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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.

Network201.86.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
201.86.0.0
Broadcast address
201.87.255.255
First usable
201.86.0.1
Last usable
201.87.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
C (default /24)
As numbers
Hex C9560000 · Integer 3377856512 to 3377987583
Reverse DNS zones
86.201.in-addr.arpa
87.201.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11001001.01010110.00000000.00000000201.86.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network11001001.01010110.00000000.00000000201.86.0.0
Broadcast11001001.01010111.11111111.11111111201.87.255.255
Split into smaller subnets/26
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

201.86.0.0/15 makes 2,048 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1201.86.0.0/26201.86.0.1 to 201.86.0.62201.86.0.6362
2201.86.0.64/26201.86.0.65 to 201.86.0.126201.86.0.12762
3201.86.0.128/26201.86.0.129 to 201.86.0.190201.86.0.19162
4201.86.0.192/26201.86.0.193 to 201.86.0.254201.86.0.25562
5201.86.1.0/26201.86.1.1 to 201.86.1.62201.86.1.6362
6201.86.1.64/26201.86.1.65 to 201.86.1.126201.86.1.12762
7201.86.1.128/26201.86.1.129 to 201.86.1.190201.86.1.19162
8201.86.1.192/26201.86.1.193 to 201.86.1.254201.86.1.25562
9201.86.2.0/26201.86.2.1 to 201.86.2.62201.86.2.6362
10201.86.2.64/26201.86.2.65 to 201.86.2.126201.86.2.12762
11201.86.2.128/26201.86.2.129 to 201.86.2.190201.86.2.19162
12201.86.2.192/26201.86.2.193 to 201.86.2.254201.86.2.25562
13201.86.3.0/26201.86.3.1 to 201.86.3.62201.86.3.6362
14201.86.3.64/26201.86.3.65 to 201.86.3.126201.86.3.12762
15201.86.3.128/26201.86.3.129 to 201.86.3.190201.86.3.19162
16201.86.3.192/26201.86.3.193 to 201.86.3.254201.86.3.25562
17201.86.4.0/26201.86.4.1 to 201.86.4.62201.86.4.6362
18201.86.4.64/26201.86.4.65 to 201.86.4.126201.86.4.12762
19201.86.4.128/26201.86.4.129 to 201.86.4.190201.86.4.19162
20201.86.4.192/26201.86.4.193 to 201.86.4.254201.86.4.25562
21201.86.5.0/26201.86.5.1 to 201.86.5.62201.86.5.6362
22201.86.5.64/26201.86.5.65 to 201.86.5.126201.86.5.12762
23201.86.5.128/26201.86.5.129 to 201.86.5.190201.86.5.19162
24201.86.5.192/26201.86.5.193 to 201.86.5.254201.86.5.25562
25201.86.6.0/26201.86.6.1 to 201.86.6.62201.86.6.6362
26201.86.6.64/26201.86.6.65 to 201.86.6.126201.86.6.12762
27201.86.6.128/26201.86.6.129 to 201.86.6.190201.86.6.19162
28201.86.6.192/26201.86.6.193 to 201.86.6.254201.86.6.25562
29201.86.7.0/26201.86.7.1 to 201.86.7.62201.86.7.6362
30201.86.7.64/26201.86.7.65 to 201.86.7.126201.86.7.12762
31201.86.7.128/26201.86.7.129 to 201.86.7.190201.86.7.19162
32201.86.7.192/26201.86.7.193 to 201.86.7.254201.86.7.25562
33201.86.8.0/26201.86.8.1 to 201.86.8.62201.86.8.6362
34201.86.8.64/26201.86.8.65 to 201.86.8.126201.86.8.12762
35201.86.8.128/26201.86.8.129 to 201.86.8.190201.86.8.19162
36201.86.8.192/26201.86.8.193 to 201.86.8.254201.86.8.25562
37201.86.9.0/26201.86.9.1 to 201.86.9.62201.86.9.6362
38201.86.9.64/26201.86.9.65 to 201.86.9.126201.86.9.12762
39201.86.9.128/26201.86.9.129 to 201.86.9.190201.86.9.19162
40201.86.9.192/26201.86.9.193 to 201.86.9.254201.86.9.25562
41201.86.10.0/26201.86.10.1 to 201.86.10.62201.86.10.6362
42201.86.10.64/26201.86.10.65 to 201.86.10.126201.86.10.12762
43201.86.10.128/26201.86.10.129 to 201.86.10.190201.86.10.19162
44201.86.10.192/26201.86.10.193 to 201.86.10.254201.86.10.25562
45201.86.11.0/26201.86.11.1 to 201.86.11.62201.86.11.6362
46201.86.11.64/26201.86.11.65 to 201.86.11.126201.86.11.12762
47201.86.11.128/26201.86.11.129 to 201.86.11.190201.86.11.19162
48201.86.11.192/26201.86.11.193 to 201.86.11.254201.86.11.25562
49201.86.12.0/26201.86.12.1 to 201.86.12.62201.86.12.6362
50201.86.12.64/26201.86.12.65 to 201.86.12.126201.86.12.12762
51201.86.12.128/26201.86.12.129 to 201.86.12.190201.86.12.19162
52201.86.12.192/26201.86.12.193 to 201.86.12.254201.86.12.25562
53201.86.13.0/26201.86.13.1 to 201.86.13.62201.86.13.6362
54201.86.13.64/26201.86.13.65 to 201.86.13.126201.86.13.12762
55201.86.13.128/26201.86.13.129 to 201.86.13.190201.86.13.19162
56201.86.13.192/26201.86.13.193 to 201.86.13.254201.86.13.25562
57201.86.14.0/26201.86.14.1 to 201.86.14.62201.86.14.6362
58201.86.14.64/26201.86.14.65 to 201.86.14.126201.86.14.12762
59201.86.14.128/26201.86.14.129 to 201.86.14.190201.86.14.19162
60201.86.14.192/26201.86.14.193 to 201.86.14.254201.86.14.25562
61201.86.15.0/26201.86.15.1 to 201.86.15.62201.86.15.6362
62201.86.15.64/26201.86.15.65 to 201.86.15.126201.86.15.12762
63201.86.15.128/26201.86.15.129 to 201.86.15.190201.86.15.19162
64201.86.15.192/26201.86.15.193 to 201.86.15.254201.86.15.25562
65201.86.16.0/26201.86.16.1 to 201.86.16.62201.86.16.6362
66201.86.16.64/26201.86.16.65 to 201.86.16.126201.86.16.12762
67201.86.16.128/26201.86.16.129 to 201.86.16.190201.86.16.19162
68201.86.16.192/26201.86.16.193 to 201.86.16.254201.86.16.25562
69201.86.17.0/26201.86.17.1 to 201.86.17.62201.86.17.6362
70201.86.17.64/26201.86.17.65 to 201.86.17.126201.86.17.12762
71201.86.17.128/26201.86.17.129 to 201.86.17.190201.86.17.19162
72201.86.17.192/26201.86.17.193 to 201.86.17.254201.86.17.25562
73201.86.18.0/26201.86.18.1 to 201.86.18.62201.86.18.6362
74201.86.18.64/26201.86.18.65 to 201.86.18.126201.86.18.12762
75201.86.18.128/26201.86.18.129 to 201.86.18.190201.86.18.19162
76201.86.18.192/26201.86.18.193 to 201.86.18.254201.86.18.25562
77201.86.19.0/26201.86.19.1 to 201.86.19.62201.86.19.6362
78201.86.19.64/26201.86.19.65 to 201.86.19.126201.86.19.12762
79201.86.19.128/26201.86.19.129 to 201.86.19.190201.86.19.19162
80201.86.19.192/26201.86.19.193 to 201.86.19.254201.86.19.25562
81201.86.20.0/26201.86.20.1 to 201.86.20.62201.86.20.6362
82201.86.20.64/26201.86.20.65 to 201.86.20.126201.86.20.12762
83201.86.20.128/26201.86.20.129 to 201.86.20.190201.86.20.19162
84201.86.20.192/26201.86.20.193 to 201.86.20.254201.86.20.25562
85201.86.21.0/26201.86.21.1 to 201.86.21.62201.86.21.6362
86201.86.21.64/26201.86.21.65 to 201.86.21.126201.86.21.12762
87201.86.21.128/26201.86.21.129 to 201.86.21.190201.86.21.19162
88201.86.21.192/26201.86.21.193 to 201.86.21.254201.86.21.25562
89201.86.22.0/26201.86.22.1 to 201.86.22.62201.86.22.6362
90201.86.22.64/26201.86.22.65 to 201.86.22.126201.86.22.12762
91201.86.22.128/26201.86.22.129 to 201.86.22.190201.86.22.19162
92201.86.22.192/26201.86.22.193 to 201.86.22.254201.86.22.25562
93201.86.23.0/26201.86.23.1 to 201.86.23.62201.86.23.6362
94201.86.23.64/26201.86.23.65 to 201.86.23.126201.86.23.12762
95201.86.23.128/26201.86.23.129 to 201.86.23.190201.86.23.19162
96201.86.23.192/26201.86.23.193 to 201.86.23.254201.86.23.25562
97201.86.24.0/26201.86.24.1 to 201.86.24.62201.86.24.6362
98201.86.24.64/26201.86.24.65 to 201.86.24.126201.86.24.12762
99201.86.24.128/26201.86.24.129 to 201.86.24.190201.86.24.19162
100201.86.24.192/26201.86.24.193 to 201.86.24.254201.86.24.25562
101201.86.25.0/26201.86.25.1 to 201.86.25.62201.86.25.6362
102201.86.25.64/26201.86.25.65 to 201.86.25.126201.86.25.12762
103201.86.25.128/26201.86.25.129 to 201.86.25.190201.86.25.19162
104201.86.25.192/26201.86.25.193 to 201.86.25.254201.86.25.25562
105201.86.26.0/26201.86.26.1 to 201.86.26.62201.86.26.6362
106201.86.26.64/26201.86.26.65 to 201.86.26.126201.86.26.12762
107201.86.26.128/26201.86.26.129 to 201.86.26.190201.86.26.19162
108201.86.26.192/26201.86.26.193 to 201.86.26.254201.86.26.25562
109201.86.27.0/26201.86.27.1 to 201.86.27.62201.86.27.6362
110201.86.27.64/26201.86.27.65 to 201.86.27.126201.86.27.12762
111201.86.27.128/26201.86.27.129 to 201.86.27.190201.86.27.19162
112201.86.27.192/26201.86.27.193 to 201.86.27.254201.86.27.25562
113201.86.28.0/26201.86.28.1 to 201.86.28.62201.86.28.6362
114201.86.28.64/26201.86.28.65 to 201.86.28.126201.86.28.12762
115201.86.28.128/26201.86.28.129 to 201.86.28.190201.86.28.19162
116201.86.28.192/26201.86.28.193 to 201.86.28.254201.86.28.25562
117201.86.29.0/26201.86.29.1 to 201.86.29.62201.86.29.6362
118201.86.29.64/26201.86.29.65 to 201.86.29.126201.86.29.12762
119201.86.29.128/26201.86.29.129 to 201.86.29.190201.86.29.19162
120201.86.29.192/26201.86.29.193 to 201.86.29.254201.86.29.25562
121201.86.30.0/26201.86.30.1 to 201.86.30.62201.86.30.6362
122201.86.30.64/26201.86.30.65 to 201.86.30.126201.86.30.12762
123201.86.30.128/26201.86.30.129 to 201.86.30.190201.86.30.19162
124201.86.30.192/26201.86.30.193 to 201.86.30.254201.86.30.25562
125201.86.31.0/26201.86.31.1 to 201.86.31.62201.86.31.6362
126201.86.31.64/26201.86.31.65 to 201.86.31.126201.86.31.12762
127201.86.31.128/26201.86.31.129 to 201.86.31.190201.86.31.19162
128201.86.31.192/26201.86.31.193 to 201.86.31.254201.86.31.25562
129201.86.32.0/26201.86.32.1 to 201.86.32.62201.86.32.6362
130201.86.32.64/26201.86.32.65 to 201.86.32.126201.86.32.12762
131201.86.32.128/26201.86.32.129 to 201.86.32.190201.86.32.19162
132201.86.32.192/26201.86.32.193 to 201.86.32.254201.86.32.25562
133201.86.33.0/26201.86.33.1 to 201.86.33.62201.86.33.6362
134201.86.33.64/26201.86.33.65 to 201.86.33.126201.86.33.12762
135201.86.33.128/26201.86.33.129 to 201.86.33.190201.86.33.19162
136201.86.33.192/26201.86.33.193 to 201.86.33.254201.86.33.25562
137201.86.34.0/26201.86.34.1 to 201.86.34.62201.86.34.6362
138201.86.34.64/26201.86.34.65 to 201.86.34.126201.86.34.12762
139201.86.34.128/26201.86.34.129 to 201.86.34.190201.86.34.19162
140201.86.34.192/26201.86.34.193 to 201.86.34.254201.86.34.25562
141201.86.35.0/26201.86.35.1 to 201.86.35.62201.86.35.6362
142201.86.35.64/26201.86.35.65 to 201.86.35.126201.86.35.12762
143201.86.35.128/26201.86.35.129 to 201.86.35.190201.86.35.19162
144201.86.35.192/26201.86.35.193 to 201.86.35.254201.86.35.25562
145201.86.36.0/26201.86.36.1 to 201.86.36.62201.86.36.6362
146201.86.36.64/26201.86.36.65 to 201.86.36.126201.86.36.12762
147201.86.36.128/26201.86.36.129 to 201.86.36.190201.86.36.19162
148201.86.36.192/26201.86.36.193 to 201.86.36.254201.86.36.25562
149201.86.37.0/26201.86.37.1 to 201.86.37.62201.86.37.6362
150201.86.37.64/26201.86.37.65 to 201.86.37.126201.86.37.12762
151201.86.37.128/26201.86.37.129 to 201.86.37.190201.86.37.19162
152201.86.37.192/26201.86.37.193 to 201.86.37.254201.86.37.25562
153201.86.38.0/26201.86.38.1 to 201.86.38.62201.86.38.6362
154201.86.38.64/26201.86.38.65 to 201.86.38.126201.86.38.12762
155201.86.38.128/26201.86.38.129 to 201.86.38.190201.86.38.19162
156201.86.38.192/26201.86.38.193 to 201.86.38.254201.86.38.25562
157201.86.39.0/26201.86.39.1 to 201.86.39.62201.86.39.6362
158201.86.39.64/26201.86.39.65 to 201.86.39.126201.86.39.12762
159201.86.39.128/26201.86.39.129 to 201.86.39.190201.86.39.19162
160201.86.39.192/26201.86.39.193 to 201.86.39.254201.86.39.25562
161201.86.40.0/26201.86.40.1 to 201.86.40.62201.86.40.6362
162201.86.40.64/26201.86.40.65 to 201.86.40.126201.86.40.12762
163201.86.40.128/26201.86.40.129 to 201.86.40.190201.86.40.19162
164201.86.40.192/26201.86.40.193 to 201.86.40.254201.86.40.25562
165201.86.41.0/26201.86.41.1 to 201.86.41.62201.86.41.6362
166201.86.41.64/26201.86.41.65 to 201.86.41.126201.86.41.12762
167201.86.41.128/26201.86.41.129 to 201.86.41.190201.86.41.19162
168201.86.41.192/26201.86.41.193 to 201.86.41.254201.86.41.25562
169201.86.42.0/26201.86.42.1 to 201.86.42.62201.86.42.6362
170201.86.42.64/26201.86.42.65 to 201.86.42.126201.86.42.12762
171201.86.42.128/26201.86.42.129 to 201.86.42.190201.86.42.19162
172201.86.42.192/26201.86.42.193 to 201.86.42.254201.86.42.25562
173201.86.43.0/26201.86.43.1 to 201.86.43.62201.86.43.6362
174201.86.43.64/26201.86.43.65 to 201.86.43.126201.86.43.12762
175201.86.43.128/26201.86.43.129 to 201.86.43.190201.86.43.19162
176201.86.43.192/26201.86.43.193 to 201.86.43.254201.86.43.25562
177201.86.44.0/26201.86.44.1 to 201.86.44.62201.86.44.6362
178201.86.44.64/26201.86.44.65 to 201.86.44.126201.86.44.12762
179201.86.44.128/26201.86.44.129 to 201.86.44.190201.86.44.19162
180201.86.44.192/26201.86.44.193 to 201.86.44.254201.86.44.25562
181201.86.45.0/26201.86.45.1 to 201.86.45.62201.86.45.6362
182201.86.45.64/26201.86.45.65 to 201.86.45.126201.86.45.12762
183201.86.45.128/26201.86.45.129 to 201.86.45.190201.86.45.19162
184201.86.45.192/26201.86.45.193 to 201.86.45.254201.86.45.25562
185201.86.46.0/26201.86.46.1 to 201.86.46.62201.86.46.6362
186201.86.46.64/26201.86.46.65 to 201.86.46.126201.86.46.12762
187201.86.46.128/26201.86.46.129 to 201.86.46.190201.86.46.19162
188201.86.46.192/26201.86.46.193 to 201.86.46.254201.86.46.25562
189201.86.47.0/26201.86.47.1 to 201.86.47.62201.86.47.6362
190201.86.47.64/26201.86.47.65 to 201.86.47.126201.86.47.12762
191201.86.47.128/26201.86.47.129 to 201.86.47.190201.86.47.19162
192201.86.47.192/26201.86.47.193 to 201.86.47.254201.86.47.25562
193201.86.48.0/26201.86.48.1 to 201.86.48.62201.86.48.6362
194201.86.48.64/26201.86.48.65 to 201.86.48.126201.86.48.12762
195201.86.48.128/26201.86.48.129 to 201.86.48.190201.86.48.19162
196201.86.48.192/26201.86.48.193 to 201.86.48.254201.86.48.25562
197201.86.49.0/26201.86.49.1 to 201.86.49.62201.86.49.6362
198201.86.49.64/26201.86.49.65 to 201.86.49.126201.86.49.12762
199201.86.49.128/26201.86.49.129 to 201.86.49.190201.86.49.19162
200201.86.49.192/26201.86.49.193 to 201.86.49.254201.86.49.25562
201201.86.50.0/26201.86.50.1 to 201.86.50.62201.86.50.6362
202201.86.50.64/26201.86.50.65 to 201.86.50.126201.86.50.12762
203201.86.50.128/26201.86.50.129 to 201.86.50.190201.86.50.19162
204201.86.50.192/26201.86.50.193 to 201.86.50.254201.86.50.25562
205201.86.51.0/26201.86.51.1 to 201.86.51.62201.86.51.6362
206201.86.51.64/26201.86.51.65 to 201.86.51.126201.86.51.12762
207201.86.51.128/26201.86.51.129 to 201.86.51.190201.86.51.19162
208201.86.51.192/26201.86.51.193 to 201.86.51.254201.86.51.25562
209201.86.52.0/26201.86.52.1 to 201.86.52.62201.86.52.6362
210201.86.52.64/26201.86.52.65 to 201.86.52.126201.86.52.12762
211201.86.52.128/26201.86.52.129 to 201.86.52.190201.86.52.19162
212201.86.52.192/26201.86.52.193 to 201.86.52.254201.86.52.25562
213201.86.53.0/26201.86.53.1 to 201.86.53.62201.86.53.6362
214201.86.53.64/26201.86.53.65 to 201.86.53.126201.86.53.12762
215201.86.53.128/26201.86.53.129 to 201.86.53.190201.86.53.19162
216201.86.53.192/26201.86.53.193 to 201.86.53.254201.86.53.25562
217201.86.54.0/26201.86.54.1 to 201.86.54.62201.86.54.6362
218201.86.54.64/26201.86.54.65 to 201.86.54.126201.86.54.12762
219201.86.54.128/26201.86.54.129 to 201.86.54.190201.86.54.19162
220201.86.54.192/26201.86.54.193 to 201.86.54.254201.86.54.25562
221201.86.55.0/26201.86.55.1 to 201.86.55.62201.86.55.6362
222201.86.55.64/26201.86.55.65 to 201.86.55.126201.86.55.12762
223201.86.55.128/26201.86.55.129 to 201.86.55.190201.86.55.19162
224201.86.55.192/26201.86.55.193 to 201.86.55.254201.86.55.25562
225201.86.56.0/26201.86.56.1 to 201.86.56.62201.86.56.6362
226201.86.56.64/26201.86.56.65 to 201.86.56.126201.86.56.12762
227201.86.56.128/26201.86.56.129 to 201.86.56.190201.86.56.19162
228201.86.56.192/26201.86.56.193 to 201.86.56.254201.86.56.25562
229201.86.57.0/26201.86.57.1 to 201.86.57.62201.86.57.6362
230201.86.57.64/26201.86.57.65 to 201.86.57.126201.86.57.12762
231201.86.57.128/26201.86.57.129 to 201.86.57.190201.86.57.19162
232201.86.57.192/26201.86.57.193 to 201.86.57.254201.86.57.25562
233201.86.58.0/26201.86.58.1 to 201.86.58.62201.86.58.6362
234201.86.58.64/26201.86.58.65 to 201.86.58.126201.86.58.12762
235201.86.58.128/26201.86.58.129 to 201.86.58.190201.86.58.19162
236201.86.58.192/26201.86.58.193 to 201.86.58.254201.86.58.25562
237201.86.59.0/26201.86.59.1 to 201.86.59.62201.86.59.6362
238201.86.59.64/26201.86.59.65 to 201.86.59.126201.86.59.12762
239201.86.59.128/26201.86.59.129 to 201.86.59.190201.86.59.19162
240201.86.59.192/26201.86.59.193 to 201.86.59.254201.86.59.25562
241201.86.60.0/26201.86.60.1 to 201.86.60.62201.86.60.6362
242201.86.60.64/26201.86.60.65 to 201.86.60.126201.86.60.12762
243201.86.60.128/26201.86.60.129 to 201.86.60.190201.86.60.19162
244201.86.60.192/26201.86.60.193 to 201.86.60.254201.86.60.25562
245201.86.61.0/26201.86.61.1 to 201.86.61.62201.86.61.6362
246201.86.61.64/26201.86.61.65 to 201.86.61.126201.86.61.12762
247201.86.61.128/26201.86.61.129 to 201.86.61.190201.86.61.19162
248201.86.61.192/26201.86.61.193 to 201.86.61.254201.86.61.25562
249201.86.62.0/26201.86.62.1 to 201.86.62.62201.86.62.6362
250201.86.62.64/26201.86.62.65 to 201.86.62.126201.86.62.12762
251201.86.62.128/26201.86.62.129 to 201.86.62.190201.86.62.19162
252201.86.62.192/26201.86.62.193 to 201.86.62.254201.86.62.25562
253201.86.63.0/26201.86.63.1 to 201.86.63.62201.86.63.6362
254201.86.63.64/26201.86.63.65 to 201.86.63.126201.86.63.12762
255201.86.63.128/26201.86.63.129 to 201.86.63.190201.86.63.19162
256201.86.63.192/26201.86.63.193 to 201.86.63.254201.86.63.25562

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.