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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.

Network132.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
132.0.0.0
Broadcast address
133.255.255.255
First usable
132.0.0.1
Last usable
133.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
B (default /16)
As numbers
Hex 84000000 · Integer 2214592512 to 2248146943
Reverse DNS zones
132.in-addr.arpa
133.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10000100.00000000.00000000.00000000132.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10000100.00000000.00000000.00000000132.0.0.0
Broadcast10000101.11111111.11111111.11111111133.255.255.255
Split into smaller subnets/17
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

132.0.0.0/7 makes 1,024 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1132.0.0.0/17132.0.0.1 to 132.0.127.254132.0.127.25532,766
2132.0.128.0/17132.0.128.1 to 132.0.255.254132.0.255.25532,766
3132.1.0.0/17132.1.0.1 to 132.1.127.254132.1.127.25532,766
4132.1.128.0/17132.1.128.1 to 132.1.255.254132.1.255.25532,766
5132.2.0.0/17132.2.0.1 to 132.2.127.254132.2.127.25532,766
6132.2.128.0/17132.2.128.1 to 132.2.255.254132.2.255.25532,766
7132.3.0.0/17132.3.0.1 to 132.3.127.254132.3.127.25532,766
8132.3.128.0/17132.3.128.1 to 132.3.255.254132.3.255.25532,766
9132.4.0.0/17132.4.0.1 to 132.4.127.254132.4.127.25532,766
10132.4.128.0/17132.4.128.1 to 132.4.255.254132.4.255.25532,766
11132.5.0.0/17132.5.0.1 to 132.5.127.254132.5.127.25532,766
12132.5.128.0/17132.5.128.1 to 132.5.255.254132.5.255.25532,766
13132.6.0.0/17132.6.0.1 to 132.6.127.254132.6.127.25532,766
14132.6.128.0/17132.6.128.1 to 132.6.255.254132.6.255.25532,766
15132.7.0.0/17132.7.0.1 to 132.7.127.254132.7.127.25532,766
16132.7.128.0/17132.7.128.1 to 132.7.255.254132.7.255.25532,766
17132.8.0.0/17132.8.0.1 to 132.8.127.254132.8.127.25532,766
18132.8.128.0/17132.8.128.1 to 132.8.255.254132.8.255.25532,766
19132.9.0.0/17132.9.0.1 to 132.9.127.254132.9.127.25532,766
20132.9.128.0/17132.9.128.1 to 132.9.255.254132.9.255.25532,766
21132.10.0.0/17132.10.0.1 to 132.10.127.254132.10.127.25532,766
22132.10.128.0/17132.10.128.1 to 132.10.255.254132.10.255.25532,766
23132.11.0.0/17132.11.0.1 to 132.11.127.254132.11.127.25532,766
24132.11.128.0/17132.11.128.1 to 132.11.255.254132.11.255.25532,766
25132.12.0.0/17132.12.0.1 to 132.12.127.254132.12.127.25532,766
26132.12.128.0/17132.12.128.1 to 132.12.255.254132.12.255.25532,766
27132.13.0.0/17132.13.0.1 to 132.13.127.254132.13.127.25532,766
28132.13.128.0/17132.13.128.1 to 132.13.255.254132.13.255.25532,766
29132.14.0.0/17132.14.0.1 to 132.14.127.254132.14.127.25532,766
30132.14.128.0/17132.14.128.1 to 132.14.255.254132.14.255.25532,766
31132.15.0.0/17132.15.0.1 to 132.15.127.254132.15.127.25532,766
32132.15.128.0/17132.15.128.1 to 132.15.255.254132.15.255.25532,766
33132.16.0.0/17132.16.0.1 to 132.16.127.254132.16.127.25532,766
34132.16.128.0/17132.16.128.1 to 132.16.255.254132.16.255.25532,766
35132.17.0.0/17132.17.0.1 to 132.17.127.254132.17.127.25532,766
36132.17.128.0/17132.17.128.1 to 132.17.255.254132.17.255.25532,766
37132.18.0.0/17132.18.0.1 to 132.18.127.254132.18.127.25532,766
38132.18.128.0/17132.18.128.1 to 132.18.255.254132.18.255.25532,766
39132.19.0.0/17132.19.0.1 to 132.19.127.254132.19.127.25532,766
40132.19.128.0/17132.19.128.1 to 132.19.255.254132.19.255.25532,766
41132.20.0.0/17132.20.0.1 to 132.20.127.254132.20.127.25532,766
42132.20.128.0/17132.20.128.1 to 132.20.255.254132.20.255.25532,766
43132.21.0.0/17132.21.0.1 to 132.21.127.254132.21.127.25532,766
44132.21.128.0/17132.21.128.1 to 132.21.255.254132.21.255.25532,766
45132.22.0.0/17132.22.0.1 to 132.22.127.254132.22.127.25532,766
46132.22.128.0/17132.22.128.1 to 132.22.255.254132.22.255.25532,766
47132.23.0.0/17132.23.0.1 to 132.23.127.254132.23.127.25532,766
48132.23.128.0/17132.23.128.1 to 132.23.255.254132.23.255.25532,766
49132.24.0.0/17132.24.0.1 to 132.24.127.254132.24.127.25532,766
50132.24.128.0/17132.24.128.1 to 132.24.255.254132.24.255.25532,766
51132.25.0.0/17132.25.0.1 to 132.25.127.254132.25.127.25532,766
52132.25.128.0/17132.25.128.1 to 132.25.255.254132.25.255.25532,766
53132.26.0.0/17132.26.0.1 to 132.26.127.254132.26.127.25532,766
54132.26.128.0/17132.26.128.1 to 132.26.255.254132.26.255.25532,766
55132.27.0.0/17132.27.0.1 to 132.27.127.254132.27.127.25532,766
56132.27.128.0/17132.27.128.1 to 132.27.255.254132.27.255.25532,766
57132.28.0.0/17132.28.0.1 to 132.28.127.254132.28.127.25532,766
58132.28.128.0/17132.28.128.1 to 132.28.255.254132.28.255.25532,766
59132.29.0.0/17132.29.0.1 to 132.29.127.254132.29.127.25532,766
60132.29.128.0/17132.29.128.1 to 132.29.255.254132.29.255.25532,766
61132.30.0.0/17132.30.0.1 to 132.30.127.254132.30.127.25532,766
62132.30.128.0/17132.30.128.1 to 132.30.255.254132.30.255.25532,766
63132.31.0.0/17132.31.0.1 to 132.31.127.254132.31.127.25532,766
64132.31.128.0/17132.31.128.1 to 132.31.255.254132.31.255.25532,766
65132.32.0.0/17132.32.0.1 to 132.32.127.254132.32.127.25532,766
66132.32.128.0/17132.32.128.1 to 132.32.255.254132.32.255.25532,766
67132.33.0.0/17132.33.0.1 to 132.33.127.254132.33.127.25532,766
68132.33.128.0/17132.33.128.1 to 132.33.255.254132.33.255.25532,766
69132.34.0.0/17132.34.0.1 to 132.34.127.254132.34.127.25532,766
70132.34.128.0/17132.34.128.1 to 132.34.255.254132.34.255.25532,766
71132.35.0.0/17132.35.0.1 to 132.35.127.254132.35.127.25532,766
72132.35.128.0/17132.35.128.1 to 132.35.255.254132.35.255.25532,766
73132.36.0.0/17132.36.0.1 to 132.36.127.254132.36.127.25532,766
74132.36.128.0/17132.36.128.1 to 132.36.255.254132.36.255.25532,766
75132.37.0.0/17132.37.0.1 to 132.37.127.254132.37.127.25532,766
76132.37.128.0/17132.37.128.1 to 132.37.255.254132.37.255.25532,766
77132.38.0.0/17132.38.0.1 to 132.38.127.254132.38.127.25532,766
78132.38.128.0/17132.38.128.1 to 132.38.255.254132.38.255.25532,766
79132.39.0.0/17132.39.0.1 to 132.39.127.254132.39.127.25532,766
80132.39.128.0/17132.39.128.1 to 132.39.255.254132.39.255.25532,766
81132.40.0.0/17132.40.0.1 to 132.40.127.254132.40.127.25532,766
82132.40.128.0/17132.40.128.1 to 132.40.255.254132.40.255.25532,766
83132.41.0.0/17132.41.0.1 to 132.41.127.254132.41.127.25532,766
84132.41.128.0/17132.41.128.1 to 132.41.255.254132.41.255.25532,766
85132.42.0.0/17132.42.0.1 to 132.42.127.254132.42.127.25532,766
86132.42.128.0/17132.42.128.1 to 132.42.255.254132.42.255.25532,766
87132.43.0.0/17132.43.0.1 to 132.43.127.254132.43.127.25532,766
88132.43.128.0/17132.43.128.1 to 132.43.255.254132.43.255.25532,766
89132.44.0.0/17132.44.0.1 to 132.44.127.254132.44.127.25532,766
90132.44.128.0/17132.44.128.1 to 132.44.255.254132.44.255.25532,766
91132.45.0.0/17132.45.0.1 to 132.45.127.254132.45.127.25532,766
92132.45.128.0/17132.45.128.1 to 132.45.255.254132.45.255.25532,766
93132.46.0.0/17132.46.0.1 to 132.46.127.254132.46.127.25532,766
94132.46.128.0/17132.46.128.1 to 132.46.255.254132.46.255.25532,766
95132.47.0.0/17132.47.0.1 to 132.47.127.254132.47.127.25532,766
96132.47.128.0/17132.47.128.1 to 132.47.255.254132.47.255.25532,766
97132.48.0.0/17132.48.0.1 to 132.48.127.254132.48.127.25532,766
98132.48.128.0/17132.48.128.1 to 132.48.255.254132.48.255.25532,766
99132.49.0.0/17132.49.0.1 to 132.49.127.254132.49.127.25532,766
100132.49.128.0/17132.49.128.1 to 132.49.255.254132.49.255.25532,766
101132.50.0.0/17132.50.0.1 to 132.50.127.254132.50.127.25532,766
102132.50.128.0/17132.50.128.1 to 132.50.255.254132.50.255.25532,766
103132.51.0.0/17132.51.0.1 to 132.51.127.254132.51.127.25532,766
104132.51.128.0/17132.51.128.1 to 132.51.255.254132.51.255.25532,766
105132.52.0.0/17132.52.0.1 to 132.52.127.254132.52.127.25532,766
106132.52.128.0/17132.52.128.1 to 132.52.255.254132.52.255.25532,766
107132.53.0.0/17132.53.0.1 to 132.53.127.254132.53.127.25532,766
108132.53.128.0/17132.53.128.1 to 132.53.255.254132.53.255.25532,766
109132.54.0.0/17132.54.0.1 to 132.54.127.254132.54.127.25532,766
110132.54.128.0/17132.54.128.1 to 132.54.255.254132.54.255.25532,766
111132.55.0.0/17132.55.0.1 to 132.55.127.254132.55.127.25532,766
112132.55.128.0/17132.55.128.1 to 132.55.255.254132.55.255.25532,766
113132.56.0.0/17132.56.0.1 to 132.56.127.254132.56.127.25532,766
114132.56.128.0/17132.56.128.1 to 132.56.255.254132.56.255.25532,766
115132.57.0.0/17132.57.0.1 to 132.57.127.254132.57.127.25532,766
116132.57.128.0/17132.57.128.1 to 132.57.255.254132.57.255.25532,766
117132.58.0.0/17132.58.0.1 to 132.58.127.254132.58.127.25532,766
118132.58.128.0/17132.58.128.1 to 132.58.255.254132.58.255.25532,766
119132.59.0.0/17132.59.0.1 to 132.59.127.254132.59.127.25532,766
120132.59.128.0/17132.59.128.1 to 132.59.255.254132.59.255.25532,766
121132.60.0.0/17132.60.0.1 to 132.60.127.254132.60.127.25532,766
122132.60.128.0/17132.60.128.1 to 132.60.255.254132.60.255.25532,766
123132.61.0.0/17132.61.0.1 to 132.61.127.254132.61.127.25532,766
124132.61.128.0/17132.61.128.1 to 132.61.255.254132.61.255.25532,766
125132.62.0.0/17132.62.0.1 to 132.62.127.254132.62.127.25532,766
126132.62.128.0/17132.62.128.1 to 132.62.255.254132.62.255.25532,766
127132.63.0.0/17132.63.0.1 to 132.63.127.254132.63.127.25532,766
128132.63.128.0/17132.63.128.1 to 132.63.255.254132.63.255.25532,766
129132.64.0.0/17132.64.0.1 to 132.64.127.254132.64.127.25532,766
130132.64.128.0/17132.64.128.1 to 132.64.255.254132.64.255.25532,766
131132.65.0.0/17132.65.0.1 to 132.65.127.254132.65.127.25532,766
132132.65.128.0/17132.65.128.1 to 132.65.255.254132.65.255.25532,766
133132.66.0.0/17132.66.0.1 to 132.66.127.254132.66.127.25532,766
134132.66.128.0/17132.66.128.1 to 132.66.255.254132.66.255.25532,766
135132.67.0.0/17132.67.0.1 to 132.67.127.254132.67.127.25532,766
136132.67.128.0/17132.67.128.1 to 132.67.255.254132.67.255.25532,766
137132.68.0.0/17132.68.0.1 to 132.68.127.254132.68.127.25532,766
138132.68.128.0/17132.68.128.1 to 132.68.255.254132.68.255.25532,766
139132.69.0.0/17132.69.0.1 to 132.69.127.254132.69.127.25532,766
140132.69.128.0/17132.69.128.1 to 132.69.255.254132.69.255.25532,766
141132.70.0.0/17132.70.0.1 to 132.70.127.254132.70.127.25532,766
142132.70.128.0/17132.70.128.1 to 132.70.255.254132.70.255.25532,766
143132.71.0.0/17132.71.0.1 to 132.71.127.254132.71.127.25532,766
144132.71.128.0/17132.71.128.1 to 132.71.255.254132.71.255.25532,766
145132.72.0.0/17132.72.0.1 to 132.72.127.254132.72.127.25532,766
146132.72.128.0/17132.72.128.1 to 132.72.255.254132.72.255.25532,766
147132.73.0.0/17132.73.0.1 to 132.73.127.254132.73.127.25532,766
148132.73.128.0/17132.73.128.1 to 132.73.255.254132.73.255.25532,766
149132.74.0.0/17132.74.0.1 to 132.74.127.254132.74.127.25532,766
150132.74.128.0/17132.74.128.1 to 132.74.255.254132.74.255.25532,766
151132.75.0.0/17132.75.0.1 to 132.75.127.254132.75.127.25532,766
152132.75.128.0/17132.75.128.1 to 132.75.255.254132.75.255.25532,766
153132.76.0.0/17132.76.0.1 to 132.76.127.254132.76.127.25532,766
154132.76.128.0/17132.76.128.1 to 132.76.255.254132.76.255.25532,766
155132.77.0.0/17132.77.0.1 to 132.77.127.254132.77.127.25532,766
156132.77.128.0/17132.77.128.1 to 132.77.255.254132.77.255.25532,766
157132.78.0.0/17132.78.0.1 to 132.78.127.254132.78.127.25532,766
158132.78.128.0/17132.78.128.1 to 132.78.255.254132.78.255.25532,766
159132.79.0.0/17132.79.0.1 to 132.79.127.254132.79.127.25532,766
160132.79.128.0/17132.79.128.1 to 132.79.255.254132.79.255.25532,766
161132.80.0.0/17132.80.0.1 to 132.80.127.254132.80.127.25532,766
162132.80.128.0/17132.80.128.1 to 132.80.255.254132.80.255.25532,766
163132.81.0.0/17132.81.0.1 to 132.81.127.254132.81.127.25532,766
164132.81.128.0/17132.81.128.1 to 132.81.255.254132.81.255.25532,766
165132.82.0.0/17132.82.0.1 to 132.82.127.254132.82.127.25532,766
166132.82.128.0/17132.82.128.1 to 132.82.255.254132.82.255.25532,766
167132.83.0.0/17132.83.0.1 to 132.83.127.254132.83.127.25532,766
168132.83.128.0/17132.83.128.1 to 132.83.255.254132.83.255.25532,766
169132.84.0.0/17132.84.0.1 to 132.84.127.254132.84.127.25532,766
170132.84.128.0/17132.84.128.1 to 132.84.255.254132.84.255.25532,766
171132.85.0.0/17132.85.0.1 to 132.85.127.254132.85.127.25532,766
172132.85.128.0/17132.85.128.1 to 132.85.255.254132.85.255.25532,766
173132.86.0.0/17132.86.0.1 to 132.86.127.254132.86.127.25532,766
174132.86.128.0/17132.86.128.1 to 132.86.255.254132.86.255.25532,766
175132.87.0.0/17132.87.0.1 to 132.87.127.254132.87.127.25532,766
176132.87.128.0/17132.87.128.1 to 132.87.255.254132.87.255.25532,766
177132.88.0.0/17132.88.0.1 to 132.88.127.254132.88.127.25532,766
178132.88.128.0/17132.88.128.1 to 132.88.255.254132.88.255.25532,766
179132.89.0.0/17132.89.0.1 to 132.89.127.254132.89.127.25532,766
180132.89.128.0/17132.89.128.1 to 132.89.255.254132.89.255.25532,766
181132.90.0.0/17132.90.0.1 to 132.90.127.254132.90.127.25532,766
182132.90.128.0/17132.90.128.1 to 132.90.255.254132.90.255.25532,766
183132.91.0.0/17132.91.0.1 to 132.91.127.254132.91.127.25532,766
184132.91.128.0/17132.91.128.1 to 132.91.255.254132.91.255.25532,766
185132.92.0.0/17132.92.0.1 to 132.92.127.254132.92.127.25532,766
186132.92.128.0/17132.92.128.1 to 132.92.255.254132.92.255.25532,766
187132.93.0.0/17132.93.0.1 to 132.93.127.254132.93.127.25532,766
188132.93.128.0/17132.93.128.1 to 132.93.255.254132.93.255.25532,766
189132.94.0.0/17132.94.0.1 to 132.94.127.254132.94.127.25532,766
190132.94.128.0/17132.94.128.1 to 132.94.255.254132.94.255.25532,766
191132.95.0.0/17132.95.0.1 to 132.95.127.254132.95.127.25532,766
192132.95.128.0/17132.95.128.1 to 132.95.255.254132.95.255.25532,766
193132.96.0.0/17132.96.0.1 to 132.96.127.254132.96.127.25532,766
194132.96.128.0/17132.96.128.1 to 132.96.255.254132.96.255.25532,766
195132.97.0.0/17132.97.0.1 to 132.97.127.254132.97.127.25532,766
196132.97.128.0/17132.97.128.1 to 132.97.255.254132.97.255.25532,766
197132.98.0.0/17132.98.0.1 to 132.98.127.254132.98.127.25532,766
198132.98.128.0/17132.98.128.1 to 132.98.255.254132.98.255.25532,766
199132.99.0.0/17132.99.0.1 to 132.99.127.254132.99.127.25532,766
200132.99.128.0/17132.99.128.1 to 132.99.255.254132.99.255.25532,766
201132.100.0.0/17132.100.0.1 to 132.100.127.254132.100.127.25532,766
202132.100.128.0/17132.100.128.1 to 132.100.255.254132.100.255.25532,766
203132.101.0.0/17132.101.0.1 to 132.101.127.254132.101.127.25532,766
204132.101.128.0/17132.101.128.1 to 132.101.255.254132.101.255.25532,766
205132.102.0.0/17132.102.0.1 to 132.102.127.254132.102.127.25532,766
206132.102.128.0/17132.102.128.1 to 132.102.255.254132.102.255.25532,766
207132.103.0.0/17132.103.0.1 to 132.103.127.254132.103.127.25532,766
208132.103.128.0/17132.103.128.1 to 132.103.255.254132.103.255.25532,766
209132.104.0.0/17132.104.0.1 to 132.104.127.254132.104.127.25532,766
210132.104.128.0/17132.104.128.1 to 132.104.255.254132.104.255.25532,766
211132.105.0.0/17132.105.0.1 to 132.105.127.254132.105.127.25532,766
212132.105.128.0/17132.105.128.1 to 132.105.255.254132.105.255.25532,766
213132.106.0.0/17132.106.0.1 to 132.106.127.254132.106.127.25532,766
214132.106.128.0/17132.106.128.1 to 132.106.255.254132.106.255.25532,766
215132.107.0.0/17132.107.0.1 to 132.107.127.254132.107.127.25532,766
216132.107.128.0/17132.107.128.1 to 132.107.255.254132.107.255.25532,766
217132.108.0.0/17132.108.0.1 to 132.108.127.254132.108.127.25532,766
218132.108.128.0/17132.108.128.1 to 132.108.255.254132.108.255.25532,766
219132.109.0.0/17132.109.0.1 to 132.109.127.254132.109.127.25532,766
220132.109.128.0/17132.109.128.1 to 132.109.255.254132.109.255.25532,766
221132.110.0.0/17132.110.0.1 to 132.110.127.254132.110.127.25532,766
222132.110.128.0/17132.110.128.1 to 132.110.255.254132.110.255.25532,766
223132.111.0.0/17132.111.0.1 to 132.111.127.254132.111.127.25532,766
224132.111.128.0/17132.111.128.1 to 132.111.255.254132.111.255.25532,766
225132.112.0.0/17132.112.0.1 to 132.112.127.254132.112.127.25532,766
226132.112.128.0/17132.112.128.1 to 132.112.255.254132.112.255.25532,766
227132.113.0.0/17132.113.0.1 to 132.113.127.254132.113.127.25532,766
228132.113.128.0/17132.113.128.1 to 132.113.255.254132.113.255.25532,766
229132.114.0.0/17132.114.0.1 to 132.114.127.254132.114.127.25532,766
230132.114.128.0/17132.114.128.1 to 132.114.255.254132.114.255.25532,766
231132.115.0.0/17132.115.0.1 to 132.115.127.254132.115.127.25532,766
232132.115.128.0/17132.115.128.1 to 132.115.255.254132.115.255.25532,766
233132.116.0.0/17132.116.0.1 to 132.116.127.254132.116.127.25532,766
234132.116.128.0/17132.116.128.1 to 132.116.255.254132.116.255.25532,766
235132.117.0.0/17132.117.0.1 to 132.117.127.254132.117.127.25532,766
236132.117.128.0/17132.117.128.1 to 132.117.255.254132.117.255.25532,766
237132.118.0.0/17132.118.0.1 to 132.118.127.254132.118.127.25532,766
238132.118.128.0/17132.118.128.1 to 132.118.255.254132.118.255.25532,766
239132.119.0.0/17132.119.0.1 to 132.119.127.254132.119.127.25532,766
240132.119.128.0/17132.119.128.1 to 132.119.255.254132.119.255.25532,766
241132.120.0.0/17132.120.0.1 to 132.120.127.254132.120.127.25532,766
242132.120.128.0/17132.120.128.1 to 132.120.255.254132.120.255.25532,766
243132.121.0.0/17132.121.0.1 to 132.121.127.254132.121.127.25532,766
244132.121.128.0/17132.121.128.1 to 132.121.255.254132.121.255.25532,766
245132.122.0.0/17132.122.0.1 to 132.122.127.254132.122.127.25532,766
246132.122.128.0/17132.122.128.1 to 132.122.255.254132.122.255.25532,766
247132.123.0.0/17132.123.0.1 to 132.123.127.254132.123.127.25532,766
248132.123.128.0/17132.123.128.1 to 132.123.255.254132.123.255.25532,766
249132.124.0.0/17132.124.0.1 to 132.124.127.254132.124.127.25532,766
250132.124.128.0/17132.124.128.1 to 132.124.255.254132.124.255.25532,766
251132.125.0.0/17132.125.0.1 to 132.125.127.254132.125.127.25532,766
252132.125.128.0/17132.125.128.1 to 132.125.255.254132.125.255.25532,766
253132.126.0.0/17132.126.0.1 to 132.126.127.254132.126.127.25532,766
254132.126.128.0/17132.126.128.1 to 132.126.255.254132.126.255.25532,766
255132.127.0.0/17132.127.0.1 to 132.127.127.254132.127.127.25532,766
256132.127.128.0/17132.127.128.1 to 132.127.255.254132.127.255.25532,766

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.