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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.

Network110.100.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
110.100.0.0
Broadcast address
110.100.255.255
First usable
110.100.0.1
Last usable
110.100.255.254
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 6E640000 · Integer 1852047360 to 1852112895
Reverse DNS zone
100.110.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101110.01100100..00000000.00000000110.100.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01101110.01100100..00000000.00000000110.100.0.0
Broadcast01101110.01100100..11111111.11111111110.100.255.255
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)

110.100.0.0/16 makes 512 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1110.100.0.0/25110.100.0.1 to 110.100.0.126110.100.0.127126
2110.100.0.128/25110.100.0.129 to 110.100.0.254110.100.0.255126
3110.100.1.0/25110.100.1.1 to 110.100.1.126110.100.1.127126
4110.100.1.128/25110.100.1.129 to 110.100.1.254110.100.1.255126
5110.100.2.0/25110.100.2.1 to 110.100.2.126110.100.2.127126
6110.100.2.128/25110.100.2.129 to 110.100.2.254110.100.2.255126
7110.100.3.0/25110.100.3.1 to 110.100.3.126110.100.3.127126
8110.100.3.128/25110.100.3.129 to 110.100.3.254110.100.3.255126
9110.100.4.0/25110.100.4.1 to 110.100.4.126110.100.4.127126
10110.100.4.128/25110.100.4.129 to 110.100.4.254110.100.4.255126
11110.100.5.0/25110.100.5.1 to 110.100.5.126110.100.5.127126
12110.100.5.128/25110.100.5.129 to 110.100.5.254110.100.5.255126
13110.100.6.0/25110.100.6.1 to 110.100.6.126110.100.6.127126
14110.100.6.128/25110.100.6.129 to 110.100.6.254110.100.6.255126
15110.100.7.0/25110.100.7.1 to 110.100.7.126110.100.7.127126
16110.100.7.128/25110.100.7.129 to 110.100.7.254110.100.7.255126
17110.100.8.0/25110.100.8.1 to 110.100.8.126110.100.8.127126
18110.100.8.128/25110.100.8.129 to 110.100.8.254110.100.8.255126
19110.100.9.0/25110.100.9.1 to 110.100.9.126110.100.9.127126
20110.100.9.128/25110.100.9.129 to 110.100.9.254110.100.9.255126
21110.100.10.0/25110.100.10.1 to 110.100.10.126110.100.10.127126
22110.100.10.128/25110.100.10.129 to 110.100.10.254110.100.10.255126
23110.100.11.0/25110.100.11.1 to 110.100.11.126110.100.11.127126
24110.100.11.128/25110.100.11.129 to 110.100.11.254110.100.11.255126
25110.100.12.0/25110.100.12.1 to 110.100.12.126110.100.12.127126
26110.100.12.128/25110.100.12.129 to 110.100.12.254110.100.12.255126
27110.100.13.0/25110.100.13.1 to 110.100.13.126110.100.13.127126
28110.100.13.128/25110.100.13.129 to 110.100.13.254110.100.13.255126
29110.100.14.0/25110.100.14.1 to 110.100.14.126110.100.14.127126
30110.100.14.128/25110.100.14.129 to 110.100.14.254110.100.14.255126
31110.100.15.0/25110.100.15.1 to 110.100.15.126110.100.15.127126
32110.100.15.128/25110.100.15.129 to 110.100.15.254110.100.15.255126
33110.100.16.0/25110.100.16.1 to 110.100.16.126110.100.16.127126
34110.100.16.128/25110.100.16.129 to 110.100.16.254110.100.16.255126
35110.100.17.0/25110.100.17.1 to 110.100.17.126110.100.17.127126
36110.100.17.128/25110.100.17.129 to 110.100.17.254110.100.17.255126
37110.100.18.0/25110.100.18.1 to 110.100.18.126110.100.18.127126
38110.100.18.128/25110.100.18.129 to 110.100.18.254110.100.18.255126
39110.100.19.0/25110.100.19.1 to 110.100.19.126110.100.19.127126
40110.100.19.128/25110.100.19.129 to 110.100.19.254110.100.19.255126
41110.100.20.0/25110.100.20.1 to 110.100.20.126110.100.20.127126
42110.100.20.128/25110.100.20.129 to 110.100.20.254110.100.20.255126
43110.100.21.0/25110.100.21.1 to 110.100.21.126110.100.21.127126
44110.100.21.128/25110.100.21.129 to 110.100.21.254110.100.21.255126
45110.100.22.0/25110.100.22.1 to 110.100.22.126110.100.22.127126
46110.100.22.128/25110.100.22.129 to 110.100.22.254110.100.22.255126
47110.100.23.0/25110.100.23.1 to 110.100.23.126110.100.23.127126
48110.100.23.128/25110.100.23.129 to 110.100.23.254110.100.23.255126
49110.100.24.0/25110.100.24.1 to 110.100.24.126110.100.24.127126
50110.100.24.128/25110.100.24.129 to 110.100.24.254110.100.24.255126
51110.100.25.0/25110.100.25.1 to 110.100.25.126110.100.25.127126
52110.100.25.128/25110.100.25.129 to 110.100.25.254110.100.25.255126
53110.100.26.0/25110.100.26.1 to 110.100.26.126110.100.26.127126
54110.100.26.128/25110.100.26.129 to 110.100.26.254110.100.26.255126
55110.100.27.0/25110.100.27.1 to 110.100.27.126110.100.27.127126
56110.100.27.128/25110.100.27.129 to 110.100.27.254110.100.27.255126
57110.100.28.0/25110.100.28.1 to 110.100.28.126110.100.28.127126
58110.100.28.128/25110.100.28.129 to 110.100.28.254110.100.28.255126
59110.100.29.0/25110.100.29.1 to 110.100.29.126110.100.29.127126
60110.100.29.128/25110.100.29.129 to 110.100.29.254110.100.29.255126
61110.100.30.0/25110.100.30.1 to 110.100.30.126110.100.30.127126
62110.100.30.128/25110.100.30.129 to 110.100.30.254110.100.30.255126
63110.100.31.0/25110.100.31.1 to 110.100.31.126110.100.31.127126
64110.100.31.128/25110.100.31.129 to 110.100.31.254110.100.31.255126
65110.100.32.0/25110.100.32.1 to 110.100.32.126110.100.32.127126
66110.100.32.128/25110.100.32.129 to 110.100.32.254110.100.32.255126
67110.100.33.0/25110.100.33.1 to 110.100.33.126110.100.33.127126
68110.100.33.128/25110.100.33.129 to 110.100.33.254110.100.33.255126
69110.100.34.0/25110.100.34.1 to 110.100.34.126110.100.34.127126
70110.100.34.128/25110.100.34.129 to 110.100.34.254110.100.34.255126
71110.100.35.0/25110.100.35.1 to 110.100.35.126110.100.35.127126
72110.100.35.128/25110.100.35.129 to 110.100.35.254110.100.35.255126
73110.100.36.0/25110.100.36.1 to 110.100.36.126110.100.36.127126
74110.100.36.128/25110.100.36.129 to 110.100.36.254110.100.36.255126
75110.100.37.0/25110.100.37.1 to 110.100.37.126110.100.37.127126
76110.100.37.128/25110.100.37.129 to 110.100.37.254110.100.37.255126
77110.100.38.0/25110.100.38.1 to 110.100.38.126110.100.38.127126
78110.100.38.128/25110.100.38.129 to 110.100.38.254110.100.38.255126
79110.100.39.0/25110.100.39.1 to 110.100.39.126110.100.39.127126
80110.100.39.128/25110.100.39.129 to 110.100.39.254110.100.39.255126
81110.100.40.0/25110.100.40.1 to 110.100.40.126110.100.40.127126
82110.100.40.128/25110.100.40.129 to 110.100.40.254110.100.40.255126
83110.100.41.0/25110.100.41.1 to 110.100.41.126110.100.41.127126
84110.100.41.128/25110.100.41.129 to 110.100.41.254110.100.41.255126
85110.100.42.0/25110.100.42.1 to 110.100.42.126110.100.42.127126
86110.100.42.128/25110.100.42.129 to 110.100.42.254110.100.42.255126
87110.100.43.0/25110.100.43.1 to 110.100.43.126110.100.43.127126
88110.100.43.128/25110.100.43.129 to 110.100.43.254110.100.43.255126
89110.100.44.0/25110.100.44.1 to 110.100.44.126110.100.44.127126
90110.100.44.128/25110.100.44.129 to 110.100.44.254110.100.44.255126
91110.100.45.0/25110.100.45.1 to 110.100.45.126110.100.45.127126
92110.100.45.128/25110.100.45.129 to 110.100.45.254110.100.45.255126
93110.100.46.0/25110.100.46.1 to 110.100.46.126110.100.46.127126
94110.100.46.128/25110.100.46.129 to 110.100.46.254110.100.46.255126
95110.100.47.0/25110.100.47.1 to 110.100.47.126110.100.47.127126
96110.100.47.128/25110.100.47.129 to 110.100.47.254110.100.47.255126
97110.100.48.0/25110.100.48.1 to 110.100.48.126110.100.48.127126
98110.100.48.128/25110.100.48.129 to 110.100.48.254110.100.48.255126
99110.100.49.0/25110.100.49.1 to 110.100.49.126110.100.49.127126
100110.100.49.128/25110.100.49.129 to 110.100.49.254110.100.49.255126
101110.100.50.0/25110.100.50.1 to 110.100.50.126110.100.50.127126
102110.100.50.128/25110.100.50.129 to 110.100.50.254110.100.50.255126
103110.100.51.0/25110.100.51.1 to 110.100.51.126110.100.51.127126
104110.100.51.128/25110.100.51.129 to 110.100.51.254110.100.51.255126
105110.100.52.0/25110.100.52.1 to 110.100.52.126110.100.52.127126
106110.100.52.128/25110.100.52.129 to 110.100.52.254110.100.52.255126
107110.100.53.0/25110.100.53.1 to 110.100.53.126110.100.53.127126
108110.100.53.128/25110.100.53.129 to 110.100.53.254110.100.53.255126
109110.100.54.0/25110.100.54.1 to 110.100.54.126110.100.54.127126
110110.100.54.128/25110.100.54.129 to 110.100.54.254110.100.54.255126
111110.100.55.0/25110.100.55.1 to 110.100.55.126110.100.55.127126
112110.100.55.128/25110.100.55.129 to 110.100.55.254110.100.55.255126
113110.100.56.0/25110.100.56.1 to 110.100.56.126110.100.56.127126
114110.100.56.128/25110.100.56.129 to 110.100.56.254110.100.56.255126
115110.100.57.0/25110.100.57.1 to 110.100.57.126110.100.57.127126
116110.100.57.128/25110.100.57.129 to 110.100.57.254110.100.57.255126
117110.100.58.0/25110.100.58.1 to 110.100.58.126110.100.58.127126
118110.100.58.128/25110.100.58.129 to 110.100.58.254110.100.58.255126
119110.100.59.0/25110.100.59.1 to 110.100.59.126110.100.59.127126
120110.100.59.128/25110.100.59.129 to 110.100.59.254110.100.59.255126
121110.100.60.0/25110.100.60.1 to 110.100.60.126110.100.60.127126
122110.100.60.128/25110.100.60.129 to 110.100.60.254110.100.60.255126
123110.100.61.0/25110.100.61.1 to 110.100.61.126110.100.61.127126
124110.100.61.128/25110.100.61.129 to 110.100.61.254110.100.61.255126
125110.100.62.0/25110.100.62.1 to 110.100.62.126110.100.62.127126
126110.100.62.128/25110.100.62.129 to 110.100.62.254110.100.62.255126
127110.100.63.0/25110.100.63.1 to 110.100.63.126110.100.63.127126
128110.100.63.128/25110.100.63.129 to 110.100.63.254110.100.63.255126
129110.100.64.0/25110.100.64.1 to 110.100.64.126110.100.64.127126
130110.100.64.128/25110.100.64.129 to 110.100.64.254110.100.64.255126
131110.100.65.0/25110.100.65.1 to 110.100.65.126110.100.65.127126
132110.100.65.128/25110.100.65.129 to 110.100.65.254110.100.65.255126
133110.100.66.0/25110.100.66.1 to 110.100.66.126110.100.66.127126
134110.100.66.128/25110.100.66.129 to 110.100.66.254110.100.66.255126
135110.100.67.0/25110.100.67.1 to 110.100.67.126110.100.67.127126
136110.100.67.128/25110.100.67.129 to 110.100.67.254110.100.67.255126
137110.100.68.0/25110.100.68.1 to 110.100.68.126110.100.68.127126
138110.100.68.128/25110.100.68.129 to 110.100.68.254110.100.68.255126
139110.100.69.0/25110.100.69.1 to 110.100.69.126110.100.69.127126
140110.100.69.128/25110.100.69.129 to 110.100.69.254110.100.69.255126
141110.100.70.0/25110.100.70.1 to 110.100.70.126110.100.70.127126
142110.100.70.128/25110.100.70.129 to 110.100.70.254110.100.70.255126
143110.100.71.0/25110.100.71.1 to 110.100.71.126110.100.71.127126
144110.100.71.128/25110.100.71.129 to 110.100.71.254110.100.71.255126
145110.100.72.0/25110.100.72.1 to 110.100.72.126110.100.72.127126
146110.100.72.128/25110.100.72.129 to 110.100.72.254110.100.72.255126
147110.100.73.0/25110.100.73.1 to 110.100.73.126110.100.73.127126
148110.100.73.128/25110.100.73.129 to 110.100.73.254110.100.73.255126
149110.100.74.0/25110.100.74.1 to 110.100.74.126110.100.74.127126
150110.100.74.128/25110.100.74.129 to 110.100.74.254110.100.74.255126
151110.100.75.0/25110.100.75.1 to 110.100.75.126110.100.75.127126
152110.100.75.128/25110.100.75.129 to 110.100.75.254110.100.75.255126
153110.100.76.0/25110.100.76.1 to 110.100.76.126110.100.76.127126
154110.100.76.128/25110.100.76.129 to 110.100.76.254110.100.76.255126
155110.100.77.0/25110.100.77.1 to 110.100.77.126110.100.77.127126
156110.100.77.128/25110.100.77.129 to 110.100.77.254110.100.77.255126
157110.100.78.0/25110.100.78.1 to 110.100.78.126110.100.78.127126
158110.100.78.128/25110.100.78.129 to 110.100.78.254110.100.78.255126
159110.100.79.0/25110.100.79.1 to 110.100.79.126110.100.79.127126
160110.100.79.128/25110.100.79.129 to 110.100.79.254110.100.79.255126
161110.100.80.0/25110.100.80.1 to 110.100.80.126110.100.80.127126
162110.100.80.128/25110.100.80.129 to 110.100.80.254110.100.80.255126
163110.100.81.0/25110.100.81.1 to 110.100.81.126110.100.81.127126
164110.100.81.128/25110.100.81.129 to 110.100.81.254110.100.81.255126
165110.100.82.0/25110.100.82.1 to 110.100.82.126110.100.82.127126
166110.100.82.128/25110.100.82.129 to 110.100.82.254110.100.82.255126
167110.100.83.0/25110.100.83.1 to 110.100.83.126110.100.83.127126
168110.100.83.128/25110.100.83.129 to 110.100.83.254110.100.83.255126
169110.100.84.0/25110.100.84.1 to 110.100.84.126110.100.84.127126
170110.100.84.128/25110.100.84.129 to 110.100.84.254110.100.84.255126
171110.100.85.0/25110.100.85.1 to 110.100.85.126110.100.85.127126
172110.100.85.128/25110.100.85.129 to 110.100.85.254110.100.85.255126
173110.100.86.0/25110.100.86.1 to 110.100.86.126110.100.86.127126
174110.100.86.128/25110.100.86.129 to 110.100.86.254110.100.86.255126
175110.100.87.0/25110.100.87.1 to 110.100.87.126110.100.87.127126
176110.100.87.128/25110.100.87.129 to 110.100.87.254110.100.87.255126
177110.100.88.0/25110.100.88.1 to 110.100.88.126110.100.88.127126
178110.100.88.128/25110.100.88.129 to 110.100.88.254110.100.88.255126
179110.100.89.0/25110.100.89.1 to 110.100.89.126110.100.89.127126
180110.100.89.128/25110.100.89.129 to 110.100.89.254110.100.89.255126
181110.100.90.0/25110.100.90.1 to 110.100.90.126110.100.90.127126
182110.100.90.128/25110.100.90.129 to 110.100.90.254110.100.90.255126
183110.100.91.0/25110.100.91.1 to 110.100.91.126110.100.91.127126
184110.100.91.128/25110.100.91.129 to 110.100.91.254110.100.91.255126
185110.100.92.0/25110.100.92.1 to 110.100.92.126110.100.92.127126
186110.100.92.128/25110.100.92.129 to 110.100.92.254110.100.92.255126
187110.100.93.0/25110.100.93.1 to 110.100.93.126110.100.93.127126
188110.100.93.128/25110.100.93.129 to 110.100.93.254110.100.93.255126
189110.100.94.0/25110.100.94.1 to 110.100.94.126110.100.94.127126
190110.100.94.128/25110.100.94.129 to 110.100.94.254110.100.94.255126
191110.100.95.0/25110.100.95.1 to 110.100.95.126110.100.95.127126
192110.100.95.128/25110.100.95.129 to 110.100.95.254110.100.95.255126
193110.100.96.0/25110.100.96.1 to 110.100.96.126110.100.96.127126
194110.100.96.128/25110.100.96.129 to 110.100.96.254110.100.96.255126
195110.100.97.0/25110.100.97.1 to 110.100.97.126110.100.97.127126
196110.100.97.128/25110.100.97.129 to 110.100.97.254110.100.97.255126
197110.100.98.0/25110.100.98.1 to 110.100.98.126110.100.98.127126
198110.100.98.128/25110.100.98.129 to 110.100.98.254110.100.98.255126
199110.100.99.0/25110.100.99.1 to 110.100.99.126110.100.99.127126
200110.100.99.128/25110.100.99.129 to 110.100.99.254110.100.99.255126
201110.100.100.0/25110.100.100.1 to 110.100.100.126110.100.100.127126
202110.100.100.128/25110.100.100.129 to 110.100.100.254110.100.100.255126
203110.100.101.0/25110.100.101.1 to 110.100.101.126110.100.101.127126
204110.100.101.128/25110.100.101.129 to 110.100.101.254110.100.101.255126
205110.100.102.0/25110.100.102.1 to 110.100.102.126110.100.102.127126
206110.100.102.128/25110.100.102.129 to 110.100.102.254110.100.102.255126
207110.100.103.0/25110.100.103.1 to 110.100.103.126110.100.103.127126
208110.100.103.128/25110.100.103.129 to 110.100.103.254110.100.103.255126
209110.100.104.0/25110.100.104.1 to 110.100.104.126110.100.104.127126
210110.100.104.128/25110.100.104.129 to 110.100.104.254110.100.104.255126
211110.100.105.0/25110.100.105.1 to 110.100.105.126110.100.105.127126
212110.100.105.128/25110.100.105.129 to 110.100.105.254110.100.105.255126
213110.100.106.0/25110.100.106.1 to 110.100.106.126110.100.106.127126
214110.100.106.128/25110.100.106.129 to 110.100.106.254110.100.106.255126
215110.100.107.0/25110.100.107.1 to 110.100.107.126110.100.107.127126
216110.100.107.128/25110.100.107.129 to 110.100.107.254110.100.107.255126
217110.100.108.0/25110.100.108.1 to 110.100.108.126110.100.108.127126
218110.100.108.128/25110.100.108.129 to 110.100.108.254110.100.108.255126
219110.100.109.0/25110.100.109.1 to 110.100.109.126110.100.109.127126
220110.100.109.128/25110.100.109.129 to 110.100.109.254110.100.109.255126
221110.100.110.0/25110.100.110.1 to 110.100.110.126110.100.110.127126
222110.100.110.128/25110.100.110.129 to 110.100.110.254110.100.110.255126
223110.100.111.0/25110.100.111.1 to 110.100.111.126110.100.111.127126
224110.100.111.128/25110.100.111.129 to 110.100.111.254110.100.111.255126
225110.100.112.0/25110.100.112.1 to 110.100.112.126110.100.112.127126
226110.100.112.128/25110.100.112.129 to 110.100.112.254110.100.112.255126
227110.100.113.0/25110.100.113.1 to 110.100.113.126110.100.113.127126
228110.100.113.128/25110.100.113.129 to 110.100.113.254110.100.113.255126
229110.100.114.0/25110.100.114.1 to 110.100.114.126110.100.114.127126
230110.100.114.128/25110.100.114.129 to 110.100.114.254110.100.114.255126
231110.100.115.0/25110.100.115.1 to 110.100.115.126110.100.115.127126
232110.100.115.128/25110.100.115.129 to 110.100.115.254110.100.115.255126
233110.100.116.0/25110.100.116.1 to 110.100.116.126110.100.116.127126
234110.100.116.128/25110.100.116.129 to 110.100.116.254110.100.116.255126
235110.100.117.0/25110.100.117.1 to 110.100.117.126110.100.117.127126
236110.100.117.128/25110.100.117.129 to 110.100.117.254110.100.117.255126
237110.100.118.0/25110.100.118.1 to 110.100.118.126110.100.118.127126
238110.100.118.128/25110.100.118.129 to 110.100.118.254110.100.118.255126
239110.100.119.0/25110.100.119.1 to 110.100.119.126110.100.119.127126
240110.100.119.128/25110.100.119.129 to 110.100.119.254110.100.119.255126
241110.100.120.0/25110.100.120.1 to 110.100.120.126110.100.120.127126
242110.100.120.128/25110.100.120.129 to 110.100.120.254110.100.120.255126
243110.100.121.0/25110.100.121.1 to 110.100.121.126110.100.121.127126
244110.100.121.128/25110.100.121.129 to 110.100.121.254110.100.121.255126
245110.100.122.0/25110.100.122.1 to 110.100.122.126110.100.122.127126
246110.100.122.128/25110.100.122.129 to 110.100.122.254110.100.122.255126
247110.100.123.0/25110.100.123.1 to 110.100.123.126110.100.123.127126
248110.100.123.128/25110.100.123.129 to 110.100.123.254110.100.123.255126
249110.100.124.0/25110.100.124.1 to 110.100.124.126110.100.124.127126
250110.100.124.128/25110.100.124.129 to 110.100.124.254110.100.124.255126
251110.100.125.0/25110.100.125.1 to 110.100.125.126110.100.125.127126
252110.100.125.128/25110.100.125.129 to 110.100.125.254110.100.125.255126
253110.100.126.0/25110.100.126.1 to 110.100.126.126110.100.126.127126
254110.100.126.128/25110.100.126.129 to 110.100.126.254110.100.126.255126
255110.100.127.0/25110.100.127.1 to 110.100.127.126110.100.127.127126
256110.100.127.128/25110.100.127.129 to 110.100.127.254110.100.127.255126

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.