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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.

Network153.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
153.0.0.0
Broadcast address
153.255.255.255
First usable
153.0.0.1
Last usable
153.255.255.254
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 99000000 · Integer 2566914048 to 2583691263
Reverse DNS zone
153.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011001..00000000.00000000.00000000153.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10011001..00000000.00000000.00000000153.0.0.0
Broadcast10011001..11111111.11111111.11111111153.255.255.255
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)

153.0.0.0/8 makes 512 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1153.0.0.0/17153.0.0.1 to 153.0.127.254153.0.127.25532,766
2153.0.128.0/17153.0.128.1 to 153.0.255.254153.0.255.25532,766
3153.1.0.0/17153.1.0.1 to 153.1.127.254153.1.127.25532,766
4153.1.128.0/17153.1.128.1 to 153.1.255.254153.1.255.25532,766
5153.2.0.0/17153.2.0.1 to 153.2.127.254153.2.127.25532,766
6153.2.128.0/17153.2.128.1 to 153.2.255.254153.2.255.25532,766
7153.3.0.0/17153.3.0.1 to 153.3.127.254153.3.127.25532,766
8153.3.128.0/17153.3.128.1 to 153.3.255.254153.3.255.25532,766
9153.4.0.0/17153.4.0.1 to 153.4.127.254153.4.127.25532,766
10153.4.128.0/17153.4.128.1 to 153.4.255.254153.4.255.25532,766
11153.5.0.0/17153.5.0.1 to 153.5.127.254153.5.127.25532,766
12153.5.128.0/17153.5.128.1 to 153.5.255.254153.5.255.25532,766
13153.6.0.0/17153.6.0.1 to 153.6.127.254153.6.127.25532,766
14153.6.128.0/17153.6.128.1 to 153.6.255.254153.6.255.25532,766
15153.7.0.0/17153.7.0.1 to 153.7.127.254153.7.127.25532,766
16153.7.128.0/17153.7.128.1 to 153.7.255.254153.7.255.25532,766
17153.8.0.0/17153.8.0.1 to 153.8.127.254153.8.127.25532,766
18153.8.128.0/17153.8.128.1 to 153.8.255.254153.8.255.25532,766
19153.9.0.0/17153.9.0.1 to 153.9.127.254153.9.127.25532,766
20153.9.128.0/17153.9.128.1 to 153.9.255.254153.9.255.25532,766
21153.10.0.0/17153.10.0.1 to 153.10.127.254153.10.127.25532,766
22153.10.128.0/17153.10.128.1 to 153.10.255.254153.10.255.25532,766
23153.11.0.0/17153.11.0.1 to 153.11.127.254153.11.127.25532,766
24153.11.128.0/17153.11.128.1 to 153.11.255.254153.11.255.25532,766
25153.12.0.0/17153.12.0.1 to 153.12.127.254153.12.127.25532,766
26153.12.128.0/17153.12.128.1 to 153.12.255.254153.12.255.25532,766
27153.13.0.0/17153.13.0.1 to 153.13.127.254153.13.127.25532,766
28153.13.128.0/17153.13.128.1 to 153.13.255.254153.13.255.25532,766
29153.14.0.0/17153.14.0.1 to 153.14.127.254153.14.127.25532,766
30153.14.128.0/17153.14.128.1 to 153.14.255.254153.14.255.25532,766
31153.15.0.0/17153.15.0.1 to 153.15.127.254153.15.127.25532,766
32153.15.128.0/17153.15.128.1 to 153.15.255.254153.15.255.25532,766
33153.16.0.0/17153.16.0.1 to 153.16.127.254153.16.127.25532,766
34153.16.128.0/17153.16.128.1 to 153.16.255.254153.16.255.25532,766
35153.17.0.0/17153.17.0.1 to 153.17.127.254153.17.127.25532,766
36153.17.128.0/17153.17.128.1 to 153.17.255.254153.17.255.25532,766
37153.18.0.0/17153.18.0.1 to 153.18.127.254153.18.127.25532,766
38153.18.128.0/17153.18.128.1 to 153.18.255.254153.18.255.25532,766
39153.19.0.0/17153.19.0.1 to 153.19.127.254153.19.127.25532,766
40153.19.128.0/17153.19.128.1 to 153.19.255.254153.19.255.25532,766
41153.20.0.0/17153.20.0.1 to 153.20.127.254153.20.127.25532,766
42153.20.128.0/17153.20.128.1 to 153.20.255.254153.20.255.25532,766
43153.21.0.0/17153.21.0.1 to 153.21.127.254153.21.127.25532,766
44153.21.128.0/17153.21.128.1 to 153.21.255.254153.21.255.25532,766
45153.22.0.0/17153.22.0.1 to 153.22.127.254153.22.127.25532,766
46153.22.128.0/17153.22.128.1 to 153.22.255.254153.22.255.25532,766
47153.23.0.0/17153.23.0.1 to 153.23.127.254153.23.127.25532,766
48153.23.128.0/17153.23.128.1 to 153.23.255.254153.23.255.25532,766
49153.24.0.0/17153.24.0.1 to 153.24.127.254153.24.127.25532,766
50153.24.128.0/17153.24.128.1 to 153.24.255.254153.24.255.25532,766
51153.25.0.0/17153.25.0.1 to 153.25.127.254153.25.127.25532,766
52153.25.128.0/17153.25.128.1 to 153.25.255.254153.25.255.25532,766
53153.26.0.0/17153.26.0.1 to 153.26.127.254153.26.127.25532,766
54153.26.128.0/17153.26.128.1 to 153.26.255.254153.26.255.25532,766
55153.27.0.0/17153.27.0.1 to 153.27.127.254153.27.127.25532,766
56153.27.128.0/17153.27.128.1 to 153.27.255.254153.27.255.25532,766
57153.28.0.0/17153.28.0.1 to 153.28.127.254153.28.127.25532,766
58153.28.128.0/17153.28.128.1 to 153.28.255.254153.28.255.25532,766
59153.29.0.0/17153.29.0.1 to 153.29.127.254153.29.127.25532,766
60153.29.128.0/17153.29.128.1 to 153.29.255.254153.29.255.25532,766
61153.30.0.0/17153.30.0.1 to 153.30.127.254153.30.127.25532,766
62153.30.128.0/17153.30.128.1 to 153.30.255.254153.30.255.25532,766
63153.31.0.0/17153.31.0.1 to 153.31.127.254153.31.127.25532,766
64153.31.128.0/17153.31.128.1 to 153.31.255.254153.31.255.25532,766
65153.32.0.0/17153.32.0.1 to 153.32.127.254153.32.127.25532,766
66153.32.128.0/17153.32.128.1 to 153.32.255.254153.32.255.25532,766
67153.33.0.0/17153.33.0.1 to 153.33.127.254153.33.127.25532,766
68153.33.128.0/17153.33.128.1 to 153.33.255.254153.33.255.25532,766
69153.34.0.0/17153.34.0.1 to 153.34.127.254153.34.127.25532,766
70153.34.128.0/17153.34.128.1 to 153.34.255.254153.34.255.25532,766
71153.35.0.0/17153.35.0.1 to 153.35.127.254153.35.127.25532,766
72153.35.128.0/17153.35.128.1 to 153.35.255.254153.35.255.25532,766
73153.36.0.0/17153.36.0.1 to 153.36.127.254153.36.127.25532,766
74153.36.128.0/17153.36.128.1 to 153.36.255.254153.36.255.25532,766
75153.37.0.0/17153.37.0.1 to 153.37.127.254153.37.127.25532,766
76153.37.128.0/17153.37.128.1 to 153.37.255.254153.37.255.25532,766
77153.38.0.0/17153.38.0.1 to 153.38.127.254153.38.127.25532,766
78153.38.128.0/17153.38.128.1 to 153.38.255.254153.38.255.25532,766
79153.39.0.0/17153.39.0.1 to 153.39.127.254153.39.127.25532,766
80153.39.128.0/17153.39.128.1 to 153.39.255.254153.39.255.25532,766
81153.40.0.0/17153.40.0.1 to 153.40.127.254153.40.127.25532,766
82153.40.128.0/17153.40.128.1 to 153.40.255.254153.40.255.25532,766
83153.41.0.0/17153.41.0.1 to 153.41.127.254153.41.127.25532,766
84153.41.128.0/17153.41.128.1 to 153.41.255.254153.41.255.25532,766
85153.42.0.0/17153.42.0.1 to 153.42.127.254153.42.127.25532,766
86153.42.128.0/17153.42.128.1 to 153.42.255.254153.42.255.25532,766
87153.43.0.0/17153.43.0.1 to 153.43.127.254153.43.127.25532,766
88153.43.128.0/17153.43.128.1 to 153.43.255.254153.43.255.25532,766
89153.44.0.0/17153.44.0.1 to 153.44.127.254153.44.127.25532,766
90153.44.128.0/17153.44.128.1 to 153.44.255.254153.44.255.25532,766
91153.45.0.0/17153.45.0.1 to 153.45.127.254153.45.127.25532,766
92153.45.128.0/17153.45.128.1 to 153.45.255.254153.45.255.25532,766
93153.46.0.0/17153.46.0.1 to 153.46.127.254153.46.127.25532,766
94153.46.128.0/17153.46.128.1 to 153.46.255.254153.46.255.25532,766
95153.47.0.0/17153.47.0.1 to 153.47.127.254153.47.127.25532,766
96153.47.128.0/17153.47.128.1 to 153.47.255.254153.47.255.25532,766
97153.48.0.0/17153.48.0.1 to 153.48.127.254153.48.127.25532,766
98153.48.128.0/17153.48.128.1 to 153.48.255.254153.48.255.25532,766
99153.49.0.0/17153.49.0.1 to 153.49.127.254153.49.127.25532,766
100153.49.128.0/17153.49.128.1 to 153.49.255.254153.49.255.25532,766
101153.50.0.0/17153.50.0.1 to 153.50.127.254153.50.127.25532,766
102153.50.128.0/17153.50.128.1 to 153.50.255.254153.50.255.25532,766
103153.51.0.0/17153.51.0.1 to 153.51.127.254153.51.127.25532,766
104153.51.128.0/17153.51.128.1 to 153.51.255.254153.51.255.25532,766
105153.52.0.0/17153.52.0.1 to 153.52.127.254153.52.127.25532,766
106153.52.128.0/17153.52.128.1 to 153.52.255.254153.52.255.25532,766
107153.53.0.0/17153.53.0.1 to 153.53.127.254153.53.127.25532,766
108153.53.128.0/17153.53.128.1 to 153.53.255.254153.53.255.25532,766
109153.54.0.0/17153.54.0.1 to 153.54.127.254153.54.127.25532,766
110153.54.128.0/17153.54.128.1 to 153.54.255.254153.54.255.25532,766
111153.55.0.0/17153.55.0.1 to 153.55.127.254153.55.127.25532,766
112153.55.128.0/17153.55.128.1 to 153.55.255.254153.55.255.25532,766
113153.56.0.0/17153.56.0.1 to 153.56.127.254153.56.127.25532,766
114153.56.128.0/17153.56.128.1 to 153.56.255.254153.56.255.25532,766
115153.57.0.0/17153.57.0.1 to 153.57.127.254153.57.127.25532,766
116153.57.128.0/17153.57.128.1 to 153.57.255.254153.57.255.25532,766
117153.58.0.0/17153.58.0.1 to 153.58.127.254153.58.127.25532,766
118153.58.128.0/17153.58.128.1 to 153.58.255.254153.58.255.25532,766
119153.59.0.0/17153.59.0.1 to 153.59.127.254153.59.127.25532,766
120153.59.128.0/17153.59.128.1 to 153.59.255.254153.59.255.25532,766
121153.60.0.0/17153.60.0.1 to 153.60.127.254153.60.127.25532,766
122153.60.128.0/17153.60.128.1 to 153.60.255.254153.60.255.25532,766
123153.61.0.0/17153.61.0.1 to 153.61.127.254153.61.127.25532,766
124153.61.128.0/17153.61.128.1 to 153.61.255.254153.61.255.25532,766
125153.62.0.0/17153.62.0.1 to 153.62.127.254153.62.127.25532,766
126153.62.128.0/17153.62.128.1 to 153.62.255.254153.62.255.25532,766
127153.63.0.0/17153.63.0.1 to 153.63.127.254153.63.127.25532,766
128153.63.128.0/17153.63.128.1 to 153.63.255.254153.63.255.25532,766
129153.64.0.0/17153.64.0.1 to 153.64.127.254153.64.127.25532,766
130153.64.128.0/17153.64.128.1 to 153.64.255.254153.64.255.25532,766
131153.65.0.0/17153.65.0.1 to 153.65.127.254153.65.127.25532,766
132153.65.128.0/17153.65.128.1 to 153.65.255.254153.65.255.25532,766
133153.66.0.0/17153.66.0.1 to 153.66.127.254153.66.127.25532,766
134153.66.128.0/17153.66.128.1 to 153.66.255.254153.66.255.25532,766
135153.67.0.0/17153.67.0.1 to 153.67.127.254153.67.127.25532,766
136153.67.128.0/17153.67.128.1 to 153.67.255.254153.67.255.25532,766
137153.68.0.0/17153.68.0.1 to 153.68.127.254153.68.127.25532,766
138153.68.128.0/17153.68.128.1 to 153.68.255.254153.68.255.25532,766
139153.69.0.0/17153.69.0.1 to 153.69.127.254153.69.127.25532,766
140153.69.128.0/17153.69.128.1 to 153.69.255.254153.69.255.25532,766
141153.70.0.0/17153.70.0.1 to 153.70.127.254153.70.127.25532,766
142153.70.128.0/17153.70.128.1 to 153.70.255.254153.70.255.25532,766
143153.71.0.0/17153.71.0.1 to 153.71.127.254153.71.127.25532,766
144153.71.128.0/17153.71.128.1 to 153.71.255.254153.71.255.25532,766
145153.72.0.0/17153.72.0.1 to 153.72.127.254153.72.127.25532,766
146153.72.128.0/17153.72.128.1 to 153.72.255.254153.72.255.25532,766
147153.73.0.0/17153.73.0.1 to 153.73.127.254153.73.127.25532,766
148153.73.128.0/17153.73.128.1 to 153.73.255.254153.73.255.25532,766
149153.74.0.0/17153.74.0.1 to 153.74.127.254153.74.127.25532,766
150153.74.128.0/17153.74.128.1 to 153.74.255.254153.74.255.25532,766
151153.75.0.0/17153.75.0.1 to 153.75.127.254153.75.127.25532,766
152153.75.128.0/17153.75.128.1 to 153.75.255.254153.75.255.25532,766
153153.76.0.0/17153.76.0.1 to 153.76.127.254153.76.127.25532,766
154153.76.128.0/17153.76.128.1 to 153.76.255.254153.76.255.25532,766
155153.77.0.0/17153.77.0.1 to 153.77.127.254153.77.127.25532,766
156153.77.128.0/17153.77.128.1 to 153.77.255.254153.77.255.25532,766
157153.78.0.0/17153.78.0.1 to 153.78.127.254153.78.127.25532,766
158153.78.128.0/17153.78.128.1 to 153.78.255.254153.78.255.25532,766
159153.79.0.0/17153.79.0.1 to 153.79.127.254153.79.127.25532,766
160153.79.128.0/17153.79.128.1 to 153.79.255.254153.79.255.25532,766
161153.80.0.0/17153.80.0.1 to 153.80.127.254153.80.127.25532,766
162153.80.128.0/17153.80.128.1 to 153.80.255.254153.80.255.25532,766
163153.81.0.0/17153.81.0.1 to 153.81.127.254153.81.127.25532,766
164153.81.128.0/17153.81.128.1 to 153.81.255.254153.81.255.25532,766
165153.82.0.0/17153.82.0.1 to 153.82.127.254153.82.127.25532,766
166153.82.128.0/17153.82.128.1 to 153.82.255.254153.82.255.25532,766
167153.83.0.0/17153.83.0.1 to 153.83.127.254153.83.127.25532,766
168153.83.128.0/17153.83.128.1 to 153.83.255.254153.83.255.25532,766
169153.84.0.0/17153.84.0.1 to 153.84.127.254153.84.127.25532,766
170153.84.128.0/17153.84.128.1 to 153.84.255.254153.84.255.25532,766
171153.85.0.0/17153.85.0.1 to 153.85.127.254153.85.127.25532,766
172153.85.128.0/17153.85.128.1 to 153.85.255.254153.85.255.25532,766
173153.86.0.0/17153.86.0.1 to 153.86.127.254153.86.127.25532,766
174153.86.128.0/17153.86.128.1 to 153.86.255.254153.86.255.25532,766
175153.87.0.0/17153.87.0.1 to 153.87.127.254153.87.127.25532,766
176153.87.128.0/17153.87.128.1 to 153.87.255.254153.87.255.25532,766
177153.88.0.0/17153.88.0.1 to 153.88.127.254153.88.127.25532,766
178153.88.128.0/17153.88.128.1 to 153.88.255.254153.88.255.25532,766
179153.89.0.0/17153.89.0.1 to 153.89.127.254153.89.127.25532,766
180153.89.128.0/17153.89.128.1 to 153.89.255.254153.89.255.25532,766
181153.90.0.0/17153.90.0.1 to 153.90.127.254153.90.127.25532,766
182153.90.128.0/17153.90.128.1 to 153.90.255.254153.90.255.25532,766
183153.91.0.0/17153.91.0.1 to 153.91.127.254153.91.127.25532,766
184153.91.128.0/17153.91.128.1 to 153.91.255.254153.91.255.25532,766
185153.92.0.0/17153.92.0.1 to 153.92.127.254153.92.127.25532,766
186153.92.128.0/17153.92.128.1 to 153.92.255.254153.92.255.25532,766
187153.93.0.0/17153.93.0.1 to 153.93.127.254153.93.127.25532,766
188153.93.128.0/17153.93.128.1 to 153.93.255.254153.93.255.25532,766
189153.94.0.0/17153.94.0.1 to 153.94.127.254153.94.127.25532,766
190153.94.128.0/17153.94.128.1 to 153.94.255.254153.94.255.25532,766
191153.95.0.0/17153.95.0.1 to 153.95.127.254153.95.127.25532,766
192153.95.128.0/17153.95.128.1 to 153.95.255.254153.95.255.25532,766
193153.96.0.0/17153.96.0.1 to 153.96.127.254153.96.127.25532,766
194153.96.128.0/17153.96.128.1 to 153.96.255.254153.96.255.25532,766
195153.97.0.0/17153.97.0.1 to 153.97.127.254153.97.127.25532,766
196153.97.128.0/17153.97.128.1 to 153.97.255.254153.97.255.25532,766
197153.98.0.0/17153.98.0.1 to 153.98.127.254153.98.127.25532,766
198153.98.128.0/17153.98.128.1 to 153.98.255.254153.98.255.25532,766
199153.99.0.0/17153.99.0.1 to 153.99.127.254153.99.127.25532,766
200153.99.128.0/17153.99.128.1 to 153.99.255.254153.99.255.25532,766
201153.100.0.0/17153.100.0.1 to 153.100.127.254153.100.127.25532,766
202153.100.128.0/17153.100.128.1 to 153.100.255.254153.100.255.25532,766
203153.101.0.0/17153.101.0.1 to 153.101.127.254153.101.127.25532,766
204153.101.128.0/17153.101.128.1 to 153.101.255.254153.101.255.25532,766
205153.102.0.0/17153.102.0.1 to 153.102.127.254153.102.127.25532,766
206153.102.128.0/17153.102.128.1 to 153.102.255.254153.102.255.25532,766
207153.103.0.0/17153.103.0.1 to 153.103.127.254153.103.127.25532,766
208153.103.128.0/17153.103.128.1 to 153.103.255.254153.103.255.25532,766
209153.104.0.0/17153.104.0.1 to 153.104.127.254153.104.127.25532,766
210153.104.128.0/17153.104.128.1 to 153.104.255.254153.104.255.25532,766
211153.105.0.0/17153.105.0.1 to 153.105.127.254153.105.127.25532,766
212153.105.128.0/17153.105.128.1 to 153.105.255.254153.105.255.25532,766
213153.106.0.0/17153.106.0.1 to 153.106.127.254153.106.127.25532,766
214153.106.128.0/17153.106.128.1 to 153.106.255.254153.106.255.25532,766
215153.107.0.0/17153.107.0.1 to 153.107.127.254153.107.127.25532,766
216153.107.128.0/17153.107.128.1 to 153.107.255.254153.107.255.25532,766
217153.108.0.0/17153.108.0.1 to 153.108.127.254153.108.127.25532,766
218153.108.128.0/17153.108.128.1 to 153.108.255.254153.108.255.25532,766
219153.109.0.0/17153.109.0.1 to 153.109.127.254153.109.127.25532,766
220153.109.128.0/17153.109.128.1 to 153.109.255.254153.109.255.25532,766
221153.110.0.0/17153.110.0.1 to 153.110.127.254153.110.127.25532,766
222153.110.128.0/17153.110.128.1 to 153.110.255.254153.110.255.25532,766
223153.111.0.0/17153.111.0.1 to 153.111.127.254153.111.127.25532,766
224153.111.128.0/17153.111.128.1 to 153.111.255.254153.111.255.25532,766
225153.112.0.0/17153.112.0.1 to 153.112.127.254153.112.127.25532,766
226153.112.128.0/17153.112.128.1 to 153.112.255.254153.112.255.25532,766
227153.113.0.0/17153.113.0.1 to 153.113.127.254153.113.127.25532,766
228153.113.128.0/17153.113.128.1 to 153.113.255.254153.113.255.25532,766
229153.114.0.0/17153.114.0.1 to 153.114.127.254153.114.127.25532,766
230153.114.128.0/17153.114.128.1 to 153.114.255.254153.114.255.25532,766
231153.115.0.0/17153.115.0.1 to 153.115.127.254153.115.127.25532,766
232153.115.128.0/17153.115.128.1 to 153.115.255.254153.115.255.25532,766
233153.116.0.0/17153.116.0.1 to 153.116.127.254153.116.127.25532,766
234153.116.128.0/17153.116.128.1 to 153.116.255.254153.116.255.25532,766
235153.117.0.0/17153.117.0.1 to 153.117.127.254153.117.127.25532,766
236153.117.128.0/17153.117.128.1 to 153.117.255.254153.117.255.25532,766
237153.118.0.0/17153.118.0.1 to 153.118.127.254153.118.127.25532,766
238153.118.128.0/17153.118.128.1 to 153.118.255.254153.118.255.25532,766
239153.119.0.0/17153.119.0.1 to 153.119.127.254153.119.127.25532,766
240153.119.128.0/17153.119.128.1 to 153.119.255.254153.119.255.25532,766
241153.120.0.0/17153.120.0.1 to 153.120.127.254153.120.127.25532,766
242153.120.128.0/17153.120.128.1 to 153.120.255.254153.120.255.25532,766
243153.121.0.0/17153.121.0.1 to 153.121.127.254153.121.127.25532,766
244153.121.128.0/17153.121.128.1 to 153.121.255.254153.121.255.25532,766
245153.122.0.0/17153.122.0.1 to 153.122.127.254153.122.127.25532,766
246153.122.128.0/17153.122.128.1 to 153.122.255.254153.122.255.25532,766
247153.123.0.0/17153.123.0.1 to 153.123.127.254153.123.127.25532,766
248153.123.128.0/17153.123.128.1 to 153.123.255.254153.123.255.25532,766
249153.124.0.0/17153.124.0.1 to 153.124.127.254153.124.127.25532,766
250153.124.128.0/17153.124.128.1 to 153.124.255.254153.124.255.25532,766
251153.125.0.0/17153.125.0.1 to 153.125.127.254153.125.127.25532,766
252153.125.128.0/17153.125.128.1 to 153.125.255.254153.125.255.25532,766
253153.126.0.0/17153.126.0.1 to 153.126.127.254153.126.127.25532,766
254153.126.128.0/17153.126.128.1 to 153.126.255.254153.126.255.25532,766
255153.127.0.0/17153.127.0.1 to 153.127.127.254153.127.127.25532,766
256153.127.128.0/17153.127.128.1 to 153.127.255.254153.127.255.25532,766

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.