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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.

Network106.167.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
106.167.0.0
Broadcast address
106.167.127.255
First usable
106.167.0.1
Last usable
106.167.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 6AA70000 · Integer 1789329408 to 1789362175
Reverse DNS zones
0.167.106.in-addr.arpa
1.167.106.in-addr.arpa
2.167.106.in-addr.arpa
3.167.106.in-addr.arpa
4.167.106.in-addr.arpa
5.167.106.in-addr.arpa
6.167.106.in-addr.arpa
7.167.106.in-addr.arpa
8.167.106.in-addr.arpa
9.167.106.in-addr.arpa
10.167.106.in-addr.arpa
11.167.106.in-addr.arpa
12.167.106.in-addr.arpa
13.167.106.in-addr.arpa
14.167.106.in-addr.arpa
15.167.106.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101010.10100111.00000000.00000000106.167.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network01101010.10100111.00000000.00000000106.167.0.0
Broadcast01101010.10100111.01111111.11111111106.167.127.255
Split into smaller subnets/26
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

106.167.0.0/17 makes 512 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1106.167.0.0/26106.167.0.1 to 106.167.0.62106.167.0.6362
2106.167.0.64/26106.167.0.65 to 106.167.0.126106.167.0.12762
3106.167.0.128/26106.167.0.129 to 106.167.0.190106.167.0.19162
4106.167.0.192/26106.167.0.193 to 106.167.0.254106.167.0.25562
5106.167.1.0/26106.167.1.1 to 106.167.1.62106.167.1.6362
6106.167.1.64/26106.167.1.65 to 106.167.1.126106.167.1.12762
7106.167.1.128/26106.167.1.129 to 106.167.1.190106.167.1.19162
8106.167.1.192/26106.167.1.193 to 106.167.1.254106.167.1.25562
9106.167.2.0/26106.167.2.1 to 106.167.2.62106.167.2.6362
10106.167.2.64/26106.167.2.65 to 106.167.2.126106.167.2.12762
11106.167.2.128/26106.167.2.129 to 106.167.2.190106.167.2.19162
12106.167.2.192/26106.167.2.193 to 106.167.2.254106.167.2.25562
13106.167.3.0/26106.167.3.1 to 106.167.3.62106.167.3.6362
14106.167.3.64/26106.167.3.65 to 106.167.3.126106.167.3.12762
15106.167.3.128/26106.167.3.129 to 106.167.3.190106.167.3.19162
16106.167.3.192/26106.167.3.193 to 106.167.3.254106.167.3.25562
17106.167.4.0/26106.167.4.1 to 106.167.4.62106.167.4.6362
18106.167.4.64/26106.167.4.65 to 106.167.4.126106.167.4.12762
19106.167.4.128/26106.167.4.129 to 106.167.4.190106.167.4.19162
20106.167.4.192/26106.167.4.193 to 106.167.4.254106.167.4.25562
21106.167.5.0/26106.167.5.1 to 106.167.5.62106.167.5.6362
22106.167.5.64/26106.167.5.65 to 106.167.5.126106.167.5.12762
23106.167.5.128/26106.167.5.129 to 106.167.5.190106.167.5.19162
24106.167.5.192/26106.167.5.193 to 106.167.5.254106.167.5.25562
25106.167.6.0/26106.167.6.1 to 106.167.6.62106.167.6.6362
26106.167.6.64/26106.167.6.65 to 106.167.6.126106.167.6.12762
27106.167.6.128/26106.167.6.129 to 106.167.6.190106.167.6.19162
28106.167.6.192/26106.167.6.193 to 106.167.6.254106.167.6.25562
29106.167.7.0/26106.167.7.1 to 106.167.7.62106.167.7.6362
30106.167.7.64/26106.167.7.65 to 106.167.7.126106.167.7.12762
31106.167.7.128/26106.167.7.129 to 106.167.7.190106.167.7.19162
32106.167.7.192/26106.167.7.193 to 106.167.7.254106.167.7.25562
33106.167.8.0/26106.167.8.1 to 106.167.8.62106.167.8.6362
34106.167.8.64/26106.167.8.65 to 106.167.8.126106.167.8.12762
35106.167.8.128/26106.167.8.129 to 106.167.8.190106.167.8.19162
36106.167.8.192/26106.167.8.193 to 106.167.8.254106.167.8.25562
37106.167.9.0/26106.167.9.1 to 106.167.9.62106.167.9.6362
38106.167.9.64/26106.167.9.65 to 106.167.9.126106.167.9.12762
39106.167.9.128/26106.167.9.129 to 106.167.9.190106.167.9.19162
40106.167.9.192/26106.167.9.193 to 106.167.9.254106.167.9.25562
41106.167.10.0/26106.167.10.1 to 106.167.10.62106.167.10.6362
42106.167.10.64/26106.167.10.65 to 106.167.10.126106.167.10.12762
43106.167.10.128/26106.167.10.129 to 106.167.10.190106.167.10.19162
44106.167.10.192/26106.167.10.193 to 106.167.10.254106.167.10.25562
45106.167.11.0/26106.167.11.1 to 106.167.11.62106.167.11.6362
46106.167.11.64/26106.167.11.65 to 106.167.11.126106.167.11.12762
47106.167.11.128/26106.167.11.129 to 106.167.11.190106.167.11.19162
48106.167.11.192/26106.167.11.193 to 106.167.11.254106.167.11.25562
49106.167.12.0/26106.167.12.1 to 106.167.12.62106.167.12.6362
50106.167.12.64/26106.167.12.65 to 106.167.12.126106.167.12.12762
51106.167.12.128/26106.167.12.129 to 106.167.12.190106.167.12.19162
52106.167.12.192/26106.167.12.193 to 106.167.12.254106.167.12.25562
53106.167.13.0/26106.167.13.1 to 106.167.13.62106.167.13.6362
54106.167.13.64/26106.167.13.65 to 106.167.13.126106.167.13.12762
55106.167.13.128/26106.167.13.129 to 106.167.13.190106.167.13.19162
56106.167.13.192/26106.167.13.193 to 106.167.13.254106.167.13.25562
57106.167.14.0/26106.167.14.1 to 106.167.14.62106.167.14.6362
58106.167.14.64/26106.167.14.65 to 106.167.14.126106.167.14.12762
59106.167.14.128/26106.167.14.129 to 106.167.14.190106.167.14.19162
60106.167.14.192/26106.167.14.193 to 106.167.14.254106.167.14.25562
61106.167.15.0/26106.167.15.1 to 106.167.15.62106.167.15.6362
62106.167.15.64/26106.167.15.65 to 106.167.15.126106.167.15.12762
63106.167.15.128/26106.167.15.129 to 106.167.15.190106.167.15.19162
64106.167.15.192/26106.167.15.193 to 106.167.15.254106.167.15.25562
65106.167.16.0/26106.167.16.1 to 106.167.16.62106.167.16.6362
66106.167.16.64/26106.167.16.65 to 106.167.16.126106.167.16.12762
67106.167.16.128/26106.167.16.129 to 106.167.16.190106.167.16.19162
68106.167.16.192/26106.167.16.193 to 106.167.16.254106.167.16.25562
69106.167.17.0/26106.167.17.1 to 106.167.17.62106.167.17.6362
70106.167.17.64/26106.167.17.65 to 106.167.17.126106.167.17.12762
71106.167.17.128/26106.167.17.129 to 106.167.17.190106.167.17.19162
72106.167.17.192/26106.167.17.193 to 106.167.17.254106.167.17.25562
73106.167.18.0/26106.167.18.1 to 106.167.18.62106.167.18.6362
74106.167.18.64/26106.167.18.65 to 106.167.18.126106.167.18.12762
75106.167.18.128/26106.167.18.129 to 106.167.18.190106.167.18.19162
76106.167.18.192/26106.167.18.193 to 106.167.18.254106.167.18.25562
77106.167.19.0/26106.167.19.1 to 106.167.19.62106.167.19.6362
78106.167.19.64/26106.167.19.65 to 106.167.19.126106.167.19.12762
79106.167.19.128/26106.167.19.129 to 106.167.19.190106.167.19.19162
80106.167.19.192/26106.167.19.193 to 106.167.19.254106.167.19.25562
81106.167.20.0/26106.167.20.1 to 106.167.20.62106.167.20.6362
82106.167.20.64/26106.167.20.65 to 106.167.20.126106.167.20.12762
83106.167.20.128/26106.167.20.129 to 106.167.20.190106.167.20.19162
84106.167.20.192/26106.167.20.193 to 106.167.20.254106.167.20.25562
85106.167.21.0/26106.167.21.1 to 106.167.21.62106.167.21.6362
86106.167.21.64/26106.167.21.65 to 106.167.21.126106.167.21.12762
87106.167.21.128/26106.167.21.129 to 106.167.21.190106.167.21.19162
88106.167.21.192/26106.167.21.193 to 106.167.21.254106.167.21.25562
89106.167.22.0/26106.167.22.1 to 106.167.22.62106.167.22.6362
90106.167.22.64/26106.167.22.65 to 106.167.22.126106.167.22.12762
91106.167.22.128/26106.167.22.129 to 106.167.22.190106.167.22.19162
92106.167.22.192/26106.167.22.193 to 106.167.22.254106.167.22.25562
93106.167.23.0/26106.167.23.1 to 106.167.23.62106.167.23.6362
94106.167.23.64/26106.167.23.65 to 106.167.23.126106.167.23.12762
95106.167.23.128/26106.167.23.129 to 106.167.23.190106.167.23.19162
96106.167.23.192/26106.167.23.193 to 106.167.23.254106.167.23.25562
97106.167.24.0/26106.167.24.1 to 106.167.24.62106.167.24.6362
98106.167.24.64/26106.167.24.65 to 106.167.24.126106.167.24.12762
99106.167.24.128/26106.167.24.129 to 106.167.24.190106.167.24.19162
100106.167.24.192/26106.167.24.193 to 106.167.24.254106.167.24.25562
101106.167.25.0/26106.167.25.1 to 106.167.25.62106.167.25.6362
102106.167.25.64/26106.167.25.65 to 106.167.25.126106.167.25.12762
103106.167.25.128/26106.167.25.129 to 106.167.25.190106.167.25.19162
104106.167.25.192/26106.167.25.193 to 106.167.25.254106.167.25.25562
105106.167.26.0/26106.167.26.1 to 106.167.26.62106.167.26.6362
106106.167.26.64/26106.167.26.65 to 106.167.26.126106.167.26.12762
107106.167.26.128/26106.167.26.129 to 106.167.26.190106.167.26.19162
108106.167.26.192/26106.167.26.193 to 106.167.26.254106.167.26.25562
109106.167.27.0/26106.167.27.1 to 106.167.27.62106.167.27.6362
110106.167.27.64/26106.167.27.65 to 106.167.27.126106.167.27.12762
111106.167.27.128/26106.167.27.129 to 106.167.27.190106.167.27.19162
112106.167.27.192/26106.167.27.193 to 106.167.27.254106.167.27.25562
113106.167.28.0/26106.167.28.1 to 106.167.28.62106.167.28.6362
114106.167.28.64/26106.167.28.65 to 106.167.28.126106.167.28.12762
115106.167.28.128/26106.167.28.129 to 106.167.28.190106.167.28.19162
116106.167.28.192/26106.167.28.193 to 106.167.28.254106.167.28.25562
117106.167.29.0/26106.167.29.1 to 106.167.29.62106.167.29.6362
118106.167.29.64/26106.167.29.65 to 106.167.29.126106.167.29.12762
119106.167.29.128/26106.167.29.129 to 106.167.29.190106.167.29.19162
120106.167.29.192/26106.167.29.193 to 106.167.29.254106.167.29.25562
121106.167.30.0/26106.167.30.1 to 106.167.30.62106.167.30.6362
122106.167.30.64/26106.167.30.65 to 106.167.30.126106.167.30.12762
123106.167.30.128/26106.167.30.129 to 106.167.30.190106.167.30.19162
124106.167.30.192/26106.167.30.193 to 106.167.30.254106.167.30.25562
125106.167.31.0/26106.167.31.1 to 106.167.31.62106.167.31.6362
126106.167.31.64/26106.167.31.65 to 106.167.31.126106.167.31.12762
127106.167.31.128/26106.167.31.129 to 106.167.31.190106.167.31.19162
128106.167.31.192/26106.167.31.193 to 106.167.31.254106.167.31.25562
129106.167.32.0/26106.167.32.1 to 106.167.32.62106.167.32.6362
130106.167.32.64/26106.167.32.65 to 106.167.32.126106.167.32.12762
131106.167.32.128/26106.167.32.129 to 106.167.32.190106.167.32.19162
132106.167.32.192/26106.167.32.193 to 106.167.32.254106.167.32.25562
133106.167.33.0/26106.167.33.1 to 106.167.33.62106.167.33.6362
134106.167.33.64/26106.167.33.65 to 106.167.33.126106.167.33.12762
135106.167.33.128/26106.167.33.129 to 106.167.33.190106.167.33.19162
136106.167.33.192/26106.167.33.193 to 106.167.33.254106.167.33.25562
137106.167.34.0/26106.167.34.1 to 106.167.34.62106.167.34.6362
138106.167.34.64/26106.167.34.65 to 106.167.34.126106.167.34.12762
139106.167.34.128/26106.167.34.129 to 106.167.34.190106.167.34.19162
140106.167.34.192/26106.167.34.193 to 106.167.34.254106.167.34.25562
141106.167.35.0/26106.167.35.1 to 106.167.35.62106.167.35.6362
142106.167.35.64/26106.167.35.65 to 106.167.35.126106.167.35.12762
143106.167.35.128/26106.167.35.129 to 106.167.35.190106.167.35.19162
144106.167.35.192/26106.167.35.193 to 106.167.35.254106.167.35.25562
145106.167.36.0/26106.167.36.1 to 106.167.36.62106.167.36.6362
146106.167.36.64/26106.167.36.65 to 106.167.36.126106.167.36.12762
147106.167.36.128/26106.167.36.129 to 106.167.36.190106.167.36.19162
148106.167.36.192/26106.167.36.193 to 106.167.36.254106.167.36.25562
149106.167.37.0/26106.167.37.1 to 106.167.37.62106.167.37.6362
150106.167.37.64/26106.167.37.65 to 106.167.37.126106.167.37.12762
151106.167.37.128/26106.167.37.129 to 106.167.37.190106.167.37.19162
152106.167.37.192/26106.167.37.193 to 106.167.37.254106.167.37.25562
153106.167.38.0/26106.167.38.1 to 106.167.38.62106.167.38.6362
154106.167.38.64/26106.167.38.65 to 106.167.38.126106.167.38.12762
155106.167.38.128/26106.167.38.129 to 106.167.38.190106.167.38.19162
156106.167.38.192/26106.167.38.193 to 106.167.38.254106.167.38.25562
157106.167.39.0/26106.167.39.1 to 106.167.39.62106.167.39.6362
158106.167.39.64/26106.167.39.65 to 106.167.39.126106.167.39.12762
159106.167.39.128/26106.167.39.129 to 106.167.39.190106.167.39.19162
160106.167.39.192/26106.167.39.193 to 106.167.39.254106.167.39.25562
161106.167.40.0/26106.167.40.1 to 106.167.40.62106.167.40.6362
162106.167.40.64/26106.167.40.65 to 106.167.40.126106.167.40.12762
163106.167.40.128/26106.167.40.129 to 106.167.40.190106.167.40.19162
164106.167.40.192/26106.167.40.193 to 106.167.40.254106.167.40.25562
165106.167.41.0/26106.167.41.1 to 106.167.41.62106.167.41.6362
166106.167.41.64/26106.167.41.65 to 106.167.41.126106.167.41.12762
167106.167.41.128/26106.167.41.129 to 106.167.41.190106.167.41.19162
168106.167.41.192/26106.167.41.193 to 106.167.41.254106.167.41.25562
169106.167.42.0/26106.167.42.1 to 106.167.42.62106.167.42.6362
170106.167.42.64/26106.167.42.65 to 106.167.42.126106.167.42.12762
171106.167.42.128/26106.167.42.129 to 106.167.42.190106.167.42.19162
172106.167.42.192/26106.167.42.193 to 106.167.42.254106.167.42.25562
173106.167.43.0/26106.167.43.1 to 106.167.43.62106.167.43.6362
174106.167.43.64/26106.167.43.65 to 106.167.43.126106.167.43.12762
175106.167.43.128/26106.167.43.129 to 106.167.43.190106.167.43.19162
176106.167.43.192/26106.167.43.193 to 106.167.43.254106.167.43.25562
177106.167.44.0/26106.167.44.1 to 106.167.44.62106.167.44.6362
178106.167.44.64/26106.167.44.65 to 106.167.44.126106.167.44.12762
179106.167.44.128/26106.167.44.129 to 106.167.44.190106.167.44.19162
180106.167.44.192/26106.167.44.193 to 106.167.44.254106.167.44.25562
181106.167.45.0/26106.167.45.1 to 106.167.45.62106.167.45.6362
182106.167.45.64/26106.167.45.65 to 106.167.45.126106.167.45.12762
183106.167.45.128/26106.167.45.129 to 106.167.45.190106.167.45.19162
184106.167.45.192/26106.167.45.193 to 106.167.45.254106.167.45.25562
185106.167.46.0/26106.167.46.1 to 106.167.46.62106.167.46.6362
186106.167.46.64/26106.167.46.65 to 106.167.46.126106.167.46.12762
187106.167.46.128/26106.167.46.129 to 106.167.46.190106.167.46.19162
188106.167.46.192/26106.167.46.193 to 106.167.46.254106.167.46.25562
189106.167.47.0/26106.167.47.1 to 106.167.47.62106.167.47.6362
190106.167.47.64/26106.167.47.65 to 106.167.47.126106.167.47.12762
191106.167.47.128/26106.167.47.129 to 106.167.47.190106.167.47.19162
192106.167.47.192/26106.167.47.193 to 106.167.47.254106.167.47.25562
193106.167.48.0/26106.167.48.1 to 106.167.48.62106.167.48.6362
194106.167.48.64/26106.167.48.65 to 106.167.48.126106.167.48.12762
195106.167.48.128/26106.167.48.129 to 106.167.48.190106.167.48.19162
196106.167.48.192/26106.167.48.193 to 106.167.48.254106.167.48.25562
197106.167.49.0/26106.167.49.1 to 106.167.49.62106.167.49.6362
198106.167.49.64/26106.167.49.65 to 106.167.49.126106.167.49.12762
199106.167.49.128/26106.167.49.129 to 106.167.49.190106.167.49.19162
200106.167.49.192/26106.167.49.193 to 106.167.49.254106.167.49.25562
201106.167.50.0/26106.167.50.1 to 106.167.50.62106.167.50.6362
202106.167.50.64/26106.167.50.65 to 106.167.50.126106.167.50.12762
203106.167.50.128/26106.167.50.129 to 106.167.50.190106.167.50.19162
204106.167.50.192/26106.167.50.193 to 106.167.50.254106.167.50.25562
205106.167.51.0/26106.167.51.1 to 106.167.51.62106.167.51.6362
206106.167.51.64/26106.167.51.65 to 106.167.51.126106.167.51.12762
207106.167.51.128/26106.167.51.129 to 106.167.51.190106.167.51.19162
208106.167.51.192/26106.167.51.193 to 106.167.51.254106.167.51.25562
209106.167.52.0/26106.167.52.1 to 106.167.52.62106.167.52.6362
210106.167.52.64/26106.167.52.65 to 106.167.52.126106.167.52.12762
211106.167.52.128/26106.167.52.129 to 106.167.52.190106.167.52.19162
212106.167.52.192/26106.167.52.193 to 106.167.52.254106.167.52.25562
213106.167.53.0/26106.167.53.1 to 106.167.53.62106.167.53.6362
214106.167.53.64/26106.167.53.65 to 106.167.53.126106.167.53.12762
215106.167.53.128/26106.167.53.129 to 106.167.53.190106.167.53.19162
216106.167.53.192/26106.167.53.193 to 106.167.53.254106.167.53.25562
217106.167.54.0/26106.167.54.1 to 106.167.54.62106.167.54.6362
218106.167.54.64/26106.167.54.65 to 106.167.54.126106.167.54.12762
219106.167.54.128/26106.167.54.129 to 106.167.54.190106.167.54.19162
220106.167.54.192/26106.167.54.193 to 106.167.54.254106.167.54.25562
221106.167.55.0/26106.167.55.1 to 106.167.55.62106.167.55.6362
222106.167.55.64/26106.167.55.65 to 106.167.55.126106.167.55.12762
223106.167.55.128/26106.167.55.129 to 106.167.55.190106.167.55.19162
224106.167.55.192/26106.167.55.193 to 106.167.55.254106.167.55.25562
225106.167.56.0/26106.167.56.1 to 106.167.56.62106.167.56.6362
226106.167.56.64/26106.167.56.65 to 106.167.56.126106.167.56.12762
227106.167.56.128/26106.167.56.129 to 106.167.56.190106.167.56.19162
228106.167.56.192/26106.167.56.193 to 106.167.56.254106.167.56.25562
229106.167.57.0/26106.167.57.1 to 106.167.57.62106.167.57.6362
230106.167.57.64/26106.167.57.65 to 106.167.57.126106.167.57.12762
231106.167.57.128/26106.167.57.129 to 106.167.57.190106.167.57.19162
232106.167.57.192/26106.167.57.193 to 106.167.57.254106.167.57.25562
233106.167.58.0/26106.167.58.1 to 106.167.58.62106.167.58.6362
234106.167.58.64/26106.167.58.65 to 106.167.58.126106.167.58.12762
235106.167.58.128/26106.167.58.129 to 106.167.58.190106.167.58.19162
236106.167.58.192/26106.167.58.193 to 106.167.58.254106.167.58.25562
237106.167.59.0/26106.167.59.1 to 106.167.59.62106.167.59.6362
238106.167.59.64/26106.167.59.65 to 106.167.59.126106.167.59.12762
239106.167.59.128/26106.167.59.129 to 106.167.59.190106.167.59.19162
240106.167.59.192/26106.167.59.193 to 106.167.59.254106.167.59.25562
241106.167.60.0/26106.167.60.1 to 106.167.60.62106.167.60.6362
242106.167.60.64/26106.167.60.65 to 106.167.60.126106.167.60.12762
243106.167.60.128/26106.167.60.129 to 106.167.60.190106.167.60.19162
244106.167.60.192/26106.167.60.193 to 106.167.60.254106.167.60.25562
245106.167.61.0/26106.167.61.1 to 106.167.61.62106.167.61.6362
246106.167.61.64/26106.167.61.65 to 106.167.61.126106.167.61.12762
247106.167.61.128/26106.167.61.129 to 106.167.61.190106.167.61.19162
248106.167.61.192/26106.167.61.193 to 106.167.61.254106.167.61.25562
249106.167.62.0/26106.167.62.1 to 106.167.62.62106.167.62.6362
250106.167.62.64/26106.167.62.65 to 106.167.62.126106.167.62.12762
251106.167.62.128/26106.167.62.129 to 106.167.62.190106.167.62.19162
252106.167.62.192/26106.167.62.193 to 106.167.62.254106.167.62.25562
253106.167.63.0/26106.167.63.1 to 106.167.63.62106.167.63.6362
254106.167.63.64/26106.167.63.65 to 106.167.63.126106.167.63.12762
255106.167.63.128/26106.167.63.129 to 106.167.63.190106.167.63.19162
256106.167.63.192/26106.167.63.193 to 106.167.63.254106.167.63.25562

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.