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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.

Network104.232.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
104.232.0.0
Broadcast address
104.232.255.255
First usable
104.232.0.1
Last usable
104.232.255.254
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
A (default /8)
As numbers
Hex 68E80000 · Integer 1760034816 to 1760100351
Reverse DNS zone
232.104.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101000.11101000..00000000.00000000104.232.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01101000.11101000..00000000.00000000104.232.0.0
Broadcast01101000.11101000..11111111.11111111104.232.255.255
Split into smaller subnets/25
/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)

104.232.0.0/16 makes 512 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1104.232.0.0/25104.232.0.1 to 104.232.0.126104.232.0.127126
2104.232.0.128/25104.232.0.129 to 104.232.0.254104.232.0.255126
3104.232.1.0/25104.232.1.1 to 104.232.1.126104.232.1.127126
4104.232.1.128/25104.232.1.129 to 104.232.1.254104.232.1.255126
5104.232.2.0/25104.232.2.1 to 104.232.2.126104.232.2.127126
6104.232.2.128/25104.232.2.129 to 104.232.2.254104.232.2.255126
7104.232.3.0/25104.232.3.1 to 104.232.3.126104.232.3.127126
8104.232.3.128/25104.232.3.129 to 104.232.3.254104.232.3.255126
9104.232.4.0/25104.232.4.1 to 104.232.4.126104.232.4.127126
10104.232.4.128/25104.232.4.129 to 104.232.4.254104.232.4.255126
11104.232.5.0/25104.232.5.1 to 104.232.5.126104.232.5.127126
12104.232.5.128/25104.232.5.129 to 104.232.5.254104.232.5.255126
13104.232.6.0/25104.232.6.1 to 104.232.6.126104.232.6.127126
14104.232.6.128/25104.232.6.129 to 104.232.6.254104.232.6.255126
15104.232.7.0/25104.232.7.1 to 104.232.7.126104.232.7.127126
16104.232.7.128/25104.232.7.129 to 104.232.7.254104.232.7.255126
17104.232.8.0/25104.232.8.1 to 104.232.8.126104.232.8.127126
18104.232.8.128/25104.232.8.129 to 104.232.8.254104.232.8.255126
19104.232.9.0/25104.232.9.1 to 104.232.9.126104.232.9.127126
20104.232.9.128/25104.232.9.129 to 104.232.9.254104.232.9.255126
21104.232.10.0/25104.232.10.1 to 104.232.10.126104.232.10.127126
22104.232.10.128/25104.232.10.129 to 104.232.10.254104.232.10.255126
23104.232.11.0/25104.232.11.1 to 104.232.11.126104.232.11.127126
24104.232.11.128/25104.232.11.129 to 104.232.11.254104.232.11.255126
25104.232.12.0/25104.232.12.1 to 104.232.12.126104.232.12.127126
26104.232.12.128/25104.232.12.129 to 104.232.12.254104.232.12.255126
27104.232.13.0/25104.232.13.1 to 104.232.13.126104.232.13.127126
28104.232.13.128/25104.232.13.129 to 104.232.13.254104.232.13.255126
29104.232.14.0/25104.232.14.1 to 104.232.14.126104.232.14.127126
30104.232.14.128/25104.232.14.129 to 104.232.14.254104.232.14.255126
31104.232.15.0/25104.232.15.1 to 104.232.15.126104.232.15.127126
32104.232.15.128/25104.232.15.129 to 104.232.15.254104.232.15.255126
33104.232.16.0/25104.232.16.1 to 104.232.16.126104.232.16.127126
34104.232.16.128/25104.232.16.129 to 104.232.16.254104.232.16.255126
35104.232.17.0/25104.232.17.1 to 104.232.17.126104.232.17.127126
36104.232.17.128/25104.232.17.129 to 104.232.17.254104.232.17.255126
37104.232.18.0/25104.232.18.1 to 104.232.18.126104.232.18.127126
38104.232.18.128/25104.232.18.129 to 104.232.18.254104.232.18.255126
39104.232.19.0/25104.232.19.1 to 104.232.19.126104.232.19.127126
40104.232.19.128/25104.232.19.129 to 104.232.19.254104.232.19.255126
41104.232.20.0/25104.232.20.1 to 104.232.20.126104.232.20.127126
42104.232.20.128/25104.232.20.129 to 104.232.20.254104.232.20.255126
43104.232.21.0/25104.232.21.1 to 104.232.21.126104.232.21.127126
44104.232.21.128/25104.232.21.129 to 104.232.21.254104.232.21.255126
45104.232.22.0/25104.232.22.1 to 104.232.22.126104.232.22.127126
46104.232.22.128/25104.232.22.129 to 104.232.22.254104.232.22.255126
47104.232.23.0/25104.232.23.1 to 104.232.23.126104.232.23.127126
48104.232.23.128/25104.232.23.129 to 104.232.23.254104.232.23.255126
49104.232.24.0/25104.232.24.1 to 104.232.24.126104.232.24.127126
50104.232.24.128/25104.232.24.129 to 104.232.24.254104.232.24.255126
51104.232.25.0/25104.232.25.1 to 104.232.25.126104.232.25.127126
52104.232.25.128/25104.232.25.129 to 104.232.25.254104.232.25.255126
53104.232.26.0/25104.232.26.1 to 104.232.26.126104.232.26.127126
54104.232.26.128/25104.232.26.129 to 104.232.26.254104.232.26.255126
55104.232.27.0/25104.232.27.1 to 104.232.27.126104.232.27.127126
56104.232.27.128/25104.232.27.129 to 104.232.27.254104.232.27.255126
57104.232.28.0/25104.232.28.1 to 104.232.28.126104.232.28.127126
58104.232.28.128/25104.232.28.129 to 104.232.28.254104.232.28.255126
59104.232.29.0/25104.232.29.1 to 104.232.29.126104.232.29.127126
60104.232.29.128/25104.232.29.129 to 104.232.29.254104.232.29.255126
61104.232.30.0/25104.232.30.1 to 104.232.30.126104.232.30.127126
62104.232.30.128/25104.232.30.129 to 104.232.30.254104.232.30.255126
63104.232.31.0/25104.232.31.1 to 104.232.31.126104.232.31.127126
64104.232.31.128/25104.232.31.129 to 104.232.31.254104.232.31.255126
65104.232.32.0/25104.232.32.1 to 104.232.32.126104.232.32.127126
66104.232.32.128/25104.232.32.129 to 104.232.32.254104.232.32.255126
67104.232.33.0/25104.232.33.1 to 104.232.33.126104.232.33.127126
68104.232.33.128/25104.232.33.129 to 104.232.33.254104.232.33.255126
69104.232.34.0/25104.232.34.1 to 104.232.34.126104.232.34.127126
70104.232.34.128/25104.232.34.129 to 104.232.34.254104.232.34.255126
71104.232.35.0/25104.232.35.1 to 104.232.35.126104.232.35.127126
72104.232.35.128/25104.232.35.129 to 104.232.35.254104.232.35.255126
73104.232.36.0/25104.232.36.1 to 104.232.36.126104.232.36.127126
74104.232.36.128/25104.232.36.129 to 104.232.36.254104.232.36.255126
75104.232.37.0/25104.232.37.1 to 104.232.37.126104.232.37.127126
76104.232.37.128/25104.232.37.129 to 104.232.37.254104.232.37.255126
77104.232.38.0/25104.232.38.1 to 104.232.38.126104.232.38.127126
78104.232.38.128/25104.232.38.129 to 104.232.38.254104.232.38.255126
79104.232.39.0/25104.232.39.1 to 104.232.39.126104.232.39.127126
80104.232.39.128/25104.232.39.129 to 104.232.39.254104.232.39.255126
81104.232.40.0/25104.232.40.1 to 104.232.40.126104.232.40.127126
82104.232.40.128/25104.232.40.129 to 104.232.40.254104.232.40.255126
83104.232.41.0/25104.232.41.1 to 104.232.41.126104.232.41.127126
84104.232.41.128/25104.232.41.129 to 104.232.41.254104.232.41.255126
85104.232.42.0/25104.232.42.1 to 104.232.42.126104.232.42.127126
86104.232.42.128/25104.232.42.129 to 104.232.42.254104.232.42.255126
87104.232.43.0/25104.232.43.1 to 104.232.43.126104.232.43.127126
88104.232.43.128/25104.232.43.129 to 104.232.43.254104.232.43.255126
89104.232.44.0/25104.232.44.1 to 104.232.44.126104.232.44.127126
90104.232.44.128/25104.232.44.129 to 104.232.44.254104.232.44.255126
91104.232.45.0/25104.232.45.1 to 104.232.45.126104.232.45.127126
92104.232.45.128/25104.232.45.129 to 104.232.45.254104.232.45.255126
93104.232.46.0/25104.232.46.1 to 104.232.46.126104.232.46.127126
94104.232.46.128/25104.232.46.129 to 104.232.46.254104.232.46.255126
95104.232.47.0/25104.232.47.1 to 104.232.47.126104.232.47.127126
96104.232.47.128/25104.232.47.129 to 104.232.47.254104.232.47.255126
97104.232.48.0/25104.232.48.1 to 104.232.48.126104.232.48.127126
98104.232.48.128/25104.232.48.129 to 104.232.48.254104.232.48.255126
99104.232.49.0/25104.232.49.1 to 104.232.49.126104.232.49.127126
100104.232.49.128/25104.232.49.129 to 104.232.49.254104.232.49.255126
101104.232.50.0/25104.232.50.1 to 104.232.50.126104.232.50.127126
102104.232.50.128/25104.232.50.129 to 104.232.50.254104.232.50.255126
103104.232.51.0/25104.232.51.1 to 104.232.51.126104.232.51.127126
104104.232.51.128/25104.232.51.129 to 104.232.51.254104.232.51.255126
105104.232.52.0/25104.232.52.1 to 104.232.52.126104.232.52.127126
106104.232.52.128/25104.232.52.129 to 104.232.52.254104.232.52.255126
107104.232.53.0/25104.232.53.1 to 104.232.53.126104.232.53.127126
108104.232.53.128/25104.232.53.129 to 104.232.53.254104.232.53.255126
109104.232.54.0/25104.232.54.1 to 104.232.54.126104.232.54.127126
110104.232.54.128/25104.232.54.129 to 104.232.54.254104.232.54.255126
111104.232.55.0/25104.232.55.1 to 104.232.55.126104.232.55.127126
112104.232.55.128/25104.232.55.129 to 104.232.55.254104.232.55.255126
113104.232.56.0/25104.232.56.1 to 104.232.56.126104.232.56.127126
114104.232.56.128/25104.232.56.129 to 104.232.56.254104.232.56.255126
115104.232.57.0/25104.232.57.1 to 104.232.57.126104.232.57.127126
116104.232.57.128/25104.232.57.129 to 104.232.57.254104.232.57.255126
117104.232.58.0/25104.232.58.1 to 104.232.58.126104.232.58.127126
118104.232.58.128/25104.232.58.129 to 104.232.58.254104.232.58.255126
119104.232.59.0/25104.232.59.1 to 104.232.59.126104.232.59.127126
120104.232.59.128/25104.232.59.129 to 104.232.59.254104.232.59.255126
121104.232.60.0/25104.232.60.1 to 104.232.60.126104.232.60.127126
122104.232.60.128/25104.232.60.129 to 104.232.60.254104.232.60.255126
123104.232.61.0/25104.232.61.1 to 104.232.61.126104.232.61.127126
124104.232.61.128/25104.232.61.129 to 104.232.61.254104.232.61.255126
125104.232.62.0/25104.232.62.1 to 104.232.62.126104.232.62.127126
126104.232.62.128/25104.232.62.129 to 104.232.62.254104.232.62.255126
127104.232.63.0/25104.232.63.1 to 104.232.63.126104.232.63.127126
128104.232.63.128/25104.232.63.129 to 104.232.63.254104.232.63.255126
129104.232.64.0/25104.232.64.1 to 104.232.64.126104.232.64.127126
130104.232.64.128/25104.232.64.129 to 104.232.64.254104.232.64.255126
131104.232.65.0/25104.232.65.1 to 104.232.65.126104.232.65.127126
132104.232.65.128/25104.232.65.129 to 104.232.65.254104.232.65.255126
133104.232.66.0/25104.232.66.1 to 104.232.66.126104.232.66.127126
134104.232.66.128/25104.232.66.129 to 104.232.66.254104.232.66.255126
135104.232.67.0/25104.232.67.1 to 104.232.67.126104.232.67.127126
136104.232.67.128/25104.232.67.129 to 104.232.67.254104.232.67.255126
137104.232.68.0/25104.232.68.1 to 104.232.68.126104.232.68.127126
138104.232.68.128/25104.232.68.129 to 104.232.68.254104.232.68.255126
139104.232.69.0/25104.232.69.1 to 104.232.69.126104.232.69.127126
140104.232.69.128/25104.232.69.129 to 104.232.69.254104.232.69.255126
141104.232.70.0/25104.232.70.1 to 104.232.70.126104.232.70.127126
142104.232.70.128/25104.232.70.129 to 104.232.70.254104.232.70.255126
143104.232.71.0/25104.232.71.1 to 104.232.71.126104.232.71.127126
144104.232.71.128/25104.232.71.129 to 104.232.71.254104.232.71.255126
145104.232.72.0/25104.232.72.1 to 104.232.72.126104.232.72.127126
146104.232.72.128/25104.232.72.129 to 104.232.72.254104.232.72.255126
147104.232.73.0/25104.232.73.1 to 104.232.73.126104.232.73.127126
148104.232.73.128/25104.232.73.129 to 104.232.73.254104.232.73.255126
149104.232.74.0/25104.232.74.1 to 104.232.74.126104.232.74.127126
150104.232.74.128/25104.232.74.129 to 104.232.74.254104.232.74.255126
151104.232.75.0/25104.232.75.1 to 104.232.75.126104.232.75.127126
152104.232.75.128/25104.232.75.129 to 104.232.75.254104.232.75.255126
153104.232.76.0/25104.232.76.1 to 104.232.76.126104.232.76.127126
154104.232.76.128/25104.232.76.129 to 104.232.76.254104.232.76.255126
155104.232.77.0/25104.232.77.1 to 104.232.77.126104.232.77.127126
156104.232.77.128/25104.232.77.129 to 104.232.77.254104.232.77.255126
157104.232.78.0/25104.232.78.1 to 104.232.78.126104.232.78.127126
158104.232.78.128/25104.232.78.129 to 104.232.78.254104.232.78.255126
159104.232.79.0/25104.232.79.1 to 104.232.79.126104.232.79.127126
160104.232.79.128/25104.232.79.129 to 104.232.79.254104.232.79.255126
161104.232.80.0/25104.232.80.1 to 104.232.80.126104.232.80.127126
162104.232.80.128/25104.232.80.129 to 104.232.80.254104.232.80.255126
163104.232.81.0/25104.232.81.1 to 104.232.81.126104.232.81.127126
164104.232.81.128/25104.232.81.129 to 104.232.81.254104.232.81.255126
165104.232.82.0/25104.232.82.1 to 104.232.82.126104.232.82.127126
166104.232.82.128/25104.232.82.129 to 104.232.82.254104.232.82.255126
167104.232.83.0/25104.232.83.1 to 104.232.83.126104.232.83.127126
168104.232.83.128/25104.232.83.129 to 104.232.83.254104.232.83.255126
169104.232.84.0/25104.232.84.1 to 104.232.84.126104.232.84.127126
170104.232.84.128/25104.232.84.129 to 104.232.84.254104.232.84.255126
171104.232.85.0/25104.232.85.1 to 104.232.85.126104.232.85.127126
172104.232.85.128/25104.232.85.129 to 104.232.85.254104.232.85.255126
173104.232.86.0/25104.232.86.1 to 104.232.86.126104.232.86.127126
174104.232.86.128/25104.232.86.129 to 104.232.86.254104.232.86.255126
175104.232.87.0/25104.232.87.1 to 104.232.87.126104.232.87.127126
176104.232.87.128/25104.232.87.129 to 104.232.87.254104.232.87.255126
177104.232.88.0/25104.232.88.1 to 104.232.88.126104.232.88.127126
178104.232.88.128/25104.232.88.129 to 104.232.88.254104.232.88.255126
179104.232.89.0/25104.232.89.1 to 104.232.89.126104.232.89.127126
180104.232.89.128/25104.232.89.129 to 104.232.89.254104.232.89.255126
181104.232.90.0/25104.232.90.1 to 104.232.90.126104.232.90.127126
182104.232.90.128/25104.232.90.129 to 104.232.90.254104.232.90.255126
183104.232.91.0/25104.232.91.1 to 104.232.91.126104.232.91.127126
184104.232.91.128/25104.232.91.129 to 104.232.91.254104.232.91.255126
185104.232.92.0/25104.232.92.1 to 104.232.92.126104.232.92.127126
186104.232.92.128/25104.232.92.129 to 104.232.92.254104.232.92.255126
187104.232.93.0/25104.232.93.1 to 104.232.93.126104.232.93.127126
188104.232.93.128/25104.232.93.129 to 104.232.93.254104.232.93.255126
189104.232.94.0/25104.232.94.1 to 104.232.94.126104.232.94.127126
190104.232.94.128/25104.232.94.129 to 104.232.94.254104.232.94.255126
191104.232.95.0/25104.232.95.1 to 104.232.95.126104.232.95.127126
192104.232.95.128/25104.232.95.129 to 104.232.95.254104.232.95.255126
193104.232.96.0/25104.232.96.1 to 104.232.96.126104.232.96.127126
194104.232.96.128/25104.232.96.129 to 104.232.96.254104.232.96.255126
195104.232.97.0/25104.232.97.1 to 104.232.97.126104.232.97.127126
196104.232.97.128/25104.232.97.129 to 104.232.97.254104.232.97.255126
197104.232.98.0/25104.232.98.1 to 104.232.98.126104.232.98.127126
198104.232.98.128/25104.232.98.129 to 104.232.98.254104.232.98.255126
199104.232.99.0/25104.232.99.1 to 104.232.99.126104.232.99.127126
200104.232.99.128/25104.232.99.129 to 104.232.99.254104.232.99.255126
201104.232.100.0/25104.232.100.1 to 104.232.100.126104.232.100.127126
202104.232.100.128/25104.232.100.129 to 104.232.100.254104.232.100.255126
203104.232.101.0/25104.232.101.1 to 104.232.101.126104.232.101.127126
204104.232.101.128/25104.232.101.129 to 104.232.101.254104.232.101.255126
205104.232.102.0/25104.232.102.1 to 104.232.102.126104.232.102.127126
206104.232.102.128/25104.232.102.129 to 104.232.102.254104.232.102.255126
207104.232.103.0/25104.232.103.1 to 104.232.103.126104.232.103.127126
208104.232.103.128/25104.232.103.129 to 104.232.103.254104.232.103.255126
209104.232.104.0/25104.232.104.1 to 104.232.104.126104.232.104.127126
210104.232.104.128/25104.232.104.129 to 104.232.104.254104.232.104.255126
211104.232.105.0/25104.232.105.1 to 104.232.105.126104.232.105.127126
212104.232.105.128/25104.232.105.129 to 104.232.105.254104.232.105.255126
213104.232.106.0/25104.232.106.1 to 104.232.106.126104.232.106.127126
214104.232.106.128/25104.232.106.129 to 104.232.106.254104.232.106.255126
215104.232.107.0/25104.232.107.1 to 104.232.107.126104.232.107.127126
216104.232.107.128/25104.232.107.129 to 104.232.107.254104.232.107.255126
217104.232.108.0/25104.232.108.1 to 104.232.108.126104.232.108.127126
218104.232.108.128/25104.232.108.129 to 104.232.108.254104.232.108.255126
219104.232.109.0/25104.232.109.1 to 104.232.109.126104.232.109.127126
220104.232.109.128/25104.232.109.129 to 104.232.109.254104.232.109.255126
221104.232.110.0/25104.232.110.1 to 104.232.110.126104.232.110.127126
222104.232.110.128/25104.232.110.129 to 104.232.110.254104.232.110.255126
223104.232.111.0/25104.232.111.1 to 104.232.111.126104.232.111.127126
224104.232.111.128/25104.232.111.129 to 104.232.111.254104.232.111.255126
225104.232.112.0/25104.232.112.1 to 104.232.112.126104.232.112.127126
226104.232.112.128/25104.232.112.129 to 104.232.112.254104.232.112.255126
227104.232.113.0/25104.232.113.1 to 104.232.113.126104.232.113.127126
228104.232.113.128/25104.232.113.129 to 104.232.113.254104.232.113.255126
229104.232.114.0/25104.232.114.1 to 104.232.114.126104.232.114.127126
230104.232.114.128/25104.232.114.129 to 104.232.114.254104.232.114.255126
231104.232.115.0/25104.232.115.1 to 104.232.115.126104.232.115.127126
232104.232.115.128/25104.232.115.129 to 104.232.115.254104.232.115.255126
233104.232.116.0/25104.232.116.1 to 104.232.116.126104.232.116.127126
234104.232.116.128/25104.232.116.129 to 104.232.116.254104.232.116.255126
235104.232.117.0/25104.232.117.1 to 104.232.117.126104.232.117.127126
236104.232.117.128/25104.232.117.129 to 104.232.117.254104.232.117.255126
237104.232.118.0/25104.232.118.1 to 104.232.118.126104.232.118.127126
238104.232.118.128/25104.232.118.129 to 104.232.118.254104.232.118.255126
239104.232.119.0/25104.232.119.1 to 104.232.119.126104.232.119.127126
240104.232.119.128/25104.232.119.129 to 104.232.119.254104.232.119.255126
241104.232.120.0/25104.232.120.1 to 104.232.120.126104.232.120.127126
242104.232.120.128/25104.232.120.129 to 104.232.120.254104.232.120.255126
243104.232.121.0/25104.232.121.1 to 104.232.121.126104.232.121.127126
244104.232.121.128/25104.232.121.129 to 104.232.121.254104.232.121.255126
245104.232.122.0/25104.232.122.1 to 104.232.122.126104.232.122.127126
246104.232.122.128/25104.232.122.129 to 104.232.122.254104.232.122.255126
247104.232.123.0/25104.232.123.1 to 104.232.123.126104.232.123.127126
248104.232.123.128/25104.232.123.129 to 104.232.123.254104.232.123.255126
249104.232.124.0/25104.232.124.1 to 104.232.124.126104.232.124.127126
250104.232.124.128/25104.232.124.129 to 104.232.124.254104.232.124.255126
251104.232.125.0/25104.232.125.1 to 104.232.125.126104.232.125.127126
252104.232.125.128/25104.232.125.129 to 104.232.125.254104.232.125.255126
253104.232.126.0/25104.232.126.1 to 104.232.126.126104.232.126.127126
254104.232.126.128/25104.232.126.129 to 104.232.126.254104.232.126.255126
255104.232.127.0/25104.232.127.1 to 104.232.127.126104.232.127.127126
256104.232.127.128/25104.232.127.129 to 104.232.127.254104.232.127.255126

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.