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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.

Network205.136.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
205.136.0.0
Broadcast address
205.139.255.255
First usable
205.136.0.1
Last usable
205.139.255.254
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 CD880000 · Integer 3448242176 to 3448504319
Reverse DNS zones
136.205.in-addr.arpa
137.205.in-addr.arpa
138.205.in-addr.arpa
139.205.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
Address11001101.10001000.00000000.00000000205.136.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network11001101.10001000.00000000.00000000205.136.0.0
Broadcast11001101.10001011.11111111.11111111205.139.255.255
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)

205.136.0.0/14 makes 4,096 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1205.136.0.0/26205.136.0.1 to 205.136.0.62205.136.0.6362
2205.136.0.64/26205.136.0.65 to 205.136.0.126205.136.0.12762
3205.136.0.128/26205.136.0.129 to 205.136.0.190205.136.0.19162
4205.136.0.192/26205.136.0.193 to 205.136.0.254205.136.0.25562
5205.136.1.0/26205.136.1.1 to 205.136.1.62205.136.1.6362
6205.136.1.64/26205.136.1.65 to 205.136.1.126205.136.1.12762
7205.136.1.128/26205.136.1.129 to 205.136.1.190205.136.1.19162
8205.136.1.192/26205.136.1.193 to 205.136.1.254205.136.1.25562
9205.136.2.0/26205.136.2.1 to 205.136.2.62205.136.2.6362
10205.136.2.64/26205.136.2.65 to 205.136.2.126205.136.2.12762
11205.136.2.128/26205.136.2.129 to 205.136.2.190205.136.2.19162
12205.136.2.192/26205.136.2.193 to 205.136.2.254205.136.2.25562
13205.136.3.0/26205.136.3.1 to 205.136.3.62205.136.3.6362
14205.136.3.64/26205.136.3.65 to 205.136.3.126205.136.3.12762
15205.136.3.128/26205.136.3.129 to 205.136.3.190205.136.3.19162
16205.136.3.192/26205.136.3.193 to 205.136.3.254205.136.3.25562
17205.136.4.0/26205.136.4.1 to 205.136.4.62205.136.4.6362
18205.136.4.64/26205.136.4.65 to 205.136.4.126205.136.4.12762
19205.136.4.128/26205.136.4.129 to 205.136.4.190205.136.4.19162
20205.136.4.192/26205.136.4.193 to 205.136.4.254205.136.4.25562
21205.136.5.0/26205.136.5.1 to 205.136.5.62205.136.5.6362
22205.136.5.64/26205.136.5.65 to 205.136.5.126205.136.5.12762
23205.136.5.128/26205.136.5.129 to 205.136.5.190205.136.5.19162
24205.136.5.192/26205.136.5.193 to 205.136.5.254205.136.5.25562
25205.136.6.0/26205.136.6.1 to 205.136.6.62205.136.6.6362
26205.136.6.64/26205.136.6.65 to 205.136.6.126205.136.6.12762
27205.136.6.128/26205.136.6.129 to 205.136.6.190205.136.6.19162
28205.136.6.192/26205.136.6.193 to 205.136.6.254205.136.6.25562
29205.136.7.0/26205.136.7.1 to 205.136.7.62205.136.7.6362
30205.136.7.64/26205.136.7.65 to 205.136.7.126205.136.7.12762
31205.136.7.128/26205.136.7.129 to 205.136.7.190205.136.7.19162
32205.136.7.192/26205.136.7.193 to 205.136.7.254205.136.7.25562
33205.136.8.0/26205.136.8.1 to 205.136.8.62205.136.8.6362
34205.136.8.64/26205.136.8.65 to 205.136.8.126205.136.8.12762
35205.136.8.128/26205.136.8.129 to 205.136.8.190205.136.8.19162
36205.136.8.192/26205.136.8.193 to 205.136.8.254205.136.8.25562
37205.136.9.0/26205.136.9.1 to 205.136.9.62205.136.9.6362
38205.136.9.64/26205.136.9.65 to 205.136.9.126205.136.9.12762
39205.136.9.128/26205.136.9.129 to 205.136.9.190205.136.9.19162
40205.136.9.192/26205.136.9.193 to 205.136.9.254205.136.9.25562
41205.136.10.0/26205.136.10.1 to 205.136.10.62205.136.10.6362
42205.136.10.64/26205.136.10.65 to 205.136.10.126205.136.10.12762
43205.136.10.128/26205.136.10.129 to 205.136.10.190205.136.10.19162
44205.136.10.192/26205.136.10.193 to 205.136.10.254205.136.10.25562
45205.136.11.0/26205.136.11.1 to 205.136.11.62205.136.11.6362
46205.136.11.64/26205.136.11.65 to 205.136.11.126205.136.11.12762
47205.136.11.128/26205.136.11.129 to 205.136.11.190205.136.11.19162
48205.136.11.192/26205.136.11.193 to 205.136.11.254205.136.11.25562
49205.136.12.0/26205.136.12.1 to 205.136.12.62205.136.12.6362
50205.136.12.64/26205.136.12.65 to 205.136.12.126205.136.12.12762
51205.136.12.128/26205.136.12.129 to 205.136.12.190205.136.12.19162
52205.136.12.192/26205.136.12.193 to 205.136.12.254205.136.12.25562
53205.136.13.0/26205.136.13.1 to 205.136.13.62205.136.13.6362
54205.136.13.64/26205.136.13.65 to 205.136.13.126205.136.13.12762
55205.136.13.128/26205.136.13.129 to 205.136.13.190205.136.13.19162
56205.136.13.192/26205.136.13.193 to 205.136.13.254205.136.13.25562
57205.136.14.0/26205.136.14.1 to 205.136.14.62205.136.14.6362
58205.136.14.64/26205.136.14.65 to 205.136.14.126205.136.14.12762
59205.136.14.128/26205.136.14.129 to 205.136.14.190205.136.14.19162
60205.136.14.192/26205.136.14.193 to 205.136.14.254205.136.14.25562
61205.136.15.0/26205.136.15.1 to 205.136.15.62205.136.15.6362
62205.136.15.64/26205.136.15.65 to 205.136.15.126205.136.15.12762
63205.136.15.128/26205.136.15.129 to 205.136.15.190205.136.15.19162
64205.136.15.192/26205.136.15.193 to 205.136.15.254205.136.15.25562
65205.136.16.0/26205.136.16.1 to 205.136.16.62205.136.16.6362
66205.136.16.64/26205.136.16.65 to 205.136.16.126205.136.16.12762
67205.136.16.128/26205.136.16.129 to 205.136.16.190205.136.16.19162
68205.136.16.192/26205.136.16.193 to 205.136.16.254205.136.16.25562
69205.136.17.0/26205.136.17.1 to 205.136.17.62205.136.17.6362
70205.136.17.64/26205.136.17.65 to 205.136.17.126205.136.17.12762
71205.136.17.128/26205.136.17.129 to 205.136.17.190205.136.17.19162
72205.136.17.192/26205.136.17.193 to 205.136.17.254205.136.17.25562
73205.136.18.0/26205.136.18.1 to 205.136.18.62205.136.18.6362
74205.136.18.64/26205.136.18.65 to 205.136.18.126205.136.18.12762
75205.136.18.128/26205.136.18.129 to 205.136.18.190205.136.18.19162
76205.136.18.192/26205.136.18.193 to 205.136.18.254205.136.18.25562
77205.136.19.0/26205.136.19.1 to 205.136.19.62205.136.19.6362
78205.136.19.64/26205.136.19.65 to 205.136.19.126205.136.19.12762
79205.136.19.128/26205.136.19.129 to 205.136.19.190205.136.19.19162
80205.136.19.192/26205.136.19.193 to 205.136.19.254205.136.19.25562
81205.136.20.0/26205.136.20.1 to 205.136.20.62205.136.20.6362
82205.136.20.64/26205.136.20.65 to 205.136.20.126205.136.20.12762
83205.136.20.128/26205.136.20.129 to 205.136.20.190205.136.20.19162
84205.136.20.192/26205.136.20.193 to 205.136.20.254205.136.20.25562
85205.136.21.0/26205.136.21.1 to 205.136.21.62205.136.21.6362
86205.136.21.64/26205.136.21.65 to 205.136.21.126205.136.21.12762
87205.136.21.128/26205.136.21.129 to 205.136.21.190205.136.21.19162
88205.136.21.192/26205.136.21.193 to 205.136.21.254205.136.21.25562
89205.136.22.0/26205.136.22.1 to 205.136.22.62205.136.22.6362
90205.136.22.64/26205.136.22.65 to 205.136.22.126205.136.22.12762
91205.136.22.128/26205.136.22.129 to 205.136.22.190205.136.22.19162
92205.136.22.192/26205.136.22.193 to 205.136.22.254205.136.22.25562
93205.136.23.0/26205.136.23.1 to 205.136.23.62205.136.23.6362
94205.136.23.64/26205.136.23.65 to 205.136.23.126205.136.23.12762
95205.136.23.128/26205.136.23.129 to 205.136.23.190205.136.23.19162
96205.136.23.192/26205.136.23.193 to 205.136.23.254205.136.23.25562
97205.136.24.0/26205.136.24.1 to 205.136.24.62205.136.24.6362
98205.136.24.64/26205.136.24.65 to 205.136.24.126205.136.24.12762
99205.136.24.128/26205.136.24.129 to 205.136.24.190205.136.24.19162
100205.136.24.192/26205.136.24.193 to 205.136.24.254205.136.24.25562
101205.136.25.0/26205.136.25.1 to 205.136.25.62205.136.25.6362
102205.136.25.64/26205.136.25.65 to 205.136.25.126205.136.25.12762
103205.136.25.128/26205.136.25.129 to 205.136.25.190205.136.25.19162
104205.136.25.192/26205.136.25.193 to 205.136.25.254205.136.25.25562
105205.136.26.0/26205.136.26.1 to 205.136.26.62205.136.26.6362
106205.136.26.64/26205.136.26.65 to 205.136.26.126205.136.26.12762
107205.136.26.128/26205.136.26.129 to 205.136.26.190205.136.26.19162
108205.136.26.192/26205.136.26.193 to 205.136.26.254205.136.26.25562
109205.136.27.0/26205.136.27.1 to 205.136.27.62205.136.27.6362
110205.136.27.64/26205.136.27.65 to 205.136.27.126205.136.27.12762
111205.136.27.128/26205.136.27.129 to 205.136.27.190205.136.27.19162
112205.136.27.192/26205.136.27.193 to 205.136.27.254205.136.27.25562
113205.136.28.0/26205.136.28.1 to 205.136.28.62205.136.28.6362
114205.136.28.64/26205.136.28.65 to 205.136.28.126205.136.28.12762
115205.136.28.128/26205.136.28.129 to 205.136.28.190205.136.28.19162
116205.136.28.192/26205.136.28.193 to 205.136.28.254205.136.28.25562
117205.136.29.0/26205.136.29.1 to 205.136.29.62205.136.29.6362
118205.136.29.64/26205.136.29.65 to 205.136.29.126205.136.29.12762
119205.136.29.128/26205.136.29.129 to 205.136.29.190205.136.29.19162
120205.136.29.192/26205.136.29.193 to 205.136.29.254205.136.29.25562
121205.136.30.0/26205.136.30.1 to 205.136.30.62205.136.30.6362
122205.136.30.64/26205.136.30.65 to 205.136.30.126205.136.30.12762
123205.136.30.128/26205.136.30.129 to 205.136.30.190205.136.30.19162
124205.136.30.192/26205.136.30.193 to 205.136.30.254205.136.30.25562
125205.136.31.0/26205.136.31.1 to 205.136.31.62205.136.31.6362
126205.136.31.64/26205.136.31.65 to 205.136.31.126205.136.31.12762
127205.136.31.128/26205.136.31.129 to 205.136.31.190205.136.31.19162
128205.136.31.192/26205.136.31.193 to 205.136.31.254205.136.31.25562
129205.136.32.0/26205.136.32.1 to 205.136.32.62205.136.32.6362
130205.136.32.64/26205.136.32.65 to 205.136.32.126205.136.32.12762
131205.136.32.128/26205.136.32.129 to 205.136.32.190205.136.32.19162
132205.136.32.192/26205.136.32.193 to 205.136.32.254205.136.32.25562
133205.136.33.0/26205.136.33.1 to 205.136.33.62205.136.33.6362
134205.136.33.64/26205.136.33.65 to 205.136.33.126205.136.33.12762
135205.136.33.128/26205.136.33.129 to 205.136.33.190205.136.33.19162
136205.136.33.192/26205.136.33.193 to 205.136.33.254205.136.33.25562
137205.136.34.0/26205.136.34.1 to 205.136.34.62205.136.34.6362
138205.136.34.64/26205.136.34.65 to 205.136.34.126205.136.34.12762
139205.136.34.128/26205.136.34.129 to 205.136.34.190205.136.34.19162
140205.136.34.192/26205.136.34.193 to 205.136.34.254205.136.34.25562
141205.136.35.0/26205.136.35.1 to 205.136.35.62205.136.35.6362
142205.136.35.64/26205.136.35.65 to 205.136.35.126205.136.35.12762
143205.136.35.128/26205.136.35.129 to 205.136.35.190205.136.35.19162
144205.136.35.192/26205.136.35.193 to 205.136.35.254205.136.35.25562
145205.136.36.0/26205.136.36.1 to 205.136.36.62205.136.36.6362
146205.136.36.64/26205.136.36.65 to 205.136.36.126205.136.36.12762
147205.136.36.128/26205.136.36.129 to 205.136.36.190205.136.36.19162
148205.136.36.192/26205.136.36.193 to 205.136.36.254205.136.36.25562
149205.136.37.0/26205.136.37.1 to 205.136.37.62205.136.37.6362
150205.136.37.64/26205.136.37.65 to 205.136.37.126205.136.37.12762
151205.136.37.128/26205.136.37.129 to 205.136.37.190205.136.37.19162
152205.136.37.192/26205.136.37.193 to 205.136.37.254205.136.37.25562
153205.136.38.0/26205.136.38.1 to 205.136.38.62205.136.38.6362
154205.136.38.64/26205.136.38.65 to 205.136.38.126205.136.38.12762
155205.136.38.128/26205.136.38.129 to 205.136.38.190205.136.38.19162
156205.136.38.192/26205.136.38.193 to 205.136.38.254205.136.38.25562
157205.136.39.0/26205.136.39.1 to 205.136.39.62205.136.39.6362
158205.136.39.64/26205.136.39.65 to 205.136.39.126205.136.39.12762
159205.136.39.128/26205.136.39.129 to 205.136.39.190205.136.39.19162
160205.136.39.192/26205.136.39.193 to 205.136.39.254205.136.39.25562
161205.136.40.0/26205.136.40.1 to 205.136.40.62205.136.40.6362
162205.136.40.64/26205.136.40.65 to 205.136.40.126205.136.40.12762
163205.136.40.128/26205.136.40.129 to 205.136.40.190205.136.40.19162
164205.136.40.192/26205.136.40.193 to 205.136.40.254205.136.40.25562
165205.136.41.0/26205.136.41.1 to 205.136.41.62205.136.41.6362
166205.136.41.64/26205.136.41.65 to 205.136.41.126205.136.41.12762
167205.136.41.128/26205.136.41.129 to 205.136.41.190205.136.41.19162
168205.136.41.192/26205.136.41.193 to 205.136.41.254205.136.41.25562
169205.136.42.0/26205.136.42.1 to 205.136.42.62205.136.42.6362
170205.136.42.64/26205.136.42.65 to 205.136.42.126205.136.42.12762
171205.136.42.128/26205.136.42.129 to 205.136.42.190205.136.42.19162
172205.136.42.192/26205.136.42.193 to 205.136.42.254205.136.42.25562
173205.136.43.0/26205.136.43.1 to 205.136.43.62205.136.43.6362
174205.136.43.64/26205.136.43.65 to 205.136.43.126205.136.43.12762
175205.136.43.128/26205.136.43.129 to 205.136.43.190205.136.43.19162
176205.136.43.192/26205.136.43.193 to 205.136.43.254205.136.43.25562
177205.136.44.0/26205.136.44.1 to 205.136.44.62205.136.44.6362
178205.136.44.64/26205.136.44.65 to 205.136.44.126205.136.44.12762
179205.136.44.128/26205.136.44.129 to 205.136.44.190205.136.44.19162
180205.136.44.192/26205.136.44.193 to 205.136.44.254205.136.44.25562
181205.136.45.0/26205.136.45.1 to 205.136.45.62205.136.45.6362
182205.136.45.64/26205.136.45.65 to 205.136.45.126205.136.45.12762
183205.136.45.128/26205.136.45.129 to 205.136.45.190205.136.45.19162
184205.136.45.192/26205.136.45.193 to 205.136.45.254205.136.45.25562
185205.136.46.0/26205.136.46.1 to 205.136.46.62205.136.46.6362
186205.136.46.64/26205.136.46.65 to 205.136.46.126205.136.46.12762
187205.136.46.128/26205.136.46.129 to 205.136.46.190205.136.46.19162
188205.136.46.192/26205.136.46.193 to 205.136.46.254205.136.46.25562
189205.136.47.0/26205.136.47.1 to 205.136.47.62205.136.47.6362
190205.136.47.64/26205.136.47.65 to 205.136.47.126205.136.47.12762
191205.136.47.128/26205.136.47.129 to 205.136.47.190205.136.47.19162
192205.136.47.192/26205.136.47.193 to 205.136.47.254205.136.47.25562
193205.136.48.0/26205.136.48.1 to 205.136.48.62205.136.48.6362
194205.136.48.64/26205.136.48.65 to 205.136.48.126205.136.48.12762
195205.136.48.128/26205.136.48.129 to 205.136.48.190205.136.48.19162
196205.136.48.192/26205.136.48.193 to 205.136.48.254205.136.48.25562
197205.136.49.0/26205.136.49.1 to 205.136.49.62205.136.49.6362
198205.136.49.64/26205.136.49.65 to 205.136.49.126205.136.49.12762
199205.136.49.128/26205.136.49.129 to 205.136.49.190205.136.49.19162
200205.136.49.192/26205.136.49.193 to 205.136.49.254205.136.49.25562
201205.136.50.0/26205.136.50.1 to 205.136.50.62205.136.50.6362
202205.136.50.64/26205.136.50.65 to 205.136.50.126205.136.50.12762
203205.136.50.128/26205.136.50.129 to 205.136.50.190205.136.50.19162
204205.136.50.192/26205.136.50.193 to 205.136.50.254205.136.50.25562
205205.136.51.0/26205.136.51.1 to 205.136.51.62205.136.51.6362
206205.136.51.64/26205.136.51.65 to 205.136.51.126205.136.51.12762
207205.136.51.128/26205.136.51.129 to 205.136.51.190205.136.51.19162
208205.136.51.192/26205.136.51.193 to 205.136.51.254205.136.51.25562
209205.136.52.0/26205.136.52.1 to 205.136.52.62205.136.52.6362
210205.136.52.64/26205.136.52.65 to 205.136.52.126205.136.52.12762
211205.136.52.128/26205.136.52.129 to 205.136.52.190205.136.52.19162
212205.136.52.192/26205.136.52.193 to 205.136.52.254205.136.52.25562
213205.136.53.0/26205.136.53.1 to 205.136.53.62205.136.53.6362
214205.136.53.64/26205.136.53.65 to 205.136.53.126205.136.53.12762
215205.136.53.128/26205.136.53.129 to 205.136.53.190205.136.53.19162
216205.136.53.192/26205.136.53.193 to 205.136.53.254205.136.53.25562
217205.136.54.0/26205.136.54.1 to 205.136.54.62205.136.54.6362
218205.136.54.64/26205.136.54.65 to 205.136.54.126205.136.54.12762
219205.136.54.128/26205.136.54.129 to 205.136.54.190205.136.54.19162
220205.136.54.192/26205.136.54.193 to 205.136.54.254205.136.54.25562
221205.136.55.0/26205.136.55.1 to 205.136.55.62205.136.55.6362
222205.136.55.64/26205.136.55.65 to 205.136.55.126205.136.55.12762
223205.136.55.128/26205.136.55.129 to 205.136.55.190205.136.55.19162
224205.136.55.192/26205.136.55.193 to 205.136.55.254205.136.55.25562
225205.136.56.0/26205.136.56.1 to 205.136.56.62205.136.56.6362
226205.136.56.64/26205.136.56.65 to 205.136.56.126205.136.56.12762
227205.136.56.128/26205.136.56.129 to 205.136.56.190205.136.56.19162
228205.136.56.192/26205.136.56.193 to 205.136.56.254205.136.56.25562
229205.136.57.0/26205.136.57.1 to 205.136.57.62205.136.57.6362
230205.136.57.64/26205.136.57.65 to 205.136.57.126205.136.57.12762
231205.136.57.128/26205.136.57.129 to 205.136.57.190205.136.57.19162
232205.136.57.192/26205.136.57.193 to 205.136.57.254205.136.57.25562
233205.136.58.0/26205.136.58.1 to 205.136.58.62205.136.58.6362
234205.136.58.64/26205.136.58.65 to 205.136.58.126205.136.58.12762
235205.136.58.128/26205.136.58.129 to 205.136.58.190205.136.58.19162
236205.136.58.192/26205.136.58.193 to 205.136.58.254205.136.58.25562
237205.136.59.0/26205.136.59.1 to 205.136.59.62205.136.59.6362
238205.136.59.64/26205.136.59.65 to 205.136.59.126205.136.59.12762
239205.136.59.128/26205.136.59.129 to 205.136.59.190205.136.59.19162
240205.136.59.192/26205.136.59.193 to 205.136.59.254205.136.59.25562
241205.136.60.0/26205.136.60.1 to 205.136.60.62205.136.60.6362
242205.136.60.64/26205.136.60.65 to 205.136.60.126205.136.60.12762
243205.136.60.128/26205.136.60.129 to 205.136.60.190205.136.60.19162
244205.136.60.192/26205.136.60.193 to 205.136.60.254205.136.60.25562
245205.136.61.0/26205.136.61.1 to 205.136.61.62205.136.61.6362
246205.136.61.64/26205.136.61.65 to 205.136.61.126205.136.61.12762
247205.136.61.128/26205.136.61.129 to 205.136.61.190205.136.61.19162
248205.136.61.192/26205.136.61.193 to 205.136.61.254205.136.61.25562
249205.136.62.0/26205.136.62.1 to 205.136.62.62205.136.62.6362
250205.136.62.64/26205.136.62.65 to 205.136.62.126205.136.62.12762
251205.136.62.128/26205.136.62.129 to 205.136.62.190205.136.62.19162
252205.136.62.192/26205.136.62.193 to 205.136.62.254205.136.62.25562
253205.136.63.0/26205.136.63.1 to 205.136.63.62205.136.63.6362
254205.136.63.64/26205.136.63.65 to 205.136.63.126205.136.63.12762
255205.136.63.128/26205.136.63.129 to 205.136.63.190205.136.63.19162
256205.136.63.192/26205.136.63.193 to 205.136.63.254205.136.63.25562

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.