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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.

Network178.76.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
178.76.0.0
Broadcast address
178.76.255.255
First usable
178.76.0.1
Last usable
178.76.255.254
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
B (default /16)
As numbers
Hex B24C0000 · Integer 2991325184 to 2991390719
Reverse DNS zone
76.178.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110010.01001100..00000000.00000000178.76.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10110010.01001100..00000000.00000000178.76.0.0
Broadcast10110010.01001100..11111111.11111111178.76.255.255
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)

178.76.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1178.76.0.0/26178.76.0.1 to 178.76.0.62178.76.0.6362
2178.76.0.64/26178.76.0.65 to 178.76.0.126178.76.0.12762
3178.76.0.128/26178.76.0.129 to 178.76.0.190178.76.0.19162
4178.76.0.192/26178.76.0.193 to 178.76.0.254178.76.0.25562
5178.76.1.0/26178.76.1.1 to 178.76.1.62178.76.1.6362
6178.76.1.64/26178.76.1.65 to 178.76.1.126178.76.1.12762
7178.76.1.128/26178.76.1.129 to 178.76.1.190178.76.1.19162
8178.76.1.192/26178.76.1.193 to 178.76.1.254178.76.1.25562
9178.76.2.0/26178.76.2.1 to 178.76.2.62178.76.2.6362
10178.76.2.64/26178.76.2.65 to 178.76.2.126178.76.2.12762
11178.76.2.128/26178.76.2.129 to 178.76.2.190178.76.2.19162
12178.76.2.192/26178.76.2.193 to 178.76.2.254178.76.2.25562
13178.76.3.0/26178.76.3.1 to 178.76.3.62178.76.3.6362
14178.76.3.64/26178.76.3.65 to 178.76.3.126178.76.3.12762
15178.76.3.128/26178.76.3.129 to 178.76.3.190178.76.3.19162
16178.76.3.192/26178.76.3.193 to 178.76.3.254178.76.3.25562
17178.76.4.0/26178.76.4.1 to 178.76.4.62178.76.4.6362
18178.76.4.64/26178.76.4.65 to 178.76.4.126178.76.4.12762
19178.76.4.128/26178.76.4.129 to 178.76.4.190178.76.4.19162
20178.76.4.192/26178.76.4.193 to 178.76.4.254178.76.4.25562
21178.76.5.0/26178.76.5.1 to 178.76.5.62178.76.5.6362
22178.76.5.64/26178.76.5.65 to 178.76.5.126178.76.5.12762
23178.76.5.128/26178.76.5.129 to 178.76.5.190178.76.5.19162
24178.76.5.192/26178.76.5.193 to 178.76.5.254178.76.5.25562
25178.76.6.0/26178.76.6.1 to 178.76.6.62178.76.6.6362
26178.76.6.64/26178.76.6.65 to 178.76.6.126178.76.6.12762
27178.76.6.128/26178.76.6.129 to 178.76.6.190178.76.6.19162
28178.76.6.192/26178.76.6.193 to 178.76.6.254178.76.6.25562
29178.76.7.0/26178.76.7.1 to 178.76.7.62178.76.7.6362
30178.76.7.64/26178.76.7.65 to 178.76.7.126178.76.7.12762
31178.76.7.128/26178.76.7.129 to 178.76.7.190178.76.7.19162
32178.76.7.192/26178.76.7.193 to 178.76.7.254178.76.7.25562
33178.76.8.0/26178.76.8.1 to 178.76.8.62178.76.8.6362
34178.76.8.64/26178.76.8.65 to 178.76.8.126178.76.8.12762
35178.76.8.128/26178.76.8.129 to 178.76.8.190178.76.8.19162
36178.76.8.192/26178.76.8.193 to 178.76.8.254178.76.8.25562
37178.76.9.0/26178.76.9.1 to 178.76.9.62178.76.9.6362
38178.76.9.64/26178.76.9.65 to 178.76.9.126178.76.9.12762
39178.76.9.128/26178.76.9.129 to 178.76.9.190178.76.9.19162
40178.76.9.192/26178.76.9.193 to 178.76.9.254178.76.9.25562
41178.76.10.0/26178.76.10.1 to 178.76.10.62178.76.10.6362
42178.76.10.64/26178.76.10.65 to 178.76.10.126178.76.10.12762
43178.76.10.128/26178.76.10.129 to 178.76.10.190178.76.10.19162
44178.76.10.192/26178.76.10.193 to 178.76.10.254178.76.10.25562
45178.76.11.0/26178.76.11.1 to 178.76.11.62178.76.11.6362
46178.76.11.64/26178.76.11.65 to 178.76.11.126178.76.11.12762
47178.76.11.128/26178.76.11.129 to 178.76.11.190178.76.11.19162
48178.76.11.192/26178.76.11.193 to 178.76.11.254178.76.11.25562
49178.76.12.0/26178.76.12.1 to 178.76.12.62178.76.12.6362
50178.76.12.64/26178.76.12.65 to 178.76.12.126178.76.12.12762
51178.76.12.128/26178.76.12.129 to 178.76.12.190178.76.12.19162
52178.76.12.192/26178.76.12.193 to 178.76.12.254178.76.12.25562
53178.76.13.0/26178.76.13.1 to 178.76.13.62178.76.13.6362
54178.76.13.64/26178.76.13.65 to 178.76.13.126178.76.13.12762
55178.76.13.128/26178.76.13.129 to 178.76.13.190178.76.13.19162
56178.76.13.192/26178.76.13.193 to 178.76.13.254178.76.13.25562
57178.76.14.0/26178.76.14.1 to 178.76.14.62178.76.14.6362
58178.76.14.64/26178.76.14.65 to 178.76.14.126178.76.14.12762
59178.76.14.128/26178.76.14.129 to 178.76.14.190178.76.14.19162
60178.76.14.192/26178.76.14.193 to 178.76.14.254178.76.14.25562
61178.76.15.0/26178.76.15.1 to 178.76.15.62178.76.15.6362
62178.76.15.64/26178.76.15.65 to 178.76.15.126178.76.15.12762
63178.76.15.128/26178.76.15.129 to 178.76.15.190178.76.15.19162
64178.76.15.192/26178.76.15.193 to 178.76.15.254178.76.15.25562
65178.76.16.0/26178.76.16.1 to 178.76.16.62178.76.16.6362
66178.76.16.64/26178.76.16.65 to 178.76.16.126178.76.16.12762
67178.76.16.128/26178.76.16.129 to 178.76.16.190178.76.16.19162
68178.76.16.192/26178.76.16.193 to 178.76.16.254178.76.16.25562
69178.76.17.0/26178.76.17.1 to 178.76.17.62178.76.17.6362
70178.76.17.64/26178.76.17.65 to 178.76.17.126178.76.17.12762
71178.76.17.128/26178.76.17.129 to 178.76.17.190178.76.17.19162
72178.76.17.192/26178.76.17.193 to 178.76.17.254178.76.17.25562
73178.76.18.0/26178.76.18.1 to 178.76.18.62178.76.18.6362
74178.76.18.64/26178.76.18.65 to 178.76.18.126178.76.18.12762
75178.76.18.128/26178.76.18.129 to 178.76.18.190178.76.18.19162
76178.76.18.192/26178.76.18.193 to 178.76.18.254178.76.18.25562
77178.76.19.0/26178.76.19.1 to 178.76.19.62178.76.19.6362
78178.76.19.64/26178.76.19.65 to 178.76.19.126178.76.19.12762
79178.76.19.128/26178.76.19.129 to 178.76.19.190178.76.19.19162
80178.76.19.192/26178.76.19.193 to 178.76.19.254178.76.19.25562
81178.76.20.0/26178.76.20.1 to 178.76.20.62178.76.20.6362
82178.76.20.64/26178.76.20.65 to 178.76.20.126178.76.20.12762
83178.76.20.128/26178.76.20.129 to 178.76.20.190178.76.20.19162
84178.76.20.192/26178.76.20.193 to 178.76.20.254178.76.20.25562
85178.76.21.0/26178.76.21.1 to 178.76.21.62178.76.21.6362
86178.76.21.64/26178.76.21.65 to 178.76.21.126178.76.21.12762
87178.76.21.128/26178.76.21.129 to 178.76.21.190178.76.21.19162
88178.76.21.192/26178.76.21.193 to 178.76.21.254178.76.21.25562
89178.76.22.0/26178.76.22.1 to 178.76.22.62178.76.22.6362
90178.76.22.64/26178.76.22.65 to 178.76.22.126178.76.22.12762
91178.76.22.128/26178.76.22.129 to 178.76.22.190178.76.22.19162
92178.76.22.192/26178.76.22.193 to 178.76.22.254178.76.22.25562
93178.76.23.0/26178.76.23.1 to 178.76.23.62178.76.23.6362
94178.76.23.64/26178.76.23.65 to 178.76.23.126178.76.23.12762
95178.76.23.128/26178.76.23.129 to 178.76.23.190178.76.23.19162
96178.76.23.192/26178.76.23.193 to 178.76.23.254178.76.23.25562
97178.76.24.0/26178.76.24.1 to 178.76.24.62178.76.24.6362
98178.76.24.64/26178.76.24.65 to 178.76.24.126178.76.24.12762
99178.76.24.128/26178.76.24.129 to 178.76.24.190178.76.24.19162
100178.76.24.192/26178.76.24.193 to 178.76.24.254178.76.24.25562
101178.76.25.0/26178.76.25.1 to 178.76.25.62178.76.25.6362
102178.76.25.64/26178.76.25.65 to 178.76.25.126178.76.25.12762
103178.76.25.128/26178.76.25.129 to 178.76.25.190178.76.25.19162
104178.76.25.192/26178.76.25.193 to 178.76.25.254178.76.25.25562
105178.76.26.0/26178.76.26.1 to 178.76.26.62178.76.26.6362
106178.76.26.64/26178.76.26.65 to 178.76.26.126178.76.26.12762
107178.76.26.128/26178.76.26.129 to 178.76.26.190178.76.26.19162
108178.76.26.192/26178.76.26.193 to 178.76.26.254178.76.26.25562
109178.76.27.0/26178.76.27.1 to 178.76.27.62178.76.27.6362
110178.76.27.64/26178.76.27.65 to 178.76.27.126178.76.27.12762
111178.76.27.128/26178.76.27.129 to 178.76.27.190178.76.27.19162
112178.76.27.192/26178.76.27.193 to 178.76.27.254178.76.27.25562
113178.76.28.0/26178.76.28.1 to 178.76.28.62178.76.28.6362
114178.76.28.64/26178.76.28.65 to 178.76.28.126178.76.28.12762
115178.76.28.128/26178.76.28.129 to 178.76.28.190178.76.28.19162
116178.76.28.192/26178.76.28.193 to 178.76.28.254178.76.28.25562
117178.76.29.0/26178.76.29.1 to 178.76.29.62178.76.29.6362
118178.76.29.64/26178.76.29.65 to 178.76.29.126178.76.29.12762
119178.76.29.128/26178.76.29.129 to 178.76.29.190178.76.29.19162
120178.76.29.192/26178.76.29.193 to 178.76.29.254178.76.29.25562
121178.76.30.0/26178.76.30.1 to 178.76.30.62178.76.30.6362
122178.76.30.64/26178.76.30.65 to 178.76.30.126178.76.30.12762
123178.76.30.128/26178.76.30.129 to 178.76.30.190178.76.30.19162
124178.76.30.192/26178.76.30.193 to 178.76.30.254178.76.30.25562
125178.76.31.0/26178.76.31.1 to 178.76.31.62178.76.31.6362
126178.76.31.64/26178.76.31.65 to 178.76.31.126178.76.31.12762
127178.76.31.128/26178.76.31.129 to 178.76.31.190178.76.31.19162
128178.76.31.192/26178.76.31.193 to 178.76.31.254178.76.31.25562
129178.76.32.0/26178.76.32.1 to 178.76.32.62178.76.32.6362
130178.76.32.64/26178.76.32.65 to 178.76.32.126178.76.32.12762
131178.76.32.128/26178.76.32.129 to 178.76.32.190178.76.32.19162
132178.76.32.192/26178.76.32.193 to 178.76.32.254178.76.32.25562
133178.76.33.0/26178.76.33.1 to 178.76.33.62178.76.33.6362
134178.76.33.64/26178.76.33.65 to 178.76.33.126178.76.33.12762
135178.76.33.128/26178.76.33.129 to 178.76.33.190178.76.33.19162
136178.76.33.192/26178.76.33.193 to 178.76.33.254178.76.33.25562
137178.76.34.0/26178.76.34.1 to 178.76.34.62178.76.34.6362
138178.76.34.64/26178.76.34.65 to 178.76.34.126178.76.34.12762
139178.76.34.128/26178.76.34.129 to 178.76.34.190178.76.34.19162
140178.76.34.192/26178.76.34.193 to 178.76.34.254178.76.34.25562
141178.76.35.0/26178.76.35.1 to 178.76.35.62178.76.35.6362
142178.76.35.64/26178.76.35.65 to 178.76.35.126178.76.35.12762
143178.76.35.128/26178.76.35.129 to 178.76.35.190178.76.35.19162
144178.76.35.192/26178.76.35.193 to 178.76.35.254178.76.35.25562
145178.76.36.0/26178.76.36.1 to 178.76.36.62178.76.36.6362
146178.76.36.64/26178.76.36.65 to 178.76.36.126178.76.36.12762
147178.76.36.128/26178.76.36.129 to 178.76.36.190178.76.36.19162
148178.76.36.192/26178.76.36.193 to 178.76.36.254178.76.36.25562
149178.76.37.0/26178.76.37.1 to 178.76.37.62178.76.37.6362
150178.76.37.64/26178.76.37.65 to 178.76.37.126178.76.37.12762
151178.76.37.128/26178.76.37.129 to 178.76.37.190178.76.37.19162
152178.76.37.192/26178.76.37.193 to 178.76.37.254178.76.37.25562
153178.76.38.0/26178.76.38.1 to 178.76.38.62178.76.38.6362
154178.76.38.64/26178.76.38.65 to 178.76.38.126178.76.38.12762
155178.76.38.128/26178.76.38.129 to 178.76.38.190178.76.38.19162
156178.76.38.192/26178.76.38.193 to 178.76.38.254178.76.38.25562
157178.76.39.0/26178.76.39.1 to 178.76.39.62178.76.39.6362
158178.76.39.64/26178.76.39.65 to 178.76.39.126178.76.39.12762
159178.76.39.128/26178.76.39.129 to 178.76.39.190178.76.39.19162
160178.76.39.192/26178.76.39.193 to 178.76.39.254178.76.39.25562
161178.76.40.0/26178.76.40.1 to 178.76.40.62178.76.40.6362
162178.76.40.64/26178.76.40.65 to 178.76.40.126178.76.40.12762
163178.76.40.128/26178.76.40.129 to 178.76.40.190178.76.40.19162
164178.76.40.192/26178.76.40.193 to 178.76.40.254178.76.40.25562
165178.76.41.0/26178.76.41.1 to 178.76.41.62178.76.41.6362
166178.76.41.64/26178.76.41.65 to 178.76.41.126178.76.41.12762
167178.76.41.128/26178.76.41.129 to 178.76.41.190178.76.41.19162
168178.76.41.192/26178.76.41.193 to 178.76.41.254178.76.41.25562
169178.76.42.0/26178.76.42.1 to 178.76.42.62178.76.42.6362
170178.76.42.64/26178.76.42.65 to 178.76.42.126178.76.42.12762
171178.76.42.128/26178.76.42.129 to 178.76.42.190178.76.42.19162
172178.76.42.192/26178.76.42.193 to 178.76.42.254178.76.42.25562
173178.76.43.0/26178.76.43.1 to 178.76.43.62178.76.43.6362
174178.76.43.64/26178.76.43.65 to 178.76.43.126178.76.43.12762
175178.76.43.128/26178.76.43.129 to 178.76.43.190178.76.43.19162
176178.76.43.192/26178.76.43.193 to 178.76.43.254178.76.43.25562
177178.76.44.0/26178.76.44.1 to 178.76.44.62178.76.44.6362
178178.76.44.64/26178.76.44.65 to 178.76.44.126178.76.44.12762
179178.76.44.128/26178.76.44.129 to 178.76.44.190178.76.44.19162
180178.76.44.192/26178.76.44.193 to 178.76.44.254178.76.44.25562
181178.76.45.0/26178.76.45.1 to 178.76.45.62178.76.45.6362
182178.76.45.64/26178.76.45.65 to 178.76.45.126178.76.45.12762
183178.76.45.128/26178.76.45.129 to 178.76.45.190178.76.45.19162
184178.76.45.192/26178.76.45.193 to 178.76.45.254178.76.45.25562
185178.76.46.0/26178.76.46.1 to 178.76.46.62178.76.46.6362
186178.76.46.64/26178.76.46.65 to 178.76.46.126178.76.46.12762
187178.76.46.128/26178.76.46.129 to 178.76.46.190178.76.46.19162
188178.76.46.192/26178.76.46.193 to 178.76.46.254178.76.46.25562
189178.76.47.0/26178.76.47.1 to 178.76.47.62178.76.47.6362
190178.76.47.64/26178.76.47.65 to 178.76.47.126178.76.47.12762
191178.76.47.128/26178.76.47.129 to 178.76.47.190178.76.47.19162
192178.76.47.192/26178.76.47.193 to 178.76.47.254178.76.47.25562
193178.76.48.0/26178.76.48.1 to 178.76.48.62178.76.48.6362
194178.76.48.64/26178.76.48.65 to 178.76.48.126178.76.48.12762
195178.76.48.128/26178.76.48.129 to 178.76.48.190178.76.48.19162
196178.76.48.192/26178.76.48.193 to 178.76.48.254178.76.48.25562
197178.76.49.0/26178.76.49.1 to 178.76.49.62178.76.49.6362
198178.76.49.64/26178.76.49.65 to 178.76.49.126178.76.49.12762
199178.76.49.128/26178.76.49.129 to 178.76.49.190178.76.49.19162
200178.76.49.192/26178.76.49.193 to 178.76.49.254178.76.49.25562
201178.76.50.0/26178.76.50.1 to 178.76.50.62178.76.50.6362
202178.76.50.64/26178.76.50.65 to 178.76.50.126178.76.50.12762
203178.76.50.128/26178.76.50.129 to 178.76.50.190178.76.50.19162
204178.76.50.192/26178.76.50.193 to 178.76.50.254178.76.50.25562
205178.76.51.0/26178.76.51.1 to 178.76.51.62178.76.51.6362
206178.76.51.64/26178.76.51.65 to 178.76.51.126178.76.51.12762
207178.76.51.128/26178.76.51.129 to 178.76.51.190178.76.51.19162
208178.76.51.192/26178.76.51.193 to 178.76.51.254178.76.51.25562
209178.76.52.0/26178.76.52.1 to 178.76.52.62178.76.52.6362
210178.76.52.64/26178.76.52.65 to 178.76.52.126178.76.52.12762
211178.76.52.128/26178.76.52.129 to 178.76.52.190178.76.52.19162
212178.76.52.192/26178.76.52.193 to 178.76.52.254178.76.52.25562
213178.76.53.0/26178.76.53.1 to 178.76.53.62178.76.53.6362
214178.76.53.64/26178.76.53.65 to 178.76.53.126178.76.53.12762
215178.76.53.128/26178.76.53.129 to 178.76.53.190178.76.53.19162
216178.76.53.192/26178.76.53.193 to 178.76.53.254178.76.53.25562
217178.76.54.0/26178.76.54.1 to 178.76.54.62178.76.54.6362
218178.76.54.64/26178.76.54.65 to 178.76.54.126178.76.54.12762
219178.76.54.128/26178.76.54.129 to 178.76.54.190178.76.54.19162
220178.76.54.192/26178.76.54.193 to 178.76.54.254178.76.54.25562
221178.76.55.0/26178.76.55.1 to 178.76.55.62178.76.55.6362
222178.76.55.64/26178.76.55.65 to 178.76.55.126178.76.55.12762
223178.76.55.128/26178.76.55.129 to 178.76.55.190178.76.55.19162
224178.76.55.192/26178.76.55.193 to 178.76.55.254178.76.55.25562
225178.76.56.0/26178.76.56.1 to 178.76.56.62178.76.56.6362
226178.76.56.64/26178.76.56.65 to 178.76.56.126178.76.56.12762
227178.76.56.128/26178.76.56.129 to 178.76.56.190178.76.56.19162
228178.76.56.192/26178.76.56.193 to 178.76.56.254178.76.56.25562
229178.76.57.0/26178.76.57.1 to 178.76.57.62178.76.57.6362
230178.76.57.64/26178.76.57.65 to 178.76.57.126178.76.57.12762
231178.76.57.128/26178.76.57.129 to 178.76.57.190178.76.57.19162
232178.76.57.192/26178.76.57.193 to 178.76.57.254178.76.57.25562
233178.76.58.0/26178.76.58.1 to 178.76.58.62178.76.58.6362
234178.76.58.64/26178.76.58.65 to 178.76.58.126178.76.58.12762
235178.76.58.128/26178.76.58.129 to 178.76.58.190178.76.58.19162
236178.76.58.192/26178.76.58.193 to 178.76.58.254178.76.58.25562
237178.76.59.0/26178.76.59.1 to 178.76.59.62178.76.59.6362
238178.76.59.64/26178.76.59.65 to 178.76.59.126178.76.59.12762
239178.76.59.128/26178.76.59.129 to 178.76.59.190178.76.59.19162
240178.76.59.192/26178.76.59.193 to 178.76.59.254178.76.59.25562
241178.76.60.0/26178.76.60.1 to 178.76.60.62178.76.60.6362
242178.76.60.64/26178.76.60.65 to 178.76.60.126178.76.60.12762
243178.76.60.128/26178.76.60.129 to 178.76.60.190178.76.60.19162
244178.76.60.192/26178.76.60.193 to 178.76.60.254178.76.60.25562
245178.76.61.0/26178.76.61.1 to 178.76.61.62178.76.61.6362
246178.76.61.64/26178.76.61.65 to 178.76.61.126178.76.61.12762
247178.76.61.128/26178.76.61.129 to 178.76.61.190178.76.61.19162
248178.76.61.192/26178.76.61.193 to 178.76.61.254178.76.61.25562
249178.76.62.0/26178.76.62.1 to 178.76.62.62178.76.62.6362
250178.76.62.64/26178.76.62.65 to 178.76.62.126178.76.62.12762
251178.76.62.128/26178.76.62.129 to 178.76.62.190178.76.62.19162
252178.76.62.192/26178.76.62.193 to 178.76.62.254178.76.62.25562
253178.76.63.0/26178.76.63.1 to 178.76.63.62178.76.63.6362
254178.76.63.64/26178.76.63.65 to 178.76.63.126178.76.63.12762
255178.76.63.128/26178.76.63.129 to 178.76.63.190178.76.63.19162
256178.76.63.192/26178.76.63.193 to 178.76.63.254178.76.63.25562

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.