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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.

Network200.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
200.0.0.0
Broadcast address
201.255.255.255
First usable
200.0.0.1
Last usable
201.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
C (default /24)
As numbers
Hex C8000000 · Integer 3355443200 to 3388997631
Reverse DNS zones
200.in-addr.arpa
201.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11001000.00000000.00000000.00000000200.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11001000.00000000.00000000.00000000200.0.0.0
Broadcast11001001.11111111.11111111.11111111201.255.255.255
Split into smaller subnets/16
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

200.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1200.0.0.0/16200.0.0.1 to 200.0.255.254200.0.255.25565,534
2200.1.0.0/16200.1.0.1 to 200.1.255.254200.1.255.25565,534
3200.2.0.0/16200.2.0.1 to 200.2.255.254200.2.255.25565,534
4200.3.0.0/16200.3.0.1 to 200.3.255.254200.3.255.25565,534
5200.4.0.0/16200.4.0.1 to 200.4.255.254200.4.255.25565,534
6200.5.0.0/16200.5.0.1 to 200.5.255.254200.5.255.25565,534
7200.6.0.0/16200.6.0.1 to 200.6.255.254200.6.255.25565,534
8200.7.0.0/16200.7.0.1 to 200.7.255.254200.7.255.25565,534
9200.8.0.0/16200.8.0.1 to 200.8.255.254200.8.255.25565,534
10200.9.0.0/16200.9.0.1 to 200.9.255.254200.9.255.25565,534
11200.10.0.0/16200.10.0.1 to 200.10.255.254200.10.255.25565,534
12200.11.0.0/16200.11.0.1 to 200.11.255.254200.11.255.25565,534
13200.12.0.0/16200.12.0.1 to 200.12.255.254200.12.255.25565,534
14200.13.0.0/16200.13.0.1 to 200.13.255.254200.13.255.25565,534
15200.14.0.0/16200.14.0.1 to 200.14.255.254200.14.255.25565,534
16200.15.0.0/16200.15.0.1 to 200.15.255.254200.15.255.25565,534
17200.16.0.0/16200.16.0.1 to 200.16.255.254200.16.255.25565,534
18200.17.0.0/16200.17.0.1 to 200.17.255.254200.17.255.25565,534
19200.18.0.0/16200.18.0.1 to 200.18.255.254200.18.255.25565,534
20200.19.0.0/16200.19.0.1 to 200.19.255.254200.19.255.25565,534
21200.20.0.0/16200.20.0.1 to 200.20.255.254200.20.255.25565,534
22200.21.0.0/16200.21.0.1 to 200.21.255.254200.21.255.25565,534
23200.22.0.0/16200.22.0.1 to 200.22.255.254200.22.255.25565,534
24200.23.0.0/16200.23.0.1 to 200.23.255.254200.23.255.25565,534
25200.24.0.0/16200.24.0.1 to 200.24.255.254200.24.255.25565,534
26200.25.0.0/16200.25.0.1 to 200.25.255.254200.25.255.25565,534
27200.26.0.0/16200.26.0.1 to 200.26.255.254200.26.255.25565,534
28200.27.0.0/16200.27.0.1 to 200.27.255.254200.27.255.25565,534
29200.28.0.0/16200.28.0.1 to 200.28.255.254200.28.255.25565,534
30200.29.0.0/16200.29.0.1 to 200.29.255.254200.29.255.25565,534
31200.30.0.0/16200.30.0.1 to 200.30.255.254200.30.255.25565,534
32200.31.0.0/16200.31.0.1 to 200.31.255.254200.31.255.25565,534
33200.32.0.0/16200.32.0.1 to 200.32.255.254200.32.255.25565,534
34200.33.0.0/16200.33.0.1 to 200.33.255.254200.33.255.25565,534
35200.34.0.0/16200.34.0.1 to 200.34.255.254200.34.255.25565,534
36200.35.0.0/16200.35.0.1 to 200.35.255.254200.35.255.25565,534
37200.36.0.0/16200.36.0.1 to 200.36.255.254200.36.255.25565,534
38200.37.0.0/16200.37.0.1 to 200.37.255.254200.37.255.25565,534
39200.38.0.0/16200.38.0.1 to 200.38.255.254200.38.255.25565,534
40200.39.0.0/16200.39.0.1 to 200.39.255.254200.39.255.25565,534
41200.40.0.0/16200.40.0.1 to 200.40.255.254200.40.255.25565,534
42200.41.0.0/16200.41.0.1 to 200.41.255.254200.41.255.25565,534
43200.42.0.0/16200.42.0.1 to 200.42.255.254200.42.255.25565,534
44200.43.0.0/16200.43.0.1 to 200.43.255.254200.43.255.25565,534
45200.44.0.0/16200.44.0.1 to 200.44.255.254200.44.255.25565,534
46200.45.0.0/16200.45.0.1 to 200.45.255.254200.45.255.25565,534
47200.46.0.0/16200.46.0.1 to 200.46.255.254200.46.255.25565,534
48200.47.0.0/16200.47.0.1 to 200.47.255.254200.47.255.25565,534
49200.48.0.0/16200.48.0.1 to 200.48.255.254200.48.255.25565,534
50200.49.0.0/16200.49.0.1 to 200.49.255.254200.49.255.25565,534
51200.50.0.0/16200.50.0.1 to 200.50.255.254200.50.255.25565,534
52200.51.0.0/16200.51.0.1 to 200.51.255.254200.51.255.25565,534
53200.52.0.0/16200.52.0.1 to 200.52.255.254200.52.255.25565,534
54200.53.0.0/16200.53.0.1 to 200.53.255.254200.53.255.25565,534
55200.54.0.0/16200.54.0.1 to 200.54.255.254200.54.255.25565,534
56200.55.0.0/16200.55.0.1 to 200.55.255.254200.55.255.25565,534
57200.56.0.0/16200.56.0.1 to 200.56.255.254200.56.255.25565,534
58200.57.0.0/16200.57.0.1 to 200.57.255.254200.57.255.25565,534
59200.58.0.0/16200.58.0.1 to 200.58.255.254200.58.255.25565,534
60200.59.0.0/16200.59.0.1 to 200.59.255.254200.59.255.25565,534
61200.60.0.0/16200.60.0.1 to 200.60.255.254200.60.255.25565,534
62200.61.0.0/16200.61.0.1 to 200.61.255.254200.61.255.25565,534
63200.62.0.0/16200.62.0.1 to 200.62.255.254200.62.255.25565,534
64200.63.0.0/16200.63.0.1 to 200.63.255.254200.63.255.25565,534
65200.64.0.0/16200.64.0.1 to 200.64.255.254200.64.255.25565,534
66200.65.0.0/16200.65.0.1 to 200.65.255.254200.65.255.25565,534
67200.66.0.0/16200.66.0.1 to 200.66.255.254200.66.255.25565,534
68200.67.0.0/16200.67.0.1 to 200.67.255.254200.67.255.25565,534
69200.68.0.0/16200.68.0.1 to 200.68.255.254200.68.255.25565,534
70200.69.0.0/16200.69.0.1 to 200.69.255.254200.69.255.25565,534
71200.70.0.0/16200.70.0.1 to 200.70.255.254200.70.255.25565,534
72200.71.0.0/16200.71.0.1 to 200.71.255.254200.71.255.25565,534
73200.72.0.0/16200.72.0.1 to 200.72.255.254200.72.255.25565,534
74200.73.0.0/16200.73.0.1 to 200.73.255.254200.73.255.25565,534
75200.74.0.0/16200.74.0.1 to 200.74.255.254200.74.255.25565,534
76200.75.0.0/16200.75.0.1 to 200.75.255.254200.75.255.25565,534
77200.76.0.0/16200.76.0.1 to 200.76.255.254200.76.255.25565,534
78200.77.0.0/16200.77.0.1 to 200.77.255.254200.77.255.25565,534
79200.78.0.0/16200.78.0.1 to 200.78.255.254200.78.255.25565,534
80200.79.0.0/16200.79.0.1 to 200.79.255.254200.79.255.25565,534
81200.80.0.0/16200.80.0.1 to 200.80.255.254200.80.255.25565,534
82200.81.0.0/16200.81.0.1 to 200.81.255.254200.81.255.25565,534
83200.82.0.0/16200.82.0.1 to 200.82.255.254200.82.255.25565,534
84200.83.0.0/16200.83.0.1 to 200.83.255.254200.83.255.25565,534
85200.84.0.0/16200.84.0.1 to 200.84.255.254200.84.255.25565,534
86200.85.0.0/16200.85.0.1 to 200.85.255.254200.85.255.25565,534
87200.86.0.0/16200.86.0.1 to 200.86.255.254200.86.255.25565,534
88200.87.0.0/16200.87.0.1 to 200.87.255.254200.87.255.25565,534
89200.88.0.0/16200.88.0.1 to 200.88.255.254200.88.255.25565,534
90200.89.0.0/16200.89.0.1 to 200.89.255.254200.89.255.25565,534
91200.90.0.0/16200.90.0.1 to 200.90.255.254200.90.255.25565,534
92200.91.0.0/16200.91.0.1 to 200.91.255.254200.91.255.25565,534
93200.92.0.0/16200.92.0.1 to 200.92.255.254200.92.255.25565,534
94200.93.0.0/16200.93.0.1 to 200.93.255.254200.93.255.25565,534
95200.94.0.0/16200.94.0.1 to 200.94.255.254200.94.255.25565,534
96200.95.0.0/16200.95.0.1 to 200.95.255.254200.95.255.25565,534
97200.96.0.0/16200.96.0.1 to 200.96.255.254200.96.255.25565,534
98200.97.0.0/16200.97.0.1 to 200.97.255.254200.97.255.25565,534
99200.98.0.0/16200.98.0.1 to 200.98.255.254200.98.255.25565,534
100200.99.0.0/16200.99.0.1 to 200.99.255.254200.99.255.25565,534
101200.100.0.0/16200.100.0.1 to 200.100.255.254200.100.255.25565,534
102200.101.0.0/16200.101.0.1 to 200.101.255.254200.101.255.25565,534
103200.102.0.0/16200.102.0.1 to 200.102.255.254200.102.255.25565,534
104200.103.0.0/16200.103.0.1 to 200.103.255.254200.103.255.25565,534
105200.104.0.0/16200.104.0.1 to 200.104.255.254200.104.255.25565,534
106200.105.0.0/16200.105.0.1 to 200.105.255.254200.105.255.25565,534
107200.106.0.0/16200.106.0.1 to 200.106.255.254200.106.255.25565,534
108200.107.0.0/16200.107.0.1 to 200.107.255.254200.107.255.25565,534
109200.108.0.0/16200.108.0.1 to 200.108.255.254200.108.255.25565,534
110200.109.0.0/16200.109.0.1 to 200.109.255.254200.109.255.25565,534
111200.110.0.0/16200.110.0.1 to 200.110.255.254200.110.255.25565,534
112200.111.0.0/16200.111.0.1 to 200.111.255.254200.111.255.25565,534
113200.112.0.0/16200.112.0.1 to 200.112.255.254200.112.255.25565,534
114200.113.0.0/16200.113.0.1 to 200.113.255.254200.113.255.25565,534
115200.114.0.0/16200.114.0.1 to 200.114.255.254200.114.255.25565,534
116200.115.0.0/16200.115.0.1 to 200.115.255.254200.115.255.25565,534
117200.116.0.0/16200.116.0.1 to 200.116.255.254200.116.255.25565,534
118200.117.0.0/16200.117.0.1 to 200.117.255.254200.117.255.25565,534
119200.118.0.0/16200.118.0.1 to 200.118.255.254200.118.255.25565,534
120200.119.0.0/16200.119.0.1 to 200.119.255.254200.119.255.25565,534
121200.120.0.0/16200.120.0.1 to 200.120.255.254200.120.255.25565,534
122200.121.0.0/16200.121.0.1 to 200.121.255.254200.121.255.25565,534
123200.122.0.0/16200.122.0.1 to 200.122.255.254200.122.255.25565,534
124200.123.0.0/16200.123.0.1 to 200.123.255.254200.123.255.25565,534
125200.124.0.0/16200.124.0.1 to 200.124.255.254200.124.255.25565,534
126200.125.0.0/16200.125.0.1 to 200.125.255.254200.125.255.25565,534
127200.126.0.0/16200.126.0.1 to 200.126.255.254200.126.255.25565,534
128200.127.0.0/16200.127.0.1 to 200.127.255.254200.127.255.25565,534
129200.128.0.0/16200.128.0.1 to 200.128.255.254200.128.255.25565,534
130200.129.0.0/16200.129.0.1 to 200.129.255.254200.129.255.25565,534
131200.130.0.0/16200.130.0.1 to 200.130.255.254200.130.255.25565,534
132200.131.0.0/16200.131.0.1 to 200.131.255.254200.131.255.25565,534
133200.132.0.0/16200.132.0.1 to 200.132.255.254200.132.255.25565,534
134200.133.0.0/16200.133.0.1 to 200.133.255.254200.133.255.25565,534
135200.134.0.0/16200.134.0.1 to 200.134.255.254200.134.255.25565,534
136200.135.0.0/16200.135.0.1 to 200.135.255.254200.135.255.25565,534
137200.136.0.0/16200.136.0.1 to 200.136.255.254200.136.255.25565,534
138200.137.0.0/16200.137.0.1 to 200.137.255.254200.137.255.25565,534
139200.138.0.0/16200.138.0.1 to 200.138.255.254200.138.255.25565,534
140200.139.0.0/16200.139.0.1 to 200.139.255.254200.139.255.25565,534
141200.140.0.0/16200.140.0.1 to 200.140.255.254200.140.255.25565,534
142200.141.0.0/16200.141.0.1 to 200.141.255.254200.141.255.25565,534
143200.142.0.0/16200.142.0.1 to 200.142.255.254200.142.255.25565,534
144200.143.0.0/16200.143.0.1 to 200.143.255.254200.143.255.25565,534
145200.144.0.0/16200.144.0.1 to 200.144.255.254200.144.255.25565,534
146200.145.0.0/16200.145.0.1 to 200.145.255.254200.145.255.25565,534
147200.146.0.0/16200.146.0.1 to 200.146.255.254200.146.255.25565,534
148200.147.0.0/16200.147.0.1 to 200.147.255.254200.147.255.25565,534
149200.148.0.0/16200.148.0.1 to 200.148.255.254200.148.255.25565,534
150200.149.0.0/16200.149.0.1 to 200.149.255.254200.149.255.25565,534
151200.150.0.0/16200.150.0.1 to 200.150.255.254200.150.255.25565,534
152200.151.0.0/16200.151.0.1 to 200.151.255.254200.151.255.25565,534
153200.152.0.0/16200.152.0.1 to 200.152.255.254200.152.255.25565,534
154200.153.0.0/16200.153.0.1 to 200.153.255.254200.153.255.25565,534
155200.154.0.0/16200.154.0.1 to 200.154.255.254200.154.255.25565,534
156200.155.0.0/16200.155.0.1 to 200.155.255.254200.155.255.25565,534
157200.156.0.0/16200.156.0.1 to 200.156.255.254200.156.255.25565,534
158200.157.0.0/16200.157.0.1 to 200.157.255.254200.157.255.25565,534
159200.158.0.0/16200.158.0.1 to 200.158.255.254200.158.255.25565,534
160200.159.0.0/16200.159.0.1 to 200.159.255.254200.159.255.25565,534
161200.160.0.0/16200.160.0.1 to 200.160.255.254200.160.255.25565,534
162200.161.0.0/16200.161.0.1 to 200.161.255.254200.161.255.25565,534
163200.162.0.0/16200.162.0.1 to 200.162.255.254200.162.255.25565,534
164200.163.0.0/16200.163.0.1 to 200.163.255.254200.163.255.25565,534
165200.164.0.0/16200.164.0.1 to 200.164.255.254200.164.255.25565,534
166200.165.0.0/16200.165.0.1 to 200.165.255.254200.165.255.25565,534
167200.166.0.0/16200.166.0.1 to 200.166.255.254200.166.255.25565,534
168200.167.0.0/16200.167.0.1 to 200.167.255.254200.167.255.25565,534
169200.168.0.0/16200.168.0.1 to 200.168.255.254200.168.255.25565,534
170200.169.0.0/16200.169.0.1 to 200.169.255.254200.169.255.25565,534
171200.170.0.0/16200.170.0.1 to 200.170.255.254200.170.255.25565,534
172200.171.0.0/16200.171.0.1 to 200.171.255.254200.171.255.25565,534
173200.172.0.0/16200.172.0.1 to 200.172.255.254200.172.255.25565,534
174200.173.0.0/16200.173.0.1 to 200.173.255.254200.173.255.25565,534
175200.174.0.0/16200.174.0.1 to 200.174.255.254200.174.255.25565,534
176200.175.0.0/16200.175.0.1 to 200.175.255.254200.175.255.25565,534
177200.176.0.0/16200.176.0.1 to 200.176.255.254200.176.255.25565,534
178200.177.0.0/16200.177.0.1 to 200.177.255.254200.177.255.25565,534
179200.178.0.0/16200.178.0.1 to 200.178.255.254200.178.255.25565,534
180200.179.0.0/16200.179.0.1 to 200.179.255.254200.179.255.25565,534
181200.180.0.0/16200.180.0.1 to 200.180.255.254200.180.255.25565,534
182200.181.0.0/16200.181.0.1 to 200.181.255.254200.181.255.25565,534
183200.182.0.0/16200.182.0.1 to 200.182.255.254200.182.255.25565,534
184200.183.0.0/16200.183.0.1 to 200.183.255.254200.183.255.25565,534
185200.184.0.0/16200.184.0.1 to 200.184.255.254200.184.255.25565,534
186200.185.0.0/16200.185.0.1 to 200.185.255.254200.185.255.25565,534
187200.186.0.0/16200.186.0.1 to 200.186.255.254200.186.255.25565,534
188200.187.0.0/16200.187.0.1 to 200.187.255.254200.187.255.25565,534
189200.188.0.0/16200.188.0.1 to 200.188.255.254200.188.255.25565,534
190200.189.0.0/16200.189.0.1 to 200.189.255.254200.189.255.25565,534
191200.190.0.0/16200.190.0.1 to 200.190.255.254200.190.255.25565,534
192200.191.0.0/16200.191.0.1 to 200.191.255.254200.191.255.25565,534
193200.192.0.0/16200.192.0.1 to 200.192.255.254200.192.255.25565,534
194200.193.0.0/16200.193.0.1 to 200.193.255.254200.193.255.25565,534
195200.194.0.0/16200.194.0.1 to 200.194.255.254200.194.255.25565,534
196200.195.0.0/16200.195.0.1 to 200.195.255.254200.195.255.25565,534
197200.196.0.0/16200.196.0.1 to 200.196.255.254200.196.255.25565,534
198200.197.0.0/16200.197.0.1 to 200.197.255.254200.197.255.25565,534
199200.198.0.0/16200.198.0.1 to 200.198.255.254200.198.255.25565,534
200200.199.0.0/16200.199.0.1 to 200.199.255.254200.199.255.25565,534
201200.200.0.0/16200.200.0.1 to 200.200.255.254200.200.255.25565,534
202200.201.0.0/16200.201.0.1 to 200.201.255.254200.201.255.25565,534
203200.202.0.0/16200.202.0.1 to 200.202.255.254200.202.255.25565,534
204200.203.0.0/16200.203.0.1 to 200.203.255.254200.203.255.25565,534
205200.204.0.0/16200.204.0.1 to 200.204.255.254200.204.255.25565,534
206200.205.0.0/16200.205.0.1 to 200.205.255.254200.205.255.25565,534
207200.206.0.0/16200.206.0.1 to 200.206.255.254200.206.255.25565,534
208200.207.0.0/16200.207.0.1 to 200.207.255.254200.207.255.25565,534
209200.208.0.0/16200.208.0.1 to 200.208.255.254200.208.255.25565,534
210200.209.0.0/16200.209.0.1 to 200.209.255.254200.209.255.25565,534
211200.210.0.0/16200.210.0.1 to 200.210.255.254200.210.255.25565,534
212200.211.0.0/16200.211.0.1 to 200.211.255.254200.211.255.25565,534
213200.212.0.0/16200.212.0.1 to 200.212.255.254200.212.255.25565,534
214200.213.0.0/16200.213.0.1 to 200.213.255.254200.213.255.25565,534
215200.214.0.0/16200.214.0.1 to 200.214.255.254200.214.255.25565,534
216200.215.0.0/16200.215.0.1 to 200.215.255.254200.215.255.25565,534
217200.216.0.0/16200.216.0.1 to 200.216.255.254200.216.255.25565,534
218200.217.0.0/16200.217.0.1 to 200.217.255.254200.217.255.25565,534
219200.218.0.0/16200.218.0.1 to 200.218.255.254200.218.255.25565,534
220200.219.0.0/16200.219.0.1 to 200.219.255.254200.219.255.25565,534
221200.220.0.0/16200.220.0.1 to 200.220.255.254200.220.255.25565,534
222200.221.0.0/16200.221.0.1 to 200.221.255.254200.221.255.25565,534
223200.222.0.0/16200.222.0.1 to 200.222.255.254200.222.255.25565,534
224200.223.0.0/16200.223.0.1 to 200.223.255.254200.223.255.25565,534
225200.224.0.0/16200.224.0.1 to 200.224.255.254200.224.255.25565,534
226200.225.0.0/16200.225.0.1 to 200.225.255.254200.225.255.25565,534
227200.226.0.0/16200.226.0.1 to 200.226.255.254200.226.255.25565,534
228200.227.0.0/16200.227.0.1 to 200.227.255.254200.227.255.25565,534
229200.228.0.0/16200.228.0.1 to 200.228.255.254200.228.255.25565,534
230200.229.0.0/16200.229.0.1 to 200.229.255.254200.229.255.25565,534
231200.230.0.0/16200.230.0.1 to 200.230.255.254200.230.255.25565,534
232200.231.0.0/16200.231.0.1 to 200.231.255.254200.231.255.25565,534
233200.232.0.0/16200.232.0.1 to 200.232.255.254200.232.255.25565,534
234200.233.0.0/16200.233.0.1 to 200.233.255.254200.233.255.25565,534
235200.234.0.0/16200.234.0.1 to 200.234.255.254200.234.255.25565,534
236200.235.0.0/16200.235.0.1 to 200.235.255.254200.235.255.25565,534
237200.236.0.0/16200.236.0.1 to 200.236.255.254200.236.255.25565,534
238200.237.0.0/16200.237.0.1 to 200.237.255.254200.237.255.25565,534
239200.238.0.0/16200.238.0.1 to 200.238.255.254200.238.255.25565,534
240200.239.0.0/16200.239.0.1 to 200.239.255.254200.239.255.25565,534
241200.240.0.0/16200.240.0.1 to 200.240.255.254200.240.255.25565,534
242200.241.0.0/16200.241.0.1 to 200.241.255.254200.241.255.25565,534
243200.242.0.0/16200.242.0.1 to 200.242.255.254200.242.255.25565,534
244200.243.0.0/16200.243.0.1 to 200.243.255.254200.243.255.25565,534
245200.244.0.0/16200.244.0.1 to 200.244.255.254200.244.255.25565,534
246200.245.0.0/16200.245.0.1 to 200.245.255.254200.245.255.25565,534
247200.246.0.0/16200.246.0.1 to 200.246.255.254200.246.255.25565,534
248200.247.0.0/16200.247.0.1 to 200.247.255.254200.247.255.25565,534
249200.248.0.0/16200.248.0.1 to 200.248.255.254200.248.255.25565,534
250200.249.0.0/16200.249.0.1 to 200.249.255.254200.249.255.25565,534
251200.250.0.0/16200.250.0.1 to 200.250.255.254200.250.255.25565,534
252200.251.0.0/16200.251.0.1 to 200.251.255.254200.251.255.25565,534
253200.252.0.0/16200.252.0.1 to 200.252.255.254200.252.255.25565,534
254200.253.0.0/16200.253.0.1 to 200.253.255.254200.253.255.25565,534
255200.254.0.0/16200.254.0.1 to 200.254.255.254200.254.255.25565,534
256200.255.0.0/16200.255.0.1 to 200.255.255.254200.255.255.25565,534

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.