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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.

Network197.4.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
197.4.0.0
Broadcast address
197.7.255.255
First usable
197.4.0.1
Last usable
197.7.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
C (default /24)
As numbers
Hex C5040000 · Integer 3305373696 to 3305635839
Reverse DNS zones
4.197.in-addr.arpa
5.197.in-addr.arpa
6.197.in-addr.arpa
7.197.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000101.00000100.00000000.00000000197.4.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network11000101.00000100.00000000.00000000197.4.0.0
Broadcast11000101.00000111.11111111.11111111197.7.255.255
Split into smaller subnets/26
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

197.4.0.0/14 makes 4,096 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1197.4.0.0/26197.4.0.1 to 197.4.0.62197.4.0.6362
2197.4.0.64/26197.4.0.65 to 197.4.0.126197.4.0.12762
3197.4.0.128/26197.4.0.129 to 197.4.0.190197.4.0.19162
4197.4.0.192/26197.4.0.193 to 197.4.0.254197.4.0.25562
5197.4.1.0/26197.4.1.1 to 197.4.1.62197.4.1.6362
6197.4.1.64/26197.4.1.65 to 197.4.1.126197.4.1.12762
7197.4.1.128/26197.4.1.129 to 197.4.1.190197.4.1.19162
8197.4.1.192/26197.4.1.193 to 197.4.1.254197.4.1.25562
9197.4.2.0/26197.4.2.1 to 197.4.2.62197.4.2.6362
10197.4.2.64/26197.4.2.65 to 197.4.2.126197.4.2.12762
11197.4.2.128/26197.4.2.129 to 197.4.2.190197.4.2.19162
12197.4.2.192/26197.4.2.193 to 197.4.2.254197.4.2.25562
13197.4.3.0/26197.4.3.1 to 197.4.3.62197.4.3.6362
14197.4.3.64/26197.4.3.65 to 197.4.3.126197.4.3.12762
15197.4.3.128/26197.4.3.129 to 197.4.3.190197.4.3.19162
16197.4.3.192/26197.4.3.193 to 197.4.3.254197.4.3.25562
17197.4.4.0/26197.4.4.1 to 197.4.4.62197.4.4.6362
18197.4.4.64/26197.4.4.65 to 197.4.4.126197.4.4.12762
19197.4.4.128/26197.4.4.129 to 197.4.4.190197.4.4.19162
20197.4.4.192/26197.4.4.193 to 197.4.4.254197.4.4.25562
21197.4.5.0/26197.4.5.1 to 197.4.5.62197.4.5.6362
22197.4.5.64/26197.4.5.65 to 197.4.5.126197.4.5.12762
23197.4.5.128/26197.4.5.129 to 197.4.5.190197.4.5.19162
24197.4.5.192/26197.4.5.193 to 197.4.5.254197.4.5.25562
25197.4.6.0/26197.4.6.1 to 197.4.6.62197.4.6.6362
26197.4.6.64/26197.4.6.65 to 197.4.6.126197.4.6.12762
27197.4.6.128/26197.4.6.129 to 197.4.6.190197.4.6.19162
28197.4.6.192/26197.4.6.193 to 197.4.6.254197.4.6.25562
29197.4.7.0/26197.4.7.1 to 197.4.7.62197.4.7.6362
30197.4.7.64/26197.4.7.65 to 197.4.7.126197.4.7.12762
31197.4.7.128/26197.4.7.129 to 197.4.7.190197.4.7.19162
32197.4.7.192/26197.4.7.193 to 197.4.7.254197.4.7.25562
33197.4.8.0/26197.4.8.1 to 197.4.8.62197.4.8.6362
34197.4.8.64/26197.4.8.65 to 197.4.8.126197.4.8.12762
35197.4.8.128/26197.4.8.129 to 197.4.8.190197.4.8.19162
36197.4.8.192/26197.4.8.193 to 197.4.8.254197.4.8.25562
37197.4.9.0/26197.4.9.1 to 197.4.9.62197.4.9.6362
38197.4.9.64/26197.4.9.65 to 197.4.9.126197.4.9.12762
39197.4.9.128/26197.4.9.129 to 197.4.9.190197.4.9.19162
40197.4.9.192/26197.4.9.193 to 197.4.9.254197.4.9.25562
41197.4.10.0/26197.4.10.1 to 197.4.10.62197.4.10.6362
42197.4.10.64/26197.4.10.65 to 197.4.10.126197.4.10.12762
43197.4.10.128/26197.4.10.129 to 197.4.10.190197.4.10.19162
44197.4.10.192/26197.4.10.193 to 197.4.10.254197.4.10.25562
45197.4.11.0/26197.4.11.1 to 197.4.11.62197.4.11.6362
46197.4.11.64/26197.4.11.65 to 197.4.11.126197.4.11.12762
47197.4.11.128/26197.4.11.129 to 197.4.11.190197.4.11.19162
48197.4.11.192/26197.4.11.193 to 197.4.11.254197.4.11.25562
49197.4.12.0/26197.4.12.1 to 197.4.12.62197.4.12.6362
50197.4.12.64/26197.4.12.65 to 197.4.12.126197.4.12.12762
51197.4.12.128/26197.4.12.129 to 197.4.12.190197.4.12.19162
52197.4.12.192/26197.4.12.193 to 197.4.12.254197.4.12.25562
53197.4.13.0/26197.4.13.1 to 197.4.13.62197.4.13.6362
54197.4.13.64/26197.4.13.65 to 197.4.13.126197.4.13.12762
55197.4.13.128/26197.4.13.129 to 197.4.13.190197.4.13.19162
56197.4.13.192/26197.4.13.193 to 197.4.13.254197.4.13.25562
57197.4.14.0/26197.4.14.1 to 197.4.14.62197.4.14.6362
58197.4.14.64/26197.4.14.65 to 197.4.14.126197.4.14.12762
59197.4.14.128/26197.4.14.129 to 197.4.14.190197.4.14.19162
60197.4.14.192/26197.4.14.193 to 197.4.14.254197.4.14.25562
61197.4.15.0/26197.4.15.1 to 197.4.15.62197.4.15.6362
62197.4.15.64/26197.4.15.65 to 197.4.15.126197.4.15.12762
63197.4.15.128/26197.4.15.129 to 197.4.15.190197.4.15.19162
64197.4.15.192/26197.4.15.193 to 197.4.15.254197.4.15.25562
65197.4.16.0/26197.4.16.1 to 197.4.16.62197.4.16.6362
66197.4.16.64/26197.4.16.65 to 197.4.16.126197.4.16.12762
67197.4.16.128/26197.4.16.129 to 197.4.16.190197.4.16.19162
68197.4.16.192/26197.4.16.193 to 197.4.16.254197.4.16.25562
69197.4.17.0/26197.4.17.1 to 197.4.17.62197.4.17.6362
70197.4.17.64/26197.4.17.65 to 197.4.17.126197.4.17.12762
71197.4.17.128/26197.4.17.129 to 197.4.17.190197.4.17.19162
72197.4.17.192/26197.4.17.193 to 197.4.17.254197.4.17.25562
73197.4.18.0/26197.4.18.1 to 197.4.18.62197.4.18.6362
74197.4.18.64/26197.4.18.65 to 197.4.18.126197.4.18.12762
75197.4.18.128/26197.4.18.129 to 197.4.18.190197.4.18.19162
76197.4.18.192/26197.4.18.193 to 197.4.18.254197.4.18.25562
77197.4.19.0/26197.4.19.1 to 197.4.19.62197.4.19.6362
78197.4.19.64/26197.4.19.65 to 197.4.19.126197.4.19.12762
79197.4.19.128/26197.4.19.129 to 197.4.19.190197.4.19.19162
80197.4.19.192/26197.4.19.193 to 197.4.19.254197.4.19.25562
81197.4.20.0/26197.4.20.1 to 197.4.20.62197.4.20.6362
82197.4.20.64/26197.4.20.65 to 197.4.20.126197.4.20.12762
83197.4.20.128/26197.4.20.129 to 197.4.20.190197.4.20.19162
84197.4.20.192/26197.4.20.193 to 197.4.20.254197.4.20.25562
85197.4.21.0/26197.4.21.1 to 197.4.21.62197.4.21.6362
86197.4.21.64/26197.4.21.65 to 197.4.21.126197.4.21.12762
87197.4.21.128/26197.4.21.129 to 197.4.21.190197.4.21.19162
88197.4.21.192/26197.4.21.193 to 197.4.21.254197.4.21.25562
89197.4.22.0/26197.4.22.1 to 197.4.22.62197.4.22.6362
90197.4.22.64/26197.4.22.65 to 197.4.22.126197.4.22.12762
91197.4.22.128/26197.4.22.129 to 197.4.22.190197.4.22.19162
92197.4.22.192/26197.4.22.193 to 197.4.22.254197.4.22.25562
93197.4.23.0/26197.4.23.1 to 197.4.23.62197.4.23.6362
94197.4.23.64/26197.4.23.65 to 197.4.23.126197.4.23.12762
95197.4.23.128/26197.4.23.129 to 197.4.23.190197.4.23.19162
96197.4.23.192/26197.4.23.193 to 197.4.23.254197.4.23.25562
97197.4.24.0/26197.4.24.1 to 197.4.24.62197.4.24.6362
98197.4.24.64/26197.4.24.65 to 197.4.24.126197.4.24.12762
99197.4.24.128/26197.4.24.129 to 197.4.24.190197.4.24.19162
100197.4.24.192/26197.4.24.193 to 197.4.24.254197.4.24.25562
101197.4.25.0/26197.4.25.1 to 197.4.25.62197.4.25.6362
102197.4.25.64/26197.4.25.65 to 197.4.25.126197.4.25.12762
103197.4.25.128/26197.4.25.129 to 197.4.25.190197.4.25.19162
104197.4.25.192/26197.4.25.193 to 197.4.25.254197.4.25.25562
105197.4.26.0/26197.4.26.1 to 197.4.26.62197.4.26.6362
106197.4.26.64/26197.4.26.65 to 197.4.26.126197.4.26.12762
107197.4.26.128/26197.4.26.129 to 197.4.26.190197.4.26.19162
108197.4.26.192/26197.4.26.193 to 197.4.26.254197.4.26.25562
109197.4.27.0/26197.4.27.1 to 197.4.27.62197.4.27.6362
110197.4.27.64/26197.4.27.65 to 197.4.27.126197.4.27.12762
111197.4.27.128/26197.4.27.129 to 197.4.27.190197.4.27.19162
112197.4.27.192/26197.4.27.193 to 197.4.27.254197.4.27.25562
113197.4.28.0/26197.4.28.1 to 197.4.28.62197.4.28.6362
114197.4.28.64/26197.4.28.65 to 197.4.28.126197.4.28.12762
115197.4.28.128/26197.4.28.129 to 197.4.28.190197.4.28.19162
116197.4.28.192/26197.4.28.193 to 197.4.28.254197.4.28.25562
117197.4.29.0/26197.4.29.1 to 197.4.29.62197.4.29.6362
118197.4.29.64/26197.4.29.65 to 197.4.29.126197.4.29.12762
119197.4.29.128/26197.4.29.129 to 197.4.29.190197.4.29.19162
120197.4.29.192/26197.4.29.193 to 197.4.29.254197.4.29.25562
121197.4.30.0/26197.4.30.1 to 197.4.30.62197.4.30.6362
122197.4.30.64/26197.4.30.65 to 197.4.30.126197.4.30.12762
123197.4.30.128/26197.4.30.129 to 197.4.30.190197.4.30.19162
124197.4.30.192/26197.4.30.193 to 197.4.30.254197.4.30.25562
125197.4.31.0/26197.4.31.1 to 197.4.31.62197.4.31.6362
126197.4.31.64/26197.4.31.65 to 197.4.31.126197.4.31.12762
127197.4.31.128/26197.4.31.129 to 197.4.31.190197.4.31.19162
128197.4.31.192/26197.4.31.193 to 197.4.31.254197.4.31.25562
129197.4.32.0/26197.4.32.1 to 197.4.32.62197.4.32.6362
130197.4.32.64/26197.4.32.65 to 197.4.32.126197.4.32.12762
131197.4.32.128/26197.4.32.129 to 197.4.32.190197.4.32.19162
132197.4.32.192/26197.4.32.193 to 197.4.32.254197.4.32.25562
133197.4.33.0/26197.4.33.1 to 197.4.33.62197.4.33.6362
134197.4.33.64/26197.4.33.65 to 197.4.33.126197.4.33.12762
135197.4.33.128/26197.4.33.129 to 197.4.33.190197.4.33.19162
136197.4.33.192/26197.4.33.193 to 197.4.33.254197.4.33.25562
137197.4.34.0/26197.4.34.1 to 197.4.34.62197.4.34.6362
138197.4.34.64/26197.4.34.65 to 197.4.34.126197.4.34.12762
139197.4.34.128/26197.4.34.129 to 197.4.34.190197.4.34.19162
140197.4.34.192/26197.4.34.193 to 197.4.34.254197.4.34.25562
141197.4.35.0/26197.4.35.1 to 197.4.35.62197.4.35.6362
142197.4.35.64/26197.4.35.65 to 197.4.35.126197.4.35.12762
143197.4.35.128/26197.4.35.129 to 197.4.35.190197.4.35.19162
144197.4.35.192/26197.4.35.193 to 197.4.35.254197.4.35.25562
145197.4.36.0/26197.4.36.1 to 197.4.36.62197.4.36.6362
146197.4.36.64/26197.4.36.65 to 197.4.36.126197.4.36.12762
147197.4.36.128/26197.4.36.129 to 197.4.36.190197.4.36.19162
148197.4.36.192/26197.4.36.193 to 197.4.36.254197.4.36.25562
149197.4.37.0/26197.4.37.1 to 197.4.37.62197.4.37.6362
150197.4.37.64/26197.4.37.65 to 197.4.37.126197.4.37.12762
151197.4.37.128/26197.4.37.129 to 197.4.37.190197.4.37.19162
152197.4.37.192/26197.4.37.193 to 197.4.37.254197.4.37.25562
153197.4.38.0/26197.4.38.1 to 197.4.38.62197.4.38.6362
154197.4.38.64/26197.4.38.65 to 197.4.38.126197.4.38.12762
155197.4.38.128/26197.4.38.129 to 197.4.38.190197.4.38.19162
156197.4.38.192/26197.4.38.193 to 197.4.38.254197.4.38.25562
157197.4.39.0/26197.4.39.1 to 197.4.39.62197.4.39.6362
158197.4.39.64/26197.4.39.65 to 197.4.39.126197.4.39.12762
159197.4.39.128/26197.4.39.129 to 197.4.39.190197.4.39.19162
160197.4.39.192/26197.4.39.193 to 197.4.39.254197.4.39.25562
161197.4.40.0/26197.4.40.1 to 197.4.40.62197.4.40.6362
162197.4.40.64/26197.4.40.65 to 197.4.40.126197.4.40.12762
163197.4.40.128/26197.4.40.129 to 197.4.40.190197.4.40.19162
164197.4.40.192/26197.4.40.193 to 197.4.40.254197.4.40.25562
165197.4.41.0/26197.4.41.1 to 197.4.41.62197.4.41.6362
166197.4.41.64/26197.4.41.65 to 197.4.41.126197.4.41.12762
167197.4.41.128/26197.4.41.129 to 197.4.41.190197.4.41.19162
168197.4.41.192/26197.4.41.193 to 197.4.41.254197.4.41.25562
169197.4.42.0/26197.4.42.1 to 197.4.42.62197.4.42.6362
170197.4.42.64/26197.4.42.65 to 197.4.42.126197.4.42.12762
171197.4.42.128/26197.4.42.129 to 197.4.42.190197.4.42.19162
172197.4.42.192/26197.4.42.193 to 197.4.42.254197.4.42.25562
173197.4.43.0/26197.4.43.1 to 197.4.43.62197.4.43.6362
174197.4.43.64/26197.4.43.65 to 197.4.43.126197.4.43.12762
175197.4.43.128/26197.4.43.129 to 197.4.43.190197.4.43.19162
176197.4.43.192/26197.4.43.193 to 197.4.43.254197.4.43.25562
177197.4.44.0/26197.4.44.1 to 197.4.44.62197.4.44.6362
178197.4.44.64/26197.4.44.65 to 197.4.44.126197.4.44.12762
179197.4.44.128/26197.4.44.129 to 197.4.44.190197.4.44.19162
180197.4.44.192/26197.4.44.193 to 197.4.44.254197.4.44.25562
181197.4.45.0/26197.4.45.1 to 197.4.45.62197.4.45.6362
182197.4.45.64/26197.4.45.65 to 197.4.45.126197.4.45.12762
183197.4.45.128/26197.4.45.129 to 197.4.45.190197.4.45.19162
184197.4.45.192/26197.4.45.193 to 197.4.45.254197.4.45.25562
185197.4.46.0/26197.4.46.1 to 197.4.46.62197.4.46.6362
186197.4.46.64/26197.4.46.65 to 197.4.46.126197.4.46.12762
187197.4.46.128/26197.4.46.129 to 197.4.46.190197.4.46.19162
188197.4.46.192/26197.4.46.193 to 197.4.46.254197.4.46.25562
189197.4.47.0/26197.4.47.1 to 197.4.47.62197.4.47.6362
190197.4.47.64/26197.4.47.65 to 197.4.47.126197.4.47.12762
191197.4.47.128/26197.4.47.129 to 197.4.47.190197.4.47.19162
192197.4.47.192/26197.4.47.193 to 197.4.47.254197.4.47.25562
193197.4.48.0/26197.4.48.1 to 197.4.48.62197.4.48.6362
194197.4.48.64/26197.4.48.65 to 197.4.48.126197.4.48.12762
195197.4.48.128/26197.4.48.129 to 197.4.48.190197.4.48.19162
196197.4.48.192/26197.4.48.193 to 197.4.48.254197.4.48.25562
197197.4.49.0/26197.4.49.1 to 197.4.49.62197.4.49.6362
198197.4.49.64/26197.4.49.65 to 197.4.49.126197.4.49.12762
199197.4.49.128/26197.4.49.129 to 197.4.49.190197.4.49.19162
200197.4.49.192/26197.4.49.193 to 197.4.49.254197.4.49.25562
201197.4.50.0/26197.4.50.1 to 197.4.50.62197.4.50.6362
202197.4.50.64/26197.4.50.65 to 197.4.50.126197.4.50.12762
203197.4.50.128/26197.4.50.129 to 197.4.50.190197.4.50.19162
204197.4.50.192/26197.4.50.193 to 197.4.50.254197.4.50.25562
205197.4.51.0/26197.4.51.1 to 197.4.51.62197.4.51.6362
206197.4.51.64/26197.4.51.65 to 197.4.51.126197.4.51.12762
207197.4.51.128/26197.4.51.129 to 197.4.51.190197.4.51.19162
208197.4.51.192/26197.4.51.193 to 197.4.51.254197.4.51.25562
209197.4.52.0/26197.4.52.1 to 197.4.52.62197.4.52.6362
210197.4.52.64/26197.4.52.65 to 197.4.52.126197.4.52.12762
211197.4.52.128/26197.4.52.129 to 197.4.52.190197.4.52.19162
212197.4.52.192/26197.4.52.193 to 197.4.52.254197.4.52.25562
213197.4.53.0/26197.4.53.1 to 197.4.53.62197.4.53.6362
214197.4.53.64/26197.4.53.65 to 197.4.53.126197.4.53.12762
215197.4.53.128/26197.4.53.129 to 197.4.53.190197.4.53.19162
216197.4.53.192/26197.4.53.193 to 197.4.53.254197.4.53.25562
217197.4.54.0/26197.4.54.1 to 197.4.54.62197.4.54.6362
218197.4.54.64/26197.4.54.65 to 197.4.54.126197.4.54.12762
219197.4.54.128/26197.4.54.129 to 197.4.54.190197.4.54.19162
220197.4.54.192/26197.4.54.193 to 197.4.54.254197.4.54.25562
221197.4.55.0/26197.4.55.1 to 197.4.55.62197.4.55.6362
222197.4.55.64/26197.4.55.65 to 197.4.55.126197.4.55.12762
223197.4.55.128/26197.4.55.129 to 197.4.55.190197.4.55.19162
224197.4.55.192/26197.4.55.193 to 197.4.55.254197.4.55.25562
225197.4.56.0/26197.4.56.1 to 197.4.56.62197.4.56.6362
226197.4.56.64/26197.4.56.65 to 197.4.56.126197.4.56.12762
227197.4.56.128/26197.4.56.129 to 197.4.56.190197.4.56.19162
228197.4.56.192/26197.4.56.193 to 197.4.56.254197.4.56.25562
229197.4.57.0/26197.4.57.1 to 197.4.57.62197.4.57.6362
230197.4.57.64/26197.4.57.65 to 197.4.57.126197.4.57.12762
231197.4.57.128/26197.4.57.129 to 197.4.57.190197.4.57.19162
232197.4.57.192/26197.4.57.193 to 197.4.57.254197.4.57.25562
233197.4.58.0/26197.4.58.1 to 197.4.58.62197.4.58.6362
234197.4.58.64/26197.4.58.65 to 197.4.58.126197.4.58.12762
235197.4.58.128/26197.4.58.129 to 197.4.58.190197.4.58.19162
236197.4.58.192/26197.4.58.193 to 197.4.58.254197.4.58.25562
237197.4.59.0/26197.4.59.1 to 197.4.59.62197.4.59.6362
238197.4.59.64/26197.4.59.65 to 197.4.59.126197.4.59.12762
239197.4.59.128/26197.4.59.129 to 197.4.59.190197.4.59.19162
240197.4.59.192/26197.4.59.193 to 197.4.59.254197.4.59.25562
241197.4.60.0/26197.4.60.1 to 197.4.60.62197.4.60.6362
242197.4.60.64/26197.4.60.65 to 197.4.60.126197.4.60.12762
243197.4.60.128/26197.4.60.129 to 197.4.60.190197.4.60.19162
244197.4.60.192/26197.4.60.193 to 197.4.60.254197.4.60.25562
245197.4.61.0/26197.4.61.1 to 197.4.61.62197.4.61.6362
246197.4.61.64/26197.4.61.65 to 197.4.61.126197.4.61.12762
247197.4.61.128/26197.4.61.129 to 197.4.61.190197.4.61.19162
248197.4.61.192/26197.4.61.193 to 197.4.61.254197.4.61.25562
249197.4.62.0/26197.4.62.1 to 197.4.62.62197.4.62.6362
250197.4.62.64/26197.4.62.65 to 197.4.62.126197.4.62.12762
251197.4.62.128/26197.4.62.129 to 197.4.62.190197.4.62.19162
252197.4.62.192/26197.4.62.193 to 197.4.62.254197.4.62.25562
253197.4.63.0/26197.4.63.1 to 197.4.63.62197.4.63.6362
254197.4.63.64/26197.4.63.65 to 197.4.63.126197.4.63.12762
255197.4.63.128/26197.4.63.129 to 197.4.63.190197.4.63.19162
256197.4.63.192/26197.4.63.193 to 197.4.63.254197.4.63.25562

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.