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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.

Network254.78.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
254.78.0.0
Broadcast address
254.78.255.255
First usable
254.78.0.1
Last usable
254.78.255.254
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
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex FE4E0000 · Integer 4266524672 to 4266590207
Reverse DNS zone
78.254.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111110.01001110..00000000.00000000254.78.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11111110.01001110..00000000.00000000254.78.0.0
Broadcast11111110.01001110..11111111.11111111254.78.255.255
Split into smaller subnets/28
/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)

254.78.0.0/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1254.78.0.0/28254.78.0.1 to 254.78.0.14254.78.0.1514
2254.78.0.16/28254.78.0.17 to 254.78.0.30254.78.0.3114
3254.78.0.32/28254.78.0.33 to 254.78.0.46254.78.0.4714
4254.78.0.48/28254.78.0.49 to 254.78.0.62254.78.0.6314
5254.78.0.64/28254.78.0.65 to 254.78.0.78254.78.0.7914
6254.78.0.80/28254.78.0.81 to 254.78.0.94254.78.0.9514
7254.78.0.96/28254.78.0.97 to 254.78.0.110254.78.0.11114
8254.78.0.112/28254.78.0.113 to 254.78.0.126254.78.0.12714
9254.78.0.128/28254.78.0.129 to 254.78.0.142254.78.0.14314
10254.78.0.144/28254.78.0.145 to 254.78.0.158254.78.0.15914
11254.78.0.160/28254.78.0.161 to 254.78.0.174254.78.0.17514
12254.78.0.176/28254.78.0.177 to 254.78.0.190254.78.0.19114
13254.78.0.192/28254.78.0.193 to 254.78.0.206254.78.0.20714
14254.78.0.208/28254.78.0.209 to 254.78.0.222254.78.0.22314
15254.78.0.224/28254.78.0.225 to 254.78.0.238254.78.0.23914
16254.78.0.240/28254.78.0.241 to 254.78.0.254254.78.0.25514
17254.78.1.0/28254.78.1.1 to 254.78.1.14254.78.1.1514
18254.78.1.16/28254.78.1.17 to 254.78.1.30254.78.1.3114
19254.78.1.32/28254.78.1.33 to 254.78.1.46254.78.1.4714
20254.78.1.48/28254.78.1.49 to 254.78.1.62254.78.1.6314
21254.78.1.64/28254.78.1.65 to 254.78.1.78254.78.1.7914
22254.78.1.80/28254.78.1.81 to 254.78.1.94254.78.1.9514
23254.78.1.96/28254.78.1.97 to 254.78.1.110254.78.1.11114
24254.78.1.112/28254.78.1.113 to 254.78.1.126254.78.1.12714
25254.78.1.128/28254.78.1.129 to 254.78.1.142254.78.1.14314
26254.78.1.144/28254.78.1.145 to 254.78.1.158254.78.1.15914
27254.78.1.160/28254.78.1.161 to 254.78.1.174254.78.1.17514
28254.78.1.176/28254.78.1.177 to 254.78.1.190254.78.1.19114
29254.78.1.192/28254.78.1.193 to 254.78.1.206254.78.1.20714
30254.78.1.208/28254.78.1.209 to 254.78.1.222254.78.1.22314
31254.78.1.224/28254.78.1.225 to 254.78.1.238254.78.1.23914
32254.78.1.240/28254.78.1.241 to 254.78.1.254254.78.1.25514
33254.78.2.0/28254.78.2.1 to 254.78.2.14254.78.2.1514
34254.78.2.16/28254.78.2.17 to 254.78.2.30254.78.2.3114
35254.78.2.32/28254.78.2.33 to 254.78.2.46254.78.2.4714
36254.78.2.48/28254.78.2.49 to 254.78.2.62254.78.2.6314
37254.78.2.64/28254.78.2.65 to 254.78.2.78254.78.2.7914
38254.78.2.80/28254.78.2.81 to 254.78.2.94254.78.2.9514
39254.78.2.96/28254.78.2.97 to 254.78.2.110254.78.2.11114
40254.78.2.112/28254.78.2.113 to 254.78.2.126254.78.2.12714
41254.78.2.128/28254.78.2.129 to 254.78.2.142254.78.2.14314
42254.78.2.144/28254.78.2.145 to 254.78.2.158254.78.2.15914
43254.78.2.160/28254.78.2.161 to 254.78.2.174254.78.2.17514
44254.78.2.176/28254.78.2.177 to 254.78.2.190254.78.2.19114
45254.78.2.192/28254.78.2.193 to 254.78.2.206254.78.2.20714
46254.78.2.208/28254.78.2.209 to 254.78.2.222254.78.2.22314
47254.78.2.224/28254.78.2.225 to 254.78.2.238254.78.2.23914
48254.78.2.240/28254.78.2.241 to 254.78.2.254254.78.2.25514
49254.78.3.0/28254.78.3.1 to 254.78.3.14254.78.3.1514
50254.78.3.16/28254.78.3.17 to 254.78.3.30254.78.3.3114
51254.78.3.32/28254.78.3.33 to 254.78.3.46254.78.3.4714
52254.78.3.48/28254.78.3.49 to 254.78.3.62254.78.3.6314
53254.78.3.64/28254.78.3.65 to 254.78.3.78254.78.3.7914
54254.78.3.80/28254.78.3.81 to 254.78.3.94254.78.3.9514
55254.78.3.96/28254.78.3.97 to 254.78.3.110254.78.3.11114
56254.78.3.112/28254.78.3.113 to 254.78.3.126254.78.3.12714
57254.78.3.128/28254.78.3.129 to 254.78.3.142254.78.3.14314
58254.78.3.144/28254.78.3.145 to 254.78.3.158254.78.3.15914
59254.78.3.160/28254.78.3.161 to 254.78.3.174254.78.3.17514
60254.78.3.176/28254.78.3.177 to 254.78.3.190254.78.3.19114
61254.78.3.192/28254.78.3.193 to 254.78.3.206254.78.3.20714
62254.78.3.208/28254.78.3.209 to 254.78.3.222254.78.3.22314
63254.78.3.224/28254.78.3.225 to 254.78.3.238254.78.3.23914
64254.78.3.240/28254.78.3.241 to 254.78.3.254254.78.3.25514
65254.78.4.0/28254.78.4.1 to 254.78.4.14254.78.4.1514
66254.78.4.16/28254.78.4.17 to 254.78.4.30254.78.4.3114
67254.78.4.32/28254.78.4.33 to 254.78.4.46254.78.4.4714
68254.78.4.48/28254.78.4.49 to 254.78.4.62254.78.4.6314
69254.78.4.64/28254.78.4.65 to 254.78.4.78254.78.4.7914
70254.78.4.80/28254.78.4.81 to 254.78.4.94254.78.4.9514
71254.78.4.96/28254.78.4.97 to 254.78.4.110254.78.4.11114
72254.78.4.112/28254.78.4.113 to 254.78.4.126254.78.4.12714
73254.78.4.128/28254.78.4.129 to 254.78.4.142254.78.4.14314
74254.78.4.144/28254.78.4.145 to 254.78.4.158254.78.4.15914
75254.78.4.160/28254.78.4.161 to 254.78.4.174254.78.4.17514
76254.78.4.176/28254.78.4.177 to 254.78.4.190254.78.4.19114
77254.78.4.192/28254.78.4.193 to 254.78.4.206254.78.4.20714
78254.78.4.208/28254.78.4.209 to 254.78.4.222254.78.4.22314
79254.78.4.224/28254.78.4.225 to 254.78.4.238254.78.4.23914
80254.78.4.240/28254.78.4.241 to 254.78.4.254254.78.4.25514
81254.78.5.0/28254.78.5.1 to 254.78.5.14254.78.5.1514
82254.78.5.16/28254.78.5.17 to 254.78.5.30254.78.5.3114
83254.78.5.32/28254.78.5.33 to 254.78.5.46254.78.5.4714
84254.78.5.48/28254.78.5.49 to 254.78.5.62254.78.5.6314
85254.78.5.64/28254.78.5.65 to 254.78.5.78254.78.5.7914
86254.78.5.80/28254.78.5.81 to 254.78.5.94254.78.5.9514
87254.78.5.96/28254.78.5.97 to 254.78.5.110254.78.5.11114
88254.78.5.112/28254.78.5.113 to 254.78.5.126254.78.5.12714
89254.78.5.128/28254.78.5.129 to 254.78.5.142254.78.5.14314
90254.78.5.144/28254.78.5.145 to 254.78.5.158254.78.5.15914
91254.78.5.160/28254.78.5.161 to 254.78.5.174254.78.5.17514
92254.78.5.176/28254.78.5.177 to 254.78.5.190254.78.5.19114
93254.78.5.192/28254.78.5.193 to 254.78.5.206254.78.5.20714
94254.78.5.208/28254.78.5.209 to 254.78.5.222254.78.5.22314
95254.78.5.224/28254.78.5.225 to 254.78.5.238254.78.5.23914
96254.78.5.240/28254.78.5.241 to 254.78.5.254254.78.5.25514
97254.78.6.0/28254.78.6.1 to 254.78.6.14254.78.6.1514
98254.78.6.16/28254.78.6.17 to 254.78.6.30254.78.6.3114
99254.78.6.32/28254.78.6.33 to 254.78.6.46254.78.6.4714
100254.78.6.48/28254.78.6.49 to 254.78.6.62254.78.6.6314
101254.78.6.64/28254.78.6.65 to 254.78.6.78254.78.6.7914
102254.78.6.80/28254.78.6.81 to 254.78.6.94254.78.6.9514
103254.78.6.96/28254.78.6.97 to 254.78.6.110254.78.6.11114
104254.78.6.112/28254.78.6.113 to 254.78.6.126254.78.6.12714
105254.78.6.128/28254.78.6.129 to 254.78.6.142254.78.6.14314
106254.78.6.144/28254.78.6.145 to 254.78.6.158254.78.6.15914
107254.78.6.160/28254.78.6.161 to 254.78.6.174254.78.6.17514
108254.78.6.176/28254.78.6.177 to 254.78.6.190254.78.6.19114
109254.78.6.192/28254.78.6.193 to 254.78.6.206254.78.6.20714
110254.78.6.208/28254.78.6.209 to 254.78.6.222254.78.6.22314
111254.78.6.224/28254.78.6.225 to 254.78.6.238254.78.6.23914
112254.78.6.240/28254.78.6.241 to 254.78.6.254254.78.6.25514
113254.78.7.0/28254.78.7.1 to 254.78.7.14254.78.7.1514
114254.78.7.16/28254.78.7.17 to 254.78.7.30254.78.7.3114
115254.78.7.32/28254.78.7.33 to 254.78.7.46254.78.7.4714
116254.78.7.48/28254.78.7.49 to 254.78.7.62254.78.7.6314
117254.78.7.64/28254.78.7.65 to 254.78.7.78254.78.7.7914
118254.78.7.80/28254.78.7.81 to 254.78.7.94254.78.7.9514
119254.78.7.96/28254.78.7.97 to 254.78.7.110254.78.7.11114
120254.78.7.112/28254.78.7.113 to 254.78.7.126254.78.7.12714
121254.78.7.128/28254.78.7.129 to 254.78.7.142254.78.7.14314
122254.78.7.144/28254.78.7.145 to 254.78.7.158254.78.7.15914
123254.78.7.160/28254.78.7.161 to 254.78.7.174254.78.7.17514
124254.78.7.176/28254.78.7.177 to 254.78.7.190254.78.7.19114
125254.78.7.192/28254.78.7.193 to 254.78.7.206254.78.7.20714
126254.78.7.208/28254.78.7.209 to 254.78.7.222254.78.7.22314
127254.78.7.224/28254.78.7.225 to 254.78.7.238254.78.7.23914
128254.78.7.240/28254.78.7.241 to 254.78.7.254254.78.7.25514
129254.78.8.0/28254.78.8.1 to 254.78.8.14254.78.8.1514
130254.78.8.16/28254.78.8.17 to 254.78.8.30254.78.8.3114
131254.78.8.32/28254.78.8.33 to 254.78.8.46254.78.8.4714
132254.78.8.48/28254.78.8.49 to 254.78.8.62254.78.8.6314
133254.78.8.64/28254.78.8.65 to 254.78.8.78254.78.8.7914
134254.78.8.80/28254.78.8.81 to 254.78.8.94254.78.8.9514
135254.78.8.96/28254.78.8.97 to 254.78.8.110254.78.8.11114
136254.78.8.112/28254.78.8.113 to 254.78.8.126254.78.8.12714
137254.78.8.128/28254.78.8.129 to 254.78.8.142254.78.8.14314
138254.78.8.144/28254.78.8.145 to 254.78.8.158254.78.8.15914
139254.78.8.160/28254.78.8.161 to 254.78.8.174254.78.8.17514
140254.78.8.176/28254.78.8.177 to 254.78.8.190254.78.8.19114
141254.78.8.192/28254.78.8.193 to 254.78.8.206254.78.8.20714
142254.78.8.208/28254.78.8.209 to 254.78.8.222254.78.8.22314
143254.78.8.224/28254.78.8.225 to 254.78.8.238254.78.8.23914
144254.78.8.240/28254.78.8.241 to 254.78.8.254254.78.8.25514
145254.78.9.0/28254.78.9.1 to 254.78.9.14254.78.9.1514
146254.78.9.16/28254.78.9.17 to 254.78.9.30254.78.9.3114
147254.78.9.32/28254.78.9.33 to 254.78.9.46254.78.9.4714
148254.78.9.48/28254.78.9.49 to 254.78.9.62254.78.9.6314
149254.78.9.64/28254.78.9.65 to 254.78.9.78254.78.9.7914
150254.78.9.80/28254.78.9.81 to 254.78.9.94254.78.9.9514
151254.78.9.96/28254.78.9.97 to 254.78.9.110254.78.9.11114
152254.78.9.112/28254.78.9.113 to 254.78.9.126254.78.9.12714
153254.78.9.128/28254.78.9.129 to 254.78.9.142254.78.9.14314
154254.78.9.144/28254.78.9.145 to 254.78.9.158254.78.9.15914
155254.78.9.160/28254.78.9.161 to 254.78.9.174254.78.9.17514
156254.78.9.176/28254.78.9.177 to 254.78.9.190254.78.9.19114
157254.78.9.192/28254.78.9.193 to 254.78.9.206254.78.9.20714
158254.78.9.208/28254.78.9.209 to 254.78.9.222254.78.9.22314
159254.78.9.224/28254.78.9.225 to 254.78.9.238254.78.9.23914
160254.78.9.240/28254.78.9.241 to 254.78.9.254254.78.9.25514
161254.78.10.0/28254.78.10.1 to 254.78.10.14254.78.10.1514
162254.78.10.16/28254.78.10.17 to 254.78.10.30254.78.10.3114
163254.78.10.32/28254.78.10.33 to 254.78.10.46254.78.10.4714
164254.78.10.48/28254.78.10.49 to 254.78.10.62254.78.10.6314
165254.78.10.64/28254.78.10.65 to 254.78.10.78254.78.10.7914
166254.78.10.80/28254.78.10.81 to 254.78.10.94254.78.10.9514
167254.78.10.96/28254.78.10.97 to 254.78.10.110254.78.10.11114
168254.78.10.112/28254.78.10.113 to 254.78.10.126254.78.10.12714
169254.78.10.128/28254.78.10.129 to 254.78.10.142254.78.10.14314
170254.78.10.144/28254.78.10.145 to 254.78.10.158254.78.10.15914
171254.78.10.160/28254.78.10.161 to 254.78.10.174254.78.10.17514
172254.78.10.176/28254.78.10.177 to 254.78.10.190254.78.10.19114
173254.78.10.192/28254.78.10.193 to 254.78.10.206254.78.10.20714
174254.78.10.208/28254.78.10.209 to 254.78.10.222254.78.10.22314
175254.78.10.224/28254.78.10.225 to 254.78.10.238254.78.10.23914
176254.78.10.240/28254.78.10.241 to 254.78.10.254254.78.10.25514
177254.78.11.0/28254.78.11.1 to 254.78.11.14254.78.11.1514
178254.78.11.16/28254.78.11.17 to 254.78.11.30254.78.11.3114
179254.78.11.32/28254.78.11.33 to 254.78.11.46254.78.11.4714
180254.78.11.48/28254.78.11.49 to 254.78.11.62254.78.11.6314
181254.78.11.64/28254.78.11.65 to 254.78.11.78254.78.11.7914
182254.78.11.80/28254.78.11.81 to 254.78.11.94254.78.11.9514
183254.78.11.96/28254.78.11.97 to 254.78.11.110254.78.11.11114
184254.78.11.112/28254.78.11.113 to 254.78.11.126254.78.11.12714
185254.78.11.128/28254.78.11.129 to 254.78.11.142254.78.11.14314
186254.78.11.144/28254.78.11.145 to 254.78.11.158254.78.11.15914
187254.78.11.160/28254.78.11.161 to 254.78.11.174254.78.11.17514
188254.78.11.176/28254.78.11.177 to 254.78.11.190254.78.11.19114
189254.78.11.192/28254.78.11.193 to 254.78.11.206254.78.11.20714
190254.78.11.208/28254.78.11.209 to 254.78.11.222254.78.11.22314
191254.78.11.224/28254.78.11.225 to 254.78.11.238254.78.11.23914
192254.78.11.240/28254.78.11.241 to 254.78.11.254254.78.11.25514
193254.78.12.0/28254.78.12.1 to 254.78.12.14254.78.12.1514
194254.78.12.16/28254.78.12.17 to 254.78.12.30254.78.12.3114
195254.78.12.32/28254.78.12.33 to 254.78.12.46254.78.12.4714
196254.78.12.48/28254.78.12.49 to 254.78.12.62254.78.12.6314
197254.78.12.64/28254.78.12.65 to 254.78.12.78254.78.12.7914
198254.78.12.80/28254.78.12.81 to 254.78.12.94254.78.12.9514
199254.78.12.96/28254.78.12.97 to 254.78.12.110254.78.12.11114
200254.78.12.112/28254.78.12.113 to 254.78.12.126254.78.12.12714
201254.78.12.128/28254.78.12.129 to 254.78.12.142254.78.12.14314
202254.78.12.144/28254.78.12.145 to 254.78.12.158254.78.12.15914
203254.78.12.160/28254.78.12.161 to 254.78.12.174254.78.12.17514
204254.78.12.176/28254.78.12.177 to 254.78.12.190254.78.12.19114
205254.78.12.192/28254.78.12.193 to 254.78.12.206254.78.12.20714
206254.78.12.208/28254.78.12.209 to 254.78.12.222254.78.12.22314
207254.78.12.224/28254.78.12.225 to 254.78.12.238254.78.12.23914
208254.78.12.240/28254.78.12.241 to 254.78.12.254254.78.12.25514
209254.78.13.0/28254.78.13.1 to 254.78.13.14254.78.13.1514
210254.78.13.16/28254.78.13.17 to 254.78.13.30254.78.13.3114
211254.78.13.32/28254.78.13.33 to 254.78.13.46254.78.13.4714
212254.78.13.48/28254.78.13.49 to 254.78.13.62254.78.13.6314
213254.78.13.64/28254.78.13.65 to 254.78.13.78254.78.13.7914
214254.78.13.80/28254.78.13.81 to 254.78.13.94254.78.13.9514
215254.78.13.96/28254.78.13.97 to 254.78.13.110254.78.13.11114
216254.78.13.112/28254.78.13.113 to 254.78.13.126254.78.13.12714
217254.78.13.128/28254.78.13.129 to 254.78.13.142254.78.13.14314
218254.78.13.144/28254.78.13.145 to 254.78.13.158254.78.13.15914
219254.78.13.160/28254.78.13.161 to 254.78.13.174254.78.13.17514
220254.78.13.176/28254.78.13.177 to 254.78.13.190254.78.13.19114
221254.78.13.192/28254.78.13.193 to 254.78.13.206254.78.13.20714
222254.78.13.208/28254.78.13.209 to 254.78.13.222254.78.13.22314
223254.78.13.224/28254.78.13.225 to 254.78.13.238254.78.13.23914
224254.78.13.240/28254.78.13.241 to 254.78.13.254254.78.13.25514
225254.78.14.0/28254.78.14.1 to 254.78.14.14254.78.14.1514
226254.78.14.16/28254.78.14.17 to 254.78.14.30254.78.14.3114
227254.78.14.32/28254.78.14.33 to 254.78.14.46254.78.14.4714
228254.78.14.48/28254.78.14.49 to 254.78.14.62254.78.14.6314
229254.78.14.64/28254.78.14.65 to 254.78.14.78254.78.14.7914
230254.78.14.80/28254.78.14.81 to 254.78.14.94254.78.14.9514
231254.78.14.96/28254.78.14.97 to 254.78.14.110254.78.14.11114
232254.78.14.112/28254.78.14.113 to 254.78.14.126254.78.14.12714
233254.78.14.128/28254.78.14.129 to 254.78.14.142254.78.14.14314
234254.78.14.144/28254.78.14.145 to 254.78.14.158254.78.14.15914
235254.78.14.160/28254.78.14.161 to 254.78.14.174254.78.14.17514
236254.78.14.176/28254.78.14.177 to 254.78.14.190254.78.14.19114
237254.78.14.192/28254.78.14.193 to 254.78.14.206254.78.14.20714
238254.78.14.208/28254.78.14.209 to 254.78.14.222254.78.14.22314
239254.78.14.224/28254.78.14.225 to 254.78.14.238254.78.14.23914
240254.78.14.240/28254.78.14.241 to 254.78.14.254254.78.14.25514
241254.78.15.0/28254.78.15.1 to 254.78.15.14254.78.15.1514
242254.78.15.16/28254.78.15.17 to 254.78.15.30254.78.15.3114
243254.78.15.32/28254.78.15.33 to 254.78.15.46254.78.15.4714
244254.78.15.48/28254.78.15.49 to 254.78.15.62254.78.15.6314
245254.78.15.64/28254.78.15.65 to 254.78.15.78254.78.15.7914
246254.78.15.80/28254.78.15.81 to 254.78.15.94254.78.15.9514
247254.78.15.96/28254.78.15.97 to 254.78.15.110254.78.15.11114
248254.78.15.112/28254.78.15.113 to 254.78.15.126254.78.15.12714
249254.78.15.128/28254.78.15.129 to 254.78.15.142254.78.15.14314
250254.78.15.144/28254.78.15.145 to 254.78.15.158254.78.15.15914
251254.78.15.160/28254.78.15.161 to 254.78.15.174254.78.15.17514
252254.78.15.176/28254.78.15.177 to 254.78.15.190254.78.15.19114
253254.78.15.192/28254.78.15.193 to 254.78.15.206254.78.15.20714
254254.78.15.208/28254.78.15.209 to 254.78.15.222254.78.15.22314
255254.78.15.224/28254.78.15.225 to 254.78.15.238254.78.15.23914
256254.78.15.240/28254.78.15.241 to 254.78.15.254254.78.15.25514

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.