17177.46.0.1 to 177.46.127.254177.46.127.25532,766
94177.46.128.0/17177.46.128.1 to 177.46.255.254177.46.255.25532,766
95177.47.0.0/17177.47.0.1 to 177.47.127.254177.47.127.25532,766
96177.47.128.0/17177.47.128.1 to 177.47.255.254177.47.255.25532,766
97177.48.0.0/17177.48.0.1 to 177.48.127.254177.48.127.25532,766
98177.48.128.0/17177.48.128.1 to 177.48.255.254177.48.255.25532,766
99177.49.0.0/17177.49.0.1 to 177.49.127.254177.49.127.25532,766
100177.49.128.0/17177.49.128.1 to 177.49.255.254177.49.255.25532,766
101177.50.0.0/17177.50.0.1 to 177.50.127.254177.50.127.25532,766
102177.50.128.0/17177.50.128.1 to 177.50.255.254177.50.255.25532,766
103177.51.0.0/17177.51.0.1 to 177.51.127.254177.51.127.25532,766
104177.51.128.0/17177.51.128.1 to 177.51.255.254177.51.255.25532,766
105177.52.0.0/17177.52.0.1 to 177.52.127.254177.52.127.25532,766
106177.52.128.0/17177.52.128.1 to 177.52.255.254177.52.255.25532,766
107177.53.0.0/17177.53.0.1 to 177.53.127.254177.53.127.25532,766
108177.53.128.0/17177.53.128.1 to 177.53.255.254177.53.255.25532,766
109177.54.0.0/17177.54.0.1 to 177.54.127.254177.54.127.25532,766
110177.54.128.0/17177.54.128.1 to 177.54.255.254177.54.255.25532,766
111177.55.0.0/17177.55.0.1 to 177.55.127.254177.55.127.25532,766
112177.55.128.0/17177.55.128.1 to 177.55.255.254177.55.255.25532,766
113177.56.0.0/17177.56.0.1 to 177.56.127.254177.56.127.25532,766
114177.56.128.0/17177.56.128.1 to 177.56.255.254177.56.255.25532,766
115177.57.0.0/17177.57.0.1 to 177.57.127.254177.57.127.25532,766
116177.57.128.0/17177.57.128.1 to 177.57.255.254177.57.255.25532,766
117177.58.0.0/17177.58.0.1 to 177.58.127.254177.58.127.25532,766
118177.58.128.0/17177.58.128.1 to 177.58.255.254177.58.255.25532,766
119177.59.0.0/17177.59.0.1 to 177.59.127.254177.59.127.25532,766
120177.59.128.0/17177.59.128.1 to 177.59.255.254177.59.255.25532,766
121177.60.0.0/17177.60.0.1 to 177.60.127.254177.60.127.25532,766
122177.60.128.0/17177.60.128.1 to 177.60.255.254177.60.255.25532,766
123177.61.0.0/17177.61.0.1 to 177.61.127.254177.61.127.25532,766
124177.61.128.0/17177.61.128.1 to 177.61.255.254177.61.255.25532,766
125177.62.0.0/17177.62.0.1 to 177.62.127.254177.62.127.25532,766
126177.62.128.0/17177.62.128.1 to 177.62.255.254177.62.255.25532,766
127177.63.0.0/17177.63.0.1 to 177.63.127.254177.63.127.25532,766
128177.63.128.0/17177.63.128.1 to 177.63.255.254177.63.255.25532,766
129177.64.0.0/17177.64.0.1 to 177.64.127.254177.64.127.25532,766
130177.64.128.0/17177.64.128.1 to 177.64.255.254177.64.255.25532,766
131177.65.0.0/17177.65.0.1 to 177.65.127.254177.65.127.25532,766
132177.65.128.0/17177.65.128.1 to 177.65.255.254177.65.255.25532,766
133177.66.0.0/17177.66.0.1 to 177.66.127.254177.66.127.25532,766
134177.66.128.0/17177.66.128.1 to 177.66.255.254177.66.255.25532,766
135177.67.0.0/17177.67.0.1 to 177.67.127.254177.67.127.25532,766
136177.67.128.0/17177.67.128.1 to 177.67.255.254177.67.255.25532,766
137177.68.0.0/17177.68.0.1 to 177.68.127.254177.68.127.25532,766
138177.68.128.0/17177.68.128.1 to 177.68.255.254177.68.255.25532,766
139177.69.0.0/17177.69.0.1 to 177.69.127.254177.69.127.25532,766
140177.69.128.0/17177.69.128.1 to 177.69.255.254177.69.255.25532,766
141177.70.0.0/17177.70.0.1 to 177.70.127.254177.70.127.25532,766
142177.70.128.0/17177.70.128.1 to 177.70.255.254177.70.255.25532,766
143177.71.0.0/17177.71.0.1 to 177.71.127.254177.71.127.25532,766
144177.71.128.0/17177.71.128.1 to 177.71.255.254177.71.255.25532,766
145177.72.0.0/17177.72.0.1 to 177.72.127.254177.72.127.25532,766
146177.72.128.0/17177.72.128.1 to 177.72.255.254177.72.255.25532,766
147177.73.0.0/17177.73.0.1 to 177.73.127.254177.73.127.25532,766
148177.73.128.0/17177.73.128.1 to 177.73.255.254177.73.255.25532,766
149177.74.0.0/17177.74.0.1 to 177.74.127.254177.74.127.25532,766
150177.74.128.0/17177.74.128.1 to 177.74.255.254177.74.255.25532,766
151177.75.0.0/17177.75.0.1 to 177.75.127.254177.75.127.25532,766
152177.75.128.0/17177.75.128.1 to 177.75.255.254177.75.255.25532,766
153177.76.0.0/17177.76.0.1 to 177.76.127.254177.76.127.25532,766
154177.76.128.0/17177.76.128.1 to 177.76.255.254177.76.255.25532,766
155177.77.0.0/17177.77.0.1 to 177.77.127.254177.77.127.25532,766
156177.77.128.0/17177.77.128.1 to 177.77.255.254177.77.255.25532,766
157177.78.0.0/17177.78.0.1 to 177.78.127.254177.78.127.25532,766
158177.78.128.0/17177.78.128.1 to 177.78.255.254177.78.255.25532,766
159177.79.0.0/17177.79.0.1 to 177.79.127.254177.79.127.25532,766
160177.79.128.0/17177.79.128.1 to 177.79.255.254177.79.255.25532,766
161177.80.0.0/17177.80.0.1 to 177.80.127.254177.80.127.25532,766
162177.80.128.0/17177.80.128.1 to 177.80.255.254177.80.255.25532,766
163177.81.0.0/17177.81.0.1 to 177.81.127.254177.81.127.25532,766
164177.81.128.0/17177.81.128.1 to 177.81.255.254177.81.255.25532,766
165177.82.0.0/17177.82.0.1 to 177.82.127.254177.82.127.25532,766
166177.82.128.0/17177.82.128.1 to 177.82.255.254177.82.255.25532,766
167177.83.0.0/17177.83.0.1 to 177.83.127.254177.83.127.25532,766
168177.83.128.0/17177.83.128.1 to 177.83.255.254177.83.255.25532,766
169177.84.0.0/17177.84.0.1 to 177.84.127.254177.84.127.25532,766
170177.84.128.0/17177.84.128.1 to 177.84.255.254177.84.255.25532,766
171177.85.0.0/17177.85.0.1 to 177.85.127.254177.85.127.25532,766
172177.85.128.0/17177.85.128.1 to 177.85.255.254177.85.255.25532,766
173177.86.0.0/17177.86.0.1 to 177.86.127.254177.86.127.25532,766
174177.86.128.0/17177.86.128.1 to 177.86.255.254177.86.255.25532,766
175177.87.0.0/17177.87.0.1 to 177.87.127.254177.87.127.25532,766
176177.87.128.0/17177.87.128.1 to 177.87.255.254177.87.255.25532,766
177177.88.0.0/17177.88.0.1 to 177.88.127.254177.88.127.25532,766
178177.88.128.0/17177.88.128.1 to 177.88.255.254177.88.255.25532,766
179177.89.0.0/17177.89.0.1 to 177.89.127.254177.89.127.25532,766
180177.89.128.0/17177.89.128.1 to 177.89.255.254177.89.255.25532,766
181177.90.0.0/17177.90.0.1 to 177.90.127.254177.90.127.25532,766
182177.90.128.0/17177.90.128.1 to 177.90.255.254177.90.255.25532,766
183177.91.0.0/17177.91.0.1 to 177.91.127.254177.91.127.25532,766
184177.91.128.0/17177.91.128.1 to 177.91.255.254177.91.255.25532,766
185177.92.0.0/17177.92.0.1 to 177.92.127.254177.92.127.25532,766
186177.92.128.0/17177.92.128.1 to 177.92.255.254177.92.255.25532,766
187177.93.0.0/17177.93.0.1 to 177.93.127.254177.93.127.25532,766
188177.93.128.0/17177.93.128.1 to 177.93.255.254177.93.255.25532,766
189177.94.0.0/17177.94.0.1 to 177.94.127.254177.94.127.25532,766
190177.94.128.0/17177.94.128.1 to 177.94.255.254177.94.255.25532,766
191177.95.0.0/17177.95.0.1 to 177.95.127.254177.95.127.25532,766
192177.95.128.0/17177.95.128.1 to 177.95.255.254177.95.255.25532,766
193177.96.0.0/17177.96.0.1 to 177.96.127.254177.96.127.25532,766
194177.96.128.0/17177.96.128.1 to 177.96.255.254177.96.255.25532,766
195177.97.0.0/17177.97.0.1 to 177.97.127.254177.97.127.25532,766
196177.97.128.0/17177.97.128.1 to 177.97.255.254177.97.255.25532,766
197177.98.0.0/17177.98.0.1 to 177.98.127.254177.98.127.25532,766
198177.98.128.0/17177.98.128.1 to 177.98.255.254177.98.255.25532,766
199177.99.0.0/17177.99.0.1 to 177.99.127.254177.99.127.25532,766
200177.99.128.0/17177.99.128.1 to 177.99.255.254177.99.255.25532,766
201177.100.0.0/17177.100.0.1 to 177.100.127.254177.100.127.25532,766
202177.100.128.0/17177.100.128.1 to 177.100.255.254177.100.255.25532,766
203177.101.0.0/17177.101.0.1 to 177.101.127.254177.101.127.25532,766
204177.101.128.0/17177.101.128.1 to 177.101.255.254177.101.255.25532,766
205177.102.0.0/17177.102.0.1 to 177.102.127.254177.102.127.25532,766
206177.102.128.0/17177.102.128.1 to 177.102.255.254177.102.255.25532,766
207177.103.0.0/17177.103.0.1 to 177.103.127.254177.103.127.25532,766
208177.103.128.0/17177.103.128.1 to 177.103.255.254177.103.255.25532,766
209177.104.0.0/17177.104.0.1 to 177.104.127.254177.104.127.25532,766
210177.104.128.0/17177.104.128.1 to 177.104.255.254177.104.255.25532,766
211177.105.0.0/17177.105.0.1 to 177.105.127.254177.105.127.25532,766
212177.105.128.0/17177.105.128.1 to 177.105.255.254177.105.255.25532,766
213177.106.0.0/17177.106.0.1 to 177.106.127.254177.106.127.25532,766
214177.106.128.0/17177.106.128.1 to 177.106.255.254177.106.255.25532,766
215177.107.0.0/17177.107.0.1 to 177.107.127.254177.107.127.25532,766
216177.107.128.0/17177.107.128.1 to 177.107.255.254177.107.255.25532,766
217177.108.0.0/17177.108.0.1 to 177.108.127.254177.108.127.25532,766
218177.108.128.0/17177.108.128.1 to 177.108.255.254177.108.255.25532,766
219177.109.0.0/17177.109.0.1 to 177.109.127.254177.109.127.25532,766
220177.109.128.0/17177.109.128.1 to 177.109.255.254177.109.255.25532,766
221177.110.0.0/17177.110.0.1 to 177.110.127.254177.110.127.25532,766
222177.110.128.0/17177.110.128.1 to 177.110.255.254177.110.255.25532,766
223177.111.0.0/17177.111.0.1 to 177.111.127.254177.111.127.25532,766
224177.111.128.0/17177.111.128.1 to 177.111.255.254177.111.255.25532,766
225177.112.0.0/17177.112.0.1 to 177.112.127.254177.112.127.25532,766
226177.112.128.0/17177.112.128.1 to 177.112.255.254177.112.255.25532,766
227177.113.0.0/17177.113.0.1 to 177.113.127.254177.113.127.25532,766
228177.113.128.0/17177.113.128.1 to 177.113.255.254177.113.255.25532,766
229177.114.0.0/17177.114.0.1 to 177.114.127.254177.114.127.25532,766
230177.114.128.0/17177.114.128.1 to 177.114.255.254177.114.255.25532,766
231177.115.0.0/17177.115.0.1 to 177.115.127.254177.115.127.25532,766
232177.115.128.0/17177.115.128.1 to 177.115.255.254177.115.255.25532,766
233177.116.0.0/17177.116.0.1 to 177.116.127.254177.116.127.25532,766
234177.116.128.0/17177.116.128.1 to 177.116.255.254177.116.255.25532,766
235177.117.0.0/17177.117.0.1 to 177.117.127.254177.117.127.25532,766
236177.117.128.0/17177.117.128.1 to 177.117.255.254177.117.255.25532,766
237177.118.0.0/17177.118.0.1 to 177.118.127.254177.118.127.25532,766
238177.118.128.0/17177.118.128.1 to 177.118.255.254177.118.255.25532,766
239177.119.0.0/17177.119.0.1 to 177.119.127.254177.119.127.25532,766
240177.119.128.0/17177.119.128.1 to 177.119.255.254177.119.255.25532,766
241177.120.0.0/17177.120.0.1 to 177.120.127.254177.120.127.25532,766
242177.120.128.0/17177.120.128.1 to 177.120.255.254177.120.255.25532,766
243177.121.0.0/17177.121.0.1 to 177.121.127.254177.121.127.25532,766
244177.121.128.0/17177.121.128.1 to 177.121.255.254177.121.255.25532,766
245177.122.0.0/17177.122.0.1 to 177.122.127.254177.122.127.25532,766
246177.122.128.0/17177.122.128.1 to 177.122.255.254177.122.255.25532,766
247177.123.0.0/17177.123.0.1 to 177.123.127.254177.123.127.25532,766
248177.123.128.0/17177.123.128.1 to 177.123.255.254177.123.255.25532,766
249177.124.0.0/17177.124.0.1 to 177.124.127.254177.124.127.25532,766
250177.124.128.0/17177.124.128.1 to 177.124.255.254177.124.255.25532,766
251177.125.0.0/17177.125.0.1 to 177.125.127.254177.125.127.25532,766
252177.125.128.0/17177.125.128.1 to 177.125.255.254177.125.255.25532,766
253177.126.0.0/17177.126.0.1 to 177.126.127.254177.126.127.25532,766
254177.126.128.0/17177.126.128.1 to 177.126.255.254177.126.255.25532,766
255177.127.0.0/17177.127.0.1 to 177.127.127.254177.127.127.25532,766
256177.127.128.0/17177.127.128.1 to 177.127.255.254177.127.255.25532,766

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.