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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/16
/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 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1219.0.0.0/16219.0.0.1 to 219.0.255.254219.0.255.25565,534
2219.1.0.0/16219.1.0.1 to 219.1.255.254219.1.255.25565,534
3219.2.0.0/16219.2.0.1 to 219.2.255.254219.2.255.25565,534
4219.3.0.0/16219.3.0.1 to 219.3.255.254219.3.255.25565,534
5219.4.0.0/16219.4.0.1 to 219.4.255.254219.4.255.25565,534
6219.5.0.0/16219.5.0.1 to 219.5.255.254219.5.255.25565,534
7219.6.0.0/16219.6.0.1 to 219.6.255.254219.6.255.25565,534
8219.7.0.0/16219.7.0.1 to 219.7.255.254219.7.255.25565,534
9219.8.0.0/16219.8.0.1 to 219.8.255.254219.8.255.25565,534
10219.9.0.0/16219.9.0.1 to 219.9.255.254219.9.255.25565,534
11219.10.0.0/16219.10.0.1 to 219.10.255.254219.10.255.25565,534
12219.11.0.0/16219.11.0.1 to 219.11.255.254219.11.255.25565,534
13219.12.0.0/16219.12.0.1 to 219.12.255.254219.12.255.25565,534
14219.13.0.0/16219.13.0.1 to 219.13.255.254219.13.255.25565,534
15219.14.0.0/16219.14.0.1 to 219.14.255.254219.14.255.25565,534
16219.15.0.0/16219.15.0.1 to 219.15.255.254219.15.255.25565,534
17219.16.0.0/16219.16.0.1 to 219.16.255.254219.16.255.25565,534
18219.17.0.0/16219.17.0.1 to 219.17.255.254219.17.255.25565,534
19219.18.0.0/16219.18.0.1 to 219.18.255.254219.18.255.25565,534
20219.19.0.0/16219.19.0.1 to 219.19.255.254219.19.255.25565,534
21219.20.0.0/16219.20.0.1 to 219.20.255.254219.20.255.25565,534
22219.21.0.0/16219.21.0.1 to 219.21.255.254219.21.255.25565,534
23219.22.0.0/16219.22.0.1 to 219.22.255.254219.22.255.25565,534
24219.23.0.0/16219.23.0.1 to 219.23.255.254219.23.255.25565,534
25219.24.0.0/16219.24.0.1 to 219.24.255.254219.24.255.25565,534
26219.25.0.0/16219.25.0.1 to 219.25.255.254219.25.255.25565,534
27219.26.0.0/16219.26.0.1 to 219.26.255.254219.26.255.25565,534
28219.27.0.0/16219.27.0.1 to 219.27.255.254219.27.255.25565,534
29219.28.0.0/16219.28.0.1 to 219.28.255.254219.28.255.25565,534
30219.29.0.0/16219.29.0.1 to 219.29.255.254219.29.255.25565,534
31219.30.0.0/16219.30.0.1 to 219.30.255.254219.30.255.25565,534
32219.31.0.0/16219.31.0.1 to 219.31.255.254219.31.255.25565,534
33219.32.0.0/16219.32.0.1 to 219.32.255.254219.32.255.25565,534
34219.33.0.0/16219.33.0.1 to 219.33.255.254219.33.255.25565,534
35219.34.0.0/16219.34.0.1 to 219.34.255.254219.34.255.25565,534
36219.35.0.0/16219.35.0.1 to 219.35.255.254219.35.255.25565,534
37219.36.0.0/16219.36.0.1 to 219.36.255.254219.36.255.25565,534
38219.37.0.0/16219.37.0.1 to 219.37.255.254219.37.255.25565,534
39219.38.0.0/16219.38.0.1 to 219.38.255.254219.38.255.25565,534
40219.39.0.0/16219.39.0.1 to 219.39.255.254219.39.255.25565,534
41219.40.0.0/16219.40.0.1 to 219.40.255.254219.40.255.25565,534
42219.41.0.0/16219.41.0.1 to 219.41.255.254219.41.255.25565,534
43219.42.0.0/16219.42.0.1 to 219.42.255.254219.42.255.25565,534
44219.43.0.0/16219.43.0.1 to 219.43.255.254219.43.255.25565,534
45219.44.0.0/16219.44.0.1 to 219.44.255.254219.44.255.25565,534
46219.45.0.0/16219.45.0.1 to 219.45.255.254219.45.255.25565,534
47219.46.0.0/16219.46.0.1 to 219.46.255.254219.46.255.25565,534
48219.47.0.0/16219.47.0.1 to 219.47.255.254219.47.255.25565,534
49219.48.0.0/16219.48.0.1 to 219.48.255.254219.48.255.25565,534
50219.49.0.0/16219.49.0.1 to 219.49.255.254219.49.255.25565,534
51219.50.0.0/16219.50.0.1 to 219.50.255.254219.50.255.25565,534
52219.51.0.0/16219.51.0.1 to 219.51.255.254219.51.255.25565,534
53219.52.0.0/16219.52.0.1 to 219.52.255.254219.52.255.25565,534
54219.53.0.0/16219.53.0.1 to 219.53.255.254219.53.255.25565,534
55219.54.0.0/16219.54.0.1 to 219.54.255.254219.54.255.25565,534
56219.55.0.0/16219.55.0.1 to 219.55.255.254219.55.255.25565,534
57219.56.0.0/16219.56.0.1 to 219.56.255.254219.56.255.25565,534
58219.57.0.0/16219.57.0.1 to 219.57.255.254219.57.255.25565,534
59219.58.0.0/16219.58.0.1 to 219.58.255.254219.58.255.25565,534
60219.59.0.0/16219.59.0.1 to 219.59.255.254219.59.255.25565,534
61219.60.0.0/16219.60.0.1 to 219.60.255.254219.60.255.25565,534
62219.61.0.0/16219.61.0.1 to 219.61.255.254219.61.255.25565,534
63219.62.0.0/16219.62.0.1 to 219.62.255.254219.62.255.25565,534
64219.63.0.0/16219.63.0.1 to 219.63.255.254219.63.255.25565,534
65219.64.0.0/16219.64.0.1 to 219.64.255.254219.64.255.25565,534
66219.65.0.0/16219.65.0.1 to 219.65.255.254219.65.255.25565,534
67219.66.0.0/16219.66.0.1 to 219.66.255.254219.66.255.25565,534
68219.67.0.0/16219.67.0.1 to 219.67.255.254219.67.255.25565,534
69219.68.0.0/16219.68.0.1 to 219.68.255.254219.68.255.25565,534
70219.69.0.0/16219.69.0.1 to 219.69.255.254219.69.255.25565,534
71219.70.0.0/16219.70.0.1 to 219.70.255.254219.70.255.25565,534
72219.71.0.0/16219.71.0.1 to 219.71.255.254219.71.255.25565,534
73219.72.0.0/16219.72.0.1 to 219.72.255.254219.72.255.25565,534
74219.73.0.0/16219.73.0.1 to 219.73.255.254219.73.255.25565,534
75219.74.0.0/16219.74.0.1 to 219.74.255.254219.74.255.25565,534
76219.75.0.0/16219.75.0.1 to 219.75.255.254219.75.255.25565,534
77219.76.0.0/16219.76.0.1 to 219.76.255.254219.76.255.25565,534
78219.77.0.0/16219.77.0.1 to 219.77.255.254219.77.255.25565,534
79219.78.0.0/16219.78.0.1 to 219.78.255.254219.78.255.25565,534
80219.79.0.0/16219.79.0.1 to 219.79.255.254219.79.255.25565,534
81219.80.0.0/16219.80.0.1 to 219.80.255.254219.80.255.25565,534
82219.81.0.0/16219.81.0.1 to 219.81.255.254219.81.255.25565,534
83219.82.0.0/16219.82.0.1 to 219.82.255.254219.82.255.25565,534
84219.83.0.0/16219.83.0.1 to 219.83.255.254219.83.255.25565,534
85219.84.0.0/16219.84.0.1 to 219.84.255.254219.84.255.25565,534
86219.85.0.0/16219.85.0.1 to 219.85.255.254219.85.255.25565,534
87219.86.0.0/16219.86.0.1 to 219.86.255.254219.86.255.25565,534
88219.87.0.0/16219.87.0.1 to 219.87.255.254219.87.255.25565,534
89219.88.0.0/16219.88.0.1 to 219.88.255.254219.88.255.25565,534
90219.89.0.0/16219.89.0.1 to 219.89.255.254219.89.255.25565,534
91219.90.0.0/16219.90.0.1 to 219.90.255.254219.90.255.25565,534
92219.91.0.0/16219.91.0.1 to 219.91.255.254219.91.255.25565,534
93219.92.0.0/16219.92.0.1 to 219.92.255.254219.92.255.25565,534
94219.93.0.0/16219.93.0.1 to 219.93.255.254219.93.255.25565,534
95219.94.0.0/16219.94.0.1 to 219.94.255.254219.94.255.25565,534
96219.95.0.0/16219.95.0.1 to 219.95.255.254219.95.255.25565,534
97219.96.0.0/16219.96.0.1 to 219.96.255.254219.96.255.25565,534
98219.97.0.0/16219.97.0.1 to 219.97.255.254219.97.255.25565,534
99219.98.0.0/16219.98.0.1 to 219.98.255.254219.98.255.25565,534
100219.99.0.0/16219.99.0.1 to 219.99.255.254219.99.255.25565,534
101219.100.0.0/16219.100.0.1 to 219.100.255.254219.100.255.25565,534
102219.101.0.0/16219.101.0.1 to 219.101.255.254219.101.255.25565,534
103219.102.0.0/16219.102.0.1 to 219.102.255.254219.102.255.25565,534
104219.103.0.0/16219.103.0.1 to 219.103.255.254219.103.255.25565,534
105219.104.0.0/16219.104.0.1 to 219.104.255.254219.104.255.25565,534
106219.105.0.0/16219.105.0.1 to 219.105.255.254219.105.255.25565,534
107219.106.0.0/16219.106.0.1 to 219.106.255.254219.106.255.25565,534
108219.107.0.0/16219.107.0.1 to 219.107.255.254219.107.255.25565,534
109219.108.0.0/16219.108.0.1 to 219.108.255.254219.108.255.25565,534
110219.109.0.0/16219.109.0.1 to 219.109.255.254219.109.255.25565,534
111219.110.0.0/16219.110.0.1 to 219.110.255.254219.110.255.25565,534
112219.111.0.0/16219.111.0.1 to 219.111.255.254219.111.255.25565,534
113219.112.0.0/16219.112.0.1 to 219.112.255.254219.112.255.25565,534
114219.113.0.0/16219.113.0.1 to 219.113.255.254219.113.255.25565,534
115219.114.0.0/16219.114.0.1 to 219.114.255.254219.114.255.25565,534
116219.115.0.0/16219.115.0.1 to 219.115.255.254219.115.255.25565,534
117219.116.0.0/16219.116.0.1 to 219.116.255.254219.116.255.25565,534
118219.117.0.0/16219.117.0.1 to 219.117.255.254219.117.255.25565,534
119219.118.0.0/16219.118.0.1 to 219.118.255.254219.118.255.25565,534
120219.119.0.0/16219.119.0.1 to 219.119.255.254219.119.255.25565,534
121219.120.0.0/16219.120.0.1 to 219.120.255.254219.120.255.25565,534
122219.121.0.0/16219.121.0.1 to 219.121.255.254219.121.255.25565,534
123219.122.0.0/16219.122.0.1 to 219.122.255.254219.122.255.25565,534
124219.123.0.0/16219.123.0.1 to 219.123.255.254219.123.255.25565,534
125219.124.0.0/16219.124.0.1 to 219.124.255.254219.124.255.25565,534
126219.125.0.0/16219.125.0.1 to 219.125.255.254219.125.255.25565,534
127219.126.0.0/16219.126.0.1 to 219.126.255.254219.126.255.25565,534
128219.127.0.0/16219.127.0.1 to 219.127.255.254219.127.255.25565,534
129219.128.0.0/16219.128.0.1 to 219.128.255.254219.128.255.25565,534
130219.129.0.0/16219.129.0.1 to 219.129.255.254219.129.255.25565,534
131219.130.0.0/16219.130.0.1 to 219.130.255.254219.130.255.25565,534
132219.131.0.0/16219.131.0.1 to 219.131.255.254219.131.255.25565,534
133219.132.0.0/16219.132.0.1 to 219.132.255.254219.132.255.25565,534
134219.133.0.0/16219.133.0.1 to 219.133.255.254219.133.255.25565,534
135219.134.0.0/16219.134.0.1 to 219.134.255.254219.134.255.25565,534
136219.135.0.0/16219.135.0.1 to 219.135.255.254219.135.255.25565,534
137219.136.0.0/16219.136.0.1 to 219.136.255.254219.136.255.25565,534
138219.137.0.0/16219.137.0.1 to 219.137.255.254219.137.255.25565,534
139219.138.0.0/16219.138.0.1 to 219.138.255.254219.138.255.25565,534
140219.139.0.0/16219.139.0.1 to 219.139.255.254219.139.255.25565,534
141219.140.0.0/16219.140.0.1 to 219.140.255.254219.140.255.25565,534
142219.141.0.0/16219.141.0.1 to 219.141.255.254219.141.255.25565,534
143219.142.0.0/16219.142.0.1 to 219.142.255.254219.142.255.25565,534
144219.143.0.0/16219.143.0.1 to 219.143.255.254219.143.255.25565,534
145219.144.0.0/16219.144.0.1 to 219.144.255.254219.144.255.25565,534
146219.145.0.0/16219.145.0.1 to 219.145.255.254219.145.255.25565,534
147219.146.0.0/16219.146.0.1 to 219.146.255.254219.146.255.25565,534
148219.147.0.0/16219.147.0.1 to 219.147.255.254219.147.255.25565,534
149219.148.0.0/16219.148.0.1 to 219.148.255.254219.148.255.25565,534
150219.149.0.0/16219.149.0.1 to 219.149.255.254219.149.255.25565,534
151219.150.0.0/16219.150.0.1 to 219.150.255.254219.150.255.25565,534
152219.151.0.0/16219.151.0.1 to 219.151.255.254219.151.255.25565,534
153219.152.0.0/16219.152.0.1 to 219.152.255.254219.152.255.25565,534
154219.153.0.0/16219.153.0.1 to 219.153.255.254219.153.255.25565,534
155219.154.0.0/16219.154.0.1 to 219.154.255.254219.154.255.25565,534
156219.155.0.0/16219.155.0.1 to 219.155.255.254219.155.255.25565,534
157219.156.0.0/16219.156.0.1 to 219.156.255.254219.156.255.25565,534
158219.157.0.0/16219.157.0.1 to 219.157.255.254219.157.255.25565,534
159219.158.0.0/16219.158.0.1 to 219.158.255.254219.158.255.25565,534
160219.159.0.0/16219.159.0.1 to 219.159.255.254219.159.255.25565,534
161219.160.0.0/16219.160.0.1 to 219.160.255.254219.160.255.25565,534
162219.161.0.0/16219.161.0.1 to 219.161.255.254219.161.255.25565,534
163219.162.0.0/16219.162.0.1 to 219.162.255.254219.162.255.25565,534
164219.163.0.0/16219.163.0.1 to 219.163.255.254219.163.255.25565,534
165219.164.0.0/16219.164.0.1 to 219.164.255.254219.164.255.25565,534
166219.165.0.0/16219.165.0.1 to 219.165.255.254219.165.255.25565,534
167219.166.0.0/16219.166.0.1 to 219.166.255.254219.166.255.25565,534
168219.167.0.0/16219.167.0.1 to 219.167.255.254219.167.255.25565,534
169219.168.0.0/16219.168.0.1 to 219.168.255.254219.168.255.25565,534
170219.169.0.0/16219.169.0.1 to 219.169.255.254219.169.255.25565,534
171219.170.0.0/16219.170.0.1 to 219.170.255.254219.170.255.25565,534
172219.171.0.0/16219.171.0.1 to 219.171.255.254219.171.255.25565,534
173219.172.0.0/16219.172.0.1 to 219.172.255.254219.172.255.25565,534
174219.173.0.0/16219.173.0.1 to 219.173.255.254219.173.255.25565,534
175219.174.0.0/16219.174.0.1 to 219.174.255.254219.174.255.25565,534
176219.175.0.0/16219.175.0.1 to 219.175.255.254219.175.255.25565,534
177219.176.0.0/16219.176.0.1 to 219.176.255.254219.176.255.25565,534
178219.177.0.0/16219.177.0.1 to 219.177.255.254219.177.255.25565,534
179219.178.0.0/16219.178.0.1 to 219.178.255.254219.178.255.25565,534
180219.179.0.0/16219.179.0.1 to 219.179.255.254219.179.255.25565,534
181219.180.0.0/16219.180.0.1 to 219.180.255.254219.180.255.25565,534
182219.181.0.0/16219.181.0.1 to 219.181.255.254219.181.255.25565,534
183219.182.0.0/16219.182.0.1 to 219.182.255.254219.182.255.25565,534
184219.183.0.0/16219.183.0.1 to 219.183.255.254219.183.255.25565,534
185219.184.0.0/16219.184.0.1 to 219.184.255.254219.184.255.25565,534
186219.185.0.0/16219.185.0.1 to 219.185.255.254219.185.255.25565,534
187219.186.0.0/16219.186.0.1 to 219.186.255.254219.186.255.25565,534
188219.187.0.0/16219.187.0.1 to 219.187.255.254219.187.255.25565,534
189219.188.0.0/16219.188.0.1 to 219.188.255.254219.188.255.25565,534
190219.189.0.0/16219.189.0.1 to 219.189.255.254219.189.255.25565,534
191219.190.0.0/16219.190.0.1 to 219.190.255.254219.190.255.25565,534
192219.191.0.0/16219.191.0.1 to 219.191.255.254219.191.255.25565,534
193219.192.0.0/16219.192.0.1 to 219.192.255.254219.192.255.25565,534
194219.193.0.0/16219.193.0.1 to 219.193.255.254219.193.255.25565,534
195219.194.0.0/16219.194.0.1 to 219.194.255.254219.194.255.25565,534
196219.195.0.0/16219.195.0.1 to 219.195.255.254219.195.255.25565,534
197219.196.0.0/16219.196.0.1 to 219.196.255.254219.196.255.25565,534
198219.197.0.0/16219.197.0.1 to 219.197.255.254219.197.255.25565,534
199219.198.0.0/16219.198.0.1 to 219.198.255.254219.198.255.25565,534
200219.199.0.0/16219.199.0.1 to 219.199.255.254219.199.255.25565,534
201219.200.0.0/16219.200.0.1 to 219.200.255.254219.200.255.25565,534
202219.201.0.0/16219.201.0.1 to 219.201.255.254219.201.255.25565,534
203219.202.0.0/16219.202.0.1 to 219.202.255.254219.202.255.25565,534
204219.203.0.0/16219.203.0.1 to 219.203.255.254219.203.255.25565,534
205219.204.0.0/16219.204.0.1 to 219.204.255.254219.204.255.25565,534
206219.205.0.0/16219.205.0.1 to 219.205.255.254219.205.255.25565,534
207219.206.0.0/16219.206.0.1 to 219.206.255.254219.206.255.25565,534
208219.207.0.0/16219.207.0.1 to 219.207.255.254219.207.255.25565,534
209219.208.0.0/16219.208.0.1 to 219.208.255.254219.208.255.25565,534
210219.209.0.0/16219.209.0.1 to 219.209.255.254219.209.255.25565,534
211219.210.0.0/16219.210.0.1 to 219.210.255.254219.210.255.25565,534
212219.211.0.0/16219.211.0.1 to 219.211.255.254219.211.255.25565,534
213219.212.0.0/16219.212.0.1 to 219.212.255.254219.212.255.25565,534
214219.213.0.0/16219.213.0.1 to 219.213.255.254219.213.255.25565,534
215219.214.0.0/16219.214.0.1 to 219.214.255.254219.214.255.25565,534
216219.215.0.0/16219.215.0.1 to 219.215.255.254219.215.255.25565,534
217219.216.0.0/16219.216.0.1 to 219.216.255.254219.216.255.25565,534
218219.217.0.0/16219.217.0.1 to 219.217.255.254219.217.255.25565,534
219219.218.0.0/16219.218.0.1 to 219.218.255.254219.218.255.25565,534
220219.219.0.0/16219.219.0.1 to 219.219.255.254219.219.255.25565,534
221219.220.0.0/16219.220.0.1 to 219.220.255.254219.220.255.25565,534
222219.221.0.0/16219.221.0.1 to 219.221.255.254219.221.255.25565,534
223219.222.0.0/16219.222.0.1 to 219.222.255.254219.222.255.25565,534
224219.223.0.0/16219.223.0.1 to 219.223.255.254219.223.255.25565,534
225219.224.0.0/16219.224.0.1 to 219.224.255.254219.224.255.25565,534
226219.225.0.0/16219.225.0.1 to 219.225.255.254219.225.255.25565,534
227219.226.0.0/16219.226.0.1 to 219.226.255.254219.226.255.25565,534
228219.227.0.0/16219.227.0.1 to 219.227.255.254219.227.255.25565,534
229219.228.0.0/16219.228.0.1 to 219.228.255.254219.228.255.25565,534
230219.229.0.0/16219.229.0.1 to 219.229.255.254219.229.255.25565,534
231219.230.0.0/16219.230.0.1 to 219.230.255.254219.230.255.25565,534
232219.231.0.0/16219.231.0.1 to 219.231.255.254219.231.255.25565,534
233219.232.0.0/16219.232.0.1 to 219.232.255.254219.232.255.25565,534
234219.233.0.0/16219.233.0.1 to 219.233.255.254219.233.255.25565,534
235219.234.0.0/16219.234.0.1 to 219.234.255.254219.234.255.25565,534
236219.235.0.0/16219.235.0.1 to 219.235.255.254219.235.255.25565,534
237219.236.0.0/16219.236.0.1 to 219.236.255.254219.236.255.25565,534
238219.237.0.0/16219.237.0.1 to 219.237.255.254219.237.255.25565,534
239219.238.0.0/16219.238.0.1 to 219.238.255.254219.238.255.25565,534
240219.239.0.0/16219.239.0.1 to 219.239.255.254219.239.255.25565,534
241219.240.0.0/16219.240.0.1 to 219.240.255.254219.240.255.25565,534
242219.241.0.0/16219.241.0.1 to 219.241.255.254219.241.255.25565,534
243219.242.0.0/16219.242.0.1 to 219.242.255.254219.242.255.25565,534
244219.243.0.0/16219.243.0.1 to 219.243.255.254219.243.255.25565,534
245219.244.0.0/16219.244.0.1 to 219.244.255.254219.244.255.25565,534
246219.245.0.0/16219.245.0.1 to 219.245.255.254219.245.255.25565,534
247219.246.0.0/16219.246.0.1 to 219.246.255.254219.246.255.25565,534
248219.247.0.0/16219.247.0.1 to 219.247.255.254219.247.255.25565,534
249219.248.0.0/16219.248.0.1 to 219.248.255.254219.248.255.25565,534
250219.249.0.0/16219.249.0.1 to 219.249.255.254219.249.255.25565,534
251219.250.0.0/16219.250.0.1 to 219.250.255.254219.250.255.25565,534
252219.251.0.0/16219.251.0.1 to 219.251.255.254219.251.255.25565,534
253219.252.0.0/16219.252.0.1 to 219.252.255.254219.252.255.25565,534
254219.253.0.0/16219.253.0.1 to 219.253.255.254219.253.255.25565,534
255219.254.0.0/16219.254.0.1 to 219.254.255.254219.254.255.25565,534
256219.255.0.0/16219.255.0.1 to 219.255.255.254219.255.255.25565,534

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.