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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.

Network113.166.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
113.166.0.0
Broadcast address
113.166.255.255
First usable
113.166.0.1
Last usable
113.166.255.254
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
A (default /8)
As numbers
Hex 71A60000 · Integer 1906704384 to 1906769919
Reverse DNS zone
166.113.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110001.10100110..00000000.00000000113.166.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01110001.10100110..00000000.00000000113.166.0.0
Broadcast01110001.10100110..11111111.11111111113.166.255.255
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)

113.166.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1113.166.0.0/26113.166.0.1 to 113.166.0.62113.166.0.6362
2113.166.0.64/26113.166.0.65 to 113.166.0.126113.166.0.12762
3113.166.0.128/26113.166.0.129 to 113.166.0.190113.166.0.19162
4113.166.0.192/26113.166.0.193 to 113.166.0.254113.166.0.25562
5113.166.1.0/26113.166.1.1 to 113.166.1.62113.166.1.6362
6113.166.1.64/26113.166.1.65 to 113.166.1.126113.166.1.12762
7113.166.1.128/26113.166.1.129 to 113.166.1.190113.166.1.19162
8113.166.1.192/26113.166.1.193 to 113.166.1.254113.166.1.25562
9113.166.2.0/26113.166.2.1 to 113.166.2.62113.166.2.6362
10113.166.2.64/26113.166.2.65 to 113.166.2.126113.166.2.12762
11113.166.2.128/26113.166.2.129 to 113.166.2.190113.166.2.19162
12113.166.2.192/26113.166.2.193 to 113.166.2.254113.166.2.25562
13113.166.3.0/26113.166.3.1 to 113.166.3.62113.166.3.6362
14113.166.3.64/26113.166.3.65 to 113.166.3.126113.166.3.12762
15113.166.3.128/26113.166.3.129 to 113.166.3.190113.166.3.19162
16113.166.3.192/26113.166.3.193 to 113.166.3.254113.166.3.25562
17113.166.4.0/26113.166.4.1 to 113.166.4.62113.166.4.6362
18113.166.4.64/26113.166.4.65 to 113.166.4.126113.166.4.12762
19113.166.4.128/26113.166.4.129 to 113.166.4.190113.166.4.19162
20113.166.4.192/26113.166.4.193 to 113.166.4.254113.166.4.25562
21113.166.5.0/26113.166.5.1 to 113.166.5.62113.166.5.6362
22113.166.5.64/26113.166.5.65 to 113.166.5.126113.166.5.12762
23113.166.5.128/26113.166.5.129 to 113.166.5.190113.166.5.19162
24113.166.5.192/26113.166.5.193 to 113.166.5.254113.166.5.25562
25113.166.6.0/26113.166.6.1 to 113.166.6.62113.166.6.6362
26113.166.6.64/26113.166.6.65 to 113.166.6.126113.166.6.12762
27113.166.6.128/26113.166.6.129 to 113.166.6.190113.166.6.19162
28113.166.6.192/26113.166.6.193 to 113.166.6.254113.166.6.25562
29113.166.7.0/26113.166.7.1 to 113.166.7.62113.166.7.6362
30113.166.7.64/26113.166.7.65 to 113.166.7.126113.166.7.12762
31113.166.7.128/26113.166.7.129 to 113.166.7.190113.166.7.19162
32113.166.7.192/26113.166.7.193 to 113.166.7.254113.166.7.25562
33113.166.8.0/26113.166.8.1 to 113.166.8.62113.166.8.6362
34113.166.8.64/26113.166.8.65 to 113.166.8.126113.166.8.12762
35113.166.8.128/26113.166.8.129 to 113.166.8.190113.166.8.19162
36113.166.8.192/26113.166.8.193 to 113.166.8.254113.166.8.25562
37113.166.9.0/26113.166.9.1 to 113.166.9.62113.166.9.6362
38113.166.9.64/26113.166.9.65 to 113.166.9.126113.166.9.12762
39113.166.9.128/26113.166.9.129 to 113.166.9.190113.166.9.19162
40113.166.9.192/26113.166.9.193 to 113.166.9.254113.166.9.25562
41113.166.10.0/26113.166.10.1 to 113.166.10.62113.166.10.6362
42113.166.10.64/26113.166.10.65 to 113.166.10.126113.166.10.12762
43113.166.10.128/26113.166.10.129 to 113.166.10.190113.166.10.19162
44113.166.10.192/26113.166.10.193 to 113.166.10.254113.166.10.25562
45113.166.11.0/26113.166.11.1 to 113.166.11.62113.166.11.6362
46113.166.11.64/26113.166.11.65 to 113.166.11.126113.166.11.12762
47113.166.11.128/26113.166.11.129 to 113.166.11.190113.166.11.19162
48113.166.11.192/26113.166.11.193 to 113.166.11.254113.166.11.25562
49113.166.12.0/26113.166.12.1 to 113.166.12.62113.166.12.6362
50113.166.12.64/26113.166.12.65 to 113.166.12.126113.166.12.12762
51113.166.12.128/26113.166.12.129 to 113.166.12.190113.166.12.19162
52113.166.12.192/26113.166.12.193 to 113.166.12.254113.166.12.25562
53113.166.13.0/26113.166.13.1 to 113.166.13.62113.166.13.6362
54113.166.13.64/26113.166.13.65 to 113.166.13.126113.166.13.12762
55113.166.13.128/26113.166.13.129 to 113.166.13.190113.166.13.19162
56113.166.13.192/26113.166.13.193 to 113.166.13.254113.166.13.25562
57113.166.14.0/26113.166.14.1 to 113.166.14.62113.166.14.6362
58113.166.14.64/26113.166.14.65 to 113.166.14.126113.166.14.12762
59113.166.14.128/26113.166.14.129 to 113.166.14.190113.166.14.19162
60113.166.14.192/26113.166.14.193 to 113.166.14.254113.166.14.25562
61113.166.15.0/26113.166.15.1 to 113.166.15.62113.166.15.6362
62113.166.15.64/26113.166.15.65 to 113.166.15.126113.166.15.12762
63113.166.15.128/26113.166.15.129 to 113.166.15.190113.166.15.19162
64113.166.15.192/26113.166.15.193 to 113.166.15.254113.166.15.25562
65113.166.16.0/26113.166.16.1 to 113.166.16.62113.166.16.6362
66113.166.16.64/26113.166.16.65 to 113.166.16.126113.166.16.12762
67113.166.16.128/26113.166.16.129 to 113.166.16.190113.166.16.19162
68113.166.16.192/26113.166.16.193 to 113.166.16.254113.166.16.25562
69113.166.17.0/26113.166.17.1 to 113.166.17.62113.166.17.6362
70113.166.17.64/26113.166.17.65 to 113.166.17.126113.166.17.12762
71113.166.17.128/26113.166.17.129 to 113.166.17.190113.166.17.19162
72113.166.17.192/26113.166.17.193 to 113.166.17.254113.166.17.25562
73113.166.18.0/26113.166.18.1 to 113.166.18.62113.166.18.6362
74113.166.18.64/26113.166.18.65 to 113.166.18.126113.166.18.12762
75113.166.18.128/26113.166.18.129 to 113.166.18.190113.166.18.19162
76113.166.18.192/26113.166.18.193 to 113.166.18.254113.166.18.25562
77113.166.19.0/26113.166.19.1 to 113.166.19.62113.166.19.6362
78113.166.19.64/26113.166.19.65 to 113.166.19.126113.166.19.12762
79113.166.19.128/26113.166.19.129 to 113.166.19.190113.166.19.19162
80113.166.19.192/26113.166.19.193 to 113.166.19.254113.166.19.25562
81113.166.20.0/26113.166.20.1 to 113.166.20.62113.166.20.6362
82113.166.20.64/26113.166.20.65 to 113.166.20.126113.166.20.12762
83113.166.20.128/26113.166.20.129 to 113.166.20.190113.166.20.19162
84113.166.20.192/26113.166.20.193 to 113.166.20.254113.166.20.25562
85113.166.21.0/26113.166.21.1 to 113.166.21.62113.166.21.6362
86113.166.21.64/26113.166.21.65 to 113.166.21.126113.166.21.12762
87113.166.21.128/26113.166.21.129 to 113.166.21.190113.166.21.19162
88113.166.21.192/26113.166.21.193 to 113.166.21.254113.166.21.25562
89113.166.22.0/26113.166.22.1 to 113.166.22.62113.166.22.6362
90113.166.22.64/26113.166.22.65 to 113.166.22.126113.166.22.12762
91113.166.22.128/26113.166.22.129 to 113.166.22.190113.166.22.19162
92113.166.22.192/26113.166.22.193 to 113.166.22.254113.166.22.25562
93113.166.23.0/26113.166.23.1 to 113.166.23.62113.166.23.6362
94113.166.23.64/26113.166.23.65 to 113.166.23.126113.166.23.12762
95113.166.23.128/26113.166.23.129 to 113.166.23.190113.166.23.19162
96113.166.23.192/26113.166.23.193 to 113.166.23.254113.166.23.25562
97113.166.24.0/26113.166.24.1 to 113.166.24.62113.166.24.6362
98113.166.24.64/26113.166.24.65 to 113.166.24.126113.166.24.12762
99113.166.24.128/26113.166.24.129 to 113.166.24.190113.166.24.19162
100113.166.24.192/26113.166.24.193 to 113.166.24.254113.166.24.25562
101113.166.25.0/26113.166.25.1 to 113.166.25.62113.166.25.6362
102113.166.25.64/26113.166.25.65 to 113.166.25.126113.166.25.12762
103113.166.25.128/26113.166.25.129 to 113.166.25.190113.166.25.19162
104113.166.25.192/26113.166.25.193 to 113.166.25.254113.166.25.25562
105113.166.26.0/26113.166.26.1 to 113.166.26.62113.166.26.6362
106113.166.26.64/26113.166.26.65 to 113.166.26.126113.166.26.12762
107113.166.26.128/26113.166.26.129 to 113.166.26.190113.166.26.19162
108113.166.26.192/26113.166.26.193 to 113.166.26.254113.166.26.25562
109113.166.27.0/26113.166.27.1 to 113.166.27.62113.166.27.6362
110113.166.27.64/26113.166.27.65 to 113.166.27.126113.166.27.12762
111113.166.27.128/26113.166.27.129 to 113.166.27.190113.166.27.19162
112113.166.27.192/26113.166.27.193 to 113.166.27.254113.166.27.25562
113113.166.28.0/26113.166.28.1 to 113.166.28.62113.166.28.6362
114113.166.28.64/26113.166.28.65 to 113.166.28.126113.166.28.12762
115113.166.28.128/26113.166.28.129 to 113.166.28.190113.166.28.19162
116113.166.28.192/26113.166.28.193 to 113.166.28.254113.166.28.25562
117113.166.29.0/26113.166.29.1 to 113.166.29.62113.166.29.6362
118113.166.29.64/26113.166.29.65 to 113.166.29.126113.166.29.12762
119113.166.29.128/26113.166.29.129 to 113.166.29.190113.166.29.19162
120113.166.29.192/26113.166.29.193 to 113.166.29.254113.166.29.25562
121113.166.30.0/26113.166.30.1 to 113.166.30.62113.166.30.6362
122113.166.30.64/26113.166.30.65 to 113.166.30.126113.166.30.12762
123113.166.30.128/26113.166.30.129 to 113.166.30.190113.166.30.19162
124113.166.30.192/26113.166.30.193 to 113.166.30.254113.166.30.25562
125113.166.31.0/26113.166.31.1 to 113.166.31.62113.166.31.6362
126113.166.31.64/26113.166.31.65 to 113.166.31.126113.166.31.12762
127113.166.31.128/26113.166.31.129 to 113.166.31.190113.166.31.19162
128113.166.31.192/26113.166.31.193 to 113.166.31.254113.166.31.25562
129113.166.32.0/26113.166.32.1 to 113.166.32.62113.166.32.6362
130113.166.32.64/26113.166.32.65 to 113.166.32.126113.166.32.12762
131113.166.32.128/26113.166.32.129 to 113.166.32.190113.166.32.19162
132113.166.32.192/26113.166.32.193 to 113.166.32.254113.166.32.25562
133113.166.33.0/26113.166.33.1 to 113.166.33.62113.166.33.6362
134113.166.33.64/26113.166.33.65 to 113.166.33.126113.166.33.12762
135113.166.33.128/26113.166.33.129 to 113.166.33.190113.166.33.19162
136113.166.33.192/26113.166.33.193 to 113.166.33.254113.166.33.25562
137113.166.34.0/26113.166.34.1 to 113.166.34.62113.166.34.6362
138113.166.34.64/26113.166.34.65 to 113.166.34.126113.166.34.12762
139113.166.34.128/26113.166.34.129 to 113.166.34.190113.166.34.19162
140113.166.34.192/26113.166.34.193 to 113.166.34.254113.166.34.25562
141113.166.35.0/26113.166.35.1 to 113.166.35.62113.166.35.6362
142113.166.35.64/26113.166.35.65 to 113.166.35.126113.166.35.12762
143113.166.35.128/26113.166.35.129 to 113.166.35.190113.166.35.19162
144113.166.35.192/26113.166.35.193 to 113.166.35.254113.166.35.25562
145113.166.36.0/26113.166.36.1 to 113.166.36.62113.166.36.6362
146113.166.36.64/26113.166.36.65 to 113.166.36.126113.166.36.12762
147113.166.36.128/26113.166.36.129 to 113.166.36.190113.166.36.19162
148113.166.36.192/26113.166.36.193 to 113.166.36.254113.166.36.25562
149113.166.37.0/26113.166.37.1 to 113.166.37.62113.166.37.6362
150113.166.37.64/26113.166.37.65 to 113.166.37.126113.166.37.12762
151113.166.37.128/26113.166.37.129 to 113.166.37.190113.166.37.19162
152113.166.37.192/26113.166.37.193 to 113.166.37.254113.166.37.25562
153113.166.38.0/26113.166.38.1 to 113.166.38.62113.166.38.6362
154113.166.38.64/26113.166.38.65 to 113.166.38.126113.166.38.12762
155113.166.38.128/26113.166.38.129 to 113.166.38.190113.166.38.19162
156113.166.38.192/26113.166.38.193 to 113.166.38.254113.166.38.25562
157113.166.39.0/26113.166.39.1 to 113.166.39.62113.166.39.6362
158113.166.39.64/26113.166.39.65 to 113.166.39.126113.166.39.12762
159113.166.39.128/26113.166.39.129 to 113.166.39.190113.166.39.19162
160113.166.39.192/26113.166.39.193 to 113.166.39.254113.166.39.25562
161113.166.40.0/26113.166.40.1 to 113.166.40.62113.166.40.6362
162113.166.40.64/26113.166.40.65 to 113.166.40.126113.166.40.12762
163113.166.40.128/26113.166.40.129 to 113.166.40.190113.166.40.19162
164113.166.40.192/26113.166.40.193 to 113.166.40.254113.166.40.25562
165113.166.41.0/26113.166.41.1 to 113.166.41.62113.166.41.6362
166113.166.41.64/26113.166.41.65 to 113.166.41.126113.166.41.12762
167113.166.41.128/26113.166.41.129 to 113.166.41.190113.166.41.19162
168113.166.41.192/26113.166.41.193 to 113.166.41.254113.166.41.25562
169113.166.42.0/26113.166.42.1 to 113.166.42.62113.166.42.6362
170113.166.42.64/26113.166.42.65 to 113.166.42.126113.166.42.12762
171113.166.42.128/26113.166.42.129 to 113.166.42.190113.166.42.19162
172113.166.42.192/26113.166.42.193 to 113.166.42.254113.166.42.25562
173113.166.43.0/26113.166.43.1 to 113.166.43.62113.166.43.6362
174113.166.43.64/26113.166.43.65 to 113.166.43.126113.166.43.12762
175113.166.43.128/26113.166.43.129 to 113.166.43.190113.166.43.19162
176113.166.43.192/26113.166.43.193 to 113.166.43.254113.166.43.25562
177113.166.44.0/26113.166.44.1 to 113.166.44.62113.166.44.6362
178113.166.44.64/26113.166.44.65 to 113.166.44.126113.166.44.12762
179113.166.44.128/26113.166.44.129 to 113.166.44.190113.166.44.19162
180113.166.44.192/26113.166.44.193 to 113.166.44.254113.166.44.25562
181113.166.45.0/26113.166.45.1 to 113.166.45.62113.166.45.6362
182113.166.45.64/26113.166.45.65 to 113.166.45.126113.166.45.12762
183113.166.45.128/26113.166.45.129 to 113.166.45.190113.166.45.19162
184113.166.45.192/26113.166.45.193 to 113.166.45.254113.166.45.25562
185113.166.46.0/26113.166.46.1 to 113.166.46.62113.166.46.6362
186113.166.46.64/26113.166.46.65 to 113.166.46.126113.166.46.12762
187113.166.46.128/26113.166.46.129 to 113.166.46.190113.166.46.19162
188113.166.46.192/26113.166.46.193 to 113.166.46.254113.166.46.25562
189113.166.47.0/26113.166.47.1 to 113.166.47.62113.166.47.6362
190113.166.47.64/26113.166.47.65 to 113.166.47.126113.166.47.12762
191113.166.47.128/26113.166.47.129 to 113.166.47.190113.166.47.19162
192113.166.47.192/26113.166.47.193 to 113.166.47.254113.166.47.25562
193113.166.48.0/26113.166.48.1 to 113.166.48.62113.166.48.6362
194113.166.48.64/26113.166.48.65 to 113.166.48.126113.166.48.12762
195113.166.48.128/26113.166.48.129 to 113.166.48.190113.166.48.19162
196113.166.48.192/26113.166.48.193 to 113.166.48.254113.166.48.25562
197113.166.49.0/26113.166.49.1 to 113.166.49.62113.166.49.6362
198113.166.49.64/26113.166.49.65 to 113.166.49.126113.166.49.12762
199113.166.49.128/26113.166.49.129 to 113.166.49.190113.166.49.19162
200113.166.49.192/26113.166.49.193 to 113.166.49.254113.166.49.25562
201113.166.50.0/26113.166.50.1 to 113.166.50.62113.166.50.6362
202113.166.50.64/26113.166.50.65 to 113.166.50.126113.166.50.12762
203113.166.50.128/26113.166.50.129 to 113.166.50.190113.166.50.19162
204113.166.50.192/26113.166.50.193 to 113.166.50.254113.166.50.25562
205113.166.51.0/26113.166.51.1 to 113.166.51.62113.166.51.6362
206113.166.51.64/26113.166.51.65 to 113.166.51.126113.166.51.12762
207113.166.51.128/26113.166.51.129 to 113.166.51.190113.166.51.19162
208113.166.51.192/26113.166.51.193 to 113.166.51.254113.166.51.25562
209113.166.52.0/26113.166.52.1 to 113.166.52.62113.166.52.6362
210113.166.52.64/26113.166.52.65 to 113.166.52.126113.166.52.12762
211113.166.52.128/26113.166.52.129 to 113.166.52.190113.166.52.19162
212113.166.52.192/26113.166.52.193 to 113.166.52.254113.166.52.25562
213113.166.53.0/26113.166.53.1 to 113.166.53.62113.166.53.6362
214113.166.53.64/26113.166.53.65 to 113.166.53.126113.166.53.12762
215113.166.53.128/26113.166.53.129 to 113.166.53.190113.166.53.19162
216113.166.53.192/26113.166.53.193 to 113.166.53.254113.166.53.25562
217113.166.54.0/26113.166.54.1 to 113.166.54.62113.166.54.6362
218113.166.54.64/26113.166.54.65 to 113.166.54.126113.166.54.12762
219113.166.54.128/26113.166.54.129 to 113.166.54.190113.166.54.19162
220113.166.54.192/26113.166.54.193 to 113.166.54.254113.166.54.25562
221113.166.55.0/26113.166.55.1 to 113.166.55.62113.166.55.6362
222113.166.55.64/26113.166.55.65 to 113.166.55.126113.166.55.12762
223113.166.55.128/26113.166.55.129 to 113.166.55.190113.166.55.19162
224113.166.55.192/26113.166.55.193 to 113.166.55.254113.166.55.25562
225113.166.56.0/26113.166.56.1 to 113.166.56.62113.166.56.6362
226113.166.56.64/26113.166.56.65 to 113.166.56.126113.166.56.12762
227113.166.56.128/26113.166.56.129 to 113.166.56.190113.166.56.19162
228113.166.56.192/26113.166.56.193 to 113.166.56.254113.166.56.25562
229113.166.57.0/26113.166.57.1 to 113.166.57.62113.166.57.6362
230113.166.57.64/26113.166.57.65 to 113.166.57.126113.166.57.12762
231113.166.57.128/26113.166.57.129 to 113.166.57.190113.166.57.19162
232113.166.57.192/26113.166.57.193 to 113.166.57.254113.166.57.25562
233113.166.58.0/26113.166.58.1 to 113.166.58.62113.166.58.6362
234113.166.58.64/26113.166.58.65 to 113.166.58.126113.166.58.12762
235113.166.58.128/26113.166.58.129 to 113.166.58.190113.166.58.19162
236113.166.58.192/26113.166.58.193 to 113.166.58.254113.166.58.25562
237113.166.59.0/26113.166.59.1 to 113.166.59.62113.166.59.6362
238113.166.59.64/26113.166.59.65 to 113.166.59.126113.166.59.12762
239113.166.59.128/26113.166.59.129 to 113.166.59.190113.166.59.19162
240113.166.59.192/26113.166.59.193 to 113.166.59.254113.166.59.25562
241113.166.60.0/26113.166.60.1 to 113.166.60.62113.166.60.6362
242113.166.60.64/26113.166.60.65 to 113.166.60.126113.166.60.12762
243113.166.60.128/26113.166.60.129 to 113.166.60.190113.166.60.19162
244113.166.60.192/26113.166.60.193 to 113.166.60.254113.166.60.25562
245113.166.61.0/26113.166.61.1 to 113.166.61.62113.166.61.6362
246113.166.61.64/26113.166.61.65 to 113.166.61.126113.166.61.12762
247113.166.61.128/26113.166.61.129 to 113.166.61.190113.166.61.19162
248113.166.61.192/26113.166.61.193 to 113.166.61.254113.166.61.25562
249113.166.62.0/26113.166.62.1 to 113.166.62.62113.166.62.6362
250113.166.62.64/26113.166.62.65 to 113.166.62.126113.166.62.12762
251113.166.62.128/26113.166.62.129 to 113.166.62.190113.166.62.19162
252113.166.62.192/26113.166.62.193 to 113.166.62.254113.166.62.25562
253113.166.63.0/26113.166.63.1 to 113.166.63.62113.166.63.6362
254113.166.63.64/26113.166.63.65 to 113.166.63.126113.166.63.12762
255113.166.63.128/26113.166.63.129 to 113.166.63.190113.166.63.19162
256113.166.63.192/26113.166.63.193 to 113.166.63.254113.166.63.25562

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.