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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.

Network169.254.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
169.254.0.0
Broadcast address
169.254.255.255
First usable
169.254.0.1
Last usable
169.254.255.254
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
Link-local (APIPA) 169.254.0.0/16
Self-assigned when no DHCP server answers
Old class
B (default /16)
As numbers
Hex A9FE0000 · Integer 2851995648 to 2852061183
Reverse DNS zone
254.169.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10101001.11111110..00000000.00000000169.254.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10101001.11111110..00000000.00000000169.254.0.0
Broadcast10101001.11111110..11111111.11111111169.254.255.255
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)

169.254.0.0/16 makes 512 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1169.254.0.0/25169.254.0.1 to 169.254.0.126169.254.0.127126
2169.254.0.128/25169.254.0.129 to 169.254.0.254169.254.0.255126
3169.254.1.0/25169.254.1.1 to 169.254.1.126169.254.1.127126
4169.254.1.128/25169.254.1.129 to 169.254.1.254169.254.1.255126
5169.254.2.0/25169.254.2.1 to 169.254.2.126169.254.2.127126
6169.254.2.128/25169.254.2.129 to 169.254.2.254169.254.2.255126
7169.254.3.0/25169.254.3.1 to 169.254.3.126169.254.3.127126
8169.254.3.128/25169.254.3.129 to 169.254.3.254169.254.3.255126
9169.254.4.0/25169.254.4.1 to 169.254.4.126169.254.4.127126
10169.254.4.128/25169.254.4.129 to 169.254.4.254169.254.4.255126
11169.254.5.0/25169.254.5.1 to 169.254.5.126169.254.5.127126
12169.254.5.128/25169.254.5.129 to 169.254.5.254169.254.5.255126
13169.254.6.0/25169.254.6.1 to 169.254.6.126169.254.6.127126
14169.254.6.128/25169.254.6.129 to 169.254.6.254169.254.6.255126
15169.254.7.0/25169.254.7.1 to 169.254.7.126169.254.7.127126
16169.254.7.128/25169.254.7.129 to 169.254.7.254169.254.7.255126
17169.254.8.0/25169.254.8.1 to 169.254.8.126169.254.8.127126
18169.254.8.128/25169.254.8.129 to 169.254.8.254169.254.8.255126
19169.254.9.0/25169.254.9.1 to 169.254.9.126169.254.9.127126
20169.254.9.128/25169.254.9.129 to 169.254.9.254169.254.9.255126
21169.254.10.0/25169.254.10.1 to 169.254.10.126169.254.10.127126
22169.254.10.128/25169.254.10.129 to 169.254.10.254169.254.10.255126
23169.254.11.0/25169.254.11.1 to 169.254.11.126169.254.11.127126
24169.254.11.128/25169.254.11.129 to 169.254.11.254169.254.11.255126
25169.254.12.0/25169.254.12.1 to 169.254.12.126169.254.12.127126
26169.254.12.128/25169.254.12.129 to 169.254.12.254169.254.12.255126
27169.254.13.0/25169.254.13.1 to 169.254.13.126169.254.13.127126
28169.254.13.128/25169.254.13.129 to 169.254.13.254169.254.13.255126
29169.254.14.0/25169.254.14.1 to 169.254.14.126169.254.14.127126
30169.254.14.128/25169.254.14.129 to 169.254.14.254169.254.14.255126
31169.254.15.0/25169.254.15.1 to 169.254.15.126169.254.15.127126
32169.254.15.128/25169.254.15.129 to 169.254.15.254169.254.15.255126
33169.254.16.0/25169.254.16.1 to 169.254.16.126169.254.16.127126
34169.254.16.128/25169.254.16.129 to 169.254.16.254169.254.16.255126
35169.254.17.0/25169.254.17.1 to 169.254.17.126169.254.17.127126
36169.254.17.128/25169.254.17.129 to 169.254.17.254169.254.17.255126
37169.254.18.0/25169.254.18.1 to 169.254.18.126169.254.18.127126
38169.254.18.128/25169.254.18.129 to 169.254.18.254169.254.18.255126
39169.254.19.0/25169.254.19.1 to 169.254.19.126169.254.19.127126
40169.254.19.128/25169.254.19.129 to 169.254.19.254169.254.19.255126
41169.254.20.0/25169.254.20.1 to 169.254.20.126169.254.20.127126
42169.254.20.128/25169.254.20.129 to 169.254.20.254169.254.20.255126
43169.254.21.0/25169.254.21.1 to 169.254.21.126169.254.21.127126
44169.254.21.128/25169.254.21.129 to 169.254.21.254169.254.21.255126
45169.254.22.0/25169.254.22.1 to 169.254.22.126169.254.22.127126
46169.254.22.128/25169.254.22.129 to 169.254.22.254169.254.22.255126
47169.254.23.0/25169.254.23.1 to 169.254.23.126169.254.23.127126
48169.254.23.128/25169.254.23.129 to 169.254.23.254169.254.23.255126
49169.254.24.0/25169.254.24.1 to 169.254.24.126169.254.24.127126
50169.254.24.128/25169.254.24.129 to 169.254.24.254169.254.24.255126
51169.254.25.0/25169.254.25.1 to 169.254.25.126169.254.25.127126
52169.254.25.128/25169.254.25.129 to 169.254.25.254169.254.25.255126
53169.254.26.0/25169.254.26.1 to 169.254.26.126169.254.26.127126
54169.254.26.128/25169.254.26.129 to 169.254.26.254169.254.26.255126
55169.254.27.0/25169.254.27.1 to 169.254.27.126169.254.27.127126
56169.254.27.128/25169.254.27.129 to 169.254.27.254169.254.27.255126
57169.254.28.0/25169.254.28.1 to 169.254.28.126169.254.28.127126
58169.254.28.128/25169.254.28.129 to 169.254.28.254169.254.28.255126
59169.254.29.0/25169.254.29.1 to 169.254.29.126169.254.29.127126
60169.254.29.128/25169.254.29.129 to 169.254.29.254169.254.29.255126
61169.254.30.0/25169.254.30.1 to 169.254.30.126169.254.30.127126
62169.254.30.128/25169.254.30.129 to 169.254.30.254169.254.30.255126
63169.254.31.0/25169.254.31.1 to 169.254.31.126169.254.31.127126
64169.254.31.128/25169.254.31.129 to 169.254.31.254169.254.31.255126
65169.254.32.0/25169.254.32.1 to 169.254.32.126169.254.32.127126
66169.254.32.128/25169.254.32.129 to 169.254.32.254169.254.32.255126
67169.254.33.0/25169.254.33.1 to 169.254.33.126169.254.33.127126
68169.254.33.128/25169.254.33.129 to 169.254.33.254169.254.33.255126
69169.254.34.0/25169.254.34.1 to 169.254.34.126169.254.34.127126
70169.254.34.128/25169.254.34.129 to 169.254.34.254169.254.34.255126
71169.254.35.0/25169.254.35.1 to 169.254.35.126169.254.35.127126
72169.254.35.128/25169.254.35.129 to 169.254.35.254169.254.35.255126
73169.254.36.0/25169.254.36.1 to 169.254.36.126169.254.36.127126
74169.254.36.128/25169.254.36.129 to 169.254.36.254169.254.36.255126
75169.254.37.0/25169.254.37.1 to 169.254.37.126169.254.37.127126
76169.254.37.128/25169.254.37.129 to 169.254.37.254169.254.37.255126
77169.254.38.0/25169.254.38.1 to 169.254.38.126169.254.38.127126
78169.254.38.128/25169.254.38.129 to 169.254.38.254169.254.38.255126
79169.254.39.0/25169.254.39.1 to 169.254.39.126169.254.39.127126
80169.254.39.128/25169.254.39.129 to 169.254.39.254169.254.39.255126
81169.254.40.0/25169.254.40.1 to 169.254.40.126169.254.40.127126
82169.254.40.128/25169.254.40.129 to 169.254.40.254169.254.40.255126
83169.254.41.0/25169.254.41.1 to 169.254.41.126169.254.41.127126
84169.254.41.128/25169.254.41.129 to 169.254.41.254169.254.41.255126
85169.254.42.0/25169.254.42.1 to 169.254.42.126169.254.42.127126
86169.254.42.128/25169.254.42.129 to 169.254.42.254169.254.42.255126
87169.254.43.0/25169.254.43.1 to 169.254.43.126169.254.43.127126
88169.254.43.128/25169.254.43.129 to 169.254.43.254169.254.43.255126
89169.254.44.0/25169.254.44.1 to 169.254.44.126169.254.44.127126
90169.254.44.128/25169.254.44.129 to 169.254.44.254169.254.44.255126
91169.254.45.0/25169.254.45.1 to 169.254.45.126169.254.45.127126
92169.254.45.128/25169.254.45.129 to 169.254.45.254169.254.45.255126
93169.254.46.0/25169.254.46.1 to 169.254.46.126169.254.46.127126
94169.254.46.128/25169.254.46.129 to 169.254.46.254169.254.46.255126
95169.254.47.0/25169.254.47.1 to 169.254.47.126169.254.47.127126
96169.254.47.128/25169.254.47.129 to 169.254.47.254169.254.47.255126
97169.254.48.0/25169.254.48.1 to 169.254.48.126169.254.48.127126
98169.254.48.128/25169.254.48.129 to 169.254.48.254169.254.48.255126
99169.254.49.0/25169.254.49.1 to 169.254.49.126169.254.49.127126
100169.254.49.128/25169.254.49.129 to 169.254.49.254169.254.49.255126
101169.254.50.0/25169.254.50.1 to 169.254.50.126169.254.50.127126
102169.254.50.128/25169.254.50.129 to 169.254.50.254169.254.50.255126
103169.254.51.0/25169.254.51.1 to 169.254.51.126169.254.51.127126
104169.254.51.128/25169.254.51.129 to 169.254.51.254169.254.51.255126
105169.254.52.0/25169.254.52.1 to 169.254.52.126169.254.52.127126
106169.254.52.128/25169.254.52.129 to 169.254.52.254169.254.52.255126
107169.254.53.0/25169.254.53.1 to 169.254.53.126169.254.53.127126
108169.254.53.128/25169.254.53.129 to 169.254.53.254169.254.53.255126
109169.254.54.0/25169.254.54.1 to 169.254.54.126169.254.54.127126
110169.254.54.128/25169.254.54.129 to 169.254.54.254169.254.54.255126
111169.254.55.0/25169.254.55.1 to 169.254.55.126169.254.55.127126
112169.254.55.128/25169.254.55.129 to 169.254.55.254169.254.55.255126
113169.254.56.0/25169.254.56.1 to 169.254.56.126169.254.56.127126
114169.254.56.128/25169.254.56.129 to 169.254.56.254169.254.56.255126
115169.254.57.0/25169.254.57.1 to 169.254.57.126169.254.57.127126
116169.254.57.128/25169.254.57.129 to 169.254.57.254169.254.57.255126
117169.254.58.0/25169.254.58.1 to 169.254.58.126169.254.58.127126
118169.254.58.128/25169.254.58.129 to 169.254.58.254169.254.58.255126
119169.254.59.0/25169.254.59.1 to 169.254.59.126169.254.59.127126
120169.254.59.128/25169.254.59.129 to 169.254.59.254169.254.59.255126
121169.254.60.0/25169.254.60.1 to 169.254.60.126169.254.60.127126
122169.254.60.128/25169.254.60.129 to 169.254.60.254169.254.60.255126
123169.254.61.0/25169.254.61.1 to 169.254.61.126169.254.61.127126
124169.254.61.128/25169.254.61.129 to 169.254.61.254169.254.61.255126
125169.254.62.0/25169.254.62.1 to 169.254.62.126169.254.62.127126
126169.254.62.128/25169.254.62.129 to 169.254.62.254169.254.62.255126
127169.254.63.0/25169.254.63.1 to 169.254.63.126169.254.63.127126
128169.254.63.128/25169.254.63.129 to 169.254.63.254169.254.63.255126
129169.254.64.0/25169.254.64.1 to 169.254.64.126169.254.64.127126
130169.254.64.128/25169.254.64.129 to 169.254.64.254169.254.64.255126
131169.254.65.0/25169.254.65.1 to 169.254.65.126169.254.65.127126
132169.254.65.128/25169.254.65.129 to 169.254.65.254169.254.65.255126
133169.254.66.0/25169.254.66.1 to 169.254.66.126169.254.66.127126
134169.254.66.128/25169.254.66.129 to 169.254.66.254169.254.66.255126
135169.254.67.0/25169.254.67.1 to 169.254.67.126169.254.67.127126
136169.254.67.128/25169.254.67.129 to 169.254.67.254169.254.67.255126
137169.254.68.0/25169.254.68.1 to 169.254.68.126169.254.68.127126
138169.254.68.128/25169.254.68.129 to 169.254.68.254169.254.68.255126
139169.254.69.0/25169.254.69.1 to 169.254.69.126169.254.69.127126
140169.254.69.128/25169.254.69.129 to 169.254.69.254169.254.69.255126
141169.254.70.0/25169.254.70.1 to 169.254.70.126169.254.70.127126
142169.254.70.128/25169.254.70.129 to 169.254.70.254169.254.70.255126
143169.254.71.0/25169.254.71.1 to 169.254.71.126169.254.71.127126
144169.254.71.128/25169.254.71.129 to 169.254.71.254169.254.71.255126
145169.254.72.0/25169.254.72.1 to 169.254.72.126169.254.72.127126
146169.254.72.128/25169.254.72.129 to 169.254.72.254169.254.72.255126
147169.254.73.0/25169.254.73.1 to 169.254.73.126169.254.73.127126
148169.254.73.128/25169.254.73.129 to 169.254.73.254169.254.73.255126
149169.254.74.0/25169.254.74.1 to 169.254.74.126169.254.74.127126
150169.254.74.128/25169.254.74.129 to 169.254.74.254169.254.74.255126
151169.254.75.0/25169.254.75.1 to 169.254.75.126169.254.75.127126
152169.254.75.128/25169.254.75.129 to 169.254.75.254169.254.75.255126
153169.254.76.0/25169.254.76.1 to 169.254.76.126169.254.76.127126
154169.254.76.128/25169.254.76.129 to 169.254.76.254169.254.76.255126
155169.254.77.0/25169.254.77.1 to 169.254.77.126169.254.77.127126
156169.254.77.128/25169.254.77.129 to 169.254.77.254169.254.77.255126
157169.254.78.0/25169.254.78.1 to 169.254.78.126169.254.78.127126
158169.254.78.128/25169.254.78.129 to 169.254.78.254169.254.78.255126
159169.254.79.0/25169.254.79.1 to 169.254.79.126169.254.79.127126
160169.254.79.128/25169.254.79.129 to 169.254.79.254169.254.79.255126
161169.254.80.0/25169.254.80.1 to 169.254.80.126169.254.80.127126
162169.254.80.128/25169.254.80.129 to 169.254.80.254169.254.80.255126
163169.254.81.0/25169.254.81.1 to 169.254.81.126169.254.81.127126
164169.254.81.128/25169.254.81.129 to 169.254.81.254169.254.81.255126
165169.254.82.0/25169.254.82.1 to 169.254.82.126169.254.82.127126
166169.254.82.128/25169.254.82.129 to 169.254.82.254169.254.82.255126
167169.254.83.0/25169.254.83.1 to 169.254.83.126169.254.83.127126
168169.254.83.128/25169.254.83.129 to 169.254.83.254169.254.83.255126
169169.254.84.0/25169.254.84.1 to 169.254.84.126169.254.84.127126
170169.254.84.128/25169.254.84.129 to 169.254.84.254169.254.84.255126
171169.254.85.0/25169.254.85.1 to 169.254.85.126169.254.85.127126
172169.254.85.128/25169.254.85.129 to 169.254.85.254169.254.85.255126
173169.254.86.0/25169.254.86.1 to 169.254.86.126169.254.86.127126
174169.254.86.128/25169.254.86.129 to 169.254.86.254169.254.86.255126
175169.254.87.0/25169.254.87.1 to 169.254.87.126169.254.87.127126
176169.254.87.128/25169.254.87.129 to 169.254.87.254169.254.87.255126
177169.254.88.0/25169.254.88.1 to 169.254.88.126169.254.88.127126
178169.254.88.128/25169.254.88.129 to 169.254.88.254169.254.88.255126
179169.254.89.0/25169.254.89.1 to 169.254.89.126169.254.89.127126
180169.254.89.128/25169.254.89.129 to 169.254.89.254169.254.89.255126
181169.254.90.0/25169.254.90.1 to 169.254.90.126169.254.90.127126
182169.254.90.128/25169.254.90.129 to 169.254.90.254169.254.90.255126
183169.254.91.0/25169.254.91.1 to 169.254.91.126169.254.91.127126
184169.254.91.128/25169.254.91.129 to 169.254.91.254169.254.91.255126
185169.254.92.0/25169.254.92.1 to 169.254.92.126169.254.92.127126
186169.254.92.128/25169.254.92.129 to 169.254.92.254169.254.92.255126
187169.254.93.0/25169.254.93.1 to 169.254.93.126169.254.93.127126
188169.254.93.128/25169.254.93.129 to 169.254.93.254169.254.93.255126
189169.254.94.0/25169.254.94.1 to 169.254.94.126169.254.94.127126
190169.254.94.128/25169.254.94.129 to 169.254.94.254169.254.94.255126
191169.254.95.0/25169.254.95.1 to 169.254.95.126169.254.95.127126
192169.254.95.128/25169.254.95.129 to 169.254.95.254169.254.95.255126
193169.254.96.0/25169.254.96.1 to 169.254.96.126169.254.96.127126
194169.254.96.128/25169.254.96.129 to 169.254.96.254169.254.96.255126
195169.254.97.0/25169.254.97.1 to 169.254.97.126169.254.97.127126
196169.254.97.128/25169.254.97.129 to 169.254.97.254169.254.97.255126
197169.254.98.0/25169.254.98.1 to 169.254.98.126169.254.98.127126
198169.254.98.128/25169.254.98.129 to 169.254.98.254169.254.98.255126
199169.254.99.0/25169.254.99.1 to 169.254.99.126169.254.99.127126
200169.254.99.128/25169.254.99.129 to 169.254.99.254169.254.99.255126
201169.254.100.0/25169.254.100.1 to 169.254.100.126169.254.100.127126
202169.254.100.128/25169.254.100.129 to 169.254.100.254169.254.100.255126
203169.254.101.0/25169.254.101.1 to 169.254.101.126169.254.101.127126
204169.254.101.128/25169.254.101.129 to 169.254.101.254169.254.101.255126
205169.254.102.0/25169.254.102.1 to 169.254.102.126169.254.102.127126
206169.254.102.128/25169.254.102.129 to 169.254.102.254169.254.102.255126
207169.254.103.0/25169.254.103.1 to 169.254.103.126169.254.103.127126
208169.254.103.128/25169.254.103.129 to 169.254.103.254169.254.103.255126
209169.254.104.0/25169.254.104.1 to 169.254.104.126169.254.104.127126
210169.254.104.128/25169.254.104.129 to 169.254.104.254169.254.104.255126
211169.254.105.0/25169.254.105.1 to 169.254.105.126169.254.105.127126
212169.254.105.128/25169.254.105.129 to 169.254.105.254169.254.105.255126
213169.254.106.0/25169.254.106.1 to 169.254.106.126169.254.106.127126
214169.254.106.128/25169.254.106.129 to 169.254.106.254169.254.106.255126
215169.254.107.0/25169.254.107.1 to 169.254.107.126169.254.107.127126
216169.254.107.128/25169.254.107.129 to 169.254.107.254169.254.107.255126
217169.254.108.0/25169.254.108.1 to 169.254.108.126169.254.108.127126
218169.254.108.128/25169.254.108.129 to 169.254.108.254169.254.108.255126
219169.254.109.0/25169.254.109.1 to 169.254.109.126169.254.109.127126
220169.254.109.128/25169.254.109.129 to 169.254.109.254169.254.109.255126
221169.254.110.0/25169.254.110.1 to 169.254.110.126169.254.110.127126
222169.254.110.128/25169.254.110.129 to 169.254.110.254169.254.110.255126
223169.254.111.0/25169.254.111.1 to 169.254.111.126169.254.111.127126
224169.254.111.128/25169.254.111.129 to 169.254.111.254169.254.111.255126
225169.254.112.0/25169.254.112.1 to 169.254.112.126169.254.112.127126
226169.254.112.128/25169.254.112.129 to 169.254.112.254169.254.112.255126
227169.254.113.0/25169.254.113.1 to 169.254.113.126169.254.113.127126
228169.254.113.128/25169.254.113.129 to 169.254.113.254169.254.113.255126
229169.254.114.0/25169.254.114.1 to 169.254.114.126169.254.114.127126
230169.254.114.128/25169.254.114.129 to 169.254.114.254169.254.114.255126
231169.254.115.0/25169.254.115.1 to 169.254.115.126169.254.115.127126
232169.254.115.128/25169.254.115.129 to 169.254.115.254169.254.115.255126
233169.254.116.0/25169.254.116.1 to 169.254.116.126169.254.116.127126
234169.254.116.128/25169.254.116.129 to 169.254.116.254169.254.116.255126
235169.254.117.0/25169.254.117.1 to 169.254.117.126169.254.117.127126
236169.254.117.128/25169.254.117.129 to 169.254.117.254169.254.117.255126
237169.254.118.0/25169.254.118.1 to 169.254.118.126169.254.118.127126
238169.254.118.128/25169.254.118.129 to 169.254.118.254169.254.118.255126
239169.254.119.0/25169.254.119.1 to 169.254.119.126169.254.119.127126
240169.254.119.128/25169.254.119.129 to 169.254.119.254169.254.119.255126
241169.254.120.0/25169.254.120.1 to 169.254.120.126169.254.120.127126
242169.254.120.128/25169.254.120.129 to 169.254.120.254169.254.120.255126
243169.254.121.0/25169.254.121.1 to 169.254.121.126169.254.121.127126
244169.254.121.128/25169.254.121.129 to 169.254.121.254169.254.121.255126
245169.254.122.0/25169.254.122.1 to 169.254.122.126169.254.122.127126
246169.254.122.128/25169.254.122.129 to 169.254.122.254169.254.122.255126
247169.254.123.0/25169.254.123.1 to 169.254.123.126169.254.123.127126
248169.254.123.128/25169.254.123.129 to 169.254.123.254169.254.123.255126
249169.254.124.0/25169.254.124.1 to 169.254.124.126169.254.124.127126
250169.254.124.128/25169.254.124.129 to 169.254.124.254169.254.124.255126
251169.254.125.0/25169.254.125.1 to 169.254.125.126169.254.125.127126
252169.254.125.128/25169.254.125.129 to 169.254.125.254169.254.125.255126
253169.254.126.0/25169.254.126.1 to 169.254.126.126169.254.126.127126
254169.254.126.128/25169.254.126.129 to 169.254.126.254169.254.126.255126
255169.254.127.0/25169.254.127.1 to 169.254.127.126169.254.127.127126
256169.254.127.128/25169.254.127.129 to 169.254.127.254169.254.127.255126

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.