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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.

Network176.166.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
176.166.0.0
Broadcast address
176.166.255.255
First usable
176.166.0.1
Last usable
176.166.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
B (default /16)
As numbers
Hex B0A60000 · Integer 2963668992 to 2963734527
Reverse DNS zone
166.176.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110000.10100110..00000000.00000000176.166.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10110000.10100110..00000000.00000000176.166.0.0
Broadcast10110000.10100110..11111111.11111111176.166.255.255
Split into smaller subnets/26
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

176.166.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1176.166.0.0/26176.166.0.1 to 176.166.0.62176.166.0.6362
2176.166.0.64/26176.166.0.65 to 176.166.0.126176.166.0.12762
3176.166.0.128/26176.166.0.129 to 176.166.0.190176.166.0.19162
4176.166.0.192/26176.166.0.193 to 176.166.0.254176.166.0.25562
5176.166.1.0/26176.166.1.1 to 176.166.1.62176.166.1.6362
6176.166.1.64/26176.166.1.65 to 176.166.1.126176.166.1.12762
7176.166.1.128/26176.166.1.129 to 176.166.1.190176.166.1.19162
8176.166.1.192/26176.166.1.193 to 176.166.1.254176.166.1.25562
9176.166.2.0/26176.166.2.1 to 176.166.2.62176.166.2.6362
10176.166.2.64/26176.166.2.65 to 176.166.2.126176.166.2.12762
11176.166.2.128/26176.166.2.129 to 176.166.2.190176.166.2.19162
12176.166.2.192/26176.166.2.193 to 176.166.2.254176.166.2.25562
13176.166.3.0/26176.166.3.1 to 176.166.3.62176.166.3.6362
14176.166.3.64/26176.166.3.65 to 176.166.3.126176.166.3.12762
15176.166.3.128/26176.166.3.129 to 176.166.3.190176.166.3.19162
16176.166.3.192/26176.166.3.193 to 176.166.3.254176.166.3.25562
17176.166.4.0/26176.166.4.1 to 176.166.4.62176.166.4.6362
18176.166.4.64/26176.166.4.65 to 176.166.4.126176.166.4.12762
19176.166.4.128/26176.166.4.129 to 176.166.4.190176.166.4.19162
20176.166.4.192/26176.166.4.193 to 176.166.4.254176.166.4.25562
21176.166.5.0/26176.166.5.1 to 176.166.5.62176.166.5.6362
22176.166.5.64/26176.166.5.65 to 176.166.5.126176.166.5.12762
23176.166.5.128/26176.166.5.129 to 176.166.5.190176.166.5.19162
24176.166.5.192/26176.166.5.193 to 176.166.5.254176.166.5.25562
25176.166.6.0/26176.166.6.1 to 176.166.6.62176.166.6.6362
26176.166.6.64/26176.166.6.65 to 176.166.6.126176.166.6.12762
27176.166.6.128/26176.166.6.129 to 176.166.6.190176.166.6.19162
28176.166.6.192/26176.166.6.193 to 176.166.6.254176.166.6.25562
29176.166.7.0/26176.166.7.1 to 176.166.7.62176.166.7.6362
30176.166.7.64/26176.166.7.65 to 176.166.7.126176.166.7.12762
31176.166.7.128/26176.166.7.129 to 176.166.7.190176.166.7.19162
32176.166.7.192/26176.166.7.193 to 176.166.7.254176.166.7.25562
33176.166.8.0/26176.166.8.1 to 176.166.8.62176.166.8.6362
34176.166.8.64/26176.166.8.65 to 176.166.8.126176.166.8.12762
35176.166.8.128/26176.166.8.129 to 176.166.8.190176.166.8.19162
36176.166.8.192/26176.166.8.193 to 176.166.8.254176.166.8.25562
37176.166.9.0/26176.166.9.1 to 176.166.9.62176.166.9.6362
38176.166.9.64/26176.166.9.65 to 176.166.9.126176.166.9.12762
39176.166.9.128/26176.166.9.129 to 176.166.9.190176.166.9.19162
40176.166.9.192/26176.166.9.193 to 176.166.9.254176.166.9.25562
41176.166.10.0/26176.166.10.1 to 176.166.10.62176.166.10.6362
42176.166.10.64/26176.166.10.65 to 176.166.10.126176.166.10.12762
43176.166.10.128/26176.166.10.129 to 176.166.10.190176.166.10.19162
44176.166.10.192/26176.166.10.193 to 176.166.10.254176.166.10.25562
45176.166.11.0/26176.166.11.1 to 176.166.11.62176.166.11.6362
46176.166.11.64/26176.166.11.65 to 176.166.11.126176.166.11.12762
47176.166.11.128/26176.166.11.129 to 176.166.11.190176.166.11.19162
48176.166.11.192/26176.166.11.193 to 176.166.11.254176.166.11.25562
49176.166.12.0/26176.166.12.1 to 176.166.12.62176.166.12.6362
50176.166.12.64/26176.166.12.65 to 176.166.12.126176.166.12.12762
51176.166.12.128/26176.166.12.129 to 176.166.12.190176.166.12.19162
52176.166.12.192/26176.166.12.193 to 176.166.12.254176.166.12.25562
53176.166.13.0/26176.166.13.1 to 176.166.13.62176.166.13.6362
54176.166.13.64/26176.166.13.65 to 176.166.13.126176.166.13.12762
55176.166.13.128/26176.166.13.129 to 176.166.13.190176.166.13.19162
56176.166.13.192/26176.166.13.193 to 176.166.13.254176.166.13.25562
57176.166.14.0/26176.166.14.1 to 176.166.14.62176.166.14.6362
58176.166.14.64/26176.166.14.65 to 176.166.14.126176.166.14.12762
59176.166.14.128/26176.166.14.129 to 176.166.14.190176.166.14.19162
60176.166.14.192/26176.166.14.193 to 176.166.14.254176.166.14.25562
61176.166.15.0/26176.166.15.1 to 176.166.15.62176.166.15.6362
62176.166.15.64/26176.166.15.65 to 176.166.15.126176.166.15.12762
63176.166.15.128/26176.166.15.129 to 176.166.15.190176.166.15.19162
64176.166.15.192/26176.166.15.193 to 176.166.15.254176.166.15.25562
65176.166.16.0/26176.166.16.1 to 176.166.16.62176.166.16.6362
66176.166.16.64/26176.166.16.65 to 176.166.16.126176.166.16.12762
67176.166.16.128/26176.166.16.129 to 176.166.16.190176.166.16.19162
68176.166.16.192/26176.166.16.193 to 176.166.16.254176.166.16.25562
69176.166.17.0/26176.166.17.1 to 176.166.17.62176.166.17.6362
70176.166.17.64/26176.166.17.65 to 176.166.17.126176.166.17.12762
71176.166.17.128/26176.166.17.129 to 176.166.17.190176.166.17.19162
72176.166.17.192/26176.166.17.193 to 176.166.17.254176.166.17.25562
73176.166.18.0/26176.166.18.1 to 176.166.18.62176.166.18.6362
74176.166.18.64/26176.166.18.65 to 176.166.18.126176.166.18.12762
75176.166.18.128/26176.166.18.129 to 176.166.18.190176.166.18.19162
76176.166.18.192/26176.166.18.193 to 176.166.18.254176.166.18.25562
77176.166.19.0/26176.166.19.1 to 176.166.19.62176.166.19.6362
78176.166.19.64/26176.166.19.65 to 176.166.19.126176.166.19.12762
79176.166.19.128/26176.166.19.129 to 176.166.19.190176.166.19.19162
80176.166.19.192/26176.166.19.193 to 176.166.19.254176.166.19.25562
81176.166.20.0/26176.166.20.1 to 176.166.20.62176.166.20.6362
82176.166.20.64/26176.166.20.65 to 176.166.20.126176.166.20.12762
83176.166.20.128/26176.166.20.129 to 176.166.20.190176.166.20.19162
84176.166.20.192/26176.166.20.193 to 176.166.20.254176.166.20.25562
85176.166.21.0/26176.166.21.1 to 176.166.21.62176.166.21.6362
86176.166.21.64/26176.166.21.65 to 176.166.21.126176.166.21.12762
87176.166.21.128/26176.166.21.129 to 176.166.21.190176.166.21.19162
88176.166.21.192/26176.166.21.193 to 176.166.21.254176.166.21.25562
89176.166.22.0/26176.166.22.1 to 176.166.22.62176.166.22.6362
90176.166.22.64/26176.166.22.65 to 176.166.22.126176.166.22.12762
91176.166.22.128/26176.166.22.129 to 176.166.22.190176.166.22.19162
92176.166.22.192/26176.166.22.193 to 176.166.22.254176.166.22.25562
93176.166.23.0/26176.166.23.1 to 176.166.23.62176.166.23.6362
94176.166.23.64/26176.166.23.65 to 176.166.23.126176.166.23.12762
95176.166.23.128/26176.166.23.129 to 176.166.23.190176.166.23.19162
96176.166.23.192/26176.166.23.193 to 176.166.23.254176.166.23.25562
97176.166.24.0/26176.166.24.1 to 176.166.24.62176.166.24.6362
98176.166.24.64/26176.166.24.65 to 176.166.24.126176.166.24.12762
99176.166.24.128/26176.166.24.129 to 176.166.24.190176.166.24.19162
100176.166.24.192/26176.166.24.193 to 176.166.24.254176.166.24.25562
101176.166.25.0/26176.166.25.1 to 176.166.25.62176.166.25.6362
102176.166.25.64/26176.166.25.65 to 176.166.25.126176.166.25.12762
103176.166.25.128/26176.166.25.129 to 176.166.25.190176.166.25.19162
104176.166.25.192/26176.166.25.193 to 176.166.25.254176.166.25.25562
105176.166.26.0/26176.166.26.1 to 176.166.26.62176.166.26.6362
106176.166.26.64/26176.166.26.65 to 176.166.26.126176.166.26.12762
107176.166.26.128/26176.166.26.129 to 176.166.26.190176.166.26.19162
108176.166.26.192/26176.166.26.193 to 176.166.26.254176.166.26.25562
109176.166.27.0/26176.166.27.1 to 176.166.27.62176.166.27.6362
110176.166.27.64/26176.166.27.65 to 176.166.27.126176.166.27.12762
111176.166.27.128/26176.166.27.129 to 176.166.27.190176.166.27.19162
112176.166.27.192/26176.166.27.193 to 176.166.27.254176.166.27.25562
113176.166.28.0/26176.166.28.1 to 176.166.28.62176.166.28.6362
114176.166.28.64/26176.166.28.65 to 176.166.28.126176.166.28.12762
115176.166.28.128/26176.166.28.129 to 176.166.28.190176.166.28.19162
116176.166.28.192/26176.166.28.193 to 176.166.28.254176.166.28.25562
117176.166.29.0/26176.166.29.1 to 176.166.29.62176.166.29.6362
118176.166.29.64/26176.166.29.65 to 176.166.29.126176.166.29.12762
119176.166.29.128/26176.166.29.129 to 176.166.29.190176.166.29.19162
120176.166.29.192/26176.166.29.193 to 176.166.29.254176.166.29.25562
121176.166.30.0/26176.166.30.1 to 176.166.30.62176.166.30.6362
122176.166.30.64/26176.166.30.65 to 176.166.30.126176.166.30.12762
123176.166.30.128/26176.166.30.129 to 176.166.30.190176.166.30.19162
124176.166.30.192/26176.166.30.193 to 176.166.30.254176.166.30.25562
125176.166.31.0/26176.166.31.1 to 176.166.31.62176.166.31.6362
126176.166.31.64/26176.166.31.65 to 176.166.31.126176.166.31.12762
127176.166.31.128/26176.166.31.129 to 176.166.31.190176.166.31.19162
128176.166.31.192/26176.166.31.193 to 176.166.31.254176.166.31.25562
129176.166.32.0/26176.166.32.1 to 176.166.32.62176.166.32.6362
130176.166.32.64/26176.166.32.65 to 176.166.32.126176.166.32.12762
131176.166.32.128/26176.166.32.129 to 176.166.32.190176.166.32.19162
132176.166.32.192/26176.166.32.193 to 176.166.32.254176.166.32.25562
133176.166.33.0/26176.166.33.1 to 176.166.33.62176.166.33.6362
134176.166.33.64/26176.166.33.65 to 176.166.33.126176.166.33.12762
135176.166.33.128/26176.166.33.129 to 176.166.33.190176.166.33.19162
136176.166.33.192/26176.166.33.193 to 176.166.33.254176.166.33.25562
137176.166.34.0/26176.166.34.1 to 176.166.34.62176.166.34.6362
138176.166.34.64/26176.166.34.65 to 176.166.34.126176.166.34.12762
139176.166.34.128/26176.166.34.129 to 176.166.34.190176.166.34.19162
140176.166.34.192/26176.166.34.193 to 176.166.34.254176.166.34.25562
141176.166.35.0/26176.166.35.1 to 176.166.35.62176.166.35.6362
142176.166.35.64/26176.166.35.65 to 176.166.35.126176.166.35.12762
143176.166.35.128/26176.166.35.129 to 176.166.35.190176.166.35.19162
144176.166.35.192/26176.166.35.193 to 176.166.35.254176.166.35.25562
145176.166.36.0/26176.166.36.1 to 176.166.36.62176.166.36.6362
146176.166.36.64/26176.166.36.65 to 176.166.36.126176.166.36.12762
147176.166.36.128/26176.166.36.129 to 176.166.36.190176.166.36.19162
148176.166.36.192/26176.166.36.193 to 176.166.36.254176.166.36.25562
149176.166.37.0/26176.166.37.1 to 176.166.37.62176.166.37.6362
150176.166.37.64/26176.166.37.65 to 176.166.37.126176.166.37.12762
151176.166.37.128/26176.166.37.129 to 176.166.37.190176.166.37.19162
152176.166.37.192/26176.166.37.193 to 176.166.37.254176.166.37.25562
153176.166.38.0/26176.166.38.1 to 176.166.38.62176.166.38.6362
154176.166.38.64/26176.166.38.65 to 176.166.38.126176.166.38.12762
155176.166.38.128/26176.166.38.129 to 176.166.38.190176.166.38.19162
156176.166.38.192/26176.166.38.193 to 176.166.38.254176.166.38.25562
157176.166.39.0/26176.166.39.1 to 176.166.39.62176.166.39.6362
158176.166.39.64/26176.166.39.65 to 176.166.39.126176.166.39.12762
159176.166.39.128/26176.166.39.129 to 176.166.39.190176.166.39.19162
160176.166.39.192/26176.166.39.193 to 176.166.39.254176.166.39.25562
161176.166.40.0/26176.166.40.1 to 176.166.40.62176.166.40.6362
162176.166.40.64/26176.166.40.65 to 176.166.40.126176.166.40.12762
163176.166.40.128/26176.166.40.129 to 176.166.40.190176.166.40.19162
164176.166.40.192/26176.166.40.193 to 176.166.40.254176.166.40.25562
165176.166.41.0/26176.166.41.1 to 176.166.41.62176.166.41.6362
166176.166.41.64/26176.166.41.65 to 176.166.41.126176.166.41.12762
167176.166.41.128/26176.166.41.129 to 176.166.41.190176.166.41.19162
168176.166.41.192/26176.166.41.193 to 176.166.41.254176.166.41.25562
169176.166.42.0/26176.166.42.1 to 176.166.42.62176.166.42.6362
170176.166.42.64/26176.166.42.65 to 176.166.42.126176.166.42.12762
171176.166.42.128/26176.166.42.129 to 176.166.42.190176.166.42.19162
172176.166.42.192/26176.166.42.193 to 176.166.42.254176.166.42.25562
173176.166.43.0/26176.166.43.1 to 176.166.43.62176.166.43.6362
174176.166.43.64/26176.166.43.65 to 176.166.43.126176.166.43.12762
175176.166.43.128/26176.166.43.129 to 176.166.43.190176.166.43.19162
176176.166.43.192/26176.166.43.193 to 176.166.43.254176.166.43.25562
177176.166.44.0/26176.166.44.1 to 176.166.44.62176.166.44.6362
178176.166.44.64/26176.166.44.65 to 176.166.44.126176.166.44.12762
179176.166.44.128/26176.166.44.129 to 176.166.44.190176.166.44.19162
180176.166.44.192/26176.166.44.193 to 176.166.44.254176.166.44.25562
181176.166.45.0/26176.166.45.1 to 176.166.45.62176.166.45.6362
182176.166.45.64/26176.166.45.65 to 176.166.45.126176.166.45.12762
183176.166.45.128/26176.166.45.129 to 176.166.45.190176.166.45.19162
184176.166.45.192/26176.166.45.193 to 176.166.45.254176.166.45.25562
185176.166.46.0/26176.166.46.1 to 176.166.46.62176.166.46.6362
186176.166.46.64/26176.166.46.65 to 176.166.46.126176.166.46.12762
187176.166.46.128/26176.166.46.129 to 176.166.46.190176.166.46.19162
188176.166.46.192/26176.166.46.193 to 176.166.46.254176.166.46.25562
189176.166.47.0/26176.166.47.1 to 176.166.47.62176.166.47.6362
190176.166.47.64/26176.166.47.65 to 176.166.47.126176.166.47.12762
191176.166.47.128/26176.166.47.129 to 176.166.47.190176.166.47.19162
192176.166.47.192/26176.166.47.193 to 176.166.47.254176.166.47.25562
193176.166.48.0/26176.166.48.1 to 176.166.48.62176.166.48.6362
194176.166.48.64/26176.166.48.65 to 176.166.48.126176.166.48.12762
195176.166.48.128/26176.166.48.129 to 176.166.48.190176.166.48.19162
196176.166.48.192/26176.166.48.193 to 176.166.48.254176.166.48.25562
197176.166.49.0/26176.166.49.1 to 176.166.49.62176.166.49.6362
198176.166.49.64/26176.166.49.65 to 176.166.49.126176.166.49.12762
199176.166.49.128/26176.166.49.129 to 176.166.49.190176.166.49.19162
200176.166.49.192/26176.166.49.193 to 176.166.49.254176.166.49.25562
201176.166.50.0/26176.166.50.1 to 176.166.50.62176.166.50.6362
202176.166.50.64/26176.166.50.65 to 176.166.50.126176.166.50.12762
203176.166.50.128/26176.166.50.129 to 176.166.50.190176.166.50.19162
204176.166.50.192/26176.166.50.193 to 176.166.50.254176.166.50.25562
205176.166.51.0/26176.166.51.1 to 176.166.51.62176.166.51.6362
206176.166.51.64/26176.166.51.65 to 176.166.51.126176.166.51.12762
207176.166.51.128/26176.166.51.129 to 176.166.51.190176.166.51.19162
208176.166.51.192/26176.166.51.193 to 176.166.51.254176.166.51.25562
209176.166.52.0/26176.166.52.1 to 176.166.52.62176.166.52.6362
210176.166.52.64/26176.166.52.65 to 176.166.52.126176.166.52.12762
211176.166.52.128/26176.166.52.129 to 176.166.52.190176.166.52.19162
212176.166.52.192/26176.166.52.193 to 176.166.52.254176.166.52.25562
213176.166.53.0/26176.166.53.1 to 176.166.53.62176.166.53.6362
214176.166.53.64/26176.166.53.65 to 176.166.53.126176.166.53.12762
215176.166.53.128/26176.166.53.129 to 176.166.53.190176.166.53.19162
216176.166.53.192/26176.166.53.193 to 176.166.53.254176.166.53.25562
217176.166.54.0/26176.166.54.1 to 176.166.54.62176.166.54.6362
218176.166.54.64/26176.166.54.65 to 176.166.54.126176.166.54.12762
219176.166.54.128/26176.166.54.129 to 176.166.54.190176.166.54.19162
220176.166.54.192/26176.166.54.193 to 176.166.54.254176.166.54.25562
221176.166.55.0/26176.166.55.1 to 176.166.55.62176.166.55.6362
222176.166.55.64/26176.166.55.65 to 176.166.55.126176.166.55.12762
223176.166.55.128/26176.166.55.129 to 176.166.55.190176.166.55.19162
224176.166.55.192/26176.166.55.193 to 176.166.55.254176.166.55.25562
225176.166.56.0/26176.166.56.1 to 176.166.56.62176.166.56.6362
226176.166.56.64/26176.166.56.65 to 176.166.56.126176.166.56.12762
227176.166.56.128/26176.166.56.129 to 176.166.56.190176.166.56.19162
228176.166.56.192/26176.166.56.193 to 176.166.56.254176.166.56.25562
229176.166.57.0/26176.166.57.1 to 176.166.57.62176.166.57.6362
230176.166.57.64/26176.166.57.65 to 176.166.57.126176.166.57.12762
231176.166.57.128/26176.166.57.129 to 176.166.57.190176.166.57.19162
232176.166.57.192/26176.166.57.193 to 176.166.57.254176.166.57.25562
233176.166.58.0/26176.166.58.1 to 176.166.58.62176.166.58.6362
234176.166.58.64/26176.166.58.65 to 176.166.58.126176.166.58.12762
235176.166.58.128/26176.166.58.129 to 176.166.58.190176.166.58.19162
236176.166.58.192/26176.166.58.193 to 176.166.58.254176.166.58.25562
237176.166.59.0/26176.166.59.1 to 176.166.59.62176.166.59.6362
238176.166.59.64/26176.166.59.65 to 176.166.59.126176.166.59.12762
239176.166.59.128/26176.166.59.129 to 176.166.59.190176.166.59.19162
240176.166.59.192/26176.166.59.193 to 176.166.59.254176.166.59.25562
241176.166.60.0/26176.166.60.1 to 176.166.60.62176.166.60.6362
242176.166.60.64/26176.166.60.65 to 176.166.60.126176.166.60.12762
243176.166.60.128/26176.166.60.129 to 176.166.60.190176.166.60.19162
244176.166.60.192/26176.166.60.193 to 176.166.60.254176.166.60.25562
245176.166.61.0/26176.166.61.1 to 176.166.61.62176.166.61.6362
246176.166.61.64/26176.166.61.65 to 176.166.61.126176.166.61.12762
247176.166.61.128/26176.166.61.129 to 176.166.61.190176.166.61.19162
248176.166.61.192/26176.166.61.193 to 176.166.61.254176.166.61.25562
249176.166.62.0/26176.166.62.1 to 176.166.62.62176.166.62.6362
250176.166.62.64/26176.166.62.65 to 176.166.62.126176.166.62.12762
251176.166.62.128/26176.166.62.129 to 176.166.62.190176.166.62.19162
252176.166.62.192/26176.166.62.193 to 176.166.62.254176.166.62.25562
253176.166.63.0/26176.166.63.1 to 176.166.63.62176.166.63.6362
254176.166.63.64/26176.166.63.65 to 176.166.63.126176.166.63.12762
255176.166.63.128/26176.166.63.129 to 176.166.63.190176.166.63.19162
256176.166.63.192/26176.166.63.193 to 176.166.63.254176.166.63.25562

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.