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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.

Network186.63.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
186.63.0.0
Broadcast address
186.63.255.255
First usable
186.63.0.1
Last usable
186.63.255.254
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 BA3F0000 · Integer 3124690944 to 3124756479
Reverse DNS zone
63.186.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10111010.00111111..00000000.00000000186.63.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10111010.00111111..00000000.00000000186.63.0.0
Broadcast10111010.00111111..11111111.11111111186.63.255.255
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)

186.63.0.0/16 makes 1,024 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1186.63.0.0/26186.63.0.1 to 186.63.0.62186.63.0.6362
2186.63.0.64/26186.63.0.65 to 186.63.0.126186.63.0.12762
3186.63.0.128/26186.63.0.129 to 186.63.0.190186.63.0.19162
4186.63.0.192/26186.63.0.193 to 186.63.0.254186.63.0.25562
5186.63.1.0/26186.63.1.1 to 186.63.1.62186.63.1.6362
6186.63.1.64/26186.63.1.65 to 186.63.1.126186.63.1.12762
7186.63.1.128/26186.63.1.129 to 186.63.1.190186.63.1.19162
8186.63.1.192/26186.63.1.193 to 186.63.1.254186.63.1.25562
9186.63.2.0/26186.63.2.1 to 186.63.2.62186.63.2.6362
10186.63.2.64/26186.63.2.65 to 186.63.2.126186.63.2.12762
11186.63.2.128/26186.63.2.129 to 186.63.2.190186.63.2.19162
12186.63.2.192/26186.63.2.193 to 186.63.2.254186.63.2.25562
13186.63.3.0/26186.63.3.1 to 186.63.3.62186.63.3.6362
14186.63.3.64/26186.63.3.65 to 186.63.3.126186.63.3.12762
15186.63.3.128/26186.63.3.129 to 186.63.3.190186.63.3.19162
16186.63.3.192/26186.63.3.193 to 186.63.3.254186.63.3.25562
17186.63.4.0/26186.63.4.1 to 186.63.4.62186.63.4.6362
18186.63.4.64/26186.63.4.65 to 186.63.4.126186.63.4.12762
19186.63.4.128/26186.63.4.129 to 186.63.4.190186.63.4.19162
20186.63.4.192/26186.63.4.193 to 186.63.4.254186.63.4.25562
21186.63.5.0/26186.63.5.1 to 186.63.5.62186.63.5.6362
22186.63.5.64/26186.63.5.65 to 186.63.5.126186.63.5.12762
23186.63.5.128/26186.63.5.129 to 186.63.5.190186.63.5.19162
24186.63.5.192/26186.63.5.193 to 186.63.5.254186.63.5.25562
25186.63.6.0/26186.63.6.1 to 186.63.6.62186.63.6.6362
26186.63.6.64/26186.63.6.65 to 186.63.6.126186.63.6.12762
27186.63.6.128/26186.63.6.129 to 186.63.6.190186.63.6.19162
28186.63.6.192/26186.63.6.193 to 186.63.6.254186.63.6.25562
29186.63.7.0/26186.63.7.1 to 186.63.7.62186.63.7.6362
30186.63.7.64/26186.63.7.65 to 186.63.7.126186.63.7.12762
31186.63.7.128/26186.63.7.129 to 186.63.7.190186.63.7.19162
32186.63.7.192/26186.63.7.193 to 186.63.7.254186.63.7.25562
33186.63.8.0/26186.63.8.1 to 186.63.8.62186.63.8.6362
34186.63.8.64/26186.63.8.65 to 186.63.8.126186.63.8.12762
35186.63.8.128/26186.63.8.129 to 186.63.8.190186.63.8.19162
36186.63.8.192/26186.63.8.193 to 186.63.8.254186.63.8.25562
37186.63.9.0/26186.63.9.1 to 186.63.9.62186.63.9.6362
38186.63.9.64/26186.63.9.65 to 186.63.9.126186.63.9.12762
39186.63.9.128/26186.63.9.129 to 186.63.9.190186.63.9.19162
40186.63.9.192/26186.63.9.193 to 186.63.9.254186.63.9.25562
41186.63.10.0/26186.63.10.1 to 186.63.10.62186.63.10.6362
42186.63.10.64/26186.63.10.65 to 186.63.10.126186.63.10.12762
43186.63.10.128/26186.63.10.129 to 186.63.10.190186.63.10.19162
44186.63.10.192/26186.63.10.193 to 186.63.10.254186.63.10.25562
45186.63.11.0/26186.63.11.1 to 186.63.11.62186.63.11.6362
46186.63.11.64/26186.63.11.65 to 186.63.11.126186.63.11.12762
47186.63.11.128/26186.63.11.129 to 186.63.11.190186.63.11.19162
48186.63.11.192/26186.63.11.193 to 186.63.11.254186.63.11.25562
49186.63.12.0/26186.63.12.1 to 186.63.12.62186.63.12.6362
50186.63.12.64/26186.63.12.65 to 186.63.12.126186.63.12.12762
51186.63.12.128/26186.63.12.129 to 186.63.12.190186.63.12.19162
52186.63.12.192/26186.63.12.193 to 186.63.12.254186.63.12.25562
53186.63.13.0/26186.63.13.1 to 186.63.13.62186.63.13.6362
54186.63.13.64/26186.63.13.65 to 186.63.13.126186.63.13.12762
55186.63.13.128/26186.63.13.129 to 186.63.13.190186.63.13.19162
56186.63.13.192/26186.63.13.193 to 186.63.13.254186.63.13.25562
57186.63.14.0/26186.63.14.1 to 186.63.14.62186.63.14.6362
58186.63.14.64/26186.63.14.65 to 186.63.14.126186.63.14.12762
59186.63.14.128/26186.63.14.129 to 186.63.14.190186.63.14.19162
60186.63.14.192/26186.63.14.193 to 186.63.14.254186.63.14.25562
61186.63.15.0/26186.63.15.1 to 186.63.15.62186.63.15.6362
62186.63.15.64/26186.63.15.65 to 186.63.15.126186.63.15.12762
63186.63.15.128/26186.63.15.129 to 186.63.15.190186.63.15.19162
64186.63.15.192/26186.63.15.193 to 186.63.15.254186.63.15.25562
65186.63.16.0/26186.63.16.1 to 186.63.16.62186.63.16.6362
66186.63.16.64/26186.63.16.65 to 186.63.16.126186.63.16.12762
67186.63.16.128/26186.63.16.129 to 186.63.16.190186.63.16.19162
68186.63.16.192/26186.63.16.193 to 186.63.16.254186.63.16.25562
69186.63.17.0/26186.63.17.1 to 186.63.17.62186.63.17.6362
70186.63.17.64/26186.63.17.65 to 186.63.17.126186.63.17.12762
71186.63.17.128/26186.63.17.129 to 186.63.17.190186.63.17.19162
72186.63.17.192/26186.63.17.193 to 186.63.17.254186.63.17.25562
73186.63.18.0/26186.63.18.1 to 186.63.18.62186.63.18.6362
74186.63.18.64/26186.63.18.65 to 186.63.18.126186.63.18.12762
75186.63.18.128/26186.63.18.129 to 186.63.18.190186.63.18.19162
76186.63.18.192/26186.63.18.193 to 186.63.18.254186.63.18.25562
77186.63.19.0/26186.63.19.1 to 186.63.19.62186.63.19.6362
78186.63.19.64/26186.63.19.65 to 186.63.19.126186.63.19.12762
79186.63.19.128/26186.63.19.129 to 186.63.19.190186.63.19.19162
80186.63.19.192/26186.63.19.193 to 186.63.19.254186.63.19.25562
81186.63.20.0/26186.63.20.1 to 186.63.20.62186.63.20.6362
82186.63.20.64/26186.63.20.65 to 186.63.20.126186.63.20.12762
83186.63.20.128/26186.63.20.129 to 186.63.20.190186.63.20.19162
84186.63.20.192/26186.63.20.193 to 186.63.20.254186.63.20.25562
85186.63.21.0/26186.63.21.1 to 186.63.21.62186.63.21.6362
86186.63.21.64/26186.63.21.65 to 186.63.21.126186.63.21.12762
87186.63.21.128/26186.63.21.129 to 186.63.21.190186.63.21.19162
88186.63.21.192/26186.63.21.193 to 186.63.21.254186.63.21.25562
89186.63.22.0/26186.63.22.1 to 186.63.22.62186.63.22.6362
90186.63.22.64/26186.63.22.65 to 186.63.22.126186.63.22.12762
91186.63.22.128/26186.63.22.129 to 186.63.22.190186.63.22.19162
92186.63.22.192/26186.63.22.193 to 186.63.22.254186.63.22.25562
93186.63.23.0/26186.63.23.1 to 186.63.23.62186.63.23.6362
94186.63.23.64/26186.63.23.65 to 186.63.23.126186.63.23.12762
95186.63.23.128/26186.63.23.129 to 186.63.23.190186.63.23.19162
96186.63.23.192/26186.63.23.193 to 186.63.23.254186.63.23.25562
97186.63.24.0/26186.63.24.1 to 186.63.24.62186.63.24.6362
98186.63.24.64/26186.63.24.65 to 186.63.24.126186.63.24.12762
99186.63.24.128/26186.63.24.129 to 186.63.24.190186.63.24.19162
100186.63.24.192/26186.63.24.193 to 186.63.24.254186.63.24.25562
101186.63.25.0/26186.63.25.1 to 186.63.25.62186.63.25.6362
102186.63.25.64/26186.63.25.65 to 186.63.25.126186.63.25.12762
103186.63.25.128/26186.63.25.129 to 186.63.25.190186.63.25.19162
104186.63.25.192/26186.63.25.193 to 186.63.25.254186.63.25.25562
105186.63.26.0/26186.63.26.1 to 186.63.26.62186.63.26.6362
106186.63.26.64/26186.63.26.65 to 186.63.26.126186.63.26.12762
107186.63.26.128/26186.63.26.129 to 186.63.26.190186.63.26.19162
108186.63.26.192/26186.63.26.193 to 186.63.26.254186.63.26.25562
109186.63.27.0/26186.63.27.1 to 186.63.27.62186.63.27.6362
110186.63.27.64/26186.63.27.65 to 186.63.27.126186.63.27.12762
111186.63.27.128/26186.63.27.129 to 186.63.27.190186.63.27.19162
112186.63.27.192/26186.63.27.193 to 186.63.27.254186.63.27.25562
113186.63.28.0/26186.63.28.1 to 186.63.28.62186.63.28.6362
114186.63.28.64/26186.63.28.65 to 186.63.28.126186.63.28.12762
115186.63.28.128/26186.63.28.129 to 186.63.28.190186.63.28.19162
116186.63.28.192/26186.63.28.193 to 186.63.28.254186.63.28.25562
117186.63.29.0/26186.63.29.1 to 186.63.29.62186.63.29.6362
118186.63.29.64/26186.63.29.65 to 186.63.29.126186.63.29.12762
119186.63.29.128/26186.63.29.129 to 186.63.29.190186.63.29.19162
120186.63.29.192/26186.63.29.193 to 186.63.29.254186.63.29.25562
121186.63.30.0/26186.63.30.1 to 186.63.30.62186.63.30.6362
122186.63.30.64/26186.63.30.65 to 186.63.30.126186.63.30.12762
123186.63.30.128/26186.63.30.129 to 186.63.30.190186.63.30.19162
124186.63.30.192/26186.63.30.193 to 186.63.30.254186.63.30.25562
125186.63.31.0/26186.63.31.1 to 186.63.31.62186.63.31.6362
126186.63.31.64/26186.63.31.65 to 186.63.31.126186.63.31.12762
127186.63.31.128/26186.63.31.129 to 186.63.31.190186.63.31.19162
128186.63.31.192/26186.63.31.193 to 186.63.31.254186.63.31.25562
129186.63.32.0/26186.63.32.1 to 186.63.32.62186.63.32.6362
130186.63.32.64/26186.63.32.65 to 186.63.32.126186.63.32.12762
131186.63.32.128/26186.63.32.129 to 186.63.32.190186.63.32.19162
132186.63.32.192/26186.63.32.193 to 186.63.32.254186.63.32.25562
133186.63.33.0/26186.63.33.1 to 186.63.33.62186.63.33.6362
134186.63.33.64/26186.63.33.65 to 186.63.33.126186.63.33.12762
135186.63.33.128/26186.63.33.129 to 186.63.33.190186.63.33.19162
136186.63.33.192/26186.63.33.193 to 186.63.33.254186.63.33.25562
137186.63.34.0/26186.63.34.1 to 186.63.34.62186.63.34.6362
138186.63.34.64/26186.63.34.65 to 186.63.34.126186.63.34.12762
139186.63.34.128/26186.63.34.129 to 186.63.34.190186.63.34.19162
140186.63.34.192/26186.63.34.193 to 186.63.34.254186.63.34.25562
141186.63.35.0/26186.63.35.1 to 186.63.35.62186.63.35.6362
142186.63.35.64/26186.63.35.65 to 186.63.35.126186.63.35.12762
143186.63.35.128/26186.63.35.129 to 186.63.35.190186.63.35.19162
144186.63.35.192/26186.63.35.193 to 186.63.35.254186.63.35.25562
145186.63.36.0/26186.63.36.1 to 186.63.36.62186.63.36.6362
146186.63.36.64/26186.63.36.65 to 186.63.36.126186.63.36.12762
147186.63.36.128/26186.63.36.129 to 186.63.36.190186.63.36.19162
148186.63.36.192/26186.63.36.193 to 186.63.36.254186.63.36.25562
149186.63.37.0/26186.63.37.1 to 186.63.37.62186.63.37.6362
150186.63.37.64/26186.63.37.65 to 186.63.37.126186.63.37.12762
151186.63.37.128/26186.63.37.129 to 186.63.37.190186.63.37.19162
152186.63.37.192/26186.63.37.193 to 186.63.37.254186.63.37.25562
153186.63.38.0/26186.63.38.1 to 186.63.38.62186.63.38.6362
154186.63.38.64/26186.63.38.65 to 186.63.38.126186.63.38.12762
155186.63.38.128/26186.63.38.129 to 186.63.38.190186.63.38.19162
156186.63.38.192/26186.63.38.193 to 186.63.38.254186.63.38.25562
157186.63.39.0/26186.63.39.1 to 186.63.39.62186.63.39.6362
158186.63.39.64/26186.63.39.65 to 186.63.39.126186.63.39.12762
159186.63.39.128/26186.63.39.129 to 186.63.39.190186.63.39.19162
160186.63.39.192/26186.63.39.193 to 186.63.39.254186.63.39.25562
161186.63.40.0/26186.63.40.1 to 186.63.40.62186.63.40.6362
162186.63.40.64/26186.63.40.65 to 186.63.40.126186.63.40.12762
163186.63.40.128/26186.63.40.129 to 186.63.40.190186.63.40.19162
164186.63.40.192/26186.63.40.193 to 186.63.40.254186.63.40.25562
165186.63.41.0/26186.63.41.1 to 186.63.41.62186.63.41.6362
166186.63.41.64/26186.63.41.65 to 186.63.41.126186.63.41.12762
167186.63.41.128/26186.63.41.129 to 186.63.41.190186.63.41.19162
168186.63.41.192/26186.63.41.193 to 186.63.41.254186.63.41.25562
169186.63.42.0/26186.63.42.1 to 186.63.42.62186.63.42.6362
170186.63.42.64/26186.63.42.65 to 186.63.42.126186.63.42.12762
171186.63.42.128/26186.63.42.129 to 186.63.42.190186.63.42.19162
172186.63.42.192/26186.63.42.193 to 186.63.42.254186.63.42.25562
173186.63.43.0/26186.63.43.1 to 186.63.43.62186.63.43.6362
174186.63.43.64/26186.63.43.65 to 186.63.43.126186.63.43.12762
175186.63.43.128/26186.63.43.129 to 186.63.43.190186.63.43.19162
176186.63.43.192/26186.63.43.193 to 186.63.43.254186.63.43.25562
177186.63.44.0/26186.63.44.1 to 186.63.44.62186.63.44.6362
178186.63.44.64/26186.63.44.65 to 186.63.44.126186.63.44.12762
179186.63.44.128/26186.63.44.129 to 186.63.44.190186.63.44.19162
180186.63.44.192/26186.63.44.193 to 186.63.44.254186.63.44.25562
181186.63.45.0/26186.63.45.1 to 186.63.45.62186.63.45.6362
182186.63.45.64/26186.63.45.65 to 186.63.45.126186.63.45.12762
183186.63.45.128/26186.63.45.129 to 186.63.45.190186.63.45.19162
184186.63.45.192/26186.63.45.193 to 186.63.45.254186.63.45.25562
185186.63.46.0/26186.63.46.1 to 186.63.46.62186.63.46.6362
186186.63.46.64/26186.63.46.65 to 186.63.46.126186.63.46.12762
187186.63.46.128/26186.63.46.129 to 186.63.46.190186.63.46.19162
188186.63.46.192/26186.63.46.193 to 186.63.46.254186.63.46.25562
189186.63.47.0/26186.63.47.1 to 186.63.47.62186.63.47.6362
190186.63.47.64/26186.63.47.65 to 186.63.47.126186.63.47.12762
191186.63.47.128/26186.63.47.129 to 186.63.47.190186.63.47.19162
192186.63.47.192/26186.63.47.193 to 186.63.47.254186.63.47.25562
193186.63.48.0/26186.63.48.1 to 186.63.48.62186.63.48.6362
194186.63.48.64/26186.63.48.65 to 186.63.48.126186.63.48.12762
195186.63.48.128/26186.63.48.129 to 186.63.48.190186.63.48.19162
196186.63.48.192/26186.63.48.193 to 186.63.48.254186.63.48.25562
197186.63.49.0/26186.63.49.1 to 186.63.49.62186.63.49.6362
198186.63.49.64/26186.63.49.65 to 186.63.49.126186.63.49.12762
199186.63.49.128/26186.63.49.129 to 186.63.49.190186.63.49.19162
200186.63.49.192/26186.63.49.193 to 186.63.49.254186.63.49.25562
201186.63.50.0/26186.63.50.1 to 186.63.50.62186.63.50.6362
202186.63.50.64/26186.63.50.65 to 186.63.50.126186.63.50.12762
203186.63.50.128/26186.63.50.129 to 186.63.50.190186.63.50.19162
204186.63.50.192/26186.63.50.193 to 186.63.50.254186.63.50.25562
205186.63.51.0/26186.63.51.1 to 186.63.51.62186.63.51.6362
206186.63.51.64/26186.63.51.65 to 186.63.51.126186.63.51.12762
207186.63.51.128/26186.63.51.129 to 186.63.51.190186.63.51.19162
208186.63.51.192/26186.63.51.193 to 186.63.51.254186.63.51.25562
209186.63.52.0/26186.63.52.1 to 186.63.52.62186.63.52.6362
210186.63.52.64/26186.63.52.65 to 186.63.52.126186.63.52.12762
211186.63.52.128/26186.63.52.129 to 186.63.52.190186.63.52.19162
212186.63.52.192/26186.63.52.193 to 186.63.52.254186.63.52.25562
213186.63.53.0/26186.63.53.1 to 186.63.53.62186.63.53.6362
214186.63.53.64/26186.63.53.65 to 186.63.53.126186.63.53.12762
215186.63.53.128/26186.63.53.129 to 186.63.53.190186.63.53.19162
216186.63.53.192/26186.63.53.193 to 186.63.53.254186.63.53.25562
217186.63.54.0/26186.63.54.1 to 186.63.54.62186.63.54.6362
218186.63.54.64/26186.63.54.65 to 186.63.54.126186.63.54.12762
219186.63.54.128/26186.63.54.129 to 186.63.54.190186.63.54.19162
220186.63.54.192/26186.63.54.193 to 186.63.54.254186.63.54.25562
221186.63.55.0/26186.63.55.1 to 186.63.55.62186.63.55.6362
222186.63.55.64/26186.63.55.65 to 186.63.55.126186.63.55.12762
223186.63.55.128/26186.63.55.129 to 186.63.55.190186.63.55.19162
224186.63.55.192/26186.63.55.193 to 186.63.55.254186.63.55.25562
225186.63.56.0/26186.63.56.1 to 186.63.56.62186.63.56.6362
226186.63.56.64/26186.63.56.65 to 186.63.56.126186.63.56.12762
227186.63.56.128/26186.63.56.129 to 186.63.56.190186.63.56.19162
228186.63.56.192/26186.63.56.193 to 186.63.56.254186.63.56.25562
229186.63.57.0/26186.63.57.1 to 186.63.57.62186.63.57.6362
230186.63.57.64/26186.63.57.65 to 186.63.57.126186.63.57.12762
231186.63.57.128/26186.63.57.129 to 186.63.57.190186.63.57.19162
232186.63.57.192/26186.63.57.193 to 186.63.57.254186.63.57.25562
233186.63.58.0/26186.63.58.1 to 186.63.58.62186.63.58.6362
234186.63.58.64/26186.63.58.65 to 186.63.58.126186.63.58.12762
235186.63.58.128/26186.63.58.129 to 186.63.58.190186.63.58.19162
236186.63.58.192/26186.63.58.193 to 186.63.58.254186.63.58.25562
237186.63.59.0/26186.63.59.1 to 186.63.59.62186.63.59.6362
238186.63.59.64/26186.63.59.65 to 186.63.59.126186.63.59.12762
239186.63.59.128/26186.63.59.129 to 186.63.59.190186.63.59.19162
240186.63.59.192/26186.63.59.193 to 186.63.59.254186.63.59.25562
241186.63.60.0/26186.63.60.1 to 186.63.60.62186.63.60.6362
242186.63.60.64/26186.63.60.65 to 186.63.60.126186.63.60.12762
243186.63.60.128/26186.63.60.129 to 186.63.60.190186.63.60.19162
244186.63.60.192/26186.63.60.193 to 186.63.60.254186.63.60.25562
245186.63.61.0/26186.63.61.1 to 186.63.61.62186.63.61.6362
246186.63.61.64/26186.63.61.65 to 186.63.61.126186.63.61.12762
247186.63.61.128/26186.63.61.129 to 186.63.61.190186.63.61.19162
248186.63.61.192/26186.63.61.193 to 186.63.61.254186.63.61.25562
249186.63.62.0/26186.63.62.1 to 186.63.62.62186.63.62.6362
250186.63.62.64/26186.63.62.65 to 186.63.62.126186.63.62.12762
251186.63.62.128/26186.63.62.129 to 186.63.62.190186.63.62.19162
252186.63.62.192/26186.63.62.193 to 186.63.62.254186.63.62.25562
253186.63.63.0/26186.63.63.1 to 186.63.63.62186.63.63.6362
254186.63.63.64/26186.63.63.65 to 186.63.63.126186.63.63.12762
255186.63.63.128/26186.63.63.129 to 186.63.63.190186.63.63.19162
256186.63.63.192/26186.63.63.193 to 186.63.63.254186.63.63.25562

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.