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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/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)

186.63.0.0/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1186.63.0.0/28186.63.0.1 to 186.63.0.14186.63.0.1514
2186.63.0.16/28186.63.0.17 to 186.63.0.30186.63.0.3114
3186.63.0.32/28186.63.0.33 to 186.63.0.46186.63.0.4714
4186.63.0.48/28186.63.0.49 to 186.63.0.62186.63.0.6314
5186.63.0.64/28186.63.0.65 to 186.63.0.78186.63.0.7914
6186.63.0.80/28186.63.0.81 to 186.63.0.94186.63.0.9514
7186.63.0.96/28186.63.0.97 to 186.63.0.110186.63.0.11114
8186.63.0.112/28186.63.0.113 to 186.63.0.126186.63.0.12714
9186.63.0.128/28186.63.0.129 to 186.63.0.142186.63.0.14314
10186.63.0.144/28186.63.0.145 to 186.63.0.158186.63.0.15914
11186.63.0.160/28186.63.0.161 to 186.63.0.174186.63.0.17514
12186.63.0.176/28186.63.0.177 to 186.63.0.190186.63.0.19114
13186.63.0.192/28186.63.0.193 to 186.63.0.206186.63.0.20714
14186.63.0.208/28186.63.0.209 to 186.63.0.222186.63.0.22314
15186.63.0.224/28186.63.0.225 to 186.63.0.238186.63.0.23914
16186.63.0.240/28186.63.0.241 to 186.63.0.254186.63.0.25514
17186.63.1.0/28186.63.1.1 to 186.63.1.14186.63.1.1514
18186.63.1.16/28186.63.1.17 to 186.63.1.30186.63.1.3114
19186.63.1.32/28186.63.1.33 to 186.63.1.46186.63.1.4714
20186.63.1.48/28186.63.1.49 to 186.63.1.62186.63.1.6314
21186.63.1.64/28186.63.1.65 to 186.63.1.78186.63.1.7914
22186.63.1.80/28186.63.1.81 to 186.63.1.94186.63.1.9514
23186.63.1.96/28186.63.1.97 to 186.63.1.110186.63.1.11114
24186.63.1.112/28186.63.1.113 to 186.63.1.126186.63.1.12714
25186.63.1.128/28186.63.1.129 to 186.63.1.142186.63.1.14314
26186.63.1.144/28186.63.1.145 to 186.63.1.158186.63.1.15914
27186.63.1.160/28186.63.1.161 to 186.63.1.174186.63.1.17514
28186.63.1.176/28186.63.1.177 to 186.63.1.190186.63.1.19114
29186.63.1.192/28186.63.1.193 to 186.63.1.206186.63.1.20714
30186.63.1.208/28186.63.1.209 to 186.63.1.222186.63.1.22314
31186.63.1.224/28186.63.1.225 to 186.63.1.238186.63.1.23914
32186.63.1.240/28186.63.1.241 to 186.63.1.254186.63.1.25514
33186.63.2.0/28186.63.2.1 to 186.63.2.14186.63.2.1514
34186.63.2.16/28186.63.2.17 to 186.63.2.30186.63.2.3114
35186.63.2.32/28186.63.2.33 to 186.63.2.46186.63.2.4714
36186.63.2.48/28186.63.2.49 to 186.63.2.62186.63.2.6314
37186.63.2.64/28186.63.2.65 to 186.63.2.78186.63.2.7914
38186.63.2.80/28186.63.2.81 to 186.63.2.94186.63.2.9514
39186.63.2.96/28186.63.2.97 to 186.63.2.110186.63.2.11114
40186.63.2.112/28186.63.2.113 to 186.63.2.126186.63.2.12714
41186.63.2.128/28186.63.2.129 to 186.63.2.142186.63.2.14314
42186.63.2.144/28186.63.2.145 to 186.63.2.158186.63.2.15914
43186.63.2.160/28186.63.2.161 to 186.63.2.174186.63.2.17514
44186.63.2.176/28186.63.2.177 to 186.63.2.190186.63.2.19114
45186.63.2.192/28186.63.2.193 to 186.63.2.206186.63.2.20714
46186.63.2.208/28186.63.2.209 to 186.63.2.222186.63.2.22314
47186.63.2.224/28186.63.2.225 to 186.63.2.238186.63.2.23914
48186.63.2.240/28186.63.2.241 to 186.63.2.254186.63.2.25514
49186.63.3.0/28186.63.3.1 to 186.63.3.14186.63.3.1514
50186.63.3.16/28186.63.3.17 to 186.63.3.30186.63.3.3114
51186.63.3.32/28186.63.3.33 to 186.63.3.46186.63.3.4714
52186.63.3.48/28186.63.3.49 to 186.63.3.62186.63.3.6314
53186.63.3.64/28186.63.3.65 to 186.63.3.78186.63.3.7914
54186.63.3.80/28186.63.3.81 to 186.63.3.94186.63.3.9514
55186.63.3.96/28186.63.3.97 to 186.63.3.110186.63.3.11114
56186.63.3.112/28186.63.3.113 to 186.63.3.126186.63.3.12714
57186.63.3.128/28186.63.3.129 to 186.63.3.142186.63.3.14314
58186.63.3.144/28186.63.3.145 to 186.63.3.158186.63.3.15914
59186.63.3.160/28186.63.3.161 to 186.63.3.174186.63.3.17514
60186.63.3.176/28186.63.3.177 to 186.63.3.190186.63.3.19114
61186.63.3.192/28186.63.3.193 to 186.63.3.206186.63.3.20714
62186.63.3.208/28186.63.3.209 to 186.63.3.222186.63.3.22314
63186.63.3.224/28186.63.3.225 to 186.63.3.238186.63.3.23914
64186.63.3.240/28186.63.3.241 to 186.63.3.254186.63.3.25514
65186.63.4.0/28186.63.4.1 to 186.63.4.14186.63.4.1514
66186.63.4.16/28186.63.4.17 to 186.63.4.30186.63.4.3114
67186.63.4.32/28186.63.4.33 to 186.63.4.46186.63.4.4714
68186.63.4.48/28186.63.4.49 to 186.63.4.62186.63.4.6314
69186.63.4.64/28186.63.4.65 to 186.63.4.78186.63.4.7914
70186.63.4.80/28186.63.4.81 to 186.63.4.94186.63.4.9514
71186.63.4.96/28186.63.4.97 to 186.63.4.110186.63.4.11114
72186.63.4.112/28186.63.4.113 to 186.63.4.126186.63.4.12714
73186.63.4.128/28186.63.4.129 to 186.63.4.142186.63.4.14314
74186.63.4.144/28186.63.4.145 to 186.63.4.158186.63.4.15914
75186.63.4.160/28186.63.4.161 to 186.63.4.174186.63.4.17514
76186.63.4.176/28186.63.4.177 to 186.63.4.190186.63.4.19114
77186.63.4.192/28186.63.4.193 to 186.63.4.206186.63.4.20714
78186.63.4.208/28186.63.4.209 to 186.63.4.222186.63.4.22314
79186.63.4.224/28186.63.4.225 to 186.63.4.238186.63.4.23914
80186.63.4.240/28186.63.4.241 to 186.63.4.254186.63.4.25514
81186.63.5.0/28186.63.5.1 to 186.63.5.14186.63.5.1514
82186.63.5.16/28186.63.5.17 to 186.63.5.30186.63.5.3114
83186.63.5.32/28186.63.5.33 to 186.63.5.46186.63.5.4714
84186.63.5.48/28186.63.5.49 to 186.63.5.62186.63.5.6314
85186.63.5.64/28186.63.5.65 to 186.63.5.78186.63.5.7914
86186.63.5.80/28186.63.5.81 to 186.63.5.94186.63.5.9514
87186.63.5.96/28186.63.5.97 to 186.63.5.110186.63.5.11114
88186.63.5.112/28186.63.5.113 to 186.63.5.126186.63.5.12714
89186.63.5.128/28186.63.5.129 to 186.63.5.142186.63.5.14314
90186.63.5.144/28186.63.5.145 to 186.63.5.158186.63.5.15914
91186.63.5.160/28186.63.5.161 to 186.63.5.174186.63.5.17514
92186.63.5.176/28186.63.5.177 to 186.63.5.190186.63.5.19114
93186.63.5.192/28186.63.5.193 to 186.63.5.206186.63.5.20714
94186.63.5.208/28186.63.5.209 to 186.63.5.222186.63.5.22314
95186.63.5.224/28186.63.5.225 to 186.63.5.238186.63.5.23914
96186.63.5.240/28186.63.5.241 to 186.63.5.254186.63.5.25514
97186.63.6.0/28186.63.6.1 to 186.63.6.14186.63.6.1514
98186.63.6.16/28186.63.6.17 to 186.63.6.30186.63.6.3114
99186.63.6.32/28186.63.6.33 to 186.63.6.46186.63.6.4714
100186.63.6.48/28186.63.6.49 to 186.63.6.62186.63.6.6314
101186.63.6.64/28186.63.6.65 to 186.63.6.78186.63.6.7914
102186.63.6.80/28186.63.6.81 to 186.63.6.94186.63.6.9514
103186.63.6.96/28186.63.6.97 to 186.63.6.110186.63.6.11114
104186.63.6.112/28186.63.6.113 to 186.63.6.126186.63.6.12714
105186.63.6.128/28186.63.6.129 to 186.63.6.142186.63.6.14314
106186.63.6.144/28186.63.6.145 to 186.63.6.158186.63.6.15914
107186.63.6.160/28186.63.6.161 to 186.63.6.174186.63.6.17514
108186.63.6.176/28186.63.6.177 to 186.63.6.190186.63.6.19114
109186.63.6.192/28186.63.6.193 to 186.63.6.206186.63.6.20714
110186.63.6.208/28186.63.6.209 to 186.63.6.222186.63.6.22314
111186.63.6.224/28186.63.6.225 to 186.63.6.238186.63.6.23914
112186.63.6.240/28186.63.6.241 to 186.63.6.254186.63.6.25514
113186.63.7.0/28186.63.7.1 to 186.63.7.14186.63.7.1514
114186.63.7.16/28186.63.7.17 to 186.63.7.30186.63.7.3114
115186.63.7.32/28186.63.7.33 to 186.63.7.46186.63.7.4714
116186.63.7.48/28186.63.7.49 to 186.63.7.62186.63.7.6314
117186.63.7.64/28186.63.7.65 to 186.63.7.78186.63.7.7914
118186.63.7.80/28186.63.7.81 to 186.63.7.94186.63.7.9514
119186.63.7.96/28186.63.7.97 to 186.63.7.110186.63.7.11114
120186.63.7.112/28186.63.7.113 to 186.63.7.126186.63.7.12714
121186.63.7.128/28186.63.7.129 to 186.63.7.142186.63.7.14314
122186.63.7.144/28186.63.7.145 to 186.63.7.158186.63.7.15914
123186.63.7.160/28186.63.7.161 to 186.63.7.174186.63.7.17514
124186.63.7.176/28186.63.7.177 to 186.63.7.190186.63.7.19114
125186.63.7.192/28186.63.7.193 to 186.63.7.206186.63.7.20714
126186.63.7.208/28186.63.7.209 to 186.63.7.222186.63.7.22314
127186.63.7.224/28186.63.7.225 to 186.63.7.238186.63.7.23914
128186.63.7.240/28186.63.7.241 to 186.63.7.254186.63.7.25514
129186.63.8.0/28186.63.8.1 to 186.63.8.14186.63.8.1514
130186.63.8.16/28186.63.8.17 to 186.63.8.30186.63.8.3114
131186.63.8.32/28186.63.8.33 to 186.63.8.46186.63.8.4714
132186.63.8.48/28186.63.8.49 to 186.63.8.62186.63.8.6314
133186.63.8.64/28186.63.8.65 to 186.63.8.78186.63.8.7914
134186.63.8.80/28186.63.8.81 to 186.63.8.94186.63.8.9514
135186.63.8.96/28186.63.8.97 to 186.63.8.110186.63.8.11114
136186.63.8.112/28186.63.8.113 to 186.63.8.126186.63.8.12714
137186.63.8.128/28186.63.8.129 to 186.63.8.142186.63.8.14314
138186.63.8.144/28186.63.8.145 to 186.63.8.158186.63.8.15914
139186.63.8.160/28186.63.8.161 to 186.63.8.174186.63.8.17514
140186.63.8.176/28186.63.8.177 to 186.63.8.190186.63.8.19114
141186.63.8.192/28186.63.8.193 to 186.63.8.206186.63.8.20714
142186.63.8.208/28186.63.8.209 to 186.63.8.222186.63.8.22314
143186.63.8.224/28186.63.8.225 to 186.63.8.238186.63.8.23914
144186.63.8.240/28186.63.8.241 to 186.63.8.254186.63.8.25514
145186.63.9.0/28186.63.9.1 to 186.63.9.14186.63.9.1514
146186.63.9.16/28186.63.9.17 to 186.63.9.30186.63.9.3114
147186.63.9.32/28186.63.9.33 to 186.63.9.46186.63.9.4714
148186.63.9.48/28186.63.9.49 to 186.63.9.62186.63.9.6314
149186.63.9.64/28186.63.9.65 to 186.63.9.78186.63.9.7914
150186.63.9.80/28186.63.9.81 to 186.63.9.94186.63.9.9514
151186.63.9.96/28186.63.9.97 to 186.63.9.110186.63.9.11114
152186.63.9.112/28186.63.9.113 to 186.63.9.126186.63.9.12714
153186.63.9.128/28186.63.9.129 to 186.63.9.142186.63.9.14314
154186.63.9.144/28186.63.9.145 to 186.63.9.158186.63.9.15914
155186.63.9.160/28186.63.9.161 to 186.63.9.174186.63.9.17514
156186.63.9.176/28186.63.9.177 to 186.63.9.190186.63.9.19114
157186.63.9.192/28186.63.9.193 to 186.63.9.206186.63.9.20714
158186.63.9.208/28186.63.9.209 to 186.63.9.222186.63.9.22314
159186.63.9.224/28186.63.9.225 to 186.63.9.238186.63.9.23914
160186.63.9.240/28186.63.9.241 to 186.63.9.254186.63.9.25514
161186.63.10.0/28186.63.10.1 to 186.63.10.14186.63.10.1514
162186.63.10.16/28186.63.10.17 to 186.63.10.30186.63.10.3114
163186.63.10.32/28186.63.10.33 to 186.63.10.46186.63.10.4714
164186.63.10.48/28186.63.10.49 to 186.63.10.62186.63.10.6314
165186.63.10.64/28186.63.10.65 to 186.63.10.78186.63.10.7914
166186.63.10.80/28186.63.10.81 to 186.63.10.94186.63.10.9514
167186.63.10.96/28186.63.10.97 to 186.63.10.110186.63.10.11114
168186.63.10.112/28186.63.10.113 to 186.63.10.126186.63.10.12714
169186.63.10.128/28186.63.10.129 to 186.63.10.142186.63.10.14314
170186.63.10.144/28186.63.10.145 to 186.63.10.158186.63.10.15914
171186.63.10.160/28186.63.10.161 to 186.63.10.174186.63.10.17514
172186.63.10.176/28186.63.10.177 to 186.63.10.190186.63.10.19114
173186.63.10.192/28186.63.10.193 to 186.63.10.206186.63.10.20714
174186.63.10.208/28186.63.10.209 to 186.63.10.222186.63.10.22314
175186.63.10.224/28186.63.10.225 to 186.63.10.238186.63.10.23914
176186.63.10.240/28186.63.10.241 to 186.63.10.254186.63.10.25514
177186.63.11.0/28186.63.11.1 to 186.63.11.14186.63.11.1514
178186.63.11.16/28186.63.11.17 to 186.63.11.30186.63.11.3114
179186.63.11.32/28186.63.11.33 to 186.63.11.46186.63.11.4714
180186.63.11.48/28186.63.11.49 to 186.63.11.62186.63.11.6314
181186.63.11.64/28186.63.11.65 to 186.63.11.78186.63.11.7914
182186.63.11.80/28186.63.11.81 to 186.63.11.94186.63.11.9514
183186.63.11.96/28186.63.11.97 to 186.63.11.110186.63.11.11114
184186.63.11.112/28186.63.11.113 to 186.63.11.126186.63.11.12714
185186.63.11.128/28186.63.11.129 to 186.63.11.142186.63.11.14314
186186.63.11.144/28186.63.11.145 to 186.63.11.158186.63.11.15914
187186.63.11.160/28186.63.11.161 to 186.63.11.174186.63.11.17514
188186.63.11.176/28186.63.11.177 to 186.63.11.190186.63.11.19114
189186.63.11.192/28186.63.11.193 to 186.63.11.206186.63.11.20714
190186.63.11.208/28186.63.11.209 to 186.63.11.222186.63.11.22314
191186.63.11.224/28186.63.11.225 to 186.63.11.238186.63.11.23914
192186.63.11.240/28186.63.11.241 to 186.63.11.254186.63.11.25514
193186.63.12.0/28186.63.12.1 to 186.63.12.14186.63.12.1514
194186.63.12.16/28186.63.12.17 to 186.63.12.30186.63.12.3114
195186.63.12.32/28186.63.12.33 to 186.63.12.46186.63.12.4714
196186.63.12.48/28186.63.12.49 to 186.63.12.62186.63.12.6314
197186.63.12.64/28186.63.12.65 to 186.63.12.78186.63.12.7914
198186.63.12.80/28186.63.12.81 to 186.63.12.94186.63.12.9514
199186.63.12.96/28186.63.12.97 to 186.63.12.110186.63.12.11114
200186.63.12.112/28186.63.12.113 to 186.63.12.126186.63.12.12714
201186.63.12.128/28186.63.12.129 to 186.63.12.142186.63.12.14314
202186.63.12.144/28186.63.12.145 to 186.63.12.158186.63.12.15914
203186.63.12.160/28186.63.12.161 to 186.63.12.174186.63.12.17514
204186.63.12.176/28186.63.12.177 to 186.63.12.190186.63.12.19114
205186.63.12.192/28186.63.12.193 to 186.63.12.206186.63.12.20714
206186.63.12.208/28186.63.12.209 to 186.63.12.222186.63.12.22314
207186.63.12.224/28186.63.12.225 to 186.63.12.238186.63.12.23914
208186.63.12.240/28186.63.12.241 to 186.63.12.254186.63.12.25514
209186.63.13.0/28186.63.13.1 to 186.63.13.14186.63.13.1514
210186.63.13.16/28186.63.13.17 to 186.63.13.30186.63.13.3114
211186.63.13.32/28186.63.13.33 to 186.63.13.46186.63.13.4714
212186.63.13.48/28186.63.13.49 to 186.63.13.62186.63.13.6314
213186.63.13.64/28186.63.13.65 to 186.63.13.78186.63.13.7914
214186.63.13.80/28186.63.13.81 to 186.63.13.94186.63.13.9514
215186.63.13.96/28186.63.13.97 to 186.63.13.110186.63.13.11114
216186.63.13.112/28186.63.13.113 to 186.63.13.126186.63.13.12714
217186.63.13.128/28186.63.13.129 to 186.63.13.142186.63.13.14314
218186.63.13.144/28186.63.13.145 to 186.63.13.158186.63.13.15914
219186.63.13.160/28186.63.13.161 to 186.63.13.174186.63.13.17514
220186.63.13.176/28186.63.13.177 to 186.63.13.190186.63.13.19114
221186.63.13.192/28186.63.13.193 to 186.63.13.206186.63.13.20714
222186.63.13.208/28186.63.13.209 to 186.63.13.222186.63.13.22314
223186.63.13.224/28186.63.13.225 to 186.63.13.238186.63.13.23914
224186.63.13.240/28186.63.13.241 to 186.63.13.254186.63.13.25514
225186.63.14.0/28186.63.14.1 to 186.63.14.14186.63.14.1514
226186.63.14.16/28186.63.14.17 to 186.63.14.30186.63.14.3114
227186.63.14.32/28186.63.14.33 to 186.63.14.46186.63.14.4714
228186.63.14.48/28186.63.14.49 to 186.63.14.62186.63.14.6314
229186.63.14.64/28186.63.14.65 to 186.63.14.78186.63.14.7914
230186.63.14.80/28186.63.14.81 to 186.63.14.94186.63.14.9514
231186.63.14.96/28186.63.14.97 to 186.63.14.110186.63.14.11114
232186.63.14.112/28186.63.14.113 to 186.63.14.126186.63.14.12714
233186.63.14.128/28186.63.14.129 to 186.63.14.142186.63.14.14314
234186.63.14.144/28186.63.14.145 to 186.63.14.158186.63.14.15914
235186.63.14.160/28186.63.14.161 to 186.63.14.174186.63.14.17514
236186.63.14.176/28186.63.14.177 to 186.63.14.190186.63.14.19114
237186.63.14.192/28186.63.14.193 to 186.63.14.206186.63.14.20714
238186.63.14.208/28186.63.14.209 to 186.63.14.222186.63.14.22314
239186.63.14.224/28186.63.14.225 to 186.63.14.238186.63.14.23914
240186.63.14.240/28186.63.14.241 to 186.63.14.254186.63.14.25514
241186.63.15.0/28186.63.15.1 to 186.63.15.14186.63.15.1514
242186.63.15.16/28186.63.15.17 to 186.63.15.30186.63.15.3114
243186.63.15.32/28186.63.15.33 to 186.63.15.46186.63.15.4714
244186.63.15.48/28186.63.15.49 to 186.63.15.62186.63.15.6314
245186.63.15.64/28186.63.15.65 to 186.63.15.78186.63.15.7914
246186.63.15.80/28186.63.15.81 to 186.63.15.94186.63.15.9514
247186.63.15.96/28186.63.15.97 to 186.63.15.110186.63.15.11114
248186.63.15.112/28186.63.15.113 to 186.63.15.126186.63.15.12714
249186.63.15.128/28186.63.15.129 to 186.63.15.142186.63.15.14314
250186.63.15.144/28186.63.15.145 to 186.63.15.158186.63.15.15914
251186.63.15.160/28186.63.15.161 to 186.63.15.174186.63.15.17514
252186.63.15.176/28186.63.15.177 to 186.63.15.190186.63.15.19114
253186.63.15.192/28186.63.15.193 to 186.63.15.206186.63.15.20714
254186.63.15.208/28186.63.15.209 to 186.63.15.222186.63.15.22314
255186.63.15.224/28186.63.15.225 to 186.63.15.238186.63.15.23914
256186.63.15.240/28186.63.15.241 to 186.63.15.254186.63.15.25514

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.