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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.

Network220.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
220.0.0.0
Broadcast address
223.255.255.255
First usable
220.0.0.1
Last usable
223.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
C (default /24)
As numbers
Hex DC000000 · Integer 3690987520 to 3758096383
Reverse DNS zones
220.in-addr.arpa
221.in-addr.arpa
222.in-addr.arpa
223.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011100.00000000.00000000.00000000220.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network11011100.00000000.00000000.00000000220.0.0.0
Broadcast11011111.11111111.11111111.11111111223.255.255.255
Split into smaller subnets/17
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

220.0.0.0/6 makes 2,048 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1220.0.0.0/17220.0.0.1 to 220.0.127.254220.0.127.25532,766
2220.0.128.0/17220.0.128.1 to 220.0.255.254220.0.255.25532,766
3220.1.0.0/17220.1.0.1 to 220.1.127.254220.1.127.25532,766
4220.1.128.0/17220.1.128.1 to 220.1.255.254220.1.255.25532,766
5220.2.0.0/17220.2.0.1 to 220.2.127.254220.2.127.25532,766
6220.2.128.0/17220.2.128.1 to 220.2.255.254220.2.255.25532,766
7220.3.0.0/17220.3.0.1 to 220.3.127.254220.3.127.25532,766
8220.3.128.0/17220.3.128.1 to 220.3.255.254220.3.255.25532,766
9220.4.0.0/17220.4.0.1 to 220.4.127.254220.4.127.25532,766
10220.4.128.0/17220.4.128.1 to 220.4.255.254220.4.255.25532,766
11220.5.0.0/17220.5.0.1 to 220.5.127.254220.5.127.25532,766
12220.5.128.0/17220.5.128.1 to 220.5.255.254220.5.255.25532,766
13220.6.0.0/17220.6.0.1 to 220.6.127.254220.6.127.25532,766
14220.6.128.0/17220.6.128.1 to 220.6.255.254220.6.255.25532,766
15220.7.0.0/17220.7.0.1 to 220.7.127.254220.7.127.25532,766
16220.7.128.0/17220.7.128.1 to 220.7.255.254220.7.255.25532,766
17220.8.0.0/17220.8.0.1 to 220.8.127.254220.8.127.25532,766
18220.8.128.0/17220.8.128.1 to 220.8.255.254220.8.255.25532,766
19220.9.0.0/17220.9.0.1 to 220.9.127.254220.9.127.25532,766
20220.9.128.0/17220.9.128.1 to 220.9.255.254220.9.255.25532,766
21220.10.0.0/17220.10.0.1 to 220.10.127.254220.10.127.25532,766
22220.10.128.0/17220.10.128.1 to 220.10.255.254220.10.255.25532,766
23220.11.0.0/17220.11.0.1 to 220.11.127.254220.11.127.25532,766
24220.11.128.0/17220.11.128.1 to 220.11.255.254220.11.255.25532,766
25220.12.0.0/17220.12.0.1 to 220.12.127.254220.12.127.25532,766
26220.12.128.0/17220.12.128.1 to 220.12.255.254220.12.255.25532,766
27220.13.0.0/17220.13.0.1 to 220.13.127.254220.13.127.25532,766
28220.13.128.0/17220.13.128.1 to 220.13.255.254220.13.255.25532,766
29220.14.0.0/17220.14.0.1 to 220.14.127.254220.14.127.25532,766
30220.14.128.0/17220.14.128.1 to 220.14.255.254220.14.255.25532,766
31220.15.0.0/17220.15.0.1 to 220.15.127.254220.15.127.25532,766
32220.15.128.0/17220.15.128.1 to 220.15.255.254220.15.255.25532,766
33220.16.0.0/17220.16.0.1 to 220.16.127.254220.16.127.25532,766
34220.16.128.0/17220.16.128.1 to 220.16.255.254220.16.255.25532,766
35220.17.0.0/17220.17.0.1 to 220.17.127.254220.17.127.25532,766
36220.17.128.0/17220.17.128.1 to 220.17.255.254220.17.255.25532,766
37220.18.0.0/17220.18.0.1 to 220.18.127.254220.18.127.25532,766
38220.18.128.0/17220.18.128.1 to 220.18.255.254220.18.255.25532,766
39220.19.0.0/17220.19.0.1 to 220.19.127.254220.19.127.25532,766
40220.19.128.0/17220.19.128.1 to 220.19.255.254220.19.255.25532,766
41220.20.0.0/17220.20.0.1 to 220.20.127.254220.20.127.25532,766
42220.20.128.0/17220.20.128.1 to 220.20.255.254220.20.255.25532,766
43220.21.0.0/17220.21.0.1 to 220.21.127.254220.21.127.25532,766
44220.21.128.0/17220.21.128.1 to 220.21.255.254220.21.255.25532,766
45220.22.0.0/17220.22.0.1 to 220.22.127.254220.22.127.25532,766
46220.22.128.0/17220.22.128.1 to 220.22.255.254220.22.255.25532,766
47220.23.0.0/17220.23.0.1 to 220.23.127.254220.23.127.25532,766
48220.23.128.0/17220.23.128.1 to 220.23.255.254220.23.255.25532,766
49220.24.0.0/17220.24.0.1 to 220.24.127.254220.24.127.25532,766
50220.24.128.0/17220.24.128.1 to 220.24.255.254220.24.255.25532,766
51220.25.0.0/17220.25.0.1 to 220.25.127.254220.25.127.25532,766
52220.25.128.0/17220.25.128.1 to 220.25.255.254220.25.255.25532,766
53220.26.0.0/17220.26.0.1 to 220.26.127.254220.26.127.25532,766
54220.26.128.0/17220.26.128.1 to 220.26.255.254220.26.255.25532,766
55220.27.0.0/17220.27.0.1 to 220.27.127.254220.27.127.25532,766
56220.27.128.0/17220.27.128.1 to 220.27.255.254220.27.255.25532,766
57220.28.0.0/17220.28.0.1 to 220.28.127.254220.28.127.25532,766
58220.28.128.0/17220.28.128.1 to 220.28.255.254220.28.255.25532,766
59220.29.0.0/17220.29.0.1 to 220.29.127.254220.29.127.25532,766
60220.29.128.0/17220.29.128.1 to 220.29.255.254220.29.255.25532,766
61220.30.0.0/17220.30.0.1 to 220.30.127.254220.30.127.25532,766
62220.30.128.0/17220.30.128.1 to 220.30.255.254220.30.255.25532,766
63220.31.0.0/17220.31.0.1 to 220.31.127.254220.31.127.25532,766
64220.31.128.0/17220.31.128.1 to 220.31.255.254220.31.255.25532,766
65220.32.0.0/17220.32.0.1 to 220.32.127.254220.32.127.25532,766
66220.32.128.0/17220.32.128.1 to 220.32.255.254220.32.255.25532,766
67220.33.0.0/17220.33.0.1 to 220.33.127.254220.33.127.25532,766
68220.33.128.0/17220.33.128.1 to 220.33.255.254220.33.255.25532,766
69220.34.0.0/17220.34.0.1 to 220.34.127.254220.34.127.25532,766
70220.34.128.0/17220.34.128.1 to 220.34.255.254220.34.255.25532,766
71220.35.0.0/17220.35.0.1 to 220.35.127.254220.35.127.25532,766
72220.35.128.0/17220.35.128.1 to 220.35.255.254220.35.255.25532,766
73220.36.0.0/17220.36.0.1 to 220.36.127.254220.36.127.25532,766
74220.36.128.0/17220.36.128.1 to 220.36.255.254220.36.255.25532,766
75220.37.0.0/17220.37.0.1 to 220.37.127.254220.37.127.25532,766
76220.37.128.0/17220.37.128.1 to 220.37.255.254220.37.255.25532,766
77220.38.0.0/17220.38.0.1 to 220.38.127.254220.38.127.25532,766
78220.38.128.0/17220.38.128.1 to 220.38.255.254220.38.255.25532,766
79220.39.0.0/17220.39.0.1 to 220.39.127.254220.39.127.25532,766
80220.39.128.0/17220.39.128.1 to 220.39.255.254220.39.255.25532,766
81220.40.0.0/17220.40.0.1 to 220.40.127.254220.40.127.25532,766
82220.40.128.0/17220.40.128.1 to 220.40.255.254220.40.255.25532,766
83220.41.0.0/17220.41.0.1 to 220.41.127.254220.41.127.25532,766
84220.41.128.0/17220.41.128.1 to 220.41.255.254220.41.255.25532,766
85220.42.0.0/17220.42.0.1 to 220.42.127.254220.42.127.25532,766
86220.42.128.0/17220.42.128.1 to 220.42.255.254220.42.255.25532,766
87220.43.0.0/17220.43.0.1 to 220.43.127.254220.43.127.25532,766
88220.43.128.0/17220.43.128.1 to 220.43.255.254220.43.255.25532,766
89220.44.0.0/17220.44.0.1 to 220.44.127.254220.44.127.25532,766
90220.44.128.0/17220.44.128.1 to 220.44.255.254220.44.255.25532,766
91220.45.0.0/17220.45.0.1 to 220.45.127.254220.45.127.25532,766
92220.45.128.0/17220.45.128.1 to 220.45.255.254220.45.255.25532,766
93220.46.0.0/17220.46.0.1 to 220.46.127.254220.46.127.25532,766
94220.46.128.0/17220.46.128.1 to 220.46.255.254220.46.255.25532,766
95220.47.0.0/17220.47.0.1 to 220.47.127.254220.47.127.25532,766
96220.47.128.0/17220.47.128.1 to 220.47.255.254220.47.255.25532,766
97220.48.0.0/17220.48.0.1 to 220.48.127.254220.48.127.25532,766
98220.48.128.0/17220.48.128.1 to 220.48.255.254220.48.255.25532,766
99220.49.0.0/17220.49.0.1 to 220.49.127.254220.49.127.25532,766
100220.49.128.0/17220.49.128.1 to 220.49.255.254220.49.255.25532,766
101220.50.0.0/17220.50.0.1 to 220.50.127.254220.50.127.25532,766
102220.50.128.0/17220.50.128.1 to 220.50.255.254220.50.255.25532,766
103220.51.0.0/17220.51.0.1 to 220.51.127.254220.51.127.25532,766
104220.51.128.0/17220.51.128.1 to 220.51.255.254220.51.255.25532,766
105220.52.0.0/17220.52.0.1 to 220.52.127.254220.52.127.25532,766
106220.52.128.0/17220.52.128.1 to 220.52.255.254220.52.255.25532,766
107220.53.0.0/17220.53.0.1 to 220.53.127.254220.53.127.25532,766
108220.53.128.0/17220.53.128.1 to 220.53.255.254220.53.255.25532,766
109220.54.0.0/17220.54.0.1 to 220.54.127.254220.54.127.25532,766
110220.54.128.0/17220.54.128.1 to 220.54.255.254220.54.255.25532,766
111220.55.0.0/17220.55.0.1 to 220.55.127.254220.55.127.25532,766
112220.55.128.0/17220.55.128.1 to 220.55.255.254220.55.255.25532,766
113220.56.0.0/17220.56.0.1 to 220.56.127.254220.56.127.25532,766
114220.56.128.0/17220.56.128.1 to 220.56.255.254220.56.255.25532,766
115220.57.0.0/17220.57.0.1 to 220.57.127.254220.57.127.25532,766
116220.57.128.0/17220.57.128.1 to 220.57.255.254220.57.255.25532,766
117220.58.0.0/17220.58.0.1 to 220.58.127.254220.58.127.25532,766
118220.58.128.0/17220.58.128.1 to 220.58.255.254220.58.255.25532,766
119220.59.0.0/17220.59.0.1 to 220.59.127.254220.59.127.25532,766
120220.59.128.0/17220.59.128.1 to 220.59.255.254220.59.255.25532,766
121220.60.0.0/17220.60.0.1 to 220.60.127.254220.60.127.25532,766
122220.60.128.0/17220.60.128.1 to 220.60.255.254220.60.255.25532,766
123220.61.0.0/17220.61.0.1 to 220.61.127.254220.61.127.25532,766
124220.61.128.0/17220.61.128.1 to 220.61.255.254220.61.255.25532,766
125220.62.0.0/17220.62.0.1 to 220.62.127.254220.62.127.25532,766
126220.62.128.0/17220.62.128.1 to 220.62.255.254220.62.255.25532,766
127220.63.0.0/17220.63.0.1 to 220.63.127.254220.63.127.25532,766
128220.63.128.0/17220.63.128.1 to 220.63.255.254220.63.255.25532,766
129220.64.0.0/17220.64.0.1 to 220.64.127.254220.64.127.25532,766
130220.64.128.0/17220.64.128.1 to 220.64.255.254220.64.255.25532,766
131220.65.0.0/17220.65.0.1 to 220.65.127.254220.65.127.25532,766
132220.65.128.0/17220.65.128.1 to 220.65.255.254220.65.255.25532,766
133220.66.0.0/17220.66.0.1 to 220.66.127.254220.66.127.25532,766
134220.66.128.0/17220.66.128.1 to 220.66.255.254220.66.255.25532,766
135220.67.0.0/17220.67.0.1 to 220.67.127.254220.67.127.25532,766
136220.67.128.0/17220.67.128.1 to 220.67.255.254220.67.255.25532,766
137220.68.0.0/17220.68.0.1 to 220.68.127.254220.68.127.25532,766
138220.68.128.0/17220.68.128.1 to 220.68.255.254220.68.255.25532,766
139220.69.0.0/17220.69.0.1 to 220.69.127.254220.69.127.25532,766
140220.69.128.0/17220.69.128.1 to 220.69.255.254220.69.255.25532,766
141220.70.0.0/17220.70.0.1 to 220.70.127.254220.70.127.25532,766
142220.70.128.0/17220.70.128.1 to 220.70.255.254220.70.255.25532,766
143220.71.0.0/17220.71.0.1 to 220.71.127.254220.71.127.25532,766
144220.71.128.0/17220.71.128.1 to 220.71.255.254220.71.255.25532,766
145220.72.0.0/17220.72.0.1 to 220.72.127.254220.72.127.25532,766
146220.72.128.0/17220.72.128.1 to 220.72.255.254220.72.255.25532,766
147220.73.0.0/17220.73.0.1 to 220.73.127.254220.73.127.25532,766
148220.73.128.0/17220.73.128.1 to 220.73.255.254220.73.255.25532,766
149220.74.0.0/17220.74.0.1 to 220.74.127.254220.74.127.25532,766
150220.74.128.0/17220.74.128.1 to 220.74.255.254220.74.255.25532,766
151220.75.0.0/17220.75.0.1 to 220.75.127.254220.75.127.25532,766
152220.75.128.0/17220.75.128.1 to 220.75.255.254220.75.255.25532,766
153220.76.0.0/17220.76.0.1 to 220.76.127.254220.76.127.25532,766
154220.76.128.0/17220.76.128.1 to 220.76.255.254220.76.255.25532,766
155220.77.0.0/17220.77.0.1 to 220.77.127.254220.77.127.25532,766
156220.77.128.0/17220.77.128.1 to 220.77.255.254220.77.255.25532,766
157220.78.0.0/17220.78.0.1 to 220.78.127.254220.78.127.25532,766
158220.78.128.0/17220.78.128.1 to 220.78.255.254220.78.255.25532,766
159220.79.0.0/17220.79.0.1 to 220.79.127.254220.79.127.25532,766
160220.79.128.0/17220.79.128.1 to 220.79.255.254220.79.255.25532,766
161220.80.0.0/17220.80.0.1 to 220.80.127.254220.80.127.25532,766
162220.80.128.0/17220.80.128.1 to 220.80.255.254220.80.255.25532,766
163220.81.0.0/17220.81.0.1 to 220.81.127.254220.81.127.25532,766
164220.81.128.0/17220.81.128.1 to 220.81.255.254220.81.255.25532,766
165220.82.0.0/17220.82.0.1 to 220.82.127.254220.82.127.25532,766
166220.82.128.0/17220.82.128.1 to 220.82.255.254220.82.255.25532,766
167220.83.0.0/17220.83.0.1 to 220.83.127.254220.83.127.25532,766
168220.83.128.0/17220.83.128.1 to 220.83.255.254220.83.255.25532,766
169220.84.0.0/17220.84.0.1 to 220.84.127.254220.84.127.25532,766
170220.84.128.0/17220.84.128.1 to 220.84.255.254220.84.255.25532,766
171220.85.0.0/17220.85.0.1 to 220.85.127.254220.85.127.25532,766
172220.85.128.0/17220.85.128.1 to 220.85.255.254220.85.255.25532,766
173220.86.0.0/17220.86.0.1 to 220.86.127.254220.86.127.25532,766
174220.86.128.0/17220.86.128.1 to 220.86.255.254220.86.255.25532,766
175220.87.0.0/17220.87.0.1 to 220.87.127.254220.87.127.25532,766
176220.87.128.0/17220.87.128.1 to 220.87.255.254220.87.255.25532,766
177220.88.0.0/17220.88.0.1 to 220.88.127.254220.88.127.25532,766
178220.88.128.0/17220.88.128.1 to 220.88.255.254220.88.255.25532,766
179220.89.0.0/17220.89.0.1 to 220.89.127.254220.89.127.25532,766
180220.89.128.0/17220.89.128.1 to 220.89.255.254220.89.255.25532,766
181220.90.0.0/17220.90.0.1 to 220.90.127.254220.90.127.25532,766
182220.90.128.0/17220.90.128.1 to 220.90.255.254220.90.255.25532,766
183220.91.0.0/17220.91.0.1 to 220.91.127.254220.91.127.25532,766
184220.91.128.0/17220.91.128.1 to 220.91.255.254220.91.255.25532,766
185220.92.0.0/17220.92.0.1 to 220.92.127.254220.92.127.25532,766
186220.92.128.0/17220.92.128.1 to 220.92.255.254220.92.255.25532,766
187220.93.0.0/17220.93.0.1 to 220.93.127.254220.93.127.25532,766
188220.93.128.0/17220.93.128.1 to 220.93.255.254220.93.255.25532,766
189220.94.0.0/17220.94.0.1 to 220.94.127.254220.94.127.25532,766
190220.94.128.0/17220.94.128.1 to 220.94.255.254220.94.255.25532,766
191220.95.0.0/17220.95.0.1 to 220.95.127.254220.95.127.25532,766
192220.95.128.0/17220.95.128.1 to 220.95.255.254220.95.255.25532,766
193220.96.0.0/17220.96.0.1 to 220.96.127.254220.96.127.25532,766
194220.96.128.0/17220.96.128.1 to 220.96.255.254220.96.255.25532,766
195220.97.0.0/17220.97.0.1 to 220.97.127.254220.97.127.25532,766
196220.97.128.0/17220.97.128.1 to 220.97.255.254220.97.255.25532,766
197220.98.0.0/17220.98.0.1 to 220.98.127.254220.98.127.25532,766
198220.98.128.0/17220.98.128.1 to 220.98.255.254220.98.255.25532,766
199220.99.0.0/17220.99.0.1 to 220.99.127.254220.99.127.25532,766
200220.99.128.0/17220.99.128.1 to 220.99.255.254220.99.255.25532,766
201220.100.0.0/17220.100.0.1 to 220.100.127.254220.100.127.25532,766
202220.100.128.0/17220.100.128.1 to 220.100.255.254220.100.255.25532,766
203220.101.0.0/17220.101.0.1 to 220.101.127.254220.101.127.25532,766
204220.101.128.0/17220.101.128.1 to 220.101.255.254220.101.255.25532,766
205220.102.0.0/17220.102.0.1 to 220.102.127.254220.102.127.25532,766
206220.102.128.0/17220.102.128.1 to 220.102.255.254220.102.255.25532,766
207220.103.0.0/17220.103.0.1 to 220.103.127.254220.103.127.25532,766
208220.103.128.0/17220.103.128.1 to 220.103.255.254220.103.255.25532,766
209220.104.0.0/17220.104.0.1 to 220.104.127.254220.104.127.25532,766
210220.104.128.0/17220.104.128.1 to 220.104.255.254220.104.255.25532,766
211220.105.0.0/17220.105.0.1 to 220.105.127.254220.105.127.25532,766
212220.105.128.0/17220.105.128.1 to 220.105.255.254220.105.255.25532,766
213220.106.0.0/17220.106.0.1 to 220.106.127.254220.106.127.25532,766
214220.106.128.0/17220.106.128.1 to 220.106.255.254220.106.255.25532,766
215220.107.0.0/17220.107.0.1 to 220.107.127.254220.107.127.25532,766
216220.107.128.0/17220.107.128.1 to 220.107.255.254220.107.255.25532,766
217220.108.0.0/17220.108.0.1 to 220.108.127.254220.108.127.25532,766
218220.108.128.0/17220.108.128.1 to 220.108.255.254220.108.255.25532,766
219220.109.0.0/17220.109.0.1 to 220.109.127.254220.109.127.25532,766
220220.109.128.0/17220.109.128.1 to 220.109.255.254220.109.255.25532,766
221220.110.0.0/17220.110.0.1 to 220.110.127.254220.110.127.25532,766
222220.110.128.0/17220.110.128.1 to 220.110.255.254220.110.255.25532,766
223220.111.0.0/17220.111.0.1 to 220.111.127.254220.111.127.25532,766
224220.111.128.0/17220.111.128.1 to 220.111.255.254220.111.255.25532,766
225220.112.0.0/17220.112.0.1 to 220.112.127.254220.112.127.25532,766
226220.112.128.0/17220.112.128.1 to 220.112.255.254220.112.255.25532,766
227220.113.0.0/17220.113.0.1 to 220.113.127.254220.113.127.25532,766
228220.113.128.0/17220.113.128.1 to 220.113.255.254220.113.255.25532,766
229220.114.0.0/17220.114.0.1 to 220.114.127.254220.114.127.25532,766
230220.114.128.0/17220.114.128.1 to 220.114.255.254220.114.255.25532,766
231220.115.0.0/17220.115.0.1 to 220.115.127.254220.115.127.25532,766
232220.115.128.0/17220.115.128.1 to 220.115.255.254220.115.255.25532,766
233220.116.0.0/17220.116.0.1 to 220.116.127.254220.116.127.25532,766
234220.116.128.0/17220.116.128.1 to 220.116.255.254220.116.255.25532,766
235220.117.0.0/17220.117.0.1 to 220.117.127.254220.117.127.25532,766
236220.117.128.0/17220.117.128.1 to 220.117.255.254220.117.255.25532,766
237220.118.0.0/17220.118.0.1 to 220.118.127.254220.118.127.25532,766
238220.118.128.0/17220.118.128.1 to 220.118.255.254220.118.255.25532,766
239220.119.0.0/17220.119.0.1 to 220.119.127.254220.119.127.25532,766
240220.119.128.0/17220.119.128.1 to 220.119.255.254220.119.255.25532,766
241220.120.0.0/17220.120.0.1 to 220.120.127.254220.120.127.25532,766
242220.120.128.0/17220.120.128.1 to 220.120.255.254220.120.255.25532,766
243220.121.0.0/17220.121.0.1 to 220.121.127.254220.121.127.25532,766
244220.121.128.0/17220.121.128.1 to 220.121.255.254220.121.255.25532,766
245220.122.0.0/17220.122.0.1 to 220.122.127.254220.122.127.25532,766
246220.122.128.0/17220.122.128.1 to 220.122.255.254220.122.255.25532,766
247220.123.0.0/17220.123.0.1 to 220.123.127.254220.123.127.25532,766
248220.123.128.0/17220.123.128.1 to 220.123.255.254220.123.255.25532,766
249220.124.0.0/17220.124.0.1 to 220.124.127.254220.124.127.25532,766
250220.124.128.0/17220.124.128.1 to 220.124.255.254220.124.255.25532,766
251220.125.0.0/17220.125.0.1 to 220.125.127.254220.125.127.25532,766
252220.125.128.0/17220.125.128.1 to 220.125.255.254220.125.255.25532,766
253220.126.0.0/17220.126.0.1 to 220.126.127.254220.126.127.25532,766
254220.126.128.0/17220.126.128.1 to 220.126.255.254220.126.255.25532,766
255220.127.0.0/17220.127.0.1 to 220.127.127.254220.127.127.25532,766
256220.127.128.0/17220.127.128.1 to 220.127.255.254220.127.255.25532,766

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.