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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.

Network143.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
143.0.0.0
Broadcast address
143.255.255.255
First usable
143.0.0.1
Last usable
143.255.255.254
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
B (default /16)
As numbers
Hex 8F000000 · Integer 2399141888 to 2415919103
Reverse DNS zone
143.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10001111..00000000.00000000.00000000143.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network10001111..00000000.00000000.00000000143.0.0.0
Broadcast10001111..11111111.11111111.11111111143.255.255.255
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)

143.0.0.0/8 makes 1,024 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1143.0.0.0/18143.0.0.1 to 143.0.63.254143.0.63.25516,382
2143.0.64.0/18143.0.64.1 to 143.0.127.254143.0.127.25516,382
3143.0.128.0/18143.0.128.1 to 143.0.191.254143.0.191.25516,382
4143.0.192.0/18143.0.192.1 to 143.0.255.254143.0.255.25516,382
5143.1.0.0/18143.1.0.1 to 143.1.63.254143.1.63.25516,382
6143.1.64.0/18143.1.64.1 to 143.1.127.254143.1.127.25516,382
7143.1.128.0/18143.1.128.1 to 143.1.191.254143.1.191.25516,382
8143.1.192.0/18143.1.192.1 to 143.1.255.254143.1.255.25516,382
9143.2.0.0/18143.2.0.1 to 143.2.63.254143.2.63.25516,382
10143.2.64.0/18143.2.64.1 to 143.2.127.254143.2.127.25516,382
11143.2.128.0/18143.2.128.1 to 143.2.191.254143.2.191.25516,382
12143.2.192.0/18143.2.192.1 to 143.2.255.254143.2.255.25516,382
13143.3.0.0/18143.3.0.1 to 143.3.63.254143.3.63.25516,382
14143.3.64.0/18143.3.64.1 to 143.3.127.254143.3.127.25516,382
15143.3.128.0/18143.3.128.1 to 143.3.191.254143.3.191.25516,382
16143.3.192.0/18143.3.192.1 to 143.3.255.254143.3.255.25516,382
17143.4.0.0/18143.4.0.1 to 143.4.63.254143.4.63.25516,382
18143.4.64.0/18143.4.64.1 to 143.4.127.254143.4.127.25516,382
19143.4.128.0/18143.4.128.1 to 143.4.191.254143.4.191.25516,382
20143.4.192.0/18143.4.192.1 to 143.4.255.254143.4.255.25516,382
21143.5.0.0/18143.5.0.1 to 143.5.63.254143.5.63.25516,382
22143.5.64.0/18143.5.64.1 to 143.5.127.254143.5.127.25516,382
23143.5.128.0/18143.5.128.1 to 143.5.191.254143.5.191.25516,382
24143.5.192.0/18143.5.192.1 to 143.5.255.254143.5.255.25516,382
25143.6.0.0/18143.6.0.1 to 143.6.63.254143.6.63.25516,382
26143.6.64.0/18143.6.64.1 to 143.6.127.254143.6.127.25516,382
27143.6.128.0/18143.6.128.1 to 143.6.191.254143.6.191.25516,382
28143.6.192.0/18143.6.192.1 to 143.6.255.254143.6.255.25516,382
29143.7.0.0/18143.7.0.1 to 143.7.63.254143.7.63.25516,382
30143.7.64.0/18143.7.64.1 to 143.7.127.254143.7.127.25516,382
31143.7.128.0/18143.7.128.1 to 143.7.191.254143.7.191.25516,382
32143.7.192.0/18143.7.192.1 to 143.7.255.254143.7.255.25516,382
33143.8.0.0/18143.8.0.1 to 143.8.63.254143.8.63.25516,382
34143.8.64.0/18143.8.64.1 to 143.8.127.254143.8.127.25516,382
35143.8.128.0/18143.8.128.1 to 143.8.191.254143.8.191.25516,382
36143.8.192.0/18143.8.192.1 to 143.8.255.254143.8.255.25516,382
37143.9.0.0/18143.9.0.1 to 143.9.63.254143.9.63.25516,382
38143.9.64.0/18143.9.64.1 to 143.9.127.254143.9.127.25516,382
39143.9.128.0/18143.9.128.1 to 143.9.191.254143.9.191.25516,382
40143.9.192.0/18143.9.192.1 to 143.9.255.254143.9.255.25516,382
41143.10.0.0/18143.10.0.1 to 143.10.63.254143.10.63.25516,382
42143.10.64.0/18143.10.64.1 to 143.10.127.254143.10.127.25516,382
43143.10.128.0/18143.10.128.1 to 143.10.191.254143.10.191.25516,382
44143.10.192.0/18143.10.192.1 to 143.10.255.254143.10.255.25516,382
45143.11.0.0/18143.11.0.1 to 143.11.63.254143.11.63.25516,382
46143.11.64.0/18143.11.64.1 to 143.11.127.254143.11.127.25516,382
47143.11.128.0/18143.11.128.1 to 143.11.191.254143.11.191.25516,382
48143.11.192.0/18143.11.192.1 to 143.11.255.254143.11.255.25516,382
49143.12.0.0/18143.12.0.1 to 143.12.63.254143.12.63.25516,382
50143.12.64.0/18143.12.64.1 to 143.12.127.254143.12.127.25516,382
51143.12.128.0/18143.12.128.1 to 143.12.191.254143.12.191.25516,382
52143.12.192.0/18143.12.192.1 to 143.12.255.254143.12.255.25516,382
53143.13.0.0/18143.13.0.1 to 143.13.63.254143.13.63.25516,382
54143.13.64.0/18143.13.64.1 to 143.13.127.254143.13.127.25516,382
55143.13.128.0/18143.13.128.1 to 143.13.191.254143.13.191.25516,382
56143.13.192.0/18143.13.192.1 to 143.13.255.254143.13.255.25516,382
57143.14.0.0/18143.14.0.1 to 143.14.63.254143.14.63.25516,382
58143.14.64.0/18143.14.64.1 to 143.14.127.254143.14.127.25516,382
59143.14.128.0/18143.14.128.1 to 143.14.191.254143.14.191.25516,382
60143.14.192.0/18143.14.192.1 to 143.14.255.254143.14.255.25516,382
61143.15.0.0/18143.15.0.1 to 143.15.63.254143.15.63.25516,382
62143.15.64.0/18143.15.64.1 to 143.15.127.254143.15.127.25516,382
63143.15.128.0/18143.15.128.1 to 143.15.191.254143.15.191.25516,382
64143.15.192.0/18143.15.192.1 to 143.15.255.254143.15.255.25516,382
65143.16.0.0/18143.16.0.1 to 143.16.63.254143.16.63.25516,382
66143.16.64.0/18143.16.64.1 to 143.16.127.254143.16.127.25516,382
67143.16.128.0/18143.16.128.1 to 143.16.191.254143.16.191.25516,382
68143.16.192.0/18143.16.192.1 to 143.16.255.254143.16.255.25516,382
69143.17.0.0/18143.17.0.1 to 143.17.63.254143.17.63.25516,382
70143.17.64.0/18143.17.64.1 to 143.17.127.254143.17.127.25516,382
71143.17.128.0/18143.17.128.1 to 143.17.191.254143.17.191.25516,382
72143.17.192.0/18143.17.192.1 to 143.17.255.254143.17.255.25516,382
73143.18.0.0/18143.18.0.1 to 143.18.63.254143.18.63.25516,382
74143.18.64.0/18143.18.64.1 to 143.18.127.254143.18.127.25516,382
75143.18.128.0/18143.18.128.1 to 143.18.191.254143.18.191.25516,382
76143.18.192.0/18143.18.192.1 to 143.18.255.254143.18.255.25516,382
77143.19.0.0/18143.19.0.1 to 143.19.63.254143.19.63.25516,382
78143.19.64.0/18143.19.64.1 to 143.19.127.254143.19.127.25516,382
79143.19.128.0/18143.19.128.1 to 143.19.191.254143.19.191.25516,382
80143.19.192.0/18143.19.192.1 to 143.19.255.254143.19.255.25516,382
81143.20.0.0/18143.20.0.1 to 143.20.63.254143.20.63.25516,382
82143.20.64.0/18143.20.64.1 to 143.20.127.254143.20.127.25516,382
83143.20.128.0/18143.20.128.1 to 143.20.191.254143.20.191.25516,382
84143.20.192.0/18143.20.192.1 to 143.20.255.254143.20.255.25516,382
85143.21.0.0/18143.21.0.1 to 143.21.63.254143.21.63.25516,382
86143.21.64.0/18143.21.64.1 to 143.21.127.254143.21.127.25516,382
87143.21.128.0/18143.21.128.1 to 143.21.191.254143.21.191.25516,382
88143.21.192.0/18143.21.192.1 to 143.21.255.254143.21.255.25516,382
89143.22.0.0/18143.22.0.1 to 143.22.63.254143.22.63.25516,382
90143.22.64.0/18143.22.64.1 to 143.22.127.254143.22.127.25516,382
91143.22.128.0/18143.22.128.1 to 143.22.191.254143.22.191.25516,382
92143.22.192.0/18143.22.192.1 to 143.22.255.254143.22.255.25516,382
93143.23.0.0/18143.23.0.1 to 143.23.63.254143.23.63.25516,382
94143.23.64.0/18143.23.64.1 to 143.23.127.254143.23.127.25516,382
95143.23.128.0/18143.23.128.1 to 143.23.191.254143.23.191.25516,382
96143.23.192.0/18143.23.192.1 to 143.23.255.254143.23.255.25516,382
97143.24.0.0/18143.24.0.1 to 143.24.63.254143.24.63.25516,382
98143.24.64.0/18143.24.64.1 to 143.24.127.254143.24.127.25516,382
99143.24.128.0/18143.24.128.1 to 143.24.191.254143.24.191.25516,382
100143.24.192.0/18143.24.192.1 to 143.24.255.254143.24.255.25516,382
101143.25.0.0/18143.25.0.1 to 143.25.63.254143.25.63.25516,382
102143.25.64.0/18143.25.64.1 to 143.25.127.254143.25.127.25516,382
103143.25.128.0/18143.25.128.1 to 143.25.191.254143.25.191.25516,382
104143.25.192.0/18143.25.192.1 to 143.25.255.254143.25.255.25516,382
105143.26.0.0/18143.26.0.1 to 143.26.63.254143.26.63.25516,382
106143.26.64.0/18143.26.64.1 to 143.26.127.254143.26.127.25516,382
107143.26.128.0/18143.26.128.1 to 143.26.191.254143.26.191.25516,382
108143.26.192.0/18143.26.192.1 to 143.26.255.254143.26.255.25516,382
109143.27.0.0/18143.27.0.1 to 143.27.63.254143.27.63.25516,382
110143.27.64.0/18143.27.64.1 to 143.27.127.254143.27.127.25516,382
111143.27.128.0/18143.27.128.1 to 143.27.191.254143.27.191.25516,382
112143.27.192.0/18143.27.192.1 to 143.27.255.254143.27.255.25516,382
113143.28.0.0/18143.28.0.1 to 143.28.63.254143.28.63.25516,382
114143.28.64.0/18143.28.64.1 to 143.28.127.254143.28.127.25516,382
115143.28.128.0/18143.28.128.1 to 143.28.191.254143.28.191.25516,382
116143.28.192.0/18143.28.192.1 to 143.28.255.254143.28.255.25516,382
117143.29.0.0/18143.29.0.1 to 143.29.63.254143.29.63.25516,382
118143.29.64.0/18143.29.64.1 to 143.29.127.254143.29.127.25516,382
119143.29.128.0/18143.29.128.1 to 143.29.191.254143.29.191.25516,382
120143.29.192.0/18143.29.192.1 to 143.29.255.254143.29.255.25516,382
121143.30.0.0/18143.30.0.1 to 143.30.63.254143.30.63.25516,382
122143.30.64.0/18143.30.64.1 to 143.30.127.254143.30.127.25516,382
123143.30.128.0/18143.30.128.1 to 143.30.191.254143.30.191.25516,382
124143.30.192.0/18143.30.192.1 to 143.30.255.254143.30.255.25516,382
125143.31.0.0/18143.31.0.1 to 143.31.63.254143.31.63.25516,382
126143.31.64.0/18143.31.64.1 to 143.31.127.254143.31.127.25516,382
127143.31.128.0/18143.31.128.1 to 143.31.191.254143.31.191.25516,382
128143.31.192.0/18143.31.192.1 to 143.31.255.254143.31.255.25516,382
129143.32.0.0/18143.32.0.1 to 143.32.63.254143.32.63.25516,382
130143.32.64.0/18143.32.64.1 to 143.32.127.254143.32.127.25516,382
131143.32.128.0/18143.32.128.1 to 143.32.191.254143.32.191.25516,382
132143.32.192.0/18143.32.192.1 to 143.32.255.254143.32.255.25516,382
133143.33.0.0/18143.33.0.1 to 143.33.63.254143.33.63.25516,382
134143.33.64.0/18143.33.64.1 to 143.33.127.254143.33.127.25516,382
135143.33.128.0/18143.33.128.1 to 143.33.191.254143.33.191.25516,382
136143.33.192.0/18143.33.192.1 to 143.33.255.254143.33.255.25516,382
137143.34.0.0/18143.34.0.1 to 143.34.63.254143.34.63.25516,382
138143.34.64.0/18143.34.64.1 to 143.34.127.254143.34.127.25516,382
139143.34.128.0/18143.34.128.1 to 143.34.191.254143.34.191.25516,382
140143.34.192.0/18143.34.192.1 to 143.34.255.254143.34.255.25516,382
141143.35.0.0/18143.35.0.1 to 143.35.63.254143.35.63.25516,382
142143.35.64.0/18143.35.64.1 to 143.35.127.254143.35.127.25516,382
143143.35.128.0/18143.35.128.1 to 143.35.191.254143.35.191.25516,382
144143.35.192.0/18143.35.192.1 to 143.35.255.254143.35.255.25516,382
145143.36.0.0/18143.36.0.1 to 143.36.63.254143.36.63.25516,382
146143.36.64.0/18143.36.64.1 to 143.36.127.254143.36.127.25516,382
147143.36.128.0/18143.36.128.1 to 143.36.191.254143.36.191.25516,382
148143.36.192.0/18143.36.192.1 to 143.36.255.254143.36.255.25516,382
149143.37.0.0/18143.37.0.1 to 143.37.63.254143.37.63.25516,382
150143.37.64.0/18143.37.64.1 to 143.37.127.254143.37.127.25516,382
151143.37.128.0/18143.37.128.1 to 143.37.191.254143.37.191.25516,382
152143.37.192.0/18143.37.192.1 to 143.37.255.254143.37.255.25516,382
153143.38.0.0/18143.38.0.1 to 143.38.63.254143.38.63.25516,382
154143.38.64.0/18143.38.64.1 to 143.38.127.254143.38.127.25516,382
155143.38.128.0/18143.38.128.1 to 143.38.191.254143.38.191.25516,382
156143.38.192.0/18143.38.192.1 to 143.38.255.254143.38.255.25516,382
157143.39.0.0/18143.39.0.1 to 143.39.63.254143.39.63.25516,382
158143.39.64.0/18143.39.64.1 to 143.39.127.254143.39.127.25516,382
159143.39.128.0/18143.39.128.1 to 143.39.191.254143.39.191.25516,382
160143.39.192.0/18143.39.192.1 to 143.39.255.254143.39.255.25516,382
161143.40.0.0/18143.40.0.1 to 143.40.63.254143.40.63.25516,382
162143.40.64.0/18143.40.64.1 to 143.40.127.254143.40.127.25516,382
163143.40.128.0/18143.40.128.1 to 143.40.191.254143.40.191.25516,382
164143.40.192.0/18143.40.192.1 to 143.40.255.254143.40.255.25516,382
165143.41.0.0/18143.41.0.1 to 143.41.63.254143.41.63.25516,382
166143.41.64.0/18143.41.64.1 to 143.41.127.254143.41.127.25516,382
167143.41.128.0/18143.41.128.1 to 143.41.191.254143.41.191.25516,382
168143.41.192.0/18143.41.192.1 to 143.41.255.254143.41.255.25516,382
169143.42.0.0/18143.42.0.1 to 143.42.63.254143.42.63.25516,382
170143.42.64.0/18143.42.64.1 to 143.42.127.254143.42.127.25516,382
171143.42.128.0/18143.42.128.1 to 143.42.191.254143.42.191.25516,382
172143.42.192.0/18143.42.192.1 to 143.42.255.254143.42.255.25516,382
173143.43.0.0/18143.43.0.1 to 143.43.63.254143.43.63.25516,382
174143.43.64.0/18143.43.64.1 to 143.43.127.254143.43.127.25516,382
175143.43.128.0/18143.43.128.1 to 143.43.191.254143.43.191.25516,382
176143.43.192.0/18143.43.192.1 to 143.43.255.254143.43.255.25516,382
177143.44.0.0/18143.44.0.1 to 143.44.63.254143.44.63.25516,382
178143.44.64.0/18143.44.64.1 to 143.44.127.254143.44.127.25516,382
179143.44.128.0/18143.44.128.1 to 143.44.191.254143.44.191.25516,382
180143.44.192.0/18143.44.192.1 to 143.44.255.254143.44.255.25516,382
181143.45.0.0/18143.45.0.1 to 143.45.63.254143.45.63.25516,382
182143.45.64.0/18143.45.64.1 to 143.45.127.254143.45.127.25516,382
183143.45.128.0/18143.45.128.1 to 143.45.191.254143.45.191.25516,382
184143.45.192.0/18143.45.192.1 to 143.45.255.254143.45.255.25516,382
185143.46.0.0/18143.46.0.1 to 143.46.63.254143.46.63.25516,382
186143.46.64.0/18143.46.64.1 to 143.46.127.254143.46.127.25516,382
187143.46.128.0/18143.46.128.1 to 143.46.191.254143.46.191.25516,382
188143.46.192.0/18143.46.192.1 to 143.46.255.254143.46.255.25516,382
189143.47.0.0/18143.47.0.1 to 143.47.63.254143.47.63.25516,382
190143.47.64.0/18143.47.64.1 to 143.47.127.254143.47.127.25516,382
191143.47.128.0/18143.47.128.1 to 143.47.191.254143.47.191.25516,382
192143.47.192.0/18143.47.192.1 to 143.47.255.254143.47.255.25516,382
193143.48.0.0/18143.48.0.1 to 143.48.63.254143.48.63.25516,382
194143.48.64.0/18143.48.64.1 to 143.48.127.254143.48.127.25516,382
195143.48.128.0/18143.48.128.1 to 143.48.191.254143.48.191.25516,382
196143.48.192.0/18143.48.192.1 to 143.48.255.254143.48.255.25516,382
197143.49.0.0/18143.49.0.1 to 143.49.63.254143.49.63.25516,382
198143.49.64.0/18143.49.64.1 to 143.49.127.254143.49.127.25516,382
199143.49.128.0/18143.49.128.1 to 143.49.191.254143.49.191.25516,382
200143.49.192.0/18143.49.192.1 to 143.49.255.254143.49.255.25516,382
201143.50.0.0/18143.50.0.1 to 143.50.63.254143.50.63.25516,382
202143.50.64.0/18143.50.64.1 to 143.50.127.254143.50.127.25516,382
203143.50.128.0/18143.50.128.1 to 143.50.191.254143.50.191.25516,382
204143.50.192.0/18143.50.192.1 to 143.50.255.254143.50.255.25516,382
205143.51.0.0/18143.51.0.1 to 143.51.63.254143.51.63.25516,382
206143.51.64.0/18143.51.64.1 to 143.51.127.254143.51.127.25516,382
207143.51.128.0/18143.51.128.1 to 143.51.191.254143.51.191.25516,382
208143.51.192.0/18143.51.192.1 to 143.51.255.254143.51.255.25516,382
209143.52.0.0/18143.52.0.1 to 143.52.63.254143.52.63.25516,382
210143.52.64.0/18143.52.64.1 to 143.52.127.254143.52.127.25516,382
211143.52.128.0/18143.52.128.1 to 143.52.191.254143.52.191.25516,382
212143.52.192.0/18143.52.192.1 to 143.52.255.254143.52.255.25516,382
213143.53.0.0/18143.53.0.1 to 143.53.63.254143.53.63.25516,382
214143.53.64.0/18143.53.64.1 to 143.53.127.254143.53.127.25516,382
215143.53.128.0/18143.53.128.1 to 143.53.191.254143.53.191.25516,382
216143.53.192.0/18143.53.192.1 to 143.53.255.254143.53.255.25516,382
217143.54.0.0/18143.54.0.1 to 143.54.63.254143.54.63.25516,382
218143.54.64.0/18143.54.64.1 to 143.54.127.254143.54.127.25516,382
219143.54.128.0/18143.54.128.1 to 143.54.191.254143.54.191.25516,382
220143.54.192.0/18143.54.192.1 to 143.54.255.254143.54.255.25516,382
221143.55.0.0/18143.55.0.1 to 143.55.63.254143.55.63.25516,382
222143.55.64.0/18143.55.64.1 to 143.55.127.254143.55.127.25516,382
223143.55.128.0/18143.55.128.1 to 143.55.191.254143.55.191.25516,382
224143.55.192.0/18143.55.192.1 to 143.55.255.254143.55.255.25516,382
225143.56.0.0/18143.56.0.1 to 143.56.63.254143.56.63.25516,382
226143.56.64.0/18143.56.64.1 to 143.56.127.254143.56.127.25516,382
227143.56.128.0/18143.56.128.1 to 143.56.191.254143.56.191.25516,382
228143.56.192.0/18143.56.192.1 to 143.56.255.254143.56.255.25516,382
229143.57.0.0/18143.57.0.1 to 143.57.63.254143.57.63.25516,382
230143.57.64.0/18143.57.64.1 to 143.57.127.254143.57.127.25516,382
231143.57.128.0/18143.57.128.1 to 143.57.191.254143.57.191.25516,382
232143.57.192.0/18143.57.192.1 to 143.57.255.254143.57.255.25516,382
233143.58.0.0/18143.58.0.1 to 143.58.63.254143.58.63.25516,382
234143.58.64.0/18143.58.64.1 to 143.58.127.254143.58.127.25516,382
235143.58.128.0/18143.58.128.1 to 143.58.191.254143.58.191.25516,382
236143.58.192.0/18143.58.192.1 to 143.58.255.254143.58.255.25516,382
237143.59.0.0/18143.59.0.1 to 143.59.63.254143.59.63.25516,382
238143.59.64.0/18143.59.64.1 to 143.59.127.254143.59.127.25516,382
239143.59.128.0/18143.59.128.1 to 143.59.191.254143.59.191.25516,382
240143.59.192.0/18143.59.192.1 to 143.59.255.254143.59.255.25516,382
241143.60.0.0/18143.60.0.1 to 143.60.63.254143.60.63.25516,382
242143.60.64.0/18143.60.64.1 to 143.60.127.254143.60.127.25516,382
243143.60.128.0/18143.60.128.1 to 143.60.191.254143.60.191.25516,382
244143.60.192.0/18143.60.192.1 to 143.60.255.254143.60.255.25516,382
245143.61.0.0/18143.61.0.1 to 143.61.63.254143.61.63.25516,382
246143.61.64.0/18143.61.64.1 to 143.61.127.254143.61.127.25516,382
247143.61.128.0/18143.61.128.1 to 143.61.191.254143.61.191.25516,382
248143.61.192.0/18143.61.192.1 to 143.61.255.254143.61.255.25516,382
249143.62.0.0/18143.62.0.1 to 143.62.63.254143.62.63.25516,382
250143.62.64.0/18143.62.64.1 to 143.62.127.254143.62.127.25516,382
251143.62.128.0/18143.62.128.1 to 143.62.191.254143.62.191.25516,382
252143.62.192.0/18143.62.192.1 to 143.62.255.254143.62.255.25516,382
253143.63.0.0/18143.63.0.1 to 143.63.63.254143.63.63.25516,382
254143.63.64.0/18143.63.64.1 to 143.63.127.254143.63.127.25516,382
255143.63.128.0/18143.63.128.1 to 143.63.191.254143.63.191.25516,382
256143.63.192.0/18143.63.192.1 to 143.63.255.254143.63.255.25516,382

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.