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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.

Network225.216.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
225.216.0.0
Broadcast address
225.217.255.255
First usable
225.216.0.1
Last usable
225.217.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E1D80000 · Integer 3789029376 to 3789160447
Reverse DNS zones
216.225.in-addr.arpa
217.225.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100001.11011000.00000000.00000000225.216.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network11100001.11011000.00000000.00000000225.216.0.0
Broadcast11100001.11011001.11111111.11111111225.217.255.255
Split into smaller subnets/26
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

225.216.0.0/15 makes 2,048 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1225.216.0.0/26225.216.0.1 to 225.216.0.62225.216.0.6362
2225.216.0.64/26225.216.0.65 to 225.216.0.126225.216.0.12762
3225.216.0.128/26225.216.0.129 to 225.216.0.190225.216.0.19162
4225.216.0.192/26225.216.0.193 to 225.216.0.254225.216.0.25562
5225.216.1.0/26225.216.1.1 to 225.216.1.62225.216.1.6362
6225.216.1.64/26225.216.1.65 to 225.216.1.126225.216.1.12762
7225.216.1.128/26225.216.1.129 to 225.216.1.190225.216.1.19162
8225.216.1.192/26225.216.1.193 to 225.216.1.254225.216.1.25562
9225.216.2.0/26225.216.2.1 to 225.216.2.62225.216.2.6362
10225.216.2.64/26225.216.2.65 to 225.216.2.126225.216.2.12762
11225.216.2.128/26225.216.2.129 to 225.216.2.190225.216.2.19162
12225.216.2.192/26225.216.2.193 to 225.216.2.254225.216.2.25562
13225.216.3.0/26225.216.3.1 to 225.216.3.62225.216.3.6362
14225.216.3.64/26225.216.3.65 to 225.216.3.126225.216.3.12762
15225.216.3.128/26225.216.3.129 to 225.216.3.190225.216.3.19162
16225.216.3.192/26225.216.3.193 to 225.216.3.254225.216.3.25562
17225.216.4.0/26225.216.4.1 to 225.216.4.62225.216.4.6362
18225.216.4.64/26225.216.4.65 to 225.216.4.126225.216.4.12762
19225.216.4.128/26225.216.4.129 to 225.216.4.190225.216.4.19162
20225.216.4.192/26225.216.4.193 to 225.216.4.254225.216.4.25562
21225.216.5.0/26225.216.5.1 to 225.216.5.62225.216.5.6362
22225.216.5.64/26225.216.5.65 to 225.216.5.126225.216.5.12762
23225.216.5.128/26225.216.5.129 to 225.216.5.190225.216.5.19162
24225.216.5.192/26225.216.5.193 to 225.216.5.254225.216.5.25562
25225.216.6.0/26225.216.6.1 to 225.216.6.62225.216.6.6362
26225.216.6.64/26225.216.6.65 to 225.216.6.126225.216.6.12762
27225.216.6.128/26225.216.6.129 to 225.216.6.190225.216.6.19162
28225.216.6.192/26225.216.6.193 to 225.216.6.254225.216.6.25562
29225.216.7.0/26225.216.7.1 to 225.216.7.62225.216.7.6362
30225.216.7.64/26225.216.7.65 to 225.216.7.126225.216.7.12762
31225.216.7.128/26225.216.7.129 to 225.216.7.190225.216.7.19162
32225.216.7.192/26225.216.7.193 to 225.216.7.254225.216.7.25562
33225.216.8.0/26225.216.8.1 to 225.216.8.62225.216.8.6362
34225.216.8.64/26225.216.8.65 to 225.216.8.126225.216.8.12762
35225.216.8.128/26225.216.8.129 to 225.216.8.190225.216.8.19162
36225.216.8.192/26225.216.8.193 to 225.216.8.254225.216.8.25562
37225.216.9.0/26225.216.9.1 to 225.216.9.62225.216.9.6362
38225.216.9.64/26225.216.9.65 to 225.216.9.126225.216.9.12762
39225.216.9.128/26225.216.9.129 to 225.216.9.190225.216.9.19162
40225.216.9.192/26225.216.9.193 to 225.216.9.254225.216.9.25562
41225.216.10.0/26225.216.10.1 to 225.216.10.62225.216.10.6362
42225.216.10.64/26225.216.10.65 to 225.216.10.126225.216.10.12762
43225.216.10.128/26225.216.10.129 to 225.216.10.190225.216.10.19162
44225.216.10.192/26225.216.10.193 to 225.216.10.254225.216.10.25562
45225.216.11.0/26225.216.11.1 to 225.216.11.62225.216.11.6362
46225.216.11.64/26225.216.11.65 to 225.216.11.126225.216.11.12762
47225.216.11.128/26225.216.11.129 to 225.216.11.190225.216.11.19162
48225.216.11.192/26225.216.11.193 to 225.216.11.254225.216.11.25562
49225.216.12.0/26225.216.12.1 to 225.216.12.62225.216.12.6362
50225.216.12.64/26225.216.12.65 to 225.216.12.126225.216.12.12762
51225.216.12.128/26225.216.12.129 to 225.216.12.190225.216.12.19162
52225.216.12.192/26225.216.12.193 to 225.216.12.254225.216.12.25562
53225.216.13.0/26225.216.13.1 to 225.216.13.62225.216.13.6362
54225.216.13.64/26225.216.13.65 to 225.216.13.126225.216.13.12762
55225.216.13.128/26225.216.13.129 to 225.216.13.190225.216.13.19162
56225.216.13.192/26225.216.13.193 to 225.216.13.254225.216.13.25562
57225.216.14.0/26225.216.14.1 to 225.216.14.62225.216.14.6362
58225.216.14.64/26225.216.14.65 to 225.216.14.126225.216.14.12762
59225.216.14.128/26225.216.14.129 to 225.216.14.190225.216.14.19162
60225.216.14.192/26225.216.14.193 to 225.216.14.254225.216.14.25562
61225.216.15.0/26225.216.15.1 to 225.216.15.62225.216.15.6362
62225.216.15.64/26225.216.15.65 to 225.216.15.126225.216.15.12762
63225.216.15.128/26225.216.15.129 to 225.216.15.190225.216.15.19162
64225.216.15.192/26225.216.15.193 to 225.216.15.254225.216.15.25562
65225.216.16.0/26225.216.16.1 to 225.216.16.62225.216.16.6362
66225.216.16.64/26225.216.16.65 to 225.216.16.126225.216.16.12762
67225.216.16.128/26225.216.16.129 to 225.216.16.190225.216.16.19162
68225.216.16.192/26225.216.16.193 to 225.216.16.254225.216.16.25562
69225.216.17.0/26225.216.17.1 to 225.216.17.62225.216.17.6362
70225.216.17.64/26225.216.17.65 to 225.216.17.126225.216.17.12762
71225.216.17.128/26225.216.17.129 to 225.216.17.190225.216.17.19162
72225.216.17.192/26225.216.17.193 to 225.216.17.254225.216.17.25562
73225.216.18.0/26225.216.18.1 to 225.216.18.62225.216.18.6362
74225.216.18.64/26225.216.18.65 to 225.216.18.126225.216.18.12762
75225.216.18.128/26225.216.18.129 to 225.216.18.190225.216.18.19162
76225.216.18.192/26225.216.18.193 to 225.216.18.254225.216.18.25562
77225.216.19.0/26225.216.19.1 to 225.216.19.62225.216.19.6362
78225.216.19.64/26225.216.19.65 to 225.216.19.126225.216.19.12762
79225.216.19.128/26225.216.19.129 to 225.216.19.190225.216.19.19162
80225.216.19.192/26225.216.19.193 to 225.216.19.254225.216.19.25562
81225.216.20.0/26225.216.20.1 to 225.216.20.62225.216.20.6362
82225.216.20.64/26225.216.20.65 to 225.216.20.126225.216.20.12762
83225.216.20.128/26225.216.20.129 to 225.216.20.190225.216.20.19162
84225.216.20.192/26225.216.20.193 to 225.216.20.254225.216.20.25562
85225.216.21.0/26225.216.21.1 to 225.216.21.62225.216.21.6362
86225.216.21.64/26225.216.21.65 to 225.216.21.126225.216.21.12762
87225.216.21.128/26225.216.21.129 to 225.216.21.190225.216.21.19162
88225.216.21.192/26225.216.21.193 to 225.216.21.254225.216.21.25562
89225.216.22.0/26225.216.22.1 to 225.216.22.62225.216.22.6362
90225.216.22.64/26225.216.22.65 to 225.216.22.126225.216.22.12762
91225.216.22.128/26225.216.22.129 to 225.216.22.190225.216.22.19162
92225.216.22.192/26225.216.22.193 to 225.216.22.254225.216.22.25562
93225.216.23.0/26225.216.23.1 to 225.216.23.62225.216.23.6362
94225.216.23.64/26225.216.23.65 to 225.216.23.126225.216.23.12762
95225.216.23.128/26225.216.23.129 to 225.216.23.190225.216.23.19162
96225.216.23.192/26225.216.23.193 to 225.216.23.254225.216.23.25562
97225.216.24.0/26225.216.24.1 to 225.216.24.62225.216.24.6362
98225.216.24.64/26225.216.24.65 to 225.216.24.126225.216.24.12762
99225.216.24.128/26225.216.24.129 to 225.216.24.190225.216.24.19162
100225.216.24.192/26225.216.24.193 to 225.216.24.254225.216.24.25562
101225.216.25.0/26225.216.25.1 to 225.216.25.62225.216.25.6362
102225.216.25.64/26225.216.25.65 to 225.216.25.126225.216.25.12762
103225.216.25.128/26225.216.25.129 to 225.216.25.190225.216.25.19162
104225.216.25.192/26225.216.25.193 to 225.216.25.254225.216.25.25562
105225.216.26.0/26225.216.26.1 to 225.216.26.62225.216.26.6362
106225.216.26.64/26225.216.26.65 to 225.216.26.126225.216.26.12762
107225.216.26.128/26225.216.26.129 to 225.216.26.190225.216.26.19162
108225.216.26.192/26225.216.26.193 to 225.216.26.254225.216.26.25562
109225.216.27.0/26225.216.27.1 to 225.216.27.62225.216.27.6362
110225.216.27.64/26225.216.27.65 to 225.216.27.126225.216.27.12762
111225.216.27.128/26225.216.27.129 to 225.216.27.190225.216.27.19162
112225.216.27.192/26225.216.27.193 to 225.216.27.254225.216.27.25562
113225.216.28.0/26225.216.28.1 to 225.216.28.62225.216.28.6362
114225.216.28.64/26225.216.28.65 to 225.216.28.126225.216.28.12762
115225.216.28.128/26225.216.28.129 to 225.216.28.190225.216.28.19162
116225.216.28.192/26225.216.28.193 to 225.216.28.254225.216.28.25562
117225.216.29.0/26225.216.29.1 to 225.216.29.62225.216.29.6362
118225.216.29.64/26225.216.29.65 to 225.216.29.126225.216.29.12762
119225.216.29.128/26225.216.29.129 to 225.216.29.190225.216.29.19162
120225.216.29.192/26225.216.29.193 to 225.216.29.254225.216.29.25562
121225.216.30.0/26225.216.30.1 to 225.216.30.62225.216.30.6362
122225.216.30.64/26225.216.30.65 to 225.216.30.126225.216.30.12762
123225.216.30.128/26225.216.30.129 to 225.216.30.190225.216.30.19162
124225.216.30.192/26225.216.30.193 to 225.216.30.254225.216.30.25562
125225.216.31.0/26225.216.31.1 to 225.216.31.62225.216.31.6362
126225.216.31.64/26225.216.31.65 to 225.216.31.126225.216.31.12762
127225.216.31.128/26225.216.31.129 to 225.216.31.190225.216.31.19162
128225.216.31.192/26225.216.31.193 to 225.216.31.254225.216.31.25562
129225.216.32.0/26225.216.32.1 to 225.216.32.62225.216.32.6362
130225.216.32.64/26225.216.32.65 to 225.216.32.126225.216.32.12762
131225.216.32.128/26225.216.32.129 to 225.216.32.190225.216.32.19162
132225.216.32.192/26225.216.32.193 to 225.216.32.254225.216.32.25562
133225.216.33.0/26225.216.33.1 to 225.216.33.62225.216.33.6362
134225.216.33.64/26225.216.33.65 to 225.216.33.126225.216.33.12762
135225.216.33.128/26225.216.33.129 to 225.216.33.190225.216.33.19162
136225.216.33.192/26225.216.33.193 to 225.216.33.254225.216.33.25562
137225.216.34.0/26225.216.34.1 to 225.216.34.62225.216.34.6362
138225.216.34.64/26225.216.34.65 to 225.216.34.126225.216.34.12762
139225.216.34.128/26225.216.34.129 to 225.216.34.190225.216.34.19162
140225.216.34.192/26225.216.34.193 to 225.216.34.254225.216.34.25562
141225.216.35.0/26225.216.35.1 to 225.216.35.62225.216.35.6362
142225.216.35.64/26225.216.35.65 to 225.216.35.126225.216.35.12762
143225.216.35.128/26225.216.35.129 to 225.216.35.190225.216.35.19162
144225.216.35.192/26225.216.35.193 to 225.216.35.254225.216.35.25562
145225.216.36.0/26225.216.36.1 to 225.216.36.62225.216.36.6362
146225.216.36.64/26225.216.36.65 to 225.216.36.126225.216.36.12762
147225.216.36.128/26225.216.36.129 to 225.216.36.190225.216.36.19162
148225.216.36.192/26225.216.36.193 to 225.216.36.254225.216.36.25562
149225.216.37.0/26225.216.37.1 to 225.216.37.62225.216.37.6362
150225.216.37.64/26225.216.37.65 to 225.216.37.126225.216.37.12762
151225.216.37.128/26225.216.37.129 to 225.216.37.190225.216.37.19162
152225.216.37.192/26225.216.37.193 to 225.216.37.254225.216.37.25562
153225.216.38.0/26225.216.38.1 to 225.216.38.62225.216.38.6362
154225.216.38.64/26225.216.38.65 to 225.216.38.126225.216.38.12762
155225.216.38.128/26225.216.38.129 to 225.216.38.190225.216.38.19162
156225.216.38.192/26225.216.38.193 to 225.216.38.254225.216.38.25562
157225.216.39.0/26225.216.39.1 to 225.216.39.62225.216.39.6362
158225.216.39.64/26225.216.39.65 to 225.216.39.126225.216.39.12762
159225.216.39.128/26225.216.39.129 to 225.216.39.190225.216.39.19162
160225.216.39.192/26225.216.39.193 to 225.216.39.254225.216.39.25562
161225.216.40.0/26225.216.40.1 to 225.216.40.62225.216.40.6362
162225.216.40.64/26225.216.40.65 to 225.216.40.126225.216.40.12762
163225.216.40.128/26225.216.40.129 to 225.216.40.190225.216.40.19162
164225.216.40.192/26225.216.40.193 to 225.216.40.254225.216.40.25562
165225.216.41.0/26225.216.41.1 to 225.216.41.62225.216.41.6362
166225.216.41.64/26225.216.41.65 to 225.216.41.126225.216.41.12762
167225.216.41.128/26225.216.41.129 to 225.216.41.190225.216.41.19162
168225.216.41.192/26225.216.41.193 to 225.216.41.254225.216.41.25562
169225.216.42.0/26225.216.42.1 to 225.216.42.62225.216.42.6362
170225.216.42.64/26225.216.42.65 to 225.216.42.126225.216.42.12762
171225.216.42.128/26225.216.42.129 to 225.216.42.190225.216.42.19162
172225.216.42.192/26225.216.42.193 to 225.216.42.254225.216.42.25562
173225.216.43.0/26225.216.43.1 to 225.216.43.62225.216.43.6362
174225.216.43.64/26225.216.43.65 to 225.216.43.126225.216.43.12762
175225.216.43.128/26225.216.43.129 to 225.216.43.190225.216.43.19162
176225.216.43.192/26225.216.43.193 to 225.216.43.254225.216.43.25562
177225.216.44.0/26225.216.44.1 to 225.216.44.62225.216.44.6362
178225.216.44.64/26225.216.44.65 to 225.216.44.126225.216.44.12762
179225.216.44.128/26225.216.44.129 to 225.216.44.190225.216.44.19162
180225.216.44.192/26225.216.44.193 to 225.216.44.254225.216.44.25562
181225.216.45.0/26225.216.45.1 to 225.216.45.62225.216.45.6362
182225.216.45.64/26225.216.45.65 to 225.216.45.126225.216.45.12762
183225.216.45.128/26225.216.45.129 to 225.216.45.190225.216.45.19162
184225.216.45.192/26225.216.45.193 to 225.216.45.254225.216.45.25562
185225.216.46.0/26225.216.46.1 to 225.216.46.62225.216.46.6362
186225.216.46.64/26225.216.46.65 to 225.216.46.126225.216.46.12762
187225.216.46.128/26225.216.46.129 to 225.216.46.190225.216.46.19162
188225.216.46.192/26225.216.46.193 to 225.216.46.254225.216.46.25562
189225.216.47.0/26225.216.47.1 to 225.216.47.62225.216.47.6362
190225.216.47.64/26225.216.47.65 to 225.216.47.126225.216.47.12762
191225.216.47.128/26225.216.47.129 to 225.216.47.190225.216.47.19162
192225.216.47.192/26225.216.47.193 to 225.216.47.254225.216.47.25562
193225.216.48.0/26225.216.48.1 to 225.216.48.62225.216.48.6362
194225.216.48.64/26225.216.48.65 to 225.216.48.126225.216.48.12762
195225.216.48.128/26225.216.48.129 to 225.216.48.190225.216.48.19162
196225.216.48.192/26225.216.48.193 to 225.216.48.254225.216.48.25562
197225.216.49.0/26225.216.49.1 to 225.216.49.62225.216.49.6362
198225.216.49.64/26225.216.49.65 to 225.216.49.126225.216.49.12762
199225.216.49.128/26225.216.49.129 to 225.216.49.190225.216.49.19162
200225.216.49.192/26225.216.49.193 to 225.216.49.254225.216.49.25562
201225.216.50.0/26225.216.50.1 to 225.216.50.62225.216.50.6362
202225.216.50.64/26225.216.50.65 to 225.216.50.126225.216.50.12762
203225.216.50.128/26225.216.50.129 to 225.216.50.190225.216.50.19162
204225.216.50.192/26225.216.50.193 to 225.216.50.254225.216.50.25562
205225.216.51.0/26225.216.51.1 to 225.216.51.62225.216.51.6362
206225.216.51.64/26225.216.51.65 to 225.216.51.126225.216.51.12762
207225.216.51.128/26225.216.51.129 to 225.216.51.190225.216.51.19162
208225.216.51.192/26225.216.51.193 to 225.216.51.254225.216.51.25562
209225.216.52.0/26225.216.52.1 to 225.216.52.62225.216.52.6362
210225.216.52.64/26225.216.52.65 to 225.216.52.126225.216.52.12762
211225.216.52.128/26225.216.52.129 to 225.216.52.190225.216.52.19162
212225.216.52.192/26225.216.52.193 to 225.216.52.254225.216.52.25562
213225.216.53.0/26225.216.53.1 to 225.216.53.62225.216.53.6362
214225.216.53.64/26225.216.53.65 to 225.216.53.126225.216.53.12762
215225.216.53.128/26225.216.53.129 to 225.216.53.190225.216.53.19162
216225.216.53.192/26225.216.53.193 to 225.216.53.254225.216.53.25562
217225.216.54.0/26225.216.54.1 to 225.216.54.62225.216.54.6362
218225.216.54.64/26225.216.54.65 to 225.216.54.126225.216.54.12762
219225.216.54.128/26225.216.54.129 to 225.216.54.190225.216.54.19162
220225.216.54.192/26225.216.54.193 to 225.216.54.254225.216.54.25562
221225.216.55.0/26225.216.55.1 to 225.216.55.62225.216.55.6362
222225.216.55.64/26225.216.55.65 to 225.216.55.126225.216.55.12762
223225.216.55.128/26225.216.55.129 to 225.216.55.190225.216.55.19162
224225.216.55.192/26225.216.55.193 to 225.216.55.254225.216.55.25562
225225.216.56.0/26225.216.56.1 to 225.216.56.62225.216.56.6362
226225.216.56.64/26225.216.56.65 to 225.216.56.126225.216.56.12762
227225.216.56.128/26225.216.56.129 to 225.216.56.190225.216.56.19162
228225.216.56.192/26225.216.56.193 to 225.216.56.254225.216.56.25562
229225.216.57.0/26225.216.57.1 to 225.216.57.62225.216.57.6362
230225.216.57.64/26225.216.57.65 to 225.216.57.126225.216.57.12762
231225.216.57.128/26225.216.57.129 to 225.216.57.190225.216.57.19162
232225.216.57.192/26225.216.57.193 to 225.216.57.254225.216.57.25562
233225.216.58.0/26225.216.58.1 to 225.216.58.62225.216.58.6362
234225.216.58.64/26225.216.58.65 to 225.216.58.126225.216.58.12762
235225.216.58.128/26225.216.58.129 to 225.216.58.190225.216.58.19162
236225.216.58.192/26225.216.58.193 to 225.216.58.254225.216.58.25562
237225.216.59.0/26225.216.59.1 to 225.216.59.62225.216.59.6362
238225.216.59.64/26225.216.59.65 to 225.216.59.126225.216.59.12762
239225.216.59.128/26225.216.59.129 to 225.216.59.190225.216.59.19162
240225.216.59.192/26225.216.59.193 to 225.216.59.254225.216.59.25562
241225.216.60.0/26225.216.60.1 to 225.216.60.62225.216.60.6362
242225.216.60.64/26225.216.60.65 to 225.216.60.126225.216.60.12762
243225.216.60.128/26225.216.60.129 to 225.216.60.190225.216.60.19162
244225.216.60.192/26225.216.60.193 to 225.216.60.254225.216.60.25562
245225.216.61.0/26225.216.61.1 to 225.216.61.62225.216.61.6362
246225.216.61.64/26225.216.61.65 to 225.216.61.126225.216.61.12762
247225.216.61.128/26225.216.61.129 to 225.216.61.190225.216.61.19162
248225.216.61.192/26225.216.61.193 to 225.216.61.254225.216.61.25562
249225.216.62.0/26225.216.62.1 to 225.216.62.62225.216.62.6362
250225.216.62.64/26225.216.62.65 to 225.216.62.126225.216.62.12762
251225.216.62.128/26225.216.62.129 to 225.216.62.190225.216.62.19162
252225.216.62.192/26225.216.62.193 to 225.216.62.254225.216.62.25562
253225.216.63.0/26225.216.63.1 to 225.216.63.62225.216.63.6362
254225.216.63.64/26225.216.63.65 to 225.216.63.126225.216.63.12762
255225.216.63.128/26225.216.63.129 to 225.216.63.190225.216.63.19162
256225.216.63.192/26225.216.63.193 to 225.216.63.254225.216.63.25562

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.