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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.

Network219.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
219.0.0.0
Broadcast address
219.255.255.255
First usable
219.0.0.1
Last usable
219.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
C (default /24)
As numbers
Hex DB000000 · Integer 3674210304 to 3690987519
Reverse DNS zone
219.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11011011..00000000.00000000.00000000219.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11011011..00000000.00000000.00000000219.0.0.0
Broadcast11011011..11111111.11111111.11111111219.255.255.255
Split into smaller subnets/18
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

219.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1219.0.0.0/18219.0.0.1 to 219.0.63.254219.0.63.25516,382
2219.0.64.0/18219.0.64.1 to 219.0.127.254219.0.127.25516,382
3219.0.128.0/18219.0.128.1 to 219.0.191.254219.0.191.25516,382
4219.0.192.0/18219.0.192.1 to 219.0.255.254219.0.255.25516,382
5219.1.0.0/18219.1.0.1 to 219.1.63.254219.1.63.25516,382
6219.1.64.0/18219.1.64.1 to 219.1.127.254219.1.127.25516,382
7219.1.128.0/18219.1.128.1 to 219.1.191.254219.1.191.25516,382
8219.1.192.0/18219.1.192.1 to 219.1.255.254219.1.255.25516,382
9219.2.0.0/18219.2.0.1 to 219.2.63.254219.2.63.25516,382
10219.2.64.0/18219.2.64.1 to 219.2.127.254219.2.127.25516,382
11219.2.128.0/18219.2.128.1 to 219.2.191.254219.2.191.25516,382
12219.2.192.0/18219.2.192.1 to 219.2.255.254219.2.255.25516,382
13219.3.0.0/18219.3.0.1 to 219.3.63.254219.3.63.25516,382
14219.3.64.0/18219.3.64.1 to 219.3.127.254219.3.127.25516,382
15219.3.128.0/18219.3.128.1 to 219.3.191.254219.3.191.25516,382
16219.3.192.0/18219.3.192.1 to 219.3.255.254219.3.255.25516,382
17219.4.0.0/18219.4.0.1 to 219.4.63.254219.4.63.25516,382
18219.4.64.0/18219.4.64.1 to 219.4.127.254219.4.127.25516,382
19219.4.128.0/18219.4.128.1 to 219.4.191.254219.4.191.25516,382
20219.4.192.0/18219.4.192.1 to 219.4.255.254219.4.255.25516,382
21219.5.0.0/18219.5.0.1 to 219.5.63.254219.5.63.25516,382
22219.5.64.0/18219.5.64.1 to 219.5.127.254219.5.127.25516,382
23219.5.128.0/18219.5.128.1 to 219.5.191.254219.5.191.25516,382
24219.5.192.0/18219.5.192.1 to 219.5.255.254219.5.255.25516,382
25219.6.0.0/18219.6.0.1 to 219.6.63.254219.6.63.25516,382
26219.6.64.0/18219.6.64.1 to 219.6.127.254219.6.127.25516,382
27219.6.128.0/18219.6.128.1 to 219.6.191.254219.6.191.25516,382
28219.6.192.0/18219.6.192.1 to 219.6.255.254219.6.255.25516,382
29219.7.0.0/18219.7.0.1 to 219.7.63.254219.7.63.25516,382
30219.7.64.0/18219.7.64.1 to 219.7.127.254219.7.127.25516,382
31219.7.128.0/18219.7.128.1 to 219.7.191.254219.7.191.25516,382
32219.7.192.0/18219.7.192.1 to 219.7.255.254219.7.255.25516,382
33219.8.0.0/18219.8.0.1 to 219.8.63.254219.8.63.25516,382
34219.8.64.0/18219.8.64.1 to 219.8.127.254219.8.127.25516,382
35219.8.128.0/18219.8.128.1 to 219.8.191.254219.8.191.25516,382
36219.8.192.0/18219.8.192.1 to 219.8.255.254219.8.255.25516,382
37219.9.0.0/18219.9.0.1 to 219.9.63.254219.9.63.25516,382
38219.9.64.0/18219.9.64.1 to 219.9.127.254219.9.127.25516,382
39219.9.128.0/18219.9.128.1 to 219.9.191.254219.9.191.25516,382
40219.9.192.0/18219.9.192.1 to 219.9.255.254219.9.255.25516,382
41219.10.0.0/18219.10.0.1 to 219.10.63.254219.10.63.25516,382
42219.10.64.0/18219.10.64.1 to 219.10.127.254219.10.127.25516,382
43219.10.128.0/18219.10.128.1 to 219.10.191.254219.10.191.25516,382
44219.10.192.0/18219.10.192.1 to 219.10.255.254219.10.255.25516,382
45219.11.0.0/18219.11.0.1 to 219.11.63.254219.11.63.25516,382
46219.11.64.0/18219.11.64.1 to 219.11.127.254219.11.127.25516,382
47219.11.128.0/18219.11.128.1 to 219.11.191.254219.11.191.25516,382
48219.11.192.0/18219.11.192.1 to 219.11.255.254219.11.255.25516,382
49219.12.0.0/18219.12.0.1 to 219.12.63.254219.12.63.25516,382
50219.12.64.0/18219.12.64.1 to 219.12.127.254219.12.127.25516,382
51219.12.128.0/18219.12.128.1 to 219.12.191.254219.12.191.25516,382
52219.12.192.0/18219.12.192.1 to 219.12.255.254219.12.255.25516,382
53219.13.0.0/18219.13.0.1 to 219.13.63.254219.13.63.25516,382
54219.13.64.0/18219.13.64.1 to 219.13.127.254219.13.127.25516,382
55219.13.128.0/18219.13.128.1 to 219.13.191.254219.13.191.25516,382
56219.13.192.0/18219.13.192.1 to 219.13.255.254219.13.255.25516,382
57219.14.0.0/18219.14.0.1 to 219.14.63.254219.14.63.25516,382
58219.14.64.0/18219.14.64.1 to 219.14.127.254219.14.127.25516,382
59219.14.128.0/18219.14.128.1 to 219.14.191.254219.14.191.25516,382
60219.14.192.0/18219.14.192.1 to 219.14.255.254219.14.255.25516,382
61219.15.0.0/18219.15.0.1 to 219.15.63.254219.15.63.25516,382
62219.15.64.0/18219.15.64.1 to 219.15.127.254219.15.127.25516,382
63219.15.128.0/18219.15.128.1 to 219.15.191.254219.15.191.25516,382
64219.15.192.0/18219.15.192.1 to 219.15.255.254219.15.255.25516,382
65219.16.0.0/18219.16.0.1 to 219.16.63.254219.16.63.25516,382
66219.16.64.0/18219.16.64.1 to 219.16.127.254219.16.127.25516,382
67219.16.128.0/18219.16.128.1 to 219.16.191.254219.16.191.25516,382
68219.16.192.0/18219.16.192.1 to 219.16.255.254219.16.255.25516,382
69219.17.0.0/18219.17.0.1 to 219.17.63.254219.17.63.25516,382
70219.17.64.0/18219.17.64.1 to 219.17.127.254219.17.127.25516,382
71219.17.128.0/18219.17.128.1 to 219.17.191.254219.17.191.25516,382
72219.17.192.0/18219.17.192.1 to 219.17.255.254219.17.255.25516,382
73219.18.0.0/18219.18.0.1 to 219.18.63.254219.18.63.25516,382
74219.18.64.0/18219.18.64.1 to 219.18.127.254219.18.127.25516,382
75219.18.128.0/18219.18.128.1 to 219.18.191.254219.18.191.25516,382
76219.18.192.0/18219.18.192.1 to 219.18.255.254219.18.255.25516,382
77219.19.0.0/18219.19.0.1 to 219.19.63.254219.19.63.25516,382
78219.19.64.0/18219.19.64.1 to 219.19.127.254219.19.127.25516,382
79219.19.128.0/18219.19.128.1 to 219.19.191.254219.19.191.25516,382
80219.19.192.0/18219.19.192.1 to 219.19.255.254219.19.255.25516,382
81219.20.0.0/18219.20.0.1 to 219.20.63.254219.20.63.25516,382
82219.20.64.0/18219.20.64.1 to 219.20.127.254219.20.127.25516,382
83219.20.128.0/18219.20.128.1 to 219.20.191.254219.20.191.25516,382
84219.20.192.0/18219.20.192.1 to 219.20.255.254219.20.255.25516,382
85219.21.0.0/18219.21.0.1 to 219.21.63.254219.21.63.25516,382
86219.21.64.0/18219.21.64.1 to 219.21.127.254219.21.127.25516,382
87219.21.128.0/18219.21.128.1 to 219.21.191.254219.21.191.25516,382
88219.21.192.0/18219.21.192.1 to 219.21.255.254219.21.255.25516,382
89219.22.0.0/18219.22.0.1 to 219.22.63.254219.22.63.25516,382
90219.22.64.0/18219.22.64.1 to 219.22.127.254219.22.127.25516,382
91219.22.128.0/18219.22.128.1 to 219.22.191.254219.22.191.25516,382
92219.22.192.0/18219.22.192.1 to 219.22.255.254219.22.255.25516,382
93219.23.0.0/18219.23.0.1 to 219.23.63.254219.23.63.25516,382
94219.23.64.0/18219.23.64.1 to 219.23.127.254219.23.127.25516,382
95219.23.128.0/18219.23.128.1 to 219.23.191.254219.23.191.25516,382
96219.23.192.0/18219.23.192.1 to 219.23.255.254219.23.255.25516,382
97219.24.0.0/18219.24.0.1 to 219.24.63.254219.24.63.25516,382
98219.24.64.0/18219.24.64.1 to 219.24.127.254219.24.127.25516,382
99219.24.128.0/18219.24.128.1 to 219.24.191.254219.24.191.25516,382
100219.24.192.0/18219.24.192.1 to 219.24.255.254219.24.255.25516,382
101219.25.0.0/18219.25.0.1 to 219.25.63.254219.25.63.25516,382
102219.25.64.0/18219.25.64.1 to 219.25.127.254219.25.127.25516,382
103219.25.128.0/18219.25.128.1 to 219.25.191.254219.25.191.25516,382
104219.25.192.0/18219.25.192.1 to 219.25.255.254219.25.255.25516,382
105219.26.0.0/18219.26.0.1 to 219.26.63.254219.26.63.25516,382
106219.26.64.0/18219.26.64.1 to 219.26.127.254219.26.127.25516,382
107219.26.128.0/18219.26.128.1 to 219.26.191.254219.26.191.25516,382
108219.26.192.0/18219.26.192.1 to 219.26.255.254219.26.255.25516,382
109219.27.0.0/18219.27.0.1 to 219.27.63.254219.27.63.25516,382
110219.27.64.0/18219.27.64.1 to 219.27.127.254219.27.127.25516,382
111219.27.128.0/18219.27.128.1 to 219.27.191.254219.27.191.25516,382
112219.27.192.0/18219.27.192.1 to 219.27.255.254219.27.255.25516,382
113219.28.0.0/18219.28.0.1 to 219.28.63.254219.28.63.25516,382
114219.28.64.0/18219.28.64.1 to 219.28.127.254219.28.127.25516,382
115219.28.128.0/18219.28.128.1 to 219.28.191.254219.28.191.25516,382
116219.28.192.0/18219.28.192.1 to 219.28.255.254219.28.255.25516,382
117219.29.0.0/18219.29.0.1 to 219.29.63.254219.29.63.25516,382
118219.29.64.0/18219.29.64.1 to 219.29.127.254219.29.127.25516,382
119219.29.128.0/18219.29.128.1 to 219.29.191.254219.29.191.25516,382
120219.29.192.0/18219.29.192.1 to 219.29.255.254219.29.255.25516,382
121219.30.0.0/18219.30.0.1 to 219.30.63.254219.30.63.25516,382
122219.30.64.0/18219.30.64.1 to 219.30.127.254219.30.127.25516,382
123219.30.128.0/18219.30.128.1 to 219.30.191.254219.30.191.25516,382
124219.30.192.0/18219.30.192.1 to 219.30.255.254219.30.255.25516,382
125219.31.0.0/18219.31.0.1 to 219.31.63.254219.31.63.25516,382
126219.31.64.0/18219.31.64.1 to 219.31.127.254219.31.127.25516,382
127219.31.128.0/18219.31.128.1 to 219.31.191.254219.31.191.25516,382
128219.31.192.0/18219.31.192.1 to 219.31.255.254219.31.255.25516,382
129219.32.0.0/18219.32.0.1 to 219.32.63.254219.32.63.25516,382
130219.32.64.0/18219.32.64.1 to 219.32.127.254219.32.127.25516,382
131219.32.128.0/18219.32.128.1 to 219.32.191.254219.32.191.25516,382
132219.32.192.0/18219.32.192.1 to 219.32.255.254219.32.255.25516,382
133219.33.0.0/18219.33.0.1 to 219.33.63.254219.33.63.25516,382
134219.33.64.0/18219.33.64.1 to 219.33.127.254219.33.127.25516,382
135219.33.128.0/18219.33.128.1 to 219.33.191.254219.33.191.25516,382
136219.33.192.0/18219.33.192.1 to 219.33.255.254219.33.255.25516,382
137219.34.0.0/18219.34.0.1 to 219.34.63.254219.34.63.25516,382
138219.34.64.0/18219.34.64.1 to 219.34.127.254219.34.127.25516,382
139219.34.128.0/18219.34.128.1 to 219.34.191.254219.34.191.25516,382
140219.34.192.0/18219.34.192.1 to 219.34.255.254219.34.255.25516,382
141219.35.0.0/18219.35.0.1 to 219.35.63.254219.35.63.25516,382
142219.35.64.0/18219.35.64.1 to 219.35.127.254219.35.127.25516,382
143219.35.128.0/18219.35.128.1 to 219.35.191.254219.35.191.25516,382
144219.35.192.0/18219.35.192.1 to 219.35.255.254219.35.255.25516,382
145219.36.0.0/18219.36.0.1 to 219.36.63.254219.36.63.25516,382
146219.36.64.0/18219.36.64.1 to 219.36.127.254219.36.127.25516,382
147219.36.128.0/18219.36.128.1 to 219.36.191.254219.36.191.25516,382
148219.36.192.0/18219.36.192.1 to 219.36.255.254219.36.255.25516,382
149219.37.0.0/18219.37.0.1 to 219.37.63.254219.37.63.25516,382
150219.37.64.0/18219.37.64.1 to 219.37.127.254219.37.127.25516,382
151219.37.128.0/18219.37.128.1 to 219.37.191.254219.37.191.25516,382
152219.37.192.0/18219.37.192.1 to 219.37.255.254219.37.255.25516,382
153219.38.0.0/18219.38.0.1 to 219.38.63.254219.38.63.25516,382
154219.38.64.0/18219.38.64.1 to 219.38.127.254219.38.127.25516,382
155219.38.128.0/18219.38.128.1 to 219.38.191.254219.38.191.25516,382
156219.38.192.0/18219.38.192.1 to 219.38.255.254219.38.255.25516,382
157219.39.0.0/18219.39.0.1 to 219.39.63.254219.39.63.25516,382
158219.39.64.0/18219.39.64.1 to 219.39.127.254219.39.127.25516,382
159219.39.128.0/18219.39.128.1 to 219.39.191.254219.39.191.25516,382
160219.39.192.0/18219.39.192.1 to 219.39.255.254219.39.255.25516,382
161219.40.0.0/18219.40.0.1 to 219.40.63.254219.40.63.25516,382
162219.40.64.0/18219.40.64.1 to 219.40.127.254219.40.127.25516,382
163219.40.128.0/18219.40.128.1 to 219.40.191.254219.40.191.25516,382
164219.40.192.0/18219.40.192.1 to 219.40.255.254219.40.255.25516,382
165219.41.0.0/18219.41.0.1 to 219.41.63.254219.41.63.25516,382
166219.41.64.0/18219.41.64.1 to 219.41.127.254219.41.127.25516,382
167219.41.128.0/18219.41.128.1 to 219.41.191.254219.41.191.25516,382
168219.41.192.0/18219.41.192.1 to 219.41.255.254219.41.255.25516,382
169219.42.0.0/18219.42.0.1 to 219.42.63.254219.42.63.25516,382
170219.42.64.0/18219.42.64.1 to 219.42.127.254219.42.127.25516,382
171219.42.128.0/18219.42.128.1 to 219.42.191.254219.42.191.25516,382
172219.42.192.0/18219.42.192.1 to 219.42.255.254219.42.255.25516,382
173219.43.0.0/18219.43.0.1 to 219.43.63.254219.43.63.25516,382
174219.43.64.0/18219.43.64.1 to 219.43.127.254219.43.127.25516,382
175219.43.128.0/18219.43.128.1 to 219.43.191.254219.43.191.25516,382
176219.43.192.0/18219.43.192.1 to 219.43.255.254219.43.255.25516,382
177219.44.0.0/18219.44.0.1 to 219.44.63.254219.44.63.25516,382
178219.44.64.0/18219.44.64.1 to 219.44.127.254219.44.127.25516,382
179219.44.128.0/18219.44.128.1 to 219.44.191.254219.44.191.25516,382
180219.44.192.0/18219.44.192.1 to 219.44.255.254219.44.255.25516,382
181219.45.0.0/18219.45.0.1 to 219.45.63.254219.45.63.25516,382
182219.45.64.0/18219.45.64.1 to 219.45.127.254219.45.127.25516,382
183219.45.128.0/18219.45.128.1 to 219.45.191.254219.45.191.25516,382
184219.45.192.0/18219.45.192.1 to 219.45.255.254219.45.255.25516,382
185219.46.0.0/18219.46.0.1 to 219.46.63.254219.46.63.25516,382
186219.46.64.0/18219.46.64.1 to 219.46.127.254219.46.127.25516,382
187219.46.128.0/18219.46.128.1 to 219.46.191.254219.46.191.25516,382
188219.46.192.0/18219.46.192.1 to 219.46.255.254219.46.255.25516,382
189219.47.0.0/18219.47.0.1 to 219.47.63.254219.47.63.25516,382
190219.47.64.0/18219.47.64.1 to 219.47.127.254219.47.127.25516,382
191219.47.128.0/18219.47.128.1 to 219.47.191.254219.47.191.25516,382
192219.47.192.0/18219.47.192.1 to 219.47.255.254219.47.255.25516,382
193219.48.0.0/18219.48.0.1 to 219.48.63.254219.48.63.25516,382
194219.48.64.0/18219.48.64.1 to 219.48.127.254219.48.127.25516,382
195219.48.128.0/18219.48.128.1 to 219.48.191.254219.48.191.25516,382
196219.48.192.0/18219.48.192.1 to 219.48.255.254219.48.255.25516,382
197219.49.0.0/18219.49.0.1 to 219.49.63.254219.49.63.25516,382
198219.49.64.0/18219.49.64.1 to 219.49.127.254219.49.127.25516,382
199219.49.128.0/18219.49.128.1 to 219.49.191.254219.49.191.25516,382
200219.49.192.0/18219.49.192.1 to 219.49.255.254219.49.255.25516,382
201219.50.0.0/18219.50.0.1 to 219.50.63.254219.50.63.25516,382
202219.50.64.0/18219.50.64.1 to 219.50.127.254219.50.127.25516,382
203219.50.128.0/18219.50.128.1 to 219.50.191.254219.50.191.25516,382
204219.50.192.0/18219.50.192.1 to 219.50.255.254219.50.255.25516,382
205219.51.0.0/18219.51.0.1 to 219.51.63.254219.51.63.25516,382
206219.51.64.0/18219.51.64.1 to 219.51.127.254219.51.127.25516,382
207219.51.128.0/18219.51.128.1 to 219.51.191.254219.51.191.25516,382
208219.51.192.0/18219.51.192.1 to 219.51.255.254219.51.255.25516,382
209219.52.0.0/18219.52.0.1 to 219.52.63.254219.52.63.25516,382
210219.52.64.0/18219.52.64.1 to 219.52.127.254219.52.127.25516,382
211219.52.128.0/18219.52.128.1 to 219.52.191.254219.52.191.25516,382
212219.52.192.0/18219.52.192.1 to 219.52.255.254219.52.255.25516,382
213219.53.0.0/18219.53.0.1 to 219.53.63.254219.53.63.25516,382
214219.53.64.0/18219.53.64.1 to 219.53.127.254219.53.127.25516,382
215219.53.128.0/18219.53.128.1 to 219.53.191.254219.53.191.25516,382
216219.53.192.0/18219.53.192.1 to 219.53.255.254219.53.255.25516,382
217219.54.0.0/18219.54.0.1 to 219.54.63.254219.54.63.25516,382
218219.54.64.0/18219.54.64.1 to 219.54.127.254219.54.127.25516,382
219219.54.128.0/18219.54.128.1 to 219.54.191.254219.54.191.25516,382
220219.54.192.0/18219.54.192.1 to 219.54.255.254219.54.255.25516,382
221219.55.0.0/18219.55.0.1 to 219.55.63.254219.55.63.25516,382
222219.55.64.0/18219.55.64.1 to 219.55.127.254219.55.127.25516,382
223219.55.128.0/18219.55.128.1 to 219.55.191.254219.55.191.25516,382
224219.55.192.0/18219.55.192.1 to 219.55.255.254219.55.255.25516,382
225219.56.0.0/18219.56.0.1 to 219.56.63.254219.56.63.25516,382
226219.56.64.0/18219.56.64.1 to 219.56.127.254219.56.127.25516,382
227219.56.128.0/18219.56.128.1 to 219.56.191.254219.56.191.25516,382
228219.56.192.0/18219.56.192.1 to 219.56.255.254219.56.255.25516,382
229219.57.0.0/18219.57.0.1 to 219.57.63.254219.57.63.25516,382
230219.57.64.0/18219.57.64.1 to 219.57.127.254219.57.127.25516,382
231219.57.128.0/18219.57.128.1 to 219.57.191.254219.57.191.25516,382
232219.57.192.0/18219.57.192.1 to 219.57.255.254219.57.255.25516,382
233219.58.0.0/18219.58.0.1 to 219.58.63.254219.58.63.25516,382
234219.58.64.0/18219.58.64.1 to 219.58.127.254219.58.127.25516,382
235219.58.128.0/18219.58.128.1 to 219.58.191.254219.58.191.25516,382
236219.58.192.0/18219.58.192.1 to 219.58.255.254219.58.255.25516,382
237219.59.0.0/18219.59.0.1 to 219.59.63.254219.59.63.25516,382
238219.59.64.0/18219.59.64.1 to 219.59.127.254219.59.127.25516,382
239219.59.128.0/18219.59.128.1 to 219.59.191.254219.59.191.25516,382
240219.59.192.0/18219.59.192.1 to 219.59.255.254219.59.255.25516,382
241219.60.0.0/18219.60.0.1 to 219.60.63.254219.60.63.25516,382
242219.60.64.0/18219.60.64.1 to 219.60.127.254219.60.127.25516,382
243219.60.128.0/18219.60.128.1 to 219.60.191.254219.60.191.25516,382
244219.60.192.0/18219.60.192.1 to 219.60.255.254219.60.255.25516,382
245219.61.0.0/18219.61.0.1 to 219.61.63.254219.61.63.25516,382
246219.61.64.0/18219.61.64.1 to 219.61.127.254219.61.127.25516,382
247219.61.128.0/18219.61.128.1 to 219.61.191.254219.61.191.25516,382
248219.61.192.0/18219.61.192.1 to 219.61.255.254219.61.255.25516,382
249219.62.0.0/18219.62.0.1 to 219.62.63.254219.62.63.25516,382
250219.62.64.0/18219.62.64.1 to 219.62.127.254219.62.127.25516,382
251219.62.128.0/18219.62.128.1 to 219.62.191.254219.62.191.25516,382
252219.62.192.0/18219.62.192.1 to 219.62.255.254219.62.255.25516,382
253219.63.0.0/18219.63.0.1 to 219.63.63.254219.63.63.25516,382
254219.63.64.0/18219.63.64.1 to 219.63.127.254219.63.127.25516,382
255219.63.128.0/18219.63.128.1 to 219.63.191.254219.63.191.25516,382
256219.63.192.0/18219.63.192.1 to 219.63.255.254219.63.255.25516,382

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.