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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.

Network236.53.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
236.53.0.0
Broadcast address
236.53.255.255
First usable
236.53.0.1
Last usable
236.53.255.254
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
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex EC350000 · Integer 3962896384 to 3962961919
Reverse DNS zone
53.236.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101100.00110101..00000000.00000000236.53.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11101100.00110101..00000000.00000000236.53.0.0
Broadcast11101100.00110101..11111111.11111111236.53.255.255
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)

236.53.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1236.53.0.0/26236.53.0.1 to 236.53.0.62236.53.0.6362
2236.53.0.64/26236.53.0.65 to 236.53.0.126236.53.0.12762
3236.53.0.128/26236.53.0.129 to 236.53.0.190236.53.0.19162
4236.53.0.192/26236.53.0.193 to 236.53.0.254236.53.0.25562
5236.53.1.0/26236.53.1.1 to 236.53.1.62236.53.1.6362
6236.53.1.64/26236.53.1.65 to 236.53.1.126236.53.1.12762
7236.53.1.128/26236.53.1.129 to 236.53.1.190236.53.1.19162
8236.53.1.192/26236.53.1.193 to 236.53.1.254236.53.1.25562
9236.53.2.0/26236.53.2.1 to 236.53.2.62236.53.2.6362
10236.53.2.64/26236.53.2.65 to 236.53.2.126236.53.2.12762
11236.53.2.128/26236.53.2.129 to 236.53.2.190236.53.2.19162
12236.53.2.192/26236.53.2.193 to 236.53.2.254236.53.2.25562
13236.53.3.0/26236.53.3.1 to 236.53.3.62236.53.3.6362
14236.53.3.64/26236.53.3.65 to 236.53.3.126236.53.3.12762
15236.53.3.128/26236.53.3.129 to 236.53.3.190236.53.3.19162
16236.53.3.192/26236.53.3.193 to 236.53.3.254236.53.3.25562
17236.53.4.0/26236.53.4.1 to 236.53.4.62236.53.4.6362
18236.53.4.64/26236.53.4.65 to 236.53.4.126236.53.4.12762
19236.53.4.128/26236.53.4.129 to 236.53.4.190236.53.4.19162
20236.53.4.192/26236.53.4.193 to 236.53.4.254236.53.4.25562
21236.53.5.0/26236.53.5.1 to 236.53.5.62236.53.5.6362
22236.53.5.64/26236.53.5.65 to 236.53.5.126236.53.5.12762
23236.53.5.128/26236.53.5.129 to 236.53.5.190236.53.5.19162
24236.53.5.192/26236.53.5.193 to 236.53.5.254236.53.5.25562
25236.53.6.0/26236.53.6.1 to 236.53.6.62236.53.6.6362
26236.53.6.64/26236.53.6.65 to 236.53.6.126236.53.6.12762
27236.53.6.128/26236.53.6.129 to 236.53.6.190236.53.6.19162
28236.53.6.192/26236.53.6.193 to 236.53.6.254236.53.6.25562
29236.53.7.0/26236.53.7.1 to 236.53.7.62236.53.7.6362
30236.53.7.64/26236.53.7.65 to 236.53.7.126236.53.7.12762
31236.53.7.128/26236.53.7.129 to 236.53.7.190236.53.7.19162
32236.53.7.192/26236.53.7.193 to 236.53.7.254236.53.7.25562
33236.53.8.0/26236.53.8.1 to 236.53.8.62236.53.8.6362
34236.53.8.64/26236.53.8.65 to 236.53.8.126236.53.8.12762
35236.53.8.128/26236.53.8.129 to 236.53.8.190236.53.8.19162
36236.53.8.192/26236.53.8.193 to 236.53.8.254236.53.8.25562
37236.53.9.0/26236.53.9.1 to 236.53.9.62236.53.9.6362
38236.53.9.64/26236.53.9.65 to 236.53.9.126236.53.9.12762
39236.53.9.128/26236.53.9.129 to 236.53.9.190236.53.9.19162
40236.53.9.192/26236.53.9.193 to 236.53.9.254236.53.9.25562
41236.53.10.0/26236.53.10.1 to 236.53.10.62236.53.10.6362
42236.53.10.64/26236.53.10.65 to 236.53.10.126236.53.10.12762
43236.53.10.128/26236.53.10.129 to 236.53.10.190236.53.10.19162
44236.53.10.192/26236.53.10.193 to 236.53.10.254236.53.10.25562
45236.53.11.0/26236.53.11.1 to 236.53.11.62236.53.11.6362
46236.53.11.64/26236.53.11.65 to 236.53.11.126236.53.11.12762
47236.53.11.128/26236.53.11.129 to 236.53.11.190236.53.11.19162
48236.53.11.192/26236.53.11.193 to 236.53.11.254236.53.11.25562
49236.53.12.0/26236.53.12.1 to 236.53.12.62236.53.12.6362
50236.53.12.64/26236.53.12.65 to 236.53.12.126236.53.12.12762
51236.53.12.128/26236.53.12.129 to 236.53.12.190236.53.12.19162
52236.53.12.192/26236.53.12.193 to 236.53.12.254236.53.12.25562
53236.53.13.0/26236.53.13.1 to 236.53.13.62236.53.13.6362
54236.53.13.64/26236.53.13.65 to 236.53.13.126236.53.13.12762
55236.53.13.128/26236.53.13.129 to 236.53.13.190236.53.13.19162
56236.53.13.192/26236.53.13.193 to 236.53.13.254236.53.13.25562
57236.53.14.0/26236.53.14.1 to 236.53.14.62236.53.14.6362
58236.53.14.64/26236.53.14.65 to 236.53.14.126236.53.14.12762
59236.53.14.128/26236.53.14.129 to 236.53.14.190236.53.14.19162
60236.53.14.192/26236.53.14.193 to 236.53.14.254236.53.14.25562
61236.53.15.0/26236.53.15.1 to 236.53.15.62236.53.15.6362
62236.53.15.64/26236.53.15.65 to 236.53.15.126236.53.15.12762
63236.53.15.128/26236.53.15.129 to 236.53.15.190236.53.15.19162
64236.53.15.192/26236.53.15.193 to 236.53.15.254236.53.15.25562
65236.53.16.0/26236.53.16.1 to 236.53.16.62236.53.16.6362
66236.53.16.64/26236.53.16.65 to 236.53.16.126236.53.16.12762
67236.53.16.128/26236.53.16.129 to 236.53.16.190236.53.16.19162
68236.53.16.192/26236.53.16.193 to 236.53.16.254236.53.16.25562
69236.53.17.0/26236.53.17.1 to 236.53.17.62236.53.17.6362
70236.53.17.64/26236.53.17.65 to 236.53.17.126236.53.17.12762
71236.53.17.128/26236.53.17.129 to 236.53.17.190236.53.17.19162
72236.53.17.192/26236.53.17.193 to 236.53.17.254236.53.17.25562
73236.53.18.0/26236.53.18.1 to 236.53.18.62236.53.18.6362
74236.53.18.64/26236.53.18.65 to 236.53.18.126236.53.18.12762
75236.53.18.128/26236.53.18.129 to 236.53.18.190236.53.18.19162
76236.53.18.192/26236.53.18.193 to 236.53.18.254236.53.18.25562
77236.53.19.0/26236.53.19.1 to 236.53.19.62236.53.19.6362
78236.53.19.64/26236.53.19.65 to 236.53.19.126236.53.19.12762
79236.53.19.128/26236.53.19.129 to 236.53.19.190236.53.19.19162
80236.53.19.192/26236.53.19.193 to 236.53.19.254236.53.19.25562
81236.53.20.0/26236.53.20.1 to 236.53.20.62236.53.20.6362
82236.53.20.64/26236.53.20.65 to 236.53.20.126236.53.20.12762
83236.53.20.128/26236.53.20.129 to 236.53.20.190236.53.20.19162
84236.53.20.192/26236.53.20.193 to 236.53.20.254236.53.20.25562
85236.53.21.0/26236.53.21.1 to 236.53.21.62236.53.21.6362
86236.53.21.64/26236.53.21.65 to 236.53.21.126236.53.21.12762
87236.53.21.128/26236.53.21.129 to 236.53.21.190236.53.21.19162
88236.53.21.192/26236.53.21.193 to 236.53.21.254236.53.21.25562
89236.53.22.0/26236.53.22.1 to 236.53.22.62236.53.22.6362
90236.53.22.64/26236.53.22.65 to 236.53.22.126236.53.22.12762
91236.53.22.128/26236.53.22.129 to 236.53.22.190236.53.22.19162
92236.53.22.192/26236.53.22.193 to 236.53.22.254236.53.22.25562
93236.53.23.0/26236.53.23.1 to 236.53.23.62236.53.23.6362
94236.53.23.64/26236.53.23.65 to 236.53.23.126236.53.23.12762
95236.53.23.128/26236.53.23.129 to 236.53.23.190236.53.23.19162
96236.53.23.192/26236.53.23.193 to 236.53.23.254236.53.23.25562
97236.53.24.0/26236.53.24.1 to 236.53.24.62236.53.24.6362
98236.53.24.64/26236.53.24.65 to 236.53.24.126236.53.24.12762
99236.53.24.128/26236.53.24.129 to 236.53.24.190236.53.24.19162
100236.53.24.192/26236.53.24.193 to 236.53.24.254236.53.24.25562
101236.53.25.0/26236.53.25.1 to 236.53.25.62236.53.25.6362
102236.53.25.64/26236.53.25.65 to 236.53.25.126236.53.25.12762
103236.53.25.128/26236.53.25.129 to 236.53.25.190236.53.25.19162
104236.53.25.192/26236.53.25.193 to 236.53.25.254236.53.25.25562
105236.53.26.0/26236.53.26.1 to 236.53.26.62236.53.26.6362
106236.53.26.64/26236.53.26.65 to 236.53.26.126236.53.26.12762
107236.53.26.128/26236.53.26.129 to 236.53.26.190236.53.26.19162
108236.53.26.192/26236.53.26.193 to 236.53.26.254236.53.26.25562
109236.53.27.0/26236.53.27.1 to 236.53.27.62236.53.27.6362
110236.53.27.64/26236.53.27.65 to 236.53.27.126236.53.27.12762
111236.53.27.128/26236.53.27.129 to 236.53.27.190236.53.27.19162
112236.53.27.192/26236.53.27.193 to 236.53.27.254236.53.27.25562
113236.53.28.0/26236.53.28.1 to 236.53.28.62236.53.28.6362
114236.53.28.64/26236.53.28.65 to 236.53.28.126236.53.28.12762
115236.53.28.128/26236.53.28.129 to 236.53.28.190236.53.28.19162
116236.53.28.192/26236.53.28.193 to 236.53.28.254236.53.28.25562
117236.53.29.0/26236.53.29.1 to 236.53.29.62236.53.29.6362
118236.53.29.64/26236.53.29.65 to 236.53.29.126236.53.29.12762
119236.53.29.128/26236.53.29.129 to 236.53.29.190236.53.29.19162
120236.53.29.192/26236.53.29.193 to 236.53.29.254236.53.29.25562
121236.53.30.0/26236.53.30.1 to 236.53.30.62236.53.30.6362
122236.53.30.64/26236.53.30.65 to 236.53.30.126236.53.30.12762
123236.53.30.128/26236.53.30.129 to 236.53.30.190236.53.30.19162
124236.53.30.192/26236.53.30.193 to 236.53.30.254236.53.30.25562
125236.53.31.0/26236.53.31.1 to 236.53.31.62236.53.31.6362
126236.53.31.64/26236.53.31.65 to 236.53.31.126236.53.31.12762
127236.53.31.128/26236.53.31.129 to 236.53.31.190236.53.31.19162
128236.53.31.192/26236.53.31.193 to 236.53.31.254236.53.31.25562
129236.53.32.0/26236.53.32.1 to 236.53.32.62236.53.32.6362
130236.53.32.64/26236.53.32.65 to 236.53.32.126236.53.32.12762
131236.53.32.128/26236.53.32.129 to 236.53.32.190236.53.32.19162
132236.53.32.192/26236.53.32.193 to 236.53.32.254236.53.32.25562
133236.53.33.0/26236.53.33.1 to 236.53.33.62236.53.33.6362
134236.53.33.64/26236.53.33.65 to 236.53.33.126236.53.33.12762
135236.53.33.128/26236.53.33.129 to 236.53.33.190236.53.33.19162
136236.53.33.192/26236.53.33.193 to 236.53.33.254236.53.33.25562
137236.53.34.0/26236.53.34.1 to 236.53.34.62236.53.34.6362
138236.53.34.64/26236.53.34.65 to 236.53.34.126236.53.34.12762
139236.53.34.128/26236.53.34.129 to 236.53.34.190236.53.34.19162
140236.53.34.192/26236.53.34.193 to 236.53.34.254236.53.34.25562
141236.53.35.0/26236.53.35.1 to 236.53.35.62236.53.35.6362
142236.53.35.64/26236.53.35.65 to 236.53.35.126236.53.35.12762
143236.53.35.128/26236.53.35.129 to 236.53.35.190236.53.35.19162
144236.53.35.192/26236.53.35.193 to 236.53.35.254236.53.35.25562
145236.53.36.0/26236.53.36.1 to 236.53.36.62236.53.36.6362
146236.53.36.64/26236.53.36.65 to 236.53.36.126236.53.36.12762
147236.53.36.128/26236.53.36.129 to 236.53.36.190236.53.36.19162
148236.53.36.192/26236.53.36.193 to 236.53.36.254236.53.36.25562
149236.53.37.0/26236.53.37.1 to 236.53.37.62236.53.37.6362
150236.53.37.64/26236.53.37.65 to 236.53.37.126236.53.37.12762
151236.53.37.128/26236.53.37.129 to 236.53.37.190236.53.37.19162
152236.53.37.192/26236.53.37.193 to 236.53.37.254236.53.37.25562
153236.53.38.0/26236.53.38.1 to 236.53.38.62236.53.38.6362
154236.53.38.64/26236.53.38.65 to 236.53.38.126236.53.38.12762
155236.53.38.128/26236.53.38.129 to 236.53.38.190236.53.38.19162
156236.53.38.192/26236.53.38.193 to 236.53.38.254236.53.38.25562
157236.53.39.0/26236.53.39.1 to 236.53.39.62236.53.39.6362
158236.53.39.64/26236.53.39.65 to 236.53.39.126236.53.39.12762
159236.53.39.128/26236.53.39.129 to 236.53.39.190236.53.39.19162
160236.53.39.192/26236.53.39.193 to 236.53.39.254236.53.39.25562
161236.53.40.0/26236.53.40.1 to 236.53.40.62236.53.40.6362
162236.53.40.64/26236.53.40.65 to 236.53.40.126236.53.40.12762
163236.53.40.128/26236.53.40.129 to 236.53.40.190236.53.40.19162
164236.53.40.192/26236.53.40.193 to 236.53.40.254236.53.40.25562
165236.53.41.0/26236.53.41.1 to 236.53.41.62236.53.41.6362
166236.53.41.64/26236.53.41.65 to 236.53.41.126236.53.41.12762
167236.53.41.128/26236.53.41.129 to 236.53.41.190236.53.41.19162
168236.53.41.192/26236.53.41.193 to 236.53.41.254236.53.41.25562
169236.53.42.0/26236.53.42.1 to 236.53.42.62236.53.42.6362
170236.53.42.64/26236.53.42.65 to 236.53.42.126236.53.42.12762
171236.53.42.128/26236.53.42.129 to 236.53.42.190236.53.42.19162
172236.53.42.192/26236.53.42.193 to 236.53.42.254236.53.42.25562
173236.53.43.0/26236.53.43.1 to 236.53.43.62236.53.43.6362
174236.53.43.64/26236.53.43.65 to 236.53.43.126236.53.43.12762
175236.53.43.128/26236.53.43.129 to 236.53.43.190236.53.43.19162
176236.53.43.192/26236.53.43.193 to 236.53.43.254236.53.43.25562
177236.53.44.0/26236.53.44.1 to 236.53.44.62236.53.44.6362
178236.53.44.64/26236.53.44.65 to 236.53.44.126236.53.44.12762
179236.53.44.128/26236.53.44.129 to 236.53.44.190236.53.44.19162
180236.53.44.192/26236.53.44.193 to 236.53.44.254236.53.44.25562
181236.53.45.0/26236.53.45.1 to 236.53.45.62236.53.45.6362
182236.53.45.64/26236.53.45.65 to 236.53.45.126236.53.45.12762
183236.53.45.128/26236.53.45.129 to 236.53.45.190236.53.45.19162
184236.53.45.192/26236.53.45.193 to 236.53.45.254236.53.45.25562
185236.53.46.0/26236.53.46.1 to 236.53.46.62236.53.46.6362
186236.53.46.64/26236.53.46.65 to 236.53.46.126236.53.46.12762
187236.53.46.128/26236.53.46.129 to 236.53.46.190236.53.46.19162
188236.53.46.192/26236.53.46.193 to 236.53.46.254236.53.46.25562
189236.53.47.0/26236.53.47.1 to 236.53.47.62236.53.47.6362
190236.53.47.64/26236.53.47.65 to 236.53.47.126236.53.47.12762
191236.53.47.128/26236.53.47.129 to 236.53.47.190236.53.47.19162
192236.53.47.192/26236.53.47.193 to 236.53.47.254236.53.47.25562
193236.53.48.0/26236.53.48.1 to 236.53.48.62236.53.48.6362
194236.53.48.64/26236.53.48.65 to 236.53.48.126236.53.48.12762
195236.53.48.128/26236.53.48.129 to 236.53.48.190236.53.48.19162
196236.53.48.192/26236.53.48.193 to 236.53.48.254236.53.48.25562
197236.53.49.0/26236.53.49.1 to 236.53.49.62236.53.49.6362
198236.53.49.64/26236.53.49.65 to 236.53.49.126236.53.49.12762
199236.53.49.128/26236.53.49.129 to 236.53.49.190236.53.49.19162
200236.53.49.192/26236.53.49.193 to 236.53.49.254236.53.49.25562
201236.53.50.0/26236.53.50.1 to 236.53.50.62236.53.50.6362
202236.53.50.64/26236.53.50.65 to 236.53.50.126236.53.50.12762
203236.53.50.128/26236.53.50.129 to 236.53.50.190236.53.50.19162
204236.53.50.192/26236.53.50.193 to 236.53.50.254236.53.50.25562
205236.53.51.0/26236.53.51.1 to 236.53.51.62236.53.51.6362
206236.53.51.64/26236.53.51.65 to 236.53.51.126236.53.51.12762
207236.53.51.128/26236.53.51.129 to 236.53.51.190236.53.51.19162
208236.53.51.192/26236.53.51.193 to 236.53.51.254236.53.51.25562
209236.53.52.0/26236.53.52.1 to 236.53.52.62236.53.52.6362
210236.53.52.64/26236.53.52.65 to 236.53.52.126236.53.52.12762
211236.53.52.128/26236.53.52.129 to 236.53.52.190236.53.52.19162
212236.53.52.192/26236.53.52.193 to 236.53.52.254236.53.52.25562
213236.53.53.0/26236.53.53.1 to 236.53.53.62236.53.53.6362
214236.53.53.64/26236.53.53.65 to 236.53.53.126236.53.53.12762
215236.53.53.128/26236.53.53.129 to 236.53.53.190236.53.53.19162
216236.53.53.192/26236.53.53.193 to 236.53.53.254236.53.53.25562
217236.53.54.0/26236.53.54.1 to 236.53.54.62236.53.54.6362
218236.53.54.64/26236.53.54.65 to 236.53.54.126236.53.54.12762
219236.53.54.128/26236.53.54.129 to 236.53.54.190236.53.54.19162
220236.53.54.192/26236.53.54.193 to 236.53.54.254236.53.54.25562
221236.53.55.0/26236.53.55.1 to 236.53.55.62236.53.55.6362
222236.53.55.64/26236.53.55.65 to 236.53.55.126236.53.55.12762
223236.53.55.128/26236.53.55.129 to 236.53.55.190236.53.55.19162
224236.53.55.192/26236.53.55.193 to 236.53.55.254236.53.55.25562
225236.53.56.0/26236.53.56.1 to 236.53.56.62236.53.56.6362
226236.53.56.64/26236.53.56.65 to 236.53.56.126236.53.56.12762
227236.53.56.128/26236.53.56.129 to 236.53.56.190236.53.56.19162
228236.53.56.192/26236.53.56.193 to 236.53.56.254236.53.56.25562
229236.53.57.0/26236.53.57.1 to 236.53.57.62236.53.57.6362
230236.53.57.64/26236.53.57.65 to 236.53.57.126236.53.57.12762
231236.53.57.128/26236.53.57.129 to 236.53.57.190236.53.57.19162
232236.53.57.192/26236.53.57.193 to 236.53.57.254236.53.57.25562
233236.53.58.0/26236.53.58.1 to 236.53.58.62236.53.58.6362
234236.53.58.64/26236.53.58.65 to 236.53.58.126236.53.58.12762
235236.53.58.128/26236.53.58.129 to 236.53.58.190236.53.58.19162
236236.53.58.192/26236.53.58.193 to 236.53.58.254236.53.58.25562
237236.53.59.0/26236.53.59.1 to 236.53.59.62236.53.59.6362
238236.53.59.64/26236.53.59.65 to 236.53.59.126236.53.59.12762
239236.53.59.128/26236.53.59.129 to 236.53.59.190236.53.59.19162
240236.53.59.192/26236.53.59.193 to 236.53.59.254236.53.59.25562
241236.53.60.0/26236.53.60.1 to 236.53.60.62236.53.60.6362
242236.53.60.64/26236.53.60.65 to 236.53.60.126236.53.60.12762
243236.53.60.128/26236.53.60.129 to 236.53.60.190236.53.60.19162
244236.53.60.192/26236.53.60.193 to 236.53.60.254236.53.60.25562
245236.53.61.0/26236.53.61.1 to 236.53.61.62236.53.61.6362
246236.53.61.64/26236.53.61.65 to 236.53.61.126236.53.61.12762
247236.53.61.128/26236.53.61.129 to 236.53.61.190236.53.61.19162
248236.53.61.192/26236.53.61.193 to 236.53.61.254236.53.61.25562
249236.53.62.0/26236.53.62.1 to 236.53.62.62236.53.62.6362
250236.53.62.64/26236.53.62.65 to 236.53.62.126236.53.62.12762
251236.53.62.128/26236.53.62.129 to 236.53.62.190236.53.62.19162
252236.53.62.192/26236.53.62.193 to 236.53.62.254236.53.62.25562
253236.53.63.0/26236.53.63.1 to 236.53.63.62236.53.63.6362
254236.53.63.64/26236.53.63.65 to 236.53.63.126236.53.63.12762
255236.53.63.128/26236.53.63.129 to 236.53.63.190236.53.63.19162
256236.53.63.192/26236.53.63.193 to 236.53.63.254236.53.63.25562

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.