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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.

Network182.32.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
182.32.0.0
Broadcast address
182.33.255.255
First usable
182.32.0.1
Last usable
182.33.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
B (default /16)
As numbers
Hex B6200000 · Integer 3055550464 to 3055681535
Reverse DNS zones
32.182.in-addr.arpa
33.182.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10110110.00100000.00000000.00000000182.32.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10110110.00100000.00000000.00000000182.32.0.0
Broadcast10110110.00100001.11111111.11111111182.33.255.255
Split into smaller subnets/25
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

182.32.0.0/15 makes 1,024 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1182.32.0.0/25182.32.0.1 to 182.32.0.126182.32.0.127126
2182.32.0.128/25182.32.0.129 to 182.32.0.254182.32.0.255126
3182.32.1.0/25182.32.1.1 to 182.32.1.126182.32.1.127126
4182.32.1.128/25182.32.1.129 to 182.32.1.254182.32.1.255126
5182.32.2.0/25182.32.2.1 to 182.32.2.126182.32.2.127126
6182.32.2.128/25182.32.2.129 to 182.32.2.254182.32.2.255126
7182.32.3.0/25182.32.3.1 to 182.32.3.126182.32.3.127126
8182.32.3.128/25182.32.3.129 to 182.32.3.254182.32.3.255126
9182.32.4.0/25182.32.4.1 to 182.32.4.126182.32.4.127126
10182.32.4.128/25182.32.4.129 to 182.32.4.254182.32.4.255126
11182.32.5.0/25182.32.5.1 to 182.32.5.126182.32.5.127126
12182.32.5.128/25182.32.5.129 to 182.32.5.254182.32.5.255126
13182.32.6.0/25182.32.6.1 to 182.32.6.126182.32.6.127126
14182.32.6.128/25182.32.6.129 to 182.32.6.254182.32.6.255126
15182.32.7.0/25182.32.7.1 to 182.32.7.126182.32.7.127126
16182.32.7.128/25182.32.7.129 to 182.32.7.254182.32.7.255126
17182.32.8.0/25182.32.8.1 to 182.32.8.126182.32.8.127126
18182.32.8.128/25182.32.8.129 to 182.32.8.254182.32.8.255126
19182.32.9.0/25182.32.9.1 to 182.32.9.126182.32.9.127126
20182.32.9.128/25182.32.9.129 to 182.32.9.254182.32.9.255126
21182.32.10.0/25182.32.10.1 to 182.32.10.126182.32.10.127126
22182.32.10.128/25182.32.10.129 to 182.32.10.254182.32.10.255126
23182.32.11.0/25182.32.11.1 to 182.32.11.126182.32.11.127126
24182.32.11.128/25182.32.11.129 to 182.32.11.254182.32.11.255126
25182.32.12.0/25182.32.12.1 to 182.32.12.126182.32.12.127126
26182.32.12.128/25182.32.12.129 to 182.32.12.254182.32.12.255126
27182.32.13.0/25182.32.13.1 to 182.32.13.126182.32.13.127126
28182.32.13.128/25182.32.13.129 to 182.32.13.254182.32.13.255126
29182.32.14.0/25182.32.14.1 to 182.32.14.126182.32.14.127126
30182.32.14.128/25182.32.14.129 to 182.32.14.254182.32.14.255126
31182.32.15.0/25182.32.15.1 to 182.32.15.126182.32.15.127126
32182.32.15.128/25182.32.15.129 to 182.32.15.254182.32.15.255126
33182.32.16.0/25182.32.16.1 to 182.32.16.126182.32.16.127126
34182.32.16.128/25182.32.16.129 to 182.32.16.254182.32.16.255126
35182.32.17.0/25182.32.17.1 to 182.32.17.126182.32.17.127126
36182.32.17.128/25182.32.17.129 to 182.32.17.254182.32.17.255126
37182.32.18.0/25182.32.18.1 to 182.32.18.126182.32.18.127126
38182.32.18.128/25182.32.18.129 to 182.32.18.254182.32.18.255126
39182.32.19.0/25182.32.19.1 to 182.32.19.126182.32.19.127126
40182.32.19.128/25182.32.19.129 to 182.32.19.254182.32.19.255126
41182.32.20.0/25182.32.20.1 to 182.32.20.126182.32.20.127126
42182.32.20.128/25182.32.20.129 to 182.32.20.254182.32.20.255126
43182.32.21.0/25182.32.21.1 to 182.32.21.126182.32.21.127126
44182.32.21.128/25182.32.21.129 to 182.32.21.254182.32.21.255126
45182.32.22.0/25182.32.22.1 to 182.32.22.126182.32.22.127126
46182.32.22.128/25182.32.22.129 to 182.32.22.254182.32.22.255126
47182.32.23.0/25182.32.23.1 to 182.32.23.126182.32.23.127126
48182.32.23.128/25182.32.23.129 to 182.32.23.254182.32.23.255126
49182.32.24.0/25182.32.24.1 to 182.32.24.126182.32.24.127126
50182.32.24.128/25182.32.24.129 to 182.32.24.254182.32.24.255126
51182.32.25.0/25182.32.25.1 to 182.32.25.126182.32.25.127126
52182.32.25.128/25182.32.25.129 to 182.32.25.254182.32.25.255126
53182.32.26.0/25182.32.26.1 to 182.32.26.126182.32.26.127126
54182.32.26.128/25182.32.26.129 to 182.32.26.254182.32.26.255126
55182.32.27.0/25182.32.27.1 to 182.32.27.126182.32.27.127126
56182.32.27.128/25182.32.27.129 to 182.32.27.254182.32.27.255126
57182.32.28.0/25182.32.28.1 to 182.32.28.126182.32.28.127126
58182.32.28.128/25182.32.28.129 to 182.32.28.254182.32.28.255126
59182.32.29.0/25182.32.29.1 to 182.32.29.126182.32.29.127126
60182.32.29.128/25182.32.29.129 to 182.32.29.254182.32.29.255126
61182.32.30.0/25182.32.30.1 to 182.32.30.126182.32.30.127126
62182.32.30.128/25182.32.30.129 to 182.32.30.254182.32.30.255126
63182.32.31.0/25182.32.31.1 to 182.32.31.126182.32.31.127126
64182.32.31.128/25182.32.31.129 to 182.32.31.254182.32.31.255126
65182.32.32.0/25182.32.32.1 to 182.32.32.126182.32.32.127126
66182.32.32.128/25182.32.32.129 to 182.32.32.254182.32.32.255126
67182.32.33.0/25182.32.33.1 to 182.32.33.126182.32.33.127126
68182.32.33.128/25182.32.33.129 to 182.32.33.254182.32.33.255126
69182.32.34.0/25182.32.34.1 to 182.32.34.126182.32.34.127126
70182.32.34.128/25182.32.34.129 to 182.32.34.254182.32.34.255126
71182.32.35.0/25182.32.35.1 to 182.32.35.126182.32.35.127126
72182.32.35.128/25182.32.35.129 to 182.32.35.254182.32.35.255126
73182.32.36.0/25182.32.36.1 to 182.32.36.126182.32.36.127126
74182.32.36.128/25182.32.36.129 to 182.32.36.254182.32.36.255126
75182.32.37.0/25182.32.37.1 to 182.32.37.126182.32.37.127126
76182.32.37.128/25182.32.37.129 to 182.32.37.254182.32.37.255126
77182.32.38.0/25182.32.38.1 to 182.32.38.126182.32.38.127126
78182.32.38.128/25182.32.38.129 to 182.32.38.254182.32.38.255126
79182.32.39.0/25182.32.39.1 to 182.32.39.126182.32.39.127126
80182.32.39.128/25182.32.39.129 to 182.32.39.254182.32.39.255126
81182.32.40.0/25182.32.40.1 to 182.32.40.126182.32.40.127126
82182.32.40.128/25182.32.40.129 to 182.32.40.254182.32.40.255126
83182.32.41.0/25182.32.41.1 to 182.32.41.126182.32.41.127126
84182.32.41.128/25182.32.41.129 to 182.32.41.254182.32.41.255126
85182.32.42.0/25182.32.42.1 to 182.32.42.126182.32.42.127126
86182.32.42.128/25182.32.42.129 to 182.32.42.254182.32.42.255126
87182.32.43.0/25182.32.43.1 to 182.32.43.126182.32.43.127126
88182.32.43.128/25182.32.43.129 to 182.32.43.254182.32.43.255126
89182.32.44.0/25182.32.44.1 to 182.32.44.126182.32.44.127126
90182.32.44.128/25182.32.44.129 to 182.32.44.254182.32.44.255126
91182.32.45.0/25182.32.45.1 to 182.32.45.126182.32.45.127126
92182.32.45.128/25182.32.45.129 to 182.32.45.254182.32.45.255126
93182.32.46.0/25182.32.46.1 to 182.32.46.126182.32.46.127126
94182.32.46.128/25182.32.46.129 to 182.32.46.254182.32.46.255126
95182.32.47.0/25182.32.47.1 to 182.32.47.126182.32.47.127126
96182.32.47.128/25182.32.47.129 to 182.32.47.254182.32.47.255126
97182.32.48.0/25182.32.48.1 to 182.32.48.126182.32.48.127126
98182.32.48.128/25182.32.48.129 to 182.32.48.254182.32.48.255126
99182.32.49.0/25182.32.49.1 to 182.32.49.126182.32.49.127126
100182.32.49.128/25182.32.49.129 to 182.32.49.254182.32.49.255126
101182.32.50.0/25182.32.50.1 to 182.32.50.126182.32.50.127126
102182.32.50.128/25182.32.50.129 to 182.32.50.254182.32.50.255126
103182.32.51.0/25182.32.51.1 to 182.32.51.126182.32.51.127126
104182.32.51.128/25182.32.51.129 to 182.32.51.254182.32.51.255126
105182.32.52.0/25182.32.52.1 to 182.32.52.126182.32.52.127126
106182.32.52.128/25182.32.52.129 to 182.32.52.254182.32.52.255126
107182.32.53.0/25182.32.53.1 to 182.32.53.126182.32.53.127126
108182.32.53.128/25182.32.53.129 to 182.32.53.254182.32.53.255126
109182.32.54.0/25182.32.54.1 to 182.32.54.126182.32.54.127126
110182.32.54.128/25182.32.54.129 to 182.32.54.254182.32.54.255126
111182.32.55.0/25182.32.55.1 to 182.32.55.126182.32.55.127126
112182.32.55.128/25182.32.55.129 to 182.32.55.254182.32.55.255126
113182.32.56.0/25182.32.56.1 to 182.32.56.126182.32.56.127126
114182.32.56.128/25182.32.56.129 to 182.32.56.254182.32.56.255126
115182.32.57.0/25182.32.57.1 to 182.32.57.126182.32.57.127126
116182.32.57.128/25182.32.57.129 to 182.32.57.254182.32.57.255126
117182.32.58.0/25182.32.58.1 to 182.32.58.126182.32.58.127126
118182.32.58.128/25182.32.58.129 to 182.32.58.254182.32.58.255126
119182.32.59.0/25182.32.59.1 to 182.32.59.126182.32.59.127126
120182.32.59.128/25182.32.59.129 to 182.32.59.254182.32.59.255126
121182.32.60.0/25182.32.60.1 to 182.32.60.126182.32.60.127126
122182.32.60.128/25182.32.60.129 to 182.32.60.254182.32.60.255126
123182.32.61.0/25182.32.61.1 to 182.32.61.126182.32.61.127126
124182.32.61.128/25182.32.61.129 to 182.32.61.254182.32.61.255126
125182.32.62.0/25182.32.62.1 to 182.32.62.126182.32.62.127126
126182.32.62.128/25182.32.62.129 to 182.32.62.254182.32.62.255126
127182.32.63.0/25182.32.63.1 to 182.32.63.126182.32.63.127126
128182.32.63.128/25182.32.63.129 to 182.32.63.254182.32.63.255126
129182.32.64.0/25182.32.64.1 to 182.32.64.126182.32.64.127126
130182.32.64.128/25182.32.64.129 to 182.32.64.254182.32.64.255126
131182.32.65.0/25182.32.65.1 to 182.32.65.126182.32.65.127126
132182.32.65.128/25182.32.65.129 to 182.32.65.254182.32.65.255126
133182.32.66.0/25182.32.66.1 to 182.32.66.126182.32.66.127126
134182.32.66.128/25182.32.66.129 to 182.32.66.254182.32.66.255126
135182.32.67.0/25182.32.67.1 to 182.32.67.126182.32.67.127126
136182.32.67.128/25182.32.67.129 to 182.32.67.254182.32.67.255126
137182.32.68.0/25182.32.68.1 to 182.32.68.126182.32.68.127126
138182.32.68.128/25182.32.68.129 to 182.32.68.254182.32.68.255126
139182.32.69.0/25182.32.69.1 to 182.32.69.126182.32.69.127126
140182.32.69.128/25182.32.69.129 to 182.32.69.254182.32.69.255126
141182.32.70.0/25182.32.70.1 to 182.32.70.126182.32.70.127126
142182.32.70.128/25182.32.70.129 to 182.32.70.254182.32.70.255126
143182.32.71.0/25182.32.71.1 to 182.32.71.126182.32.71.127126
144182.32.71.128/25182.32.71.129 to 182.32.71.254182.32.71.255126
145182.32.72.0/25182.32.72.1 to 182.32.72.126182.32.72.127126
146182.32.72.128/25182.32.72.129 to 182.32.72.254182.32.72.255126
147182.32.73.0/25182.32.73.1 to 182.32.73.126182.32.73.127126
148182.32.73.128/25182.32.73.129 to 182.32.73.254182.32.73.255126
149182.32.74.0/25182.32.74.1 to 182.32.74.126182.32.74.127126
150182.32.74.128/25182.32.74.129 to 182.32.74.254182.32.74.255126
151182.32.75.0/25182.32.75.1 to 182.32.75.126182.32.75.127126
152182.32.75.128/25182.32.75.129 to 182.32.75.254182.32.75.255126
153182.32.76.0/25182.32.76.1 to 182.32.76.126182.32.76.127126
154182.32.76.128/25182.32.76.129 to 182.32.76.254182.32.76.255126
155182.32.77.0/25182.32.77.1 to 182.32.77.126182.32.77.127126
156182.32.77.128/25182.32.77.129 to 182.32.77.254182.32.77.255126
157182.32.78.0/25182.32.78.1 to 182.32.78.126182.32.78.127126
158182.32.78.128/25182.32.78.129 to 182.32.78.254182.32.78.255126
159182.32.79.0/25182.32.79.1 to 182.32.79.126182.32.79.127126
160182.32.79.128/25182.32.79.129 to 182.32.79.254182.32.79.255126
161182.32.80.0/25182.32.80.1 to 182.32.80.126182.32.80.127126
162182.32.80.128/25182.32.80.129 to 182.32.80.254182.32.80.255126
163182.32.81.0/25182.32.81.1 to 182.32.81.126182.32.81.127126
164182.32.81.128/25182.32.81.129 to 182.32.81.254182.32.81.255126
165182.32.82.0/25182.32.82.1 to 182.32.82.126182.32.82.127126
166182.32.82.128/25182.32.82.129 to 182.32.82.254182.32.82.255126
167182.32.83.0/25182.32.83.1 to 182.32.83.126182.32.83.127126
168182.32.83.128/25182.32.83.129 to 182.32.83.254182.32.83.255126
169182.32.84.0/25182.32.84.1 to 182.32.84.126182.32.84.127126
170182.32.84.128/25182.32.84.129 to 182.32.84.254182.32.84.255126
171182.32.85.0/25182.32.85.1 to 182.32.85.126182.32.85.127126
172182.32.85.128/25182.32.85.129 to 182.32.85.254182.32.85.255126
173182.32.86.0/25182.32.86.1 to 182.32.86.126182.32.86.127126
174182.32.86.128/25182.32.86.129 to 182.32.86.254182.32.86.255126
175182.32.87.0/25182.32.87.1 to 182.32.87.126182.32.87.127126
176182.32.87.128/25182.32.87.129 to 182.32.87.254182.32.87.255126
177182.32.88.0/25182.32.88.1 to 182.32.88.126182.32.88.127126
178182.32.88.128/25182.32.88.129 to 182.32.88.254182.32.88.255126
179182.32.89.0/25182.32.89.1 to 182.32.89.126182.32.89.127126
180182.32.89.128/25182.32.89.129 to 182.32.89.254182.32.89.255126
181182.32.90.0/25182.32.90.1 to 182.32.90.126182.32.90.127126
182182.32.90.128/25182.32.90.129 to 182.32.90.254182.32.90.255126
183182.32.91.0/25182.32.91.1 to 182.32.91.126182.32.91.127126
184182.32.91.128/25182.32.91.129 to 182.32.91.254182.32.91.255126
185182.32.92.0/25182.32.92.1 to 182.32.92.126182.32.92.127126
186182.32.92.128/25182.32.92.129 to 182.32.92.254182.32.92.255126
187182.32.93.0/25182.32.93.1 to 182.32.93.126182.32.93.127126
188182.32.93.128/25182.32.93.129 to 182.32.93.254182.32.93.255126
189182.32.94.0/25182.32.94.1 to 182.32.94.126182.32.94.127126
190182.32.94.128/25182.32.94.129 to 182.32.94.254182.32.94.255126
191182.32.95.0/25182.32.95.1 to 182.32.95.126182.32.95.127126
192182.32.95.128/25182.32.95.129 to 182.32.95.254182.32.95.255126
193182.32.96.0/25182.32.96.1 to 182.32.96.126182.32.96.127126
194182.32.96.128/25182.32.96.129 to 182.32.96.254182.32.96.255126
195182.32.97.0/25182.32.97.1 to 182.32.97.126182.32.97.127126
196182.32.97.128/25182.32.97.129 to 182.32.97.254182.32.97.255126
197182.32.98.0/25182.32.98.1 to 182.32.98.126182.32.98.127126
198182.32.98.128/25182.32.98.129 to 182.32.98.254182.32.98.255126
199182.32.99.0/25182.32.99.1 to 182.32.99.126182.32.99.127126
200182.32.99.128/25182.32.99.129 to 182.32.99.254182.32.99.255126
201182.32.100.0/25182.32.100.1 to 182.32.100.126182.32.100.127126
202182.32.100.128/25182.32.100.129 to 182.32.100.254182.32.100.255126
203182.32.101.0/25182.32.101.1 to 182.32.101.126182.32.101.127126
204182.32.101.128/25182.32.101.129 to 182.32.101.254182.32.101.255126
205182.32.102.0/25182.32.102.1 to 182.32.102.126182.32.102.127126
206182.32.102.128/25182.32.102.129 to 182.32.102.254182.32.102.255126
207182.32.103.0/25182.32.103.1 to 182.32.103.126182.32.103.127126
208182.32.103.128/25182.32.103.129 to 182.32.103.254182.32.103.255126
209182.32.104.0/25182.32.104.1 to 182.32.104.126182.32.104.127126
210182.32.104.128/25182.32.104.129 to 182.32.104.254182.32.104.255126
211182.32.105.0/25182.32.105.1 to 182.32.105.126182.32.105.127126
212182.32.105.128/25182.32.105.129 to 182.32.105.254182.32.105.255126
213182.32.106.0/25182.32.106.1 to 182.32.106.126182.32.106.127126
214182.32.106.128/25182.32.106.129 to 182.32.106.254182.32.106.255126
215182.32.107.0/25182.32.107.1 to 182.32.107.126182.32.107.127126
216182.32.107.128/25182.32.107.129 to 182.32.107.254182.32.107.255126
217182.32.108.0/25182.32.108.1 to 182.32.108.126182.32.108.127126
218182.32.108.128/25182.32.108.129 to 182.32.108.254182.32.108.255126
219182.32.109.0/25182.32.109.1 to 182.32.109.126182.32.109.127126
220182.32.109.128/25182.32.109.129 to 182.32.109.254182.32.109.255126
221182.32.110.0/25182.32.110.1 to 182.32.110.126182.32.110.127126
222182.32.110.128/25182.32.110.129 to 182.32.110.254182.32.110.255126
223182.32.111.0/25182.32.111.1 to 182.32.111.126182.32.111.127126
224182.32.111.128/25182.32.111.129 to 182.32.111.254182.32.111.255126
225182.32.112.0/25182.32.112.1 to 182.32.112.126182.32.112.127126
226182.32.112.128/25182.32.112.129 to 182.32.112.254182.32.112.255126
227182.32.113.0/25182.32.113.1 to 182.32.113.126182.32.113.127126
228182.32.113.128/25182.32.113.129 to 182.32.113.254182.32.113.255126
229182.32.114.0/25182.32.114.1 to 182.32.114.126182.32.114.127126
230182.32.114.128/25182.32.114.129 to 182.32.114.254182.32.114.255126
231182.32.115.0/25182.32.115.1 to 182.32.115.126182.32.115.127126
232182.32.115.128/25182.32.115.129 to 182.32.115.254182.32.115.255126
233182.32.116.0/25182.32.116.1 to 182.32.116.126182.32.116.127126
234182.32.116.128/25182.32.116.129 to 182.32.116.254182.32.116.255126
235182.32.117.0/25182.32.117.1 to 182.32.117.126182.32.117.127126
236182.32.117.128/25182.32.117.129 to 182.32.117.254182.32.117.255126
237182.32.118.0/25182.32.118.1 to 182.32.118.126182.32.118.127126
238182.32.118.128/25182.32.118.129 to 182.32.118.254182.32.118.255126
239182.32.119.0/25182.32.119.1 to 182.32.119.126182.32.119.127126
240182.32.119.128/25182.32.119.129 to 182.32.119.254182.32.119.255126
241182.32.120.0/25182.32.120.1 to 182.32.120.126182.32.120.127126
242182.32.120.128/25182.32.120.129 to 182.32.120.254182.32.120.255126
243182.32.121.0/25182.32.121.1 to 182.32.121.126182.32.121.127126
244182.32.121.128/25182.32.121.129 to 182.32.121.254182.32.121.255126
245182.32.122.0/25182.32.122.1 to 182.32.122.126182.32.122.127126
246182.32.122.128/25182.32.122.129 to 182.32.122.254182.32.122.255126
247182.32.123.0/25182.32.123.1 to 182.32.123.126182.32.123.127126
248182.32.123.128/25182.32.123.129 to 182.32.123.254182.32.123.255126
249182.32.124.0/25182.32.124.1 to 182.32.124.126182.32.124.127126
250182.32.124.128/25182.32.124.129 to 182.32.124.254182.32.124.255126
251182.32.125.0/25182.32.125.1 to 182.32.125.126182.32.125.127126
252182.32.125.128/25182.32.125.129 to 182.32.125.254182.32.125.255126
253182.32.126.0/25182.32.126.1 to 182.32.126.126182.32.126.127126
254182.32.126.128/25182.32.126.129 to 182.32.126.254182.32.126.255126
255182.32.127.0/25182.32.127.1 to 182.32.127.126182.32.127.127126
256182.32.127.128/25182.32.127.129 to 182.32.127.254182.32.127.255126

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.