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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.

Network158.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
158.167.0.0
Broadcast address
158.167.255.255
First usable
158.167.0.1
Last usable
158.167.255.254
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 9EA70000 · Integer 2661744640 to 2661810175
Reverse DNS zone
167.158.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011110.10100111..00000000.00000000158.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10011110.10100111..00000000.00000000158.167.0.0
Broadcast10011110.10100111..11111111.11111111158.167.255.255
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)

158.167.0.0/16 makes 512 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1158.167.0.0/25158.167.0.1 to 158.167.0.126158.167.0.127126
2158.167.0.128/25158.167.0.129 to 158.167.0.254158.167.0.255126
3158.167.1.0/25158.167.1.1 to 158.167.1.126158.167.1.127126
4158.167.1.128/25158.167.1.129 to 158.167.1.254158.167.1.255126
5158.167.2.0/25158.167.2.1 to 158.167.2.126158.167.2.127126
6158.167.2.128/25158.167.2.129 to 158.167.2.254158.167.2.255126
7158.167.3.0/25158.167.3.1 to 158.167.3.126158.167.3.127126
8158.167.3.128/25158.167.3.129 to 158.167.3.254158.167.3.255126
9158.167.4.0/25158.167.4.1 to 158.167.4.126158.167.4.127126
10158.167.4.128/25158.167.4.129 to 158.167.4.254158.167.4.255126
11158.167.5.0/25158.167.5.1 to 158.167.5.126158.167.5.127126
12158.167.5.128/25158.167.5.129 to 158.167.5.254158.167.5.255126
13158.167.6.0/25158.167.6.1 to 158.167.6.126158.167.6.127126
14158.167.6.128/25158.167.6.129 to 158.167.6.254158.167.6.255126
15158.167.7.0/25158.167.7.1 to 158.167.7.126158.167.7.127126
16158.167.7.128/25158.167.7.129 to 158.167.7.254158.167.7.255126
17158.167.8.0/25158.167.8.1 to 158.167.8.126158.167.8.127126
18158.167.8.128/25158.167.8.129 to 158.167.8.254158.167.8.255126
19158.167.9.0/25158.167.9.1 to 158.167.9.126158.167.9.127126
20158.167.9.128/25158.167.9.129 to 158.167.9.254158.167.9.255126
21158.167.10.0/25158.167.10.1 to 158.167.10.126158.167.10.127126
22158.167.10.128/25158.167.10.129 to 158.167.10.254158.167.10.255126
23158.167.11.0/25158.167.11.1 to 158.167.11.126158.167.11.127126
24158.167.11.128/25158.167.11.129 to 158.167.11.254158.167.11.255126
25158.167.12.0/25158.167.12.1 to 158.167.12.126158.167.12.127126
26158.167.12.128/25158.167.12.129 to 158.167.12.254158.167.12.255126
27158.167.13.0/25158.167.13.1 to 158.167.13.126158.167.13.127126
28158.167.13.128/25158.167.13.129 to 158.167.13.254158.167.13.255126
29158.167.14.0/25158.167.14.1 to 158.167.14.126158.167.14.127126
30158.167.14.128/25158.167.14.129 to 158.167.14.254158.167.14.255126
31158.167.15.0/25158.167.15.1 to 158.167.15.126158.167.15.127126
32158.167.15.128/25158.167.15.129 to 158.167.15.254158.167.15.255126
33158.167.16.0/25158.167.16.1 to 158.167.16.126158.167.16.127126
34158.167.16.128/25158.167.16.129 to 158.167.16.254158.167.16.255126
35158.167.17.0/25158.167.17.1 to 158.167.17.126158.167.17.127126
36158.167.17.128/25158.167.17.129 to 158.167.17.254158.167.17.255126
37158.167.18.0/25158.167.18.1 to 158.167.18.126158.167.18.127126
38158.167.18.128/25158.167.18.129 to 158.167.18.254158.167.18.255126
39158.167.19.0/25158.167.19.1 to 158.167.19.126158.167.19.127126
40158.167.19.128/25158.167.19.129 to 158.167.19.254158.167.19.255126
41158.167.20.0/25158.167.20.1 to 158.167.20.126158.167.20.127126
42158.167.20.128/25158.167.20.129 to 158.167.20.254158.167.20.255126
43158.167.21.0/25158.167.21.1 to 158.167.21.126158.167.21.127126
44158.167.21.128/25158.167.21.129 to 158.167.21.254158.167.21.255126
45158.167.22.0/25158.167.22.1 to 158.167.22.126158.167.22.127126
46158.167.22.128/25158.167.22.129 to 158.167.22.254158.167.22.255126
47158.167.23.0/25158.167.23.1 to 158.167.23.126158.167.23.127126
48158.167.23.128/25158.167.23.129 to 158.167.23.254158.167.23.255126
49158.167.24.0/25158.167.24.1 to 158.167.24.126158.167.24.127126
50158.167.24.128/25158.167.24.129 to 158.167.24.254158.167.24.255126
51158.167.25.0/25158.167.25.1 to 158.167.25.126158.167.25.127126
52158.167.25.128/25158.167.25.129 to 158.167.25.254158.167.25.255126
53158.167.26.0/25158.167.26.1 to 158.167.26.126158.167.26.127126
54158.167.26.128/25158.167.26.129 to 158.167.26.254158.167.26.255126
55158.167.27.0/25158.167.27.1 to 158.167.27.126158.167.27.127126
56158.167.27.128/25158.167.27.129 to 158.167.27.254158.167.27.255126
57158.167.28.0/25158.167.28.1 to 158.167.28.126158.167.28.127126
58158.167.28.128/25158.167.28.129 to 158.167.28.254158.167.28.255126
59158.167.29.0/25158.167.29.1 to 158.167.29.126158.167.29.127126
60158.167.29.128/25158.167.29.129 to 158.167.29.254158.167.29.255126
61158.167.30.0/25158.167.30.1 to 158.167.30.126158.167.30.127126
62158.167.30.128/25158.167.30.129 to 158.167.30.254158.167.30.255126
63158.167.31.0/25158.167.31.1 to 158.167.31.126158.167.31.127126
64158.167.31.128/25158.167.31.129 to 158.167.31.254158.167.31.255126
65158.167.32.0/25158.167.32.1 to 158.167.32.126158.167.32.127126
66158.167.32.128/25158.167.32.129 to 158.167.32.254158.167.32.255126
67158.167.33.0/25158.167.33.1 to 158.167.33.126158.167.33.127126
68158.167.33.128/25158.167.33.129 to 158.167.33.254158.167.33.255126
69158.167.34.0/25158.167.34.1 to 158.167.34.126158.167.34.127126
70158.167.34.128/25158.167.34.129 to 158.167.34.254158.167.34.255126
71158.167.35.0/25158.167.35.1 to 158.167.35.126158.167.35.127126
72158.167.35.128/25158.167.35.129 to 158.167.35.254158.167.35.255126
73158.167.36.0/25158.167.36.1 to 158.167.36.126158.167.36.127126
74158.167.36.128/25158.167.36.129 to 158.167.36.254158.167.36.255126
75158.167.37.0/25158.167.37.1 to 158.167.37.126158.167.37.127126
76158.167.37.128/25158.167.37.129 to 158.167.37.254158.167.37.255126
77158.167.38.0/25158.167.38.1 to 158.167.38.126158.167.38.127126
78158.167.38.128/25158.167.38.129 to 158.167.38.254158.167.38.255126
79158.167.39.0/25158.167.39.1 to 158.167.39.126158.167.39.127126
80158.167.39.128/25158.167.39.129 to 158.167.39.254158.167.39.255126
81158.167.40.0/25158.167.40.1 to 158.167.40.126158.167.40.127126
82158.167.40.128/25158.167.40.129 to 158.167.40.254158.167.40.255126
83158.167.41.0/25158.167.41.1 to 158.167.41.126158.167.41.127126
84158.167.41.128/25158.167.41.129 to 158.167.41.254158.167.41.255126
85158.167.42.0/25158.167.42.1 to 158.167.42.126158.167.42.127126
86158.167.42.128/25158.167.42.129 to 158.167.42.254158.167.42.255126
87158.167.43.0/25158.167.43.1 to 158.167.43.126158.167.43.127126
88158.167.43.128/25158.167.43.129 to 158.167.43.254158.167.43.255126
89158.167.44.0/25158.167.44.1 to 158.167.44.126158.167.44.127126
90158.167.44.128/25158.167.44.129 to 158.167.44.254158.167.44.255126
91158.167.45.0/25158.167.45.1 to 158.167.45.126158.167.45.127126
92158.167.45.128/25158.167.45.129 to 158.167.45.254158.167.45.255126
93158.167.46.0/25158.167.46.1 to 158.167.46.126158.167.46.127126
94158.167.46.128/25158.167.46.129 to 158.167.46.254158.167.46.255126
95158.167.47.0/25158.167.47.1 to 158.167.47.126158.167.47.127126
96158.167.47.128/25158.167.47.129 to 158.167.47.254158.167.47.255126
97158.167.48.0/25158.167.48.1 to 158.167.48.126158.167.48.127126
98158.167.48.128/25158.167.48.129 to 158.167.48.254158.167.48.255126
99158.167.49.0/25158.167.49.1 to 158.167.49.126158.167.49.127126
100158.167.49.128/25158.167.49.129 to 158.167.49.254158.167.49.255126
101158.167.50.0/25158.167.50.1 to 158.167.50.126158.167.50.127126
102158.167.50.128/25158.167.50.129 to 158.167.50.254158.167.50.255126
103158.167.51.0/25158.167.51.1 to 158.167.51.126158.167.51.127126
104158.167.51.128/25158.167.51.129 to 158.167.51.254158.167.51.255126
105158.167.52.0/25158.167.52.1 to 158.167.52.126158.167.52.127126
106158.167.52.128/25158.167.52.129 to 158.167.52.254158.167.52.255126
107158.167.53.0/25158.167.53.1 to 158.167.53.126158.167.53.127126
108158.167.53.128/25158.167.53.129 to 158.167.53.254158.167.53.255126
109158.167.54.0/25158.167.54.1 to 158.167.54.126158.167.54.127126
110158.167.54.128/25158.167.54.129 to 158.167.54.254158.167.54.255126
111158.167.55.0/25158.167.55.1 to 158.167.55.126158.167.55.127126
112158.167.55.128/25158.167.55.129 to 158.167.55.254158.167.55.255126
113158.167.56.0/25158.167.56.1 to 158.167.56.126158.167.56.127126
114158.167.56.128/25158.167.56.129 to 158.167.56.254158.167.56.255126
115158.167.57.0/25158.167.57.1 to 158.167.57.126158.167.57.127126
116158.167.57.128/25158.167.57.129 to 158.167.57.254158.167.57.255126
117158.167.58.0/25158.167.58.1 to 158.167.58.126158.167.58.127126
118158.167.58.128/25158.167.58.129 to 158.167.58.254158.167.58.255126
119158.167.59.0/25158.167.59.1 to 158.167.59.126158.167.59.127126
120158.167.59.128/25158.167.59.129 to 158.167.59.254158.167.59.255126
121158.167.60.0/25158.167.60.1 to 158.167.60.126158.167.60.127126
122158.167.60.128/25158.167.60.129 to 158.167.60.254158.167.60.255126
123158.167.61.0/25158.167.61.1 to 158.167.61.126158.167.61.127126
124158.167.61.128/25158.167.61.129 to 158.167.61.254158.167.61.255126
125158.167.62.0/25158.167.62.1 to 158.167.62.126158.167.62.127126
126158.167.62.128/25158.167.62.129 to 158.167.62.254158.167.62.255126
127158.167.63.0/25158.167.63.1 to 158.167.63.126158.167.63.127126
128158.167.63.128/25158.167.63.129 to 158.167.63.254158.167.63.255126
129158.167.64.0/25158.167.64.1 to 158.167.64.126158.167.64.127126
130158.167.64.128/25158.167.64.129 to 158.167.64.254158.167.64.255126
131158.167.65.0/25158.167.65.1 to 158.167.65.126158.167.65.127126
132158.167.65.128/25158.167.65.129 to 158.167.65.254158.167.65.255126
133158.167.66.0/25158.167.66.1 to 158.167.66.126158.167.66.127126
134158.167.66.128/25158.167.66.129 to 158.167.66.254158.167.66.255126
135158.167.67.0/25158.167.67.1 to 158.167.67.126158.167.67.127126
136158.167.67.128/25158.167.67.129 to 158.167.67.254158.167.67.255126
137158.167.68.0/25158.167.68.1 to 158.167.68.126158.167.68.127126
138158.167.68.128/25158.167.68.129 to 158.167.68.254158.167.68.255126
139158.167.69.0/25158.167.69.1 to 158.167.69.126158.167.69.127126
140158.167.69.128/25158.167.69.129 to 158.167.69.254158.167.69.255126
141158.167.70.0/25158.167.70.1 to 158.167.70.126158.167.70.127126
142158.167.70.128/25158.167.70.129 to 158.167.70.254158.167.70.255126
143158.167.71.0/25158.167.71.1 to 158.167.71.126158.167.71.127126
144158.167.71.128/25158.167.71.129 to 158.167.71.254158.167.71.255126
145158.167.72.0/25158.167.72.1 to 158.167.72.126158.167.72.127126
146158.167.72.128/25158.167.72.129 to 158.167.72.254158.167.72.255126
147158.167.73.0/25158.167.73.1 to 158.167.73.126158.167.73.127126
148158.167.73.128/25158.167.73.129 to 158.167.73.254158.167.73.255126
149158.167.74.0/25158.167.74.1 to 158.167.74.126158.167.74.127126
150158.167.74.128/25158.167.74.129 to 158.167.74.254158.167.74.255126
151158.167.75.0/25158.167.75.1 to 158.167.75.126158.167.75.127126
152158.167.75.128/25158.167.75.129 to 158.167.75.254158.167.75.255126
153158.167.76.0/25158.167.76.1 to 158.167.76.126158.167.76.127126
154158.167.76.128/25158.167.76.129 to 158.167.76.254158.167.76.255126
155158.167.77.0/25158.167.77.1 to 158.167.77.126158.167.77.127126
156158.167.77.128/25158.167.77.129 to 158.167.77.254158.167.77.255126
157158.167.78.0/25158.167.78.1 to 158.167.78.126158.167.78.127126
158158.167.78.128/25158.167.78.129 to 158.167.78.254158.167.78.255126
159158.167.79.0/25158.167.79.1 to 158.167.79.126158.167.79.127126
160158.167.79.128/25158.167.79.129 to 158.167.79.254158.167.79.255126
161158.167.80.0/25158.167.80.1 to 158.167.80.126158.167.80.127126
162158.167.80.128/25158.167.80.129 to 158.167.80.254158.167.80.255126
163158.167.81.0/25158.167.81.1 to 158.167.81.126158.167.81.127126
164158.167.81.128/25158.167.81.129 to 158.167.81.254158.167.81.255126
165158.167.82.0/25158.167.82.1 to 158.167.82.126158.167.82.127126
166158.167.82.128/25158.167.82.129 to 158.167.82.254158.167.82.255126
167158.167.83.0/25158.167.83.1 to 158.167.83.126158.167.83.127126
168158.167.83.128/25158.167.83.129 to 158.167.83.254158.167.83.255126
169158.167.84.0/25158.167.84.1 to 158.167.84.126158.167.84.127126
170158.167.84.128/25158.167.84.129 to 158.167.84.254158.167.84.255126
171158.167.85.0/25158.167.85.1 to 158.167.85.126158.167.85.127126
172158.167.85.128/25158.167.85.129 to 158.167.85.254158.167.85.255126
173158.167.86.0/25158.167.86.1 to 158.167.86.126158.167.86.127126
174158.167.86.128/25158.167.86.129 to 158.167.86.254158.167.86.255126
175158.167.87.0/25158.167.87.1 to 158.167.87.126158.167.87.127126
176158.167.87.128/25158.167.87.129 to 158.167.87.254158.167.87.255126
177158.167.88.0/25158.167.88.1 to 158.167.88.126158.167.88.127126
178158.167.88.128/25158.167.88.129 to 158.167.88.254158.167.88.255126
179158.167.89.0/25158.167.89.1 to 158.167.89.126158.167.89.127126
180158.167.89.128/25158.167.89.129 to 158.167.89.254158.167.89.255126
181158.167.90.0/25158.167.90.1 to 158.167.90.126158.167.90.127126
182158.167.90.128/25158.167.90.129 to 158.167.90.254158.167.90.255126
183158.167.91.0/25158.167.91.1 to 158.167.91.126158.167.91.127126
184158.167.91.128/25158.167.91.129 to 158.167.91.254158.167.91.255126
185158.167.92.0/25158.167.92.1 to 158.167.92.126158.167.92.127126
186158.167.92.128/25158.167.92.129 to 158.167.92.254158.167.92.255126
187158.167.93.0/25158.167.93.1 to 158.167.93.126158.167.93.127126
188158.167.93.128/25158.167.93.129 to 158.167.93.254158.167.93.255126
189158.167.94.0/25158.167.94.1 to 158.167.94.126158.167.94.127126
190158.167.94.128/25158.167.94.129 to 158.167.94.254158.167.94.255126
191158.167.95.0/25158.167.95.1 to 158.167.95.126158.167.95.127126
192158.167.95.128/25158.167.95.129 to 158.167.95.254158.167.95.255126
193158.167.96.0/25158.167.96.1 to 158.167.96.126158.167.96.127126
194158.167.96.128/25158.167.96.129 to 158.167.96.254158.167.96.255126
195158.167.97.0/25158.167.97.1 to 158.167.97.126158.167.97.127126
196158.167.97.128/25158.167.97.129 to 158.167.97.254158.167.97.255126
197158.167.98.0/25158.167.98.1 to 158.167.98.126158.167.98.127126
198158.167.98.128/25158.167.98.129 to 158.167.98.254158.167.98.255126
199158.167.99.0/25158.167.99.1 to 158.167.99.126158.167.99.127126
200158.167.99.128/25158.167.99.129 to 158.167.99.254158.167.99.255126
201158.167.100.0/25158.167.100.1 to 158.167.100.126158.167.100.127126
202158.167.100.128/25158.167.100.129 to 158.167.100.254158.167.100.255126
203158.167.101.0/25158.167.101.1 to 158.167.101.126158.167.101.127126
204158.167.101.128/25158.167.101.129 to 158.167.101.254158.167.101.255126
205158.167.102.0/25158.167.102.1 to 158.167.102.126158.167.102.127126
206158.167.102.128/25158.167.102.129 to 158.167.102.254158.167.102.255126
207158.167.103.0/25158.167.103.1 to 158.167.103.126158.167.103.127126
208158.167.103.128/25158.167.103.129 to 158.167.103.254158.167.103.255126
209158.167.104.0/25158.167.104.1 to 158.167.104.126158.167.104.127126
210158.167.104.128/25158.167.104.129 to 158.167.104.254158.167.104.255126
211158.167.105.0/25158.167.105.1 to 158.167.105.126158.167.105.127126
212158.167.105.128/25158.167.105.129 to 158.167.105.254158.167.105.255126
213158.167.106.0/25158.167.106.1 to 158.167.106.126158.167.106.127126
214158.167.106.128/25158.167.106.129 to 158.167.106.254158.167.106.255126
215158.167.107.0/25158.167.107.1 to 158.167.107.126158.167.107.127126
216158.167.107.128/25158.167.107.129 to 158.167.107.254158.167.107.255126
217158.167.108.0/25158.167.108.1 to 158.167.108.126158.167.108.127126
218158.167.108.128/25158.167.108.129 to 158.167.108.254158.167.108.255126
219158.167.109.0/25158.167.109.1 to 158.167.109.126158.167.109.127126
220158.167.109.128/25158.167.109.129 to 158.167.109.254158.167.109.255126
221158.167.110.0/25158.167.110.1 to 158.167.110.126158.167.110.127126
222158.167.110.128/25158.167.110.129 to 158.167.110.254158.167.110.255126
223158.167.111.0/25158.167.111.1 to 158.167.111.126158.167.111.127126
224158.167.111.128/25158.167.111.129 to 158.167.111.254158.167.111.255126
225158.167.112.0/25158.167.112.1 to 158.167.112.126158.167.112.127126
226158.167.112.128/25158.167.112.129 to 158.167.112.254158.167.112.255126
227158.167.113.0/25158.167.113.1 to 158.167.113.126158.167.113.127126
228158.167.113.128/25158.167.113.129 to 158.167.113.254158.167.113.255126
229158.167.114.0/25158.167.114.1 to 158.167.114.126158.167.114.127126
230158.167.114.128/25158.167.114.129 to 158.167.114.254158.167.114.255126
231158.167.115.0/25158.167.115.1 to 158.167.115.126158.167.115.127126
232158.167.115.128/25158.167.115.129 to 158.167.115.254158.167.115.255126
233158.167.116.0/25158.167.116.1 to 158.167.116.126158.167.116.127126
234158.167.116.128/25158.167.116.129 to 158.167.116.254158.167.116.255126
235158.167.117.0/25158.167.117.1 to 158.167.117.126158.167.117.127126
236158.167.117.128/25158.167.117.129 to 158.167.117.254158.167.117.255126
237158.167.118.0/25158.167.118.1 to 158.167.118.126158.167.118.127126
238158.167.118.128/25158.167.118.129 to 158.167.118.254158.167.118.255126
239158.167.119.0/25158.167.119.1 to 158.167.119.126158.167.119.127126
240158.167.119.128/25158.167.119.129 to 158.167.119.254158.167.119.255126
241158.167.120.0/25158.167.120.1 to 158.167.120.126158.167.120.127126
242158.167.120.128/25158.167.120.129 to 158.167.120.254158.167.120.255126
243158.167.121.0/25158.167.121.1 to 158.167.121.126158.167.121.127126
244158.167.121.128/25158.167.121.129 to 158.167.121.254158.167.121.255126
245158.167.122.0/25158.167.122.1 to 158.167.122.126158.167.122.127126
246158.167.122.128/25158.167.122.129 to 158.167.122.254158.167.122.255126
247158.167.123.0/25158.167.123.1 to 158.167.123.126158.167.123.127126
248158.167.123.128/25158.167.123.129 to 158.167.123.254158.167.123.255126
249158.167.124.0/25158.167.124.1 to 158.167.124.126158.167.124.127126
250158.167.124.128/25158.167.124.129 to 158.167.124.254158.167.124.255126
251158.167.125.0/25158.167.125.1 to 158.167.125.126158.167.125.127126
252158.167.125.128/25158.167.125.129 to 158.167.125.254158.167.125.255126
253158.167.126.0/25158.167.126.1 to 158.167.126.126158.167.126.127126
254158.167.126.128/25158.167.126.129 to 158.167.126.254158.167.126.255126
255158.167.127.0/25158.167.127.1 to 158.167.127.126158.167.127.127126
256158.167.127.128/25158.167.127.129 to 158.167.127.254158.167.127.255126

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.