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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.

Network199.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
199.0.0.0
Broadcast address
199.255.255.255
First usable
199.0.0.1
Last usable
199.255.255.254
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 C7000000 · Integer 3338665984 to 3355443199
Reverse DNS zone
199.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000111..00000000.00000000.00000000199.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network11000111..00000000.00000000.00000000199.0.0.0
Broadcast11000111..11111111.11111111.11111111199.255.255.255
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)

199.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1199.0.0.0/16199.0.0.1 to 199.0.255.254199.0.255.25565,534
2199.1.0.0/16199.1.0.1 to 199.1.255.254199.1.255.25565,534
3199.2.0.0/16199.2.0.1 to 199.2.255.254199.2.255.25565,534
4199.3.0.0/16199.3.0.1 to 199.3.255.254199.3.255.25565,534
5199.4.0.0/16199.4.0.1 to 199.4.255.254199.4.255.25565,534
6199.5.0.0/16199.5.0.1 to 199.5.255.254199.5.255.25565,534
7199.6.0.0/16199.6.0.1 to 199.6.255.254199.6.255.25565,534
8199.7.0.0/16199.7.0.1 to 199.7.255.254199.7.255.25565,534
9199.8.0.0/16199.8.0.1 to 199.8.255.254199.8.255.25565,534
10199.9.0.0/16199.9.0.1 to 199.9.255.254199.9.255.25565,534
11199.10.0.0/16199.10.0.1 to 199.10.255.254199.10.255.25565,534
12199.11.0.0/16199.11.0.1 to 199.11.255.254199.11.255.25565,534
13199.12.0.0/16199.12.0.1 to 199.12.255.254199.12.255.25565,534
14199.13.0.0/16199.13.0.1 to 199.13.255.254199.13.255.25565,534
15199.14.0.0/16199.14.0.1 to 199.14.255.254199.14.255.25565,534
16199.15.0.0/16199.15.0.1 to 199.15.255.254199.15.255.25565,534
17199.16.0.0/16199.16.0.1 to 199.16.255.254199.16.255.25565,534
18199.17.0.0/16199.17.0.1 to 199.17.255.254199.17.255.25565,534
19199.18.0.0/16199.18.0.1 to 199.18.255.254199.18.255.25565,534
20199.19.0.0/16199.19.0.1 to 199.19.255.254199.19.255.25565,534
21199.20.0.0/16199.20.0.1 to 199.20.255.254199.20.255.25565,534
22199.21.0.0/16199.21.0.1 to 199.21.255.254199.21.255.25565,534
23199.22.0.0/16199.22.0.1 to 199.22.255.254199.22.255.25565,534
24199.23.0.0/16199.23.0.1 to 199.23.255.254199.23.255.25565,534
25199.24.0.0/16199.24.0.1 to 199.24.255.254199.24.255.25565,534
26199.25.0.0/16199.25.0.1 to 199.25.255.254199.25.255.25565,534
27199.26.0.0/16199.26.0.1 to 199.26.255.254199.26.255.25565,534
28199.27.0.0/16199.27.0.1 to 199.27.255.254199.27.255.25565,534
29199.28.0.0/16199.28.0.1 to 199.28.255.254199.28.255.25565,534
30199.29.0.0/16199.29.0.1 to 199.29.255.254199.29.255.25565,534
31199.30.0.0/16199.30.0.1 to 199.30.255.254199.30.255.25565,534
32199.31.0.0/16199.31.0.1 to 199.31.255.254199.31.255.25565,534
33199.32.0.0/16199.32.0.1 to 199.32.255.254199.32.255.25565,534
34199.33.0.0/16199.33.0.1 to 199.33.255.254199.33.255.25565,534
35199.34.0.0/16199.34.0.1 to 199.34.255.254199.34.255.25565,534
36199.35.0.0/16199.35.0.1 to 199.35.255.254199.35.255.25565,534
37199.36.0.0/16199.36.0.1 to 199.36.255.254199.36.255.25565,534
38199.37.0.0/16199.37.0.1 to 199.37.255.254199.37.255.25565,534
39199.38.0.0/16199.38.0.1 to 199.38.255.254199.38.255.25565,534
40199.39.0.0/16199.39.0.1 to 199.39.255.254199.39.255.25565,534
41199.40.0.0/16199.40.0.1 to 199.40.255.254199.40.255.25565,534
42199.41.0.0/16199.41.0.1 to 199.41.255.254199.41.255.25565,534
43199.42.0.0/16199.42.0.1 to 199.42.255.254199.42.255.25565,534
44199.43.0.0/16199.43.0.1 to 199.43.255.254199.43.255.25565,534
45199.44.0.0/16199.44.0.1 to 199.44.255.254199.44.255.25565,534
46199.45.0.0/16199.45.0.1 to 199.45.255.254199.45.255.25565,534
47199.46.0.0/16199.46.0.1 to 199.46.255.254199.46.255.25565,534
48199.47.0.0/16199.47.0.1 to 199.47.255.254199.47.255.25565,534
49199.48.0.0/16199.48.0.1 to 199.48.255.254199.48.255.25565,534
50199.49.0.0/16199.49.0.1 to 199.49.255.254199.49.255.25565,534
51199.50.0.0/16199.50.0.1 to 199.50.255.254199.50.255.25565,534
52199.51.0.0/16199.51.0.1 to 199.51.255.254199.51.255.25565,534
53199.52.0.0/16199.52.0.1 to 199.52.255.254199.52.255.25565,534
54199.53.0.0/16199.53.0.1 to 199.53.255.254199.53.255.25565,534
55199.54.0.0/16199.54.0.1 to 199.54.255.254199.54.255.25565,534
56199.55.0.0/16199.55.0.1 to 199.55.255.254199.55.255.25565,534
57199.56.0.0/16199.56.0.1 to 199.56.255.254199.56.255.25565,534
58199.57.0.0/16199.57.0.1 to 199.57.255.254199.57.255.25565,534
59199.58.0.0/16199.58.0.1 to 199.58.255.254199.58.255.25565,534
60199.59.0.0/16199.59.0.1 to 199.59.255.254199.59.255.25565,534
61199.60.0.0/16199.60.0.1 to 199.60.255.254199.60.255.25565,534
62199.61.0.0/16199.61.0.1 to 199.61.255.254199.61.255.25565,534
63199.62.0.0/16199.62.0.1 to 199.62.255.254199.62.255.25565,534
64199.63.0.0/16199.63.0.1 to 199.63.255.254199.63.255.25565,534
65199.64.0.0/16199.64.0.1 to 199.64.255.254199.64.255.25565,534
66199.65.0.0/16199.65.0.1 to 199.65.255.254199.65.255.25565,534
67199.66.0.0/16199.66.0.1 to 199.66.255.254199.66.255.25565,534
68199.67.0.0/16199.67.0.1 to 199.67.255.254199.67.255.25565,534
69199.68.0.0/16199.68.0.1 to 199.68.255.254199.68.255.25565,534
70199.69.0.0/16199.69.0.1 to 199.69.255.254199.69.255.25565,534
71199.70.0.0/16199.70.0.1 to 199.70.255.254199.70.255.25565,534
72199.71.0.0/16199.71.0.1 to 199.71.255.254199.71.255.25565,534
73199.72.0.0/16199.72.0.1 to 199.72.255.254199.72.255.25565,534
74199.73.0.0/16199.73.0.1 to 199.73.255.254199.73.255.25565,534
75199.74.0.0/16199.74.0.1 to 199.74.255.254199.74.255.25565,534
76199.75.0.0/16199.75.0.1 to 199.75.255.254199.75.255.25565,534
77199.76.0.0/16199.76.0.1 to 199.76.255.254199.76.255.25565,534
78199.77.0.0/16199.77.0.1 to 199.77.255.254199.77.255.25565,534
79199.78.0.0/16199.78.0.1 to 199.78.255.254199.78.255.25565,534
80199.79.0.0/16199.79.0.1 to 199.79.255.254199.79.255.25565,534
81199.80.0.0/16199.80.0.1 to 199.80.255.254199.80.255.25565,534
82199.81.0.0/16199.81.0.1 to 199.81.255.254199.81.255.25565,534
83199.82.0.0/16199.82.0.1 to 199.82.255.254199.82.255.25565,534
84199.83.0.0/16199.83.0.1 to 199.83.255.254199.83.255.25565,534
85199.84.0.0/16199.84.0.1 to 199.84.255.254199.84.255.25565,534
86199.85.0.0/16199.85.0.1 to 199.85.255.254199.85.255.25565,534
87199.86.0.0/16199.86.0.1 to 199.86.255.254199.86.255.25565,534
88199.87.0.0/16199.87.0.1 to 199.87.255.254199.87.255.25565,534
89199.88.0.0/16199.88.0.1 to 199.88.255.254199.88.255.25565,534
90199.89.0.0/16199.89.0.1 to 199.89.255.254199.89.255.25565,534
91199.90.0.0/16199.90.0.1 to 199.90.255.254199.90.255.25565,534
92199.91.0.0/16199.91.0.1 to 199.91.255.254199.91.255.25565,534
93199.92.0.0/16199.92.0.1 to 199.92.255.254199.92.255.25565,534
94199.93.0.0/16199.93.0.1 to 199.93.255.254199.93.255.25565,534
95199.94.0.0/16199.94.0.1 to 199.94.255.254199.94.255.25565,534
96199.95.0.0/16199.95.0.1 to 199.95.255.254199.95.255.25565,534
97199.96.0.0/16199.96.0.1 to 199.96.255.254199.96.255.25565,534
98199.97.0.0/16199.97.0.1 to 199.97.255.254199.97.255.25565,534
99199.98.0.0/16199.98.0.1 to 199.98.255.254199.98.255.25565,534
100199.99.0.0/16199.99.0.1 to 199.99.255.254199.99.255.25565,534
101199.100.0.0/16199.100.0.1 to 199.100.255.254199.100.255.25565,534
102199.101.0.0/16199.101.0.1 to 199.101.255.254199.101.255.25565,534
103199.102.0.0/16199.102.0.1 to 199.102.255.254199.102.255.25565,534
104199.103.0.0/16199.103.0.1 to 199.103.255.254199.103.255.25565,534
105199.104.0.0/16199.104.0.1 to 199.104.255.254199.104.255.25565,534
106199.105.0.0/16199.105.0.1 to 199.105.255.254199.105.255.25565,534
107199.106.0.0/16199.106.0.1 to 199.106.255.254199.106.255.25565,534
108199.107.0.0/16199.107.0.1 to 199.107.255.254199.107.255.25565,534
109199.108.0.0/16199.108.0.1 to 199.108.255.254199.108.255.25565,534
110199.109.0.0/16199.109.0.1 to 199.109.255.254199.109.255.25565,534
111199.110.0.0/16199.110.0.1 to 199.110.255.254199.110.255.25565,534
112199.111.0.0/16199.111.0.1 to 199.111.255.254199.111.255.25565,534
113199.112.0.0/16199.112.0.1 to 199.112.255.254199.112.255.25565,534
114199.113.0.0/16199.113.0.1 to 199.113.255.254199.113.255.25565,534
115199.114.0.0/16199.114.0.1 to 199.114.255.254199.114.255.25565,534
116199.115.0.0/16199.115.0.1 to 199.115.255.254199.115.255.25565,534
117199.116.0.0/16199.116.0.1 to 199.116.255.254199.116.255.25565,534
118199.117.0.0/16199.117.0.1 to 199.117.255.254199.117.255.25565,534
119199.118.0.0/16199.118.0.1 to 199.118.255.254199.118.255.25565,534
120199.119.0.0/16199.119.0.1 to 199.119.255.254199.119.255.25565,534
121199.120.0.0/16199.120.0.1 to 199.120.255.254199.120.255.25565,534
122199.121.0.0/16199.121.0.1 to 199.121.255.254199.121.255.25565,534
123199.122.0.0/16199.122.0.1 to 199.122.255.254199.122.255.25565,534
124199.123.0.0/16199.123.0.1 to 199.123.255.254199.123.255.25565,534
125199.124.0.0/16199.124.0.1 to 199.124.255.254199.124.255.25565,534
126199.125.0.0/16199.125.0.1 to 199.125.255.254199.125.255.25565,534
127199.126.0.0/16199.126.0.1 to 199.126.255.254199.126.255.25565,534
128199.127.0.0/16199.127.0.1 to 199.127.255.254199.127.255.25565,534
129199.128.0.0/16199.128.0.1 to 199.128.255.254199.128.255.25565,534
130199.129.0.0/16199.129.0.1 to 199.129.255.254199.129.255.25565,534
131199.130.0.0/16199.130.0.1 to 199.130.255.254199.130.255.25565,534
132199.131.0.0/16199.131.0.1 to 199.131.255.254199.131.255.25565,534
133199.132.0.0/16199.132.0.1 to 199.132.255.254199.132.255.25565,534
134199.133.0.0/16199.133.0.1 to 199.133.255.254199.133.255.25565,534
135199.134.0.0/16199.134.0.1 to 199.134.255.254199.134.255.25565,534
136199.135.0.0/16199.135.0.1 to 199.135.255.254199.135.255.25565,534
137199.136.0.0/16199.136.0.1 to 199.136.255.254199.136.255.25565,534
138199.137.0.0/16199.137.0.1 to 199.137.255.254199.137.255.25565,534
139199.138.0.0/16199.138.0.1 to 199.138.255.254199.138.255.25565,534
140199.139.0.0/16199.139.0.1 to 199.139.255.254199.139.255.25565,534
141199.140.0.0/16199.140.0.1 to 199.140.255.254199.140.255.25565,534
142199.141.0.0/16199.141.0.1 to 199.141.255.254199.141.255.25565,534
143199.142.0.0/16199.142.0.1 to 199.142.255.254199.142.255.25565,534
144199.143.0.0/16199.143.0.1 to 199.143.255.254199.143.255.25565,534
145199.144.0.0/16199.144.0.1 to 199.144.255.254199.144.255.25565,534
146199.145.0.0/16199.145.0.1 to 199.145.255.254199.145.255.25565,534
147199.146.0.0/16199.146.0.1 to 199.146.255.254199.146.255.25565,534
148199.147.0.0/16199.147.0.1 to 199.147.255.254199.147.255.25565,534
149199.148.0.0/16199.148.0.1 to 199.148.255.254199.148.255.25565,534
150199.149.0.0/16199.149.0.1 to 199.149.255.254199.149.255.25565,534
151199.150.0.0/16199.150.0.1 to 199.150.255.254199.150.255.25565,534
152199.151.0.0/16199.151.0.1 to 199.151.255.254199.151.255.25565,534
153199.152.0.0/16199.152.0.1 to 199.152.255.254199.152.255.25565,534
154199.153.0.0/16199.153.0.1 to 199.153.255.254199.153.255.25565,534
155199.154.0.0/16199.154.0.1 to 199.154.255.254199.154.255.25565,534
156199.155.0.0/16199.155.0.1 to 199.155.255.254199.155.255.25565,534
157199.156.0.0/16199.156.0.1 to 199.156.255.254199.156.255.25565,534
158199.157.0.0/16199.157.0.1 to 199.157.255.254199.157.255.25565,534
159199.158.0.0/16199.158.0.1 to 199.158.255.254199.158.255.25565,534
160199.159.0.0/16199.159.0.1 to 199.159.255.254199.159.255.25565,534
161199.160.0.0/16199.160.0.1 to 199.160.255.254199.160.255.25565,534
162199.161.0.0/16199.161.0.1 to 199.161.255.254199.161.255.25565,534
163199.162.0.0/16199.162.0.1 to 199.162.255.254199.162.255.25565,534
164199.163.0.0/16199.163.0.1 to 199.163.255.254199.163.255.25565,534
165199.164.0.0/16199.164.0.1 to 199.164.255.254199.164.255.25565,534
166199.165.0.0/16199.165.0.1 to 199.165.255.254199.165.255.25565,534
167199.166.0.0/16199.166.0.1 to 199.166.255.254199.166.255.25565,534
168199.167.0.0/16199.167.0.1 to 199.167.255.254199.167.255.25565,534
169199.168.0.0/16199.168.0.1 to 199.168.255.254199.168.255.25565,534
170199.169.0.0/16199.169.0.1 to 199.169.255.254199.169.255.25565,534
171199.170.0.0/16199.170.0.1 to 199.170.255.254199.170.255.25565,534
172199.171.0.0/16199.171.0.1 to 199.171.255.254199.171.255.25565,534
173199.172.0.0/16199.172.0.1 to 199.172.255.254199.172.255.25565,534
174199.173.0.0/16199.173.0.1 to 199.173.255.254199.173.255.25565,534
175199.174.0.0/16199.174.0.1 to 199.174.255.254199.174.255.25565,534
176199.175.0.0/16199.175.0.1 to 199.175.255.254199.175.255.25565,534
177199.176.0.0/16199.176.0.1 to 199.176.255.254199.176.255.25565,534
178199.177.0.0/16199.177.0.1 to 199.177.255.254199.177.255.25565,534
179199.178.0.0/16199.178.0.1 to 199.178.255.254199.178.255.25565,534
180199.179.0.0/16199.179.0.1 to 199.179.255.254199.179.255.25565,534
181199.180.0.0/16199.180.0.1 to 199.180.255.254199.180.255.25565,534
182199.181.0.0/16199.181.0.1 to 199.181.255.254199.181.255.25565,534
183199.182.0.0/16199.182.0.1 to 199.182.255.254199.182.255.25565,534
184199.183.0.0/16199.183.0.1 to 199.183.255.254199.183.255.25565,534
185199.184.0.0/16199.184.0.1 to 199.184.255.254199.184.255.25565,534
186199.185.0.0/16199.185.0.1 to 199.185.255.254199.185.255.25565,534
187199.186.0.0/16199.186.0.1 to 199.186.255.254199.186.255.25565,534
188199.187.0.0/16199.187.0.1 to 199.187.255.254199.187.255.25565,534
189199.188.0.0/16199.188.0.1 to 199.188.255.254199.188.255.25565,534
190199.189.0.0/16199.189.0.1 to 199.189.255.254199.189.255.25565,534
191199.190.0.0/16199.190.0.1 to 199.190.255.254199.190.255.25565,534
192199.191.0.0/16199.191.0.1 to 199.191.255.254199.191.255.25565,534
193199.192.0.0/16199.192.0.1 to 199.192.255.254199.192.255.25565,534
194199.193.0.0/16199.193.0.1 to 199.193.255.254199.193.255.25565,534
195199.194.0.0/16199.194.0.1 to 199.194.255.254199.194.255.25565,534
196199.195.0.0/16199.195.0.1 to 199.195.255.254199.195.255.25565,534
197199.196.0.0/16199.196.0.1 to 199.196.255.254199.196.255.25565,534
198199.197.0.0/16199.197.0.1 to 199.197.255.254199.197.255.25565,534
199199.198.0.0/16199.198.0.1 to 199.198.255.254199.198.255.25565,534
200199.199.0.0/16199.199.0.1 to 199.199.255.254199.199.255.25565,534
201199.200.0.0/16199.200.0.1 to 199.200.255.254199.200.255.25565,534
202199.201.0.0/16199.201.0.1 to 199.201.255.254199.201.255.25565,534
203199.202.0.0/16199.202.0.1 to 199.202.255.254199.202.255.25565,534
204199.203.0.0/16199.203.0.1 to 199.203.255.254199.203.255.25565,534
205199.204.0.0/16199.204.0.1 to 199.204.255.254199.204.255.25565,534
206199.205.0.0/16199.205.0.1 to 199.205.255.254199.205.255.25565,534
207199.206.0.0/16199.206.0.1 to 199.206.255.254199.206.255.25565,534
208199.207.0.0/16199.207.0.1 to 199.207.255.254199.207.255.25565,534
209199.208.0.0/16199.208.0.1 to 199.208.255.254199.208.255.25565,534
210199.209.0.0/16199.209.0.1 to 199.209.255.254199.209.255.25565,534
211199.210.0.0/16199.210.0.1 to 199.210.255.254199.210.255.25565,534
212199.211.0.0/16199.211.0.1 to 199.211.255.254199.211.255.25565,534
213199.212.0.0/16199.212.0.1 to 199.212.255.254199.212.255.25565,534
214199.213.0.0/16199.213.0.1 to 199.213.255.254199.213.255.25565,534
215199.214.0.0/16199.214.0.1 to 199.214.255.254199.214.255.25565,534
216199.215.0.0/16199.215.0.1 to 199.215.255.254199.215.255.25565,534
217199.216.0.0/16199.216.0.1 to 199.216.255.254199.216.255.25565,534
218199.217.0.0/16199.217.0.1 to 199.217.255.254199.217.255.25565,534
219199.218.0.0/16199.218.0.1 to 199.218.255.254199.218.255.25565,534
220199.219.0.0/16199.219.0.1 to 199.219.255.254199.219.255.25565,534
221199.220.0.0/16199.220.0.1 to 199.220.255.254199.220.255.25565,534
222199.221.0.0/16199.221.0.1 to 199.221.255.254199.221.255.25565,534
223199.222.0.0/16199.222.0.1 to 199.222.255.254199.222.255.25565,534
224199.223.0.0/16199.223.0.1 to 199.223.255.254199.223.255.25565,534
225199.224.0.0/16199.224.0.1 to 199.224.255.254199.224.255.25565,534
226199.225.0.0/16199.225.0.1 to 199.225.255.254199.225.255.25565,534
227199.226.0.0/16199.226.0.1 to 199.226.255.254199.226.255.25565,534
228199.227.0.0/16199.227.0.1 to 199.227.255.254199.227.255.25565,534
229199.228.0.0/16199.228.0.1 to 199.228.255.254199.228.255.25565,534
230199.229.0.0/16199.229.0.1 to 199.229.255.254199.229.255.25565,534
231199.230.0.0/16199.230.0.1 to 199.230.255.254199.230.255.25565,534
232199.231.0.0/16199.231.0.1 to 199.231.255.254199.231.255.25565,534
233199.232.0.0/16199.232.0.1 to 199.232.255.254199.232.255.25565,534
234199.233.0.0/16199.233.0.1 to 199.233.255.254199.233.255.25565,534
235199.234.0.0/16199.234.0.1 to 199.234.255.254199.234.255.25565,534
236199.235.0.0/16199.235.0.1 to 199.235.255.254199.235.255.25565,534
237199.236.0.0/16199.236.0.1 to 199.236.255.254199.236.255.25565,534
238199.237.0.0/16199.237.0.1 to 199.237.255.254199.237.255.25565,534
239199.238.0.0/16199.238.0.1 to 199.238.255.254199.238.255.25565,534
240199.239.0.0/16199.239.0.1 to 199.239.255.254199.239.255.25565,534
241199.240.0.0/16199.240.0.1 to 199.240.255.254199.240.255.25565,534
242199.241.0.0/16199.241.0.1 to 199.241.255.254199.241.255.25565,534
243199.242.0.0/16199.242.0.1 to 199.242.255.254199.242.255.25565,534
244199.243.0.0/16199.243.0.1 to 199.243.255.254199.243.255.25565,534
245199.244.0.0/16199.244.0.1 to 199.244.255.254199.244.255.25565,534
246199.245.0.0/16199.245.0.1 to 199.245.255.254199.245.255.25565,534
247199.246.0.0/16199.246.0.1 to 199.246.255.254199.246.255.25565,534
248199.247.0.0/16199.247.0.1 to 199.247.255.254199.247.255.25565,534
249199.248.0.0/16199.248.0.1 to 199.248.255.254199.248.255.25565,534
250199.249.0.0/16199.249.0.1 to 199.249.255.254199.249.255.25565,534
251199.250.0.0/16199.250.0.1 to 199.250.255.254199.250.255.25565,534
252199.251.0.0/16199.251.0.1 to 199.251.255.254199.251.255.25565,534
253199.252.0.0/16199.252.0.1 to 199.252.255.254199.252.255.25565,534
254199.253.0.0/16199.253.0.1 to 199.253.255.254199.253.255.25565,534
255199.254.0.0/16199.254.0.1 to 199.254.255.254199.254.255.25565,534
256199.255.0.0/16199.255.0.1 to 199.255.255.254199.255.255.25565,534

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.