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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.

Network199.149.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
199.149.0.0
Broadcast address
199.149.255.255
First usable
199.149.0.1
Last usable
199.149.255.254
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
C (default /24)
As numbers
Hex C7950000 · Integer 3348430848 to 3348496383
Reverse DNS zone
149.199.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000111.10010101..00000000.00000000199.149.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11000111.10010101..00000000.00000000199.149.0.0
Broadcast11000111.10010101..11111111.11111111199.149.255.255
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)

199.149.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1199.149.0.0/26199.149.0.1 to 199.149.0.62199.149.0.6362
2199.149.0.64/26199.149.0.65 to 199.149.0.126199.149.0.12762
3199.149.0.128/26199.149.0.129 to 199.149.0.190199.149.0.19162
4199.149.0.192/26199.149.0.193 to 199.149.0.254199.149.0.25562
5199.149.1.0/26199.149.1.1 to 199.149.1.62199.149.1.6362
6199.149.1.64/26199.149.1.65 to 199.149.1.126199.149.1.12762
7199.149.1.128/26199.149.1.129 to 199.149.1.190199.149.1.19162
8199.149.1.192/26199.149.1.193 to 199.149.1.254199.149.1.25562
9199.149.2.0/26199.149.2.1 to 199.149.2.62199.149.2.6362
10199.149.2.64/26199.149.2.65 to 199.149.2.126199.149.2.12762
11199.149.2.128/26199.149.2.129 to 199.149.2.190199.149.2.19162
12199.149.2.192/26199.149.2.193 to 199.149.2.254199.149.2.25562
13199.149.3.0/26199.149.3.1 to 199.149.3.62199.149.3.6362
14199.149.3.64/26199.149.3.65 to 199.149.3.126199.149.3.12762
15199.149.3.128/26199.149.3.129 to 199.149.3.190199.149.3.19162
16199.149.3.192/26199.149.3.193 to 199.149.3.254199.149.3.25562
17199.149.4.0/26199.149.4.1 to 199.149.4.62199.149.4.6362
18199.149.4.64/26199.149.4.65 to 199.149.4.126199.149.4.12762
19199.149.4.128/26199.149.4.129 to 199.149.4.190199.149.4.19162
20199.149.4.192/26199.149.4.193 to 199.149.4.254199.149.4.25562
21199.149.5.0/26199.149.5.1 to 199.149.5.62199.149.5.6362
22199.149.5.64/26199.149.5.65 to 199.149.5.126199.149.5.12762
23199.149.5.128/26199.149.5.129 to 199.149.5.190199.149.5.19162
24199.149.5.192/26199.149.5.193 to 199.149.5.254199.149.5.25562
25199.149.6.0/26199.149.6.1 to 199.149.6.62199.149.6.6362
26199.149.6.64/26199.149.6.65 to 199.149.6.126199.149.6.12762
27199.149.6.128/26199.149.6.129 to 199.149.6.190199.149.6.19162
28199.149.6.192/26199.149.6.193 to 199.149.6.254199.149.6.25562
29199.149.7.0/26199.149.7.1 to 199.149.7.62199.149.7.6362
30199.149.7.64/26199.149.7.65 to 199.149.7.126199.149.7.12762
31199.149.7.128/26199.149.7.129 to 199.149.7.190199.149.7.19162
32199.149.7.192/26199.149.7.193 to 199.149.7.254199.149.7.25562
33199.149.8.0/26199.149.8.1 to 199.149.8.62199.149.8.6362
34199.149.8.64/26199.149.8.65 to 199.149.8.126199.149.8.12762
35199.149.8.128/26199.149.8.129 to 199.149.8.190199.149.8.19162
36199.149.8.192/26199.149.8.193 to 199.149.8.254199.149.8.25562
37199.149.9.0/26199.149.9.1 to 199.149.9.62199.149.9.6362
38199.149.9.64/26199.149.9.65 to 199.149.9.126199.149.9.12762
39199.149.9.128/26199.149.9.129 to 199.149.9.190199.149.9.19162
40199.149.9.192/26199.149.9.193 to 199.149.9.254199.149.9.25562
41199.149.10.0/26199.149.10.1 to 199.149.10.62199.149.10.6362
42199.149.10.64/26199.149.10.65 to 199.149.10.126199.149.10.12762
43199.149.10.128/26199.149.10.129 to 199.149.10.190199.149.10.19162
44199.149.10.192/26199.149.10.193 to 199.149.10.254199.149.10.25562
45199.149.11.0/26199.149.11.1 to 199.149.11.62199.149.11.6362
46199.149.11.64/26199.149.11.65 to 199.149.11.126199.149.11.12762
47199.149.11.128/26199.149.11.129 to 199.149.11.190199.149.11.19162
48199.149.11.192/26199.149.11.193 to 199.149.11.254199.149.11.25562
49199.149.12.0/26199.149.12.1 to 199.149.12.62199.149.12.6362
50199.149.12.64/26199.149.12.65 to 199.149.12.126199.149.12.12762
51199.149.12.128/26199.149.12.129 to 199.149.12.190199.149.12.19162
52199.149.12.192/26199.149.12.193 to 199.149.12.254199.149.12.25562
53199.149.13.0/26199.149.13.1 to 199.149.13.62199.149.13.6362
54199.149.13.64/26199.149.13.65 to 199.149.13.126199.149.13.12762
55199.149.13.128/26199.149.13.129 to 199.149.13.190199.149.13.19162
56199.149.13.192/26199.149.13.193 to 199.149.13.254199.149.13.25562
57199.149.14.0/26199.149.14.1 to 199.149.14.62199.149.14.6362
58199.149.14.64/26199.149.14.65 to 199.149.14.126199.149.14.12762
59199.149.14.128/26199.149.14.129 to 199.149.14.190199.149.14.19162
60199.149.14.192/26199.149.14.193 to 199.149.14.254199.149.14.25562
61199.149.15.0/26199.149.15.1 to 199.149.15.62199.149.15.6362
62199.149.15.64/26199.149.15.65 to 199.149.15.126199.149.15.12762
63199.149.15.128/26199.149.15.129 to 199.149.15.190199.149.15.19162
64199.149.15.192/26199.149.15.193 to 199.149.15.254199.149.15.25562
65199.149.16.0/26199.149.16.1 to 199.149.16.62199.149.16.6362
66199.149.16.64/26199.149.16.65 to 199.149.16.126199.149.16.12762
67199.149.16.128/26199.149.16.129 to 199.149.16.190199.149.16.19162
68199.149.16.192/26199.149.16.193 to 199.149.16.254199.149.16.25562
69199.149.17.0/26199.149.17.1 to 199.149.17.62199.149.17.6362
70199.149.17.64/26199.149.17.65 to 199.149.17.126199.149.17.12762
71199.149.17.128/26199.149.17.129 to 199.149.17.190199.149.17.19162
72199.149.17.192/26199.149.17.193 to 199.149.17.254199.149.17.25562
73199.149.18.0/26199.149.18.1 to 199.149.18.62199.149.18.6362
74199.149.18.64/26199.149.18.65 to 199.149.18.126199.149.18.12762
75199.149.18.128/26199.149.18.129 to 199.149.18.190199.149.18.19162
76199.149.18.192/26199.149.18.193 to 199.149.18.254199.149.18.25562
77199.149.19.0/26199.149.19.1 to 199.149.19.62199.149.19.6362
78199.149.19.64/26199.149.19.65 to 199.149.19.126199.149.19.12762
79199.149.19.128/26199.149.19.129 to 199.149.19.190199.149.19.19162
80199.149.19.192/26199.149.19.193 to 199.149.19.254199.149.19.25562
81199.149.20.0/26199.149.20.1 to 199.149.20.62199.149.20.6362
82199.149.20.64/26199.149.20.65 to 199.149.20.126199.149.20.12762
83199.149.20.128/26199.149.20.129 to 199.149.20.190199.149.20.19162
84199.149.20.192/26199.149.20.193 to 199.149.20.254199.149.20.25562
85199.149.21.0/26199.149.21.1 to 199.149.21.62199.149.21.6362
86199.149.21.64/26199.149.21.65 to 199.149.21.126199.149.21.12762
87199.149.21.128/26199.149.21.129 to 199.149.21.190199.149.21.19162
88199.149.21.192/26199.149.21.193 to 199.149.21.254199.149.21.25562
89199.149.22.0/26199.149.22.1 to 199.149.22.62199.149.22.6362
90199.149.22.64/26199.149.22.65 to 199.149.22.126199.149.22.12762
91199.149.22.128/26199.149.22.129 to 199.149.22.190199.149.22.19162
92199.149.22.192/26199.149.22.193 to 199.149.22.254199.149.22.25562
93199.149.23.0/26199.149.23.1 to 199.149.23.62199.149.23.6362
94199.149.23.64/26199.149.23.65 to 199.149.23.126199.149.23.12762
95199.149.23.128/26199.149.23.129 to 199.149.23.190199.149.23.19162
96199.149.23.192/26199.149.23.193 to 199.149.23.254199.149.23.25562
97199.149.24.0/26199.149.24.1 to 199.149.24.62199.149.24.6362
98199.149.24.64/26199.149.24.65 to 199.149.24.126199.149.24.12762
99199.149.24.128/26199.149.24.129 to 199.149.24.190199.149.24.19162
100199.149.24.192/26199.149.24.193 to 199.149.24.254199.149.24.25562
101199.149.25.0/26199.149.25.1 to 199.149.25.62199.149.25.6362
102199.149.25.64/26199.149.25.65 to 199.149.25.126199.149.25.12762
103199.149.25.128/26199.149.25.129 to 199.149.25.190199.149.25.19162
104199.149.25.192/26199.149.25.193 to 199.149.25.254199.149.25.25562
105199.149.26.0/26199.149.26.1 to 199.149.26.62199.149.26.6362
106199.149.26.64/26199.149.26.65 to 199.149.26.126199.149.26.12762
107199.149.26.128/26199.149.26.129 to 199.149.26.190199.149.26.19162
108199.149.26.192/26199.149.26.193 to 199.149.26.254199.149.26.25562
109199.149.27.0/26199.149.27.1 to 199.149.27.62199.149.27.6362
110199.149.27.64/26199.149.27.65 to 199.149.27.126199.149.27.12762
111199.149.27.128/26199.149.27.129 to 199.149.27.190199.149.27.19162
112199.149.27.192/26199.149.27.193 to 199.149.27.254199.149.27.25562
113199.149.28.0/26199.149.28.1 to 199.149.28.62199.149.28.6362
114199.149.28.64/26199.149.28.65 to 199.149.28.126199.149.28.12762
115199.149.28.128/26199.149.28.129 to 199.149.28.190199.149.28.19162
116199.149.28.192/26199.149.28.193 to 199.149.28.254199.149.28.25562
117199.149.29.0/26199.149.29.1 to 199.149.29.62199.149.29.6362
118199.149.29.64/26199.149.29.65 to 199.149.29.126199.149.29.12762
119199.149.29.128/26199.149.29.129 to 199.149.29.190199.149.29.19162
120199.149.29.192/26199.149.29.193 to 199.149.29.254199.149.29.25562
121199.149.30.0/26199.149.30.1 to 199.149.30.62199.149.30.6362
122199.149.30.64/26199.149.30.65 to 199.149.30.126199.149.30.12762
123199.149.30.128/26199.149.30.129 to 199.149.30.190199.149.30.19162
124199.149.30.192/26199.149.30.193 to 199.149.30.254199.149.30.25562
125199.149.31.0/26199.149.31.1 to 199.149.31.62199.149.31.6362
126199.149.31.64/26199.149.31.65 to 199.149.31.126199.149.31.12762
127199.149.31.128/26199.149.31.129 to 199.149.31.190199.149.31.19162
128199.149.31.192/26199.149.31.193 to 199.149.31.254199.149.31.25562
129199.149.32.0/26199.149.32.1 to 199.149.32.62199.149.32.6362
130199.149.32.64/26199.149.32.65 to 199.149.32.126199.149.32.12762
131199.149.32.128/26199.149.32.129 to 199.149.32.190199.149.32.19162
132199.149.32.192/26199.149.32.193 to 199.149.32.254199.149.32.25562
133199.149.33.0/26199.149.33.1 to 199.149.33.62199.149.33.6362
134199.149.33.64/26199.149.33.65 to 199.149.33.126199.149.33.12762
135199.149.33.128/26199.149.33.129 to 199.149.33.190199.149.33.19162
136199.149.33.192/26199.149.33.193 to 199.149.33.254199.149.33.25562
137199.149.34.0/26199.149.34.1 to 199.149.34.62199.149.34.6362
138199.149.34.64/26199.149.34.65 to 199.149.34.126199.149.34.12762
139199.149.34.128/26199.149.34.129 to 199.149.34.190199.149.34.19162
140199.149.34.192/26199.149.34.193 to 199.149.34.254199.149.34.25562
141199.149.35.0/26199.149.35.1 to 199.149.35.62199.149.35.6362
142199.149.35.64/26199.149.35.65 to 199.149.35.126199.149.35.12762
143199.149.35.128/26199.149.35.129 to 199.149.35.190199.149.35.19162
144199.149.35.192/26199.149.35.193 to 199.149.35.254199.149.35.25562
145199.149.36.0/26199.149.36.1 to 199.149.36.62199.149.36.6362
146199.149.36.64/26199.149.36.65 to 199.149.36.126199.149.36.12762
147199.149.36.128/26199.149.36.129 to 199.149.36.190199.149.36.19162
148199.149.36.192/26199.149.36.193 to 199.149.36.254199.149.36.25562
149199.149.37.0/26199.149.37.1 to 199.149.37.62199.149.37.6362
150199.149.37.64/26199.149.37.65 to 199.149.37.126199.149.37.12762
151199.149.37.128/26199.149.37.129 to 199.149.37.190199.149.37.19162
152199.149.37.192/26199.149.37.193 to 199.149.37.254199.149.37.25562
153199.149.38.0/26199.149.38.1 to 199.149.38.62199.149.38.6362
154199.149.38.64/26199.149.38.65 to 199.149.38.126199.149.38.12762
155199.149.38.128/26199.149.38.129 to 199.149.38.190199.149.38.19162
156199.149.38.192/26199.149.38.193 to 199.149.38.254199.149.38.25562
157199.149.39.0/26199.149.39.1 to 199.149.39.62199.149.39.6362
158199.149.39.64/26199.149.39.65 to 199.149.39.126199.149.39.12762
159199.149.39.128/26199.149.39.129 to 199.149.39.190199.149.39.19162
160199.149.39.192/26199.149.39.193 to 199.149.39.254199.149.39.25562
161199.149.40.0/26199.149.40.1 to 199.149.40.62199.149.40.6362
162199.149.40.64/26199.149.40.65 to 199.149.40.126199.149.40.12762
163199.149.40.128/26199.149.40.129 to 199.149.40.190199.149.40.19162
164199.149.40.192/26199.149.40.193 to 199.149.40.254199.149.40.25562
165199.149.41.0/26199.149.41.1 to 199.149.41.62199.149.41.6362
166199.149.41.64/26199.149.41.65 to 199.149.41.126199.149.41.12762
167199.149.41.128/26199.149.41.129 to 199.149.41.190199.149.41.19162
168199.149.41.192/26199.149.41.193 to 199.149.41.254199.149.41.25562
169199.149.42.0/26199.149.42.1 to 199.149.42.62199.149.42.6362
170199.149.42.64/26199.149.42.65 to 199.149.42.126199.149.42.12762
171199.149.42.128/26199.149.42.129 to 199.149.42.190199.149.42.19162
172199.149.42.192/26199.149.42.193 to 199.149.42.254199.149.42.25562
173199.149.43.0/26199.149.43.1 to 199.149.43.62199.149.43.6362
174199.149.43.64/26199.149.43.65 to 199.149.43.126199.149.43.12762
175199.149.43.128/26199.149.43.129 to 199.149.43.190199.149.43.19162
176199.149.43.192/26199.149.43.193 to 199.149.43.254199.149.43.25562
177199.149.44.0/26199.149.44.1 to 199.149.44.62199.149.44.6362
178199.149.44.64/26199.149.44.65 to 199.149.44.126199.149.44.12762
179199.149.44.128/26199.149.44.129 to 199.149.44.190199.149.44.19162
180199.149.44.192/26199.149.44.193 to 199.149.44.254199.149.44.25562
181199.149.45.0/26199.149.45.1 to 199.149.45.62199.149.45.6362
182199.149.45.64/26199.149.45.65 to 199.149.45.126199.149.45.12762
183199.149.45.128/26199.149.45.129 to 199.149.45.190199.149.45.19162
184199.149.45.192/26199.149.45.193 to 199.149.45.254199.149.45.25562
185199.149.46.0/26199.149.46.1 to 199.149.46.62199.149.46.6362
186199.149.46.64/26199.149.46.65 to 199.149.46.126199.149.46.12762
187199.149.46.128/26199.149.46.129 to 199.149.46.190199.149.46.19162
188199.149.46.192/26199.149.46.193 to 199.149.46.254199.149.46.25562
189199.149.47.0/26199.149.47.1 to 199.149.47.62199.149.47.6362
190199.149.47.64/26199.149.47.65 to 199.149.47.126199.149.47.12762
191199.149.47.128/26199.149.47.129 to 199.149.47.190199.149.47.19162
192199.149.47.192/26199.149.47.193 to 199.149.47.254199.149.47.25562
193199.149.48.0/26199.149.48.1 to 199.149.48.62199.149.48.6362
194199.149.48.64/26199.149.48.65 to 199.149.48.126199.149.48.12762
195199.149.48.128/26199.149.48.129 to 199.149.48.190199.149.48.19162
196199.149.48.192/26199.149.48.193 to 199.149.48.254199.149.48.25562
197199.149.49.0/26199.149.49.1 to 199.149.49.62199.149.49.6362
198199.149.49.64/26199.149.49.65 to 199.149.49.126199.149.49.12762
199199.149.49.128/26199.149.49.129 to 199.149.49.190199.149.49.19162
200199.149.49.192/26199.149.49.193 to 199.149.49.254199.149.49.25562
201199.149.50.0/26199.149.50.1 to 199.149.50.62199.149.50.6362
202199.149.50.64/26199.149.50.65 to 199.149.50.126199.149.50.12762
203199.149.50.128/26199.149.50.129 to 199.149.50.190199.149.50.19162
204199.149.50.192/26199.149.50.193 to 199.149.50.254199.149.50.25562
205199.149.51.0/26199.149.51.1 to 199.149.51.62199.149.51.6362
206199.149.51.64/26199.149.51.65 to 199.149.51.126199.149.51.12762
207199.149.51.128/26199.149.51.129 to 199.149.51.190199.149.51.19162
208199.149.51.192/26199.149.51.193 to 199.149.51.254199.149.51.25562
209199.149.52.0/26199.149.52.1 to 199.149.52.62199.149.52.6362
210199.149.52.64/26199.149.52.65 to 199.149.52.126199.149.52.12762
211199.149.52.128/26199.149.52.129 to 199.149.52.190199.149.52.19162
212199.149.52.192/26199.149.52.193 to 199.149.52.254199.149.52.25562
213199.149.53.0/26199.149.53.1 to 199.149.53.62199.149.53.6362
214199.149.53.64/26199.149.53.65 to 199.149.53.126199.149.53.12762
215199.149.53.128/26199.149.53.129 to 199.149.53.190199.149.53.19162
216199.149.53.192/26199.149.53.193 to 199.149.53.254199.149.53.25562
217199.149.54.0/26199.149.54.1 to 199.149.54.62199.149.54.6362
218199.149.54.64/26199.149.54.65 to 199.149.54.126199.149.54.12762
219199.149.54.128/26199.149.54.129 to 199.149.54.190199.149.54.19162
220199.149.54.192/26199.149.54.193 to 199.149.54.254199.149.54.25562
221199.149.55.0/26199.149.55.1 to 199.149.55.62199.149.55.6362
222199.149.55.64/26199.149.55.65 to 199.149.55.126199.149.55.12762
223199.149.55.128/26199.149.55.129 to 199.149.55.190199.149.55.19162
224199.149.55.192/26199.149.55.193 to 199.149.55.254199.149.55.25562
225199.149.56.0/26199.149.56.1 to 199.149.56.62199.149.56.6362
226199.149.56.64/26199.149.56.65 to 199.149.56.126199.149.56.12762
227199.149.56.128/26199.149.56.129 to 199.149.56.190199.149.56.19162
228199.149.56.192/26199.149.56.193 to 199.149.56.254199.149.56.25562
229199.149.57.0/26199.149.57.1 to 199.149.57.62199.149.57.6362
230199.149.57.64/26199.149.57.65 to 199.149.57.126199.149.57.12762
231199.149.57.128/26199.149.57.129 to 199.149.57.190199.149.57.19162
232199.149.57.192/26199.149.57.193 to 199.149.57.254199.149.57.25562
233199.149.58.0/26199.149.58.1 to 199.149.58.62199.149.58.6362
234199.149.58.64/26199.149.58.65 to 199.149.58.126199.149.58.12762
235199.149.58.128/26199.149.58.129 to 199.149.58.190199.149.58.19162
236199.149.58.192/26199.149.58.193 to 199.149.58.254199.149.58.25562
237199.149.59.0/26199.149.59.1 to 199.149.59.62199.149.59.6362
238199.149.59.64/26199.149.59.65 to 199.149.59.126199.149.59.12762
239199.149.59.128/26199.149.59.129 to 199.149.59.190199.149.59.19162
240199.149.59.192/26199.149.59.193 to 199.149.59.254199.149.59.25562
241199.149.60.0/26199.149.60.1 to 199.149.60.62199.149.60.6362
242199.149.60.64/26199.149.60.65 to 199.149.60.126199.149.60.12762
243199.149.60.128/26199.149.60.129 to 199.149.60.190199.149.60.19162
244199.149.60.192/26199.149.60.193 to 199.149.60.254199.149.60.25562
245199.149.61.0/26199.149.61.1 to 199.149.61.62199.149.61.6362
246199.149.61.64/26199.149.61.65 to 199.149.61.126199.149.61.12762
247199.149.61.128/26199.149.61.129 to 199.149.61.190199.149.61.19162
248199.149.61.192/26199.149.61.193 to 199.149.61.254199.149.61.25562
249199.149.62.0/26199.149.62.1 to 199.149.62.62199.149.62.6362
250199.149.62.64/26199.149.62.65 to 199.149.62.126199.149.62.12762
251199.149.62.128/26199.149.62.129 to 199.149.62.190199.149.62.19162
252199.149.62.192/26199.149.62.193 to 199.149.62.254199.149.62.25562
253199.149.63.0/26199.149.63.1 to 199.149.63.62199.149.63.6362
254199.149.63.64/26199.149.63.65 to 199.149.63.126199.149.63.12762
255199.149.63.128/26199.149.63.129 to 199.149.63.190199.149.63.19162
256199.149.63.192/26199.149.63.193 to 199.149.63.254199.149.63.25562

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.