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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.

Network107.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
107.0.0.0
Broadcast address
107.127.255.255
First usable
107.0.0.1
Last usable
107.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 6B000000 · Integer 1795162112 to 1803550719
Reverse DNS zones
0.107.in-addr.arpa
1.107.in-addr.arpa
2.107.in-addr.arpa
3.107.in-addr.arpa
4.107.in-addr.arpa
5.107.in-addr.arpa
6.107.in-addr.arpa
7.107.in-addr.arpa
8.107.in-addr.arpa
9.107.in-addr.arpa
10.107.in-addr.arpa
11.107.in-addr.arpa
12.107.in-addr.arpa
13.107.in-addr.arpa
14.107.in-addr.arpa
15.107.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01101011.00000000.00000000.00000000107.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01101011.00000000.00000000.00000000107.0.0.0
Broadcast01101011.01111111.11111111.11111111107.127.255.255
Split into smaller subnets/19
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

107.0.0.0/9 makes 1,024 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1107.0.0.0/19107.0.0.1 to 107.0.31.254107.0.31.2558,190
2107.0.32.0/19107.0.32.1 to 107.0.63.254107.0.63.2558,190
3107.0.64.0/19107.0.64.1 to 107.0.95.254107.0.95.2558,190
4107.0.96.0/19107.0.96.1 to 107.0.127.254107.0.127.2558,190
5107.0.128.0/19107.0.128.1 to 107.0.159.254107.0.159.2558,190
6107.0.160.0/19107.0.160.1 to 107.0.191.254107.0.191.2558,190
7107.0.192.0/19107.0.192.1 to 107.0.223.254107.0.223.2558,190
8107.0.224.0/19107.0.224.1 to 107.0.255.254107.0.255.2558,190
9107.1.0.0/19107.1.0.1 to 107.1.31.254107.1.31.2558,190
10107.1.32.0/19107.1.32.1 to 107.1.63.254107.1.63.2558,190
11107.1.64.0/19107.1.64.1 to 107.1.95.254107.1.95.2558,190
12107.1.96.0/19107.1.96.1 to 107.1.127.254107.1.127.2558,190
13107.1.128.0/19107.1.128.1 to 107.1.159.254107.1.159.2558,190
14107.1.160.0/19107.1.160.1 to 107.1.191.254107.1.191.2558,190
15107.1.192.0/19107.1.192.1 to 107.1.223.254107.1.223.2558,190
16107.1.224.0/19107.1.224.1 to 107.1.255.254107.1.255.2558,190
17107.2.0.0/19107.2.0.1 to 107.2.31.254107.2.31.2558,190
18107.2.32.0/19107.2.32.1 to 107.2.63.254107.2.63.2558,190
19107.2.64.0/19107.2.64.1 to 107.2.95.254107.2.95.2558,190
20107.2.96.0/19107.2.96.1 to 107.2.127.254107.2.127.2558,190
21107.2.128.0/19107.2.128.1 to 107.2.159.254107.2.159.2558,190
22107.2.160.0/19107.2.160.1 to 107.2.191.254107.2.191.2558,190
23107.2.192.0/19107.2.192.1 to 107.2.223.254107.2.223.2558,190
24107.2.224.0/19107.2.224.1 to 107.2.255.254107.2.255.2558,190
25107.3.0.0/19107.3.0.1 to 107.3.31.254107.3.31.2558,190
26107.3.32.0/19107.3.32.1 to 107.3.63.254107.3.63.2558,190
27107.3.64.0/19107.3.64.1 to 107.3.95.254107.3.95.2558,190
28107.3.96.0/19107.3.96.1 to 107.3.127.254107.3.127.2558,190
29107.3.128.0/19107.3.128.1 to 107.3.159.254107.3.159.2558,190
30107.3.160.0/19107.3.160.1 to 107.3.191.254107.3.191.2558,190
31107.3.192.0/19107.3.192.1 to 107.3.223.254107.3.223.2558,190
32107.3.224.0/19107.3.224.1 to 107.3.255.254107.3.255.2558,190
33107.4.0.0/19107.4.0.1 to 107.4.31.254107.4.31.2558,190
34107.4.32.0/19107.4.32.1 to 107.4.63.254107.4.63.2558,190
35107.4.64.0/19107.4.64.1 to 107.4.95.254107.4.95.2558,190
36107.4.96.0/19107.4.96.1 to 107.4.127.254107.4.127.2558,190
37107.4.128.0/19107.4.128.1 to 107.4.159.254107.4.159.2558,190
38107.4.160.0/19107.4.160.1 to 107.4.191.254107.4.191.2558,190
39107.4.192.0/19107.4.192.1 to 107.4.223.254107.4.223.2558,190
40107.4.224.0/19107.4.224.1 to 107.4.255.254107.4.255.2558,190
41107.5.0.0/19107.5.0.1 to 107.5.31.254107.5.31.2558,190
42107.5.32.0/19107.5.32.1 to 107.5.63.254107.5.63.2558,190
43107.5.64.0/19107.5.64.1 to 107.5.95.254107.5.95.2558,190
44107.5.96.0/19107.5.96.1 to 107.5.127.254107.5.127.2558,190
45107.5.128.0/19107.5.128.1 to 107.5.159.254107.5.159.2558,190
46107.5.160.0/19107.5.160.1 to 107.5.191.254107.5.191.2558,190
47107.5.192.0/19107.5.192.1 to 107.5.223.254107.5.223.2558,190
48107.5.224.0/19107.5.224.1 to 107.5.255.254107.5.255.2558,190
49107.6.0.0/19107.6.0.1 to 107.6.31.254107.6.31.2558,190
50107.6.32.0/19107.6.32.1 to 107.6.63.254107.6.63.2558,190
51107.6.64.0/19107.6.64.1 to 107.6.95.254107.6.95.2558,190
52107.6.96.0/19107.6.96.1 to 107.6.127.254107.6.127.2558,190
53107.6.128.0/19107.6.128.1 to 107.6.159.254107.6.159.2558,190
54107.6.160.0/19107.6.160.1 to 107.6.191.254107.6.191.2558,190
55107.6.192.0/19107.6.192.1 to 107.6.223.254107.6.223.2558,190
56107.6.224.0/19107.6.224.1 to 107.6.255.254107.6.255.2558,190
57107.7.0.0/19107.7.0.1 to 107.7.31.254107.7.31.2558,190
58107.7.32.0/19107.7.32.1 to 107.7.63.254107.7.63.2558,190
59107.7.64.0/19107.7.64.1 to 107.7.95.254107.7.95.2558,190
60107.7.96.0/19107.7.96.1 to 107.7.127.254107.7.127.2558,190
61107.7.128.0/19107.7.128.1 to 107.7.159.254107.7.159.2558,190
62107.7.160.0/19107.7.160.1 to 107.7.191.254107.7.191.2558,190
63107.7.192.0/19107.7.192.1 to 107.7.223.254107.7.223.2558,190
64107.7.224.0/19107.7.224.1 to 107.7.255.254107.7.255.2558,190
65107.8.0.0/19107.8.0.1 to 107.8.31.254107.8.31.2558,190
66107.8.32.0/19107.8.32.1 to 107.8.63.254107.8.63.2558,190
67107.8.64.0/19107.8.64.1 to 107.8.95.254107.8.95.2558,190
68107.8.96.0/19107.8.96.1 to 107.8.127.254107.8.127.2558,190
69107.8.128.0/19107.8.128.1 to 107.8.159.254107.8.159.2558,190
70107.8.160.0/19107.8.160.1 to 107.8.191.254107.8.191.2558,190
71107.8.192.0/19107.8.192.1 to 107.8.223.254107.8.223.2558,190
72107.8.224.0/19107.8.224.1 to 107.8.255.254107.8.255.2558,190
73107.9.0.0/19107.9.0.1 to 107.9.31.254107.9.31.2558,190
74107.9.32.0/19107.9.32.1 to 107.9.63.254107.9.63.2558,190
75107.9.64.0/19107.9.64.1 to 107.9.95.254107.9.95.2558,190
76107.9.96.0/19107.9.96.1 to 107.9.127.254107.9.127.2558,190
77107.9.128.0/19107.9.128.1 to 107.9.159.254107.9.159.2558,190
78107.9.160.0/19107.9.160.1 to 107.9.191.254107.9.191.2558,190
79107.9.192.0/19107.9.192.1 to 107.9.223.254107.9.223.2558,190
80107.9.224.0/19107.9.224.1 to 107.9.255.254107.9.255.2558,190
81107.10.0.0/19107.10.0.1 to 107.10.31.254107.10.31.2558,190
82107.10.32.0/19107.10.32.1 to 107.10.63.254107.10.63.2558,190
83107.10.64.0/19107.10.64.1 to 107.10.95.254107.10.95.2558,190
84107.10.96.0/19107.10.96.1 to 107.10.127.254107.10.127.2558,190
85107.10.128.0/19107.10.128.1 to 107.10.159.254107.10.159.2558,190
86107.10.160.0/19107.10.160.1 to 107.10.191.254107.10.191.2558,190
87107.10.192.0/19107.10.192.1 to 107.10.223.254107.10.223.2558,190
88107.10.224.0/19107.10.224.1 to 107.10.255.254107.10.255.2558,190
89107.11.0.0/19107.11.0.1 to 107.11.31.254107.11.31.2558,190
90107.11.32.0/19107.11.32.1 to 107.11.63.254107.11.63.2558,190
91107.11.64.0/19107.11.64.1 to 107.11.95.254107.11.95.2558,190
92107.11.96.0/19107.11.96.1 to 107.11.127.254107.11.127.2558,190
93107.11.128.0/19107.11.128.1 to 107.11.159.254107.11.159.2558,190
94107.11.160.0/19107.11.160.1 to 107.11.191.254107.11.191.2558,190
95107.11.192.0/19107.11.192.1 to 107.11.223.254107.11.223.2558,190
96107.11.224.0/19107.11.224.1 to 107.11.255.254107.11.255.2558,190
97107.12.0.0/19107.12.0.1 to 107.12.31.254107.12.31.2558,190
98107.12.32.0/19107.12.32.1 to 107.12.63.254107.12.63.2558,190
99107.12.64.0/19107.12.64.1 to 107.12.95.254107.12.95.2558,190
100107.12.96.0/19107.12.96.1 to 107.12.127.254107.12.127.2558,190
101107.12.128.0/19107.12.128.1 to 107.12.159.254107.12.159.2558,190
102107.12.160.0/19107.12.160.1 to 107.12.191.254107.12.191.2558,190
103107.12.192.0/19107.12.192.1 to 107.12.223.254107.12.223.2558,190
104107.12.224.0/19107.12.224.1 to 107.12.255.254107.12.255.2558,190
105107.13.0.0/19107.13.0.1 to 107.13.31.254107.13.31.2558,190
106107.13.32.0/19107.13.32.1 to 107.13.63.254107.13.63.2558,190
107107.13.64.0/19107.13.64.1 to 107.13.95.254107.13.95.2558,190
108107.13.96.0/19107.13.96.1 to 107.13.127.254107.13.127.2558,190
109107.13.128.0/19107.13.128.1 to 107.13.159.254107.13.159.2558,190
110107.13.160.0/19107.13.160.1 to 107.13.191.254107.13.191.2558,190
111107.13.192.0/19107.13.192.1 to 107.13.223.254107.13.223.2558,190
112107.13.224.0/19107.13.224.1 to 107.13.255.254107.13.255.2558,190
113107.14.0.0/19107.14.0.1 to 107.14.31.254107.14.31.2558,190
114107.14.32.0/19107.14.32.1 to 107.14.63.254107.14.63.2558,190
115107.14.64.0/19107.14.64.1 to 107.14.95.254107.14.95.2558,190
116107.14.96.0/19107.14.96.1 to 107.14.127.254107.14.127.2558,190
117107.14.128.0/19107.14.128.1 to 107.14.159.254107.14.159.2558,190
118107.14.160.0/19107.14.160.1 to 107.14.191.254107.14.191.2558,190
119107.14.192.0/19107.14.192.1 to 107.14.223.254107.14.223.2558,190
120107.14.224.0/19107.14.224.1 to 107.14.255.254107.14.255.2558,190
121107.15.0.0/19107.15.0.1 to 107.15.31.254107.15.31.2558,190
122107.15.32.0/19107.15.32.1 to 107.15.63.254107.15.63.2558,190
123107.15.64.0/19107.15.64.1 to 107.15.95.254107.15.95.2558,190
124107.15.96.0/19107.15.96.1 to 107.15.127.254107.15.127.2558,190
125107.15.128.0/19107.15.128.1 to 107.15.159.254107.15.159.2558,190
126107.15.160.0/19107.15.160.1 to 107.15.191.254107.15.191.2558,190
127107.15.192.0/19107.15.192.1 to 107.15.223.254107.15.223.2558,190
128107.15.224.0/19107.15.224.1 to 107.15.255.254107.15.255.2558,190
129107.16.0.0/19107.16.0.1 to 107.16.31.254107.16.31.2558,190
130107.16.32.0/19107.16.32.1 to 107.16.63.254107.16.63.2558,190
131107.16.64.0/19107.16.64.1 to 107.16.95.254107.16.95.2558,190
132107.16.96.0/19107.16.96.1 to 107.16.127.254107.16.127.2558,190
133107.16.128.0/19107.16.128.1 to 107.16.159.254107.16.159.2558,190
134107.16.160.0/19107.16.160.1 to 107.16.191.254107.16.191.2558,190
135107.16.192.0/19107.16.192.1 to 107.16.223.254107.16.223.2558,190
136107.16.224.0/19107.16.224.1 to 107.16.255.254107.16.255.2558,190
137107.17.0.0/19107.17.0.1 to 107.17.31.254107.17.31.2558,190
138107.17.32.0/19107.17.32.1 to 107.17.63.254107.17.63.2558,190
139107.17.64.0/19107.17.64.1 to 107.17.95.254107.17.95.2558,190
140107.17.96.0/19107.17.96.1 to 107.17.127.254107.17.127.2558,190
141107.17.128.0/19107.17.128.1 to 107.17.159.254107.17.159.2558,190
142107.17.160.0/19107.17.160.1 to 107.17.191.254107.17.191.2558,190
143107.17.192.0/19107.17.192.1 to 107.17.223.254107.17.223.2558,190
144107.17.224.0/19107.17.224.1 to 107.17.255.254107.17.255.2558,190
145107.18.0.0/19107.18.0.1 to 107.18.31.254107.18.31.2558,190
146107.18.32.0/19107.18.32.1 to 107.18.63.254107.18.63.2558,190
147107.18.64.0/19107.18.64.1 to 107.18.95.254107.18.95.2558,190
148107.18.96.0/19107.18.96.1 to 107.18.127.254107.18.127.2558,190
149107.18.128.0/19107.18.128.1 to 107.18.159.254107.18.159.2558,190
150107.18.160.0/19107.18.160.1 to 107.18.191.254107.18.191.2558,190
151107.18.192.0/19107.18.192.1 to 107.18.223.254107.18.223.2558,190
152107.18.224.0/19107.18.224.1 to 107.18.255.254107.18.255.2558,190
153107.19.0.0/19107.19.0.1 to 107.19.31.254107.19.31.2558,190
154107.19.32.0/19107.19.32.1 to 107.19.63.254107.19.63.2558,190
155107.19.64.0/19107.19.64.1 to 107.19.95.254107.19.95.2558,190
156107.19.96.0/19107.19.96.1 to 107.19.127.254107.19.127.2558,190
157107.19.128.0/19107.19.128.1 to 107.19.159.254107.19.159.2558,190
158107.19.160.0/19107.19.160.1 to 107.19.191.254107.19.191.2558,190
159107.19.192.0/19107.19.192.1 to 107.19.223.254107.19.223.2558,190
160107.19.224.0/19107.19.224.1 to 107.19.255.254107.19.255.2558,190
161107.20.0.0/19107.20.0.1 to 107.20.31.254107.20.31.2558,190
162107.20.32.0/19107.20.32.1 to 107.20.63.254107.20.63.2558,190
163107.20.64.0/19107.20.64.1 to 107.20.95.254107.20.95.2558,190
164107.20.96.0/19107.20.96.1 to 107.20.127.254107.20.127.2558,190
165107.20.128.0/19107.20.128.1 to 107.20.159.254107.20.159.2558,190
166107.20.160.0/19107.20.160.1 to 107.20.191.254107.20.191.2558,190
167107.20.192.0/19107.20.192.1 to 107.20.223.254107.20.223.2558,190
168107.20.224.0/19107.20.224.1 to 107.20.255.254107.20.255.2558,190
169107.21.0.0/19107.21.0.1 to 107.21.31.254107.21.31.2558,190
170107.21.32.0/19107.21.32.1 to 107.21.63.254107.21.63.2558,190
171107.21.64.0/19107.21.64.1 to 107.21.95.254107.21.95.2558,190
172107.21.96.0/19107.21.96.1 to 107.21.127.254107.21.127.2558,190
173107.21.128.0/19107.21.128.1 to 107.21.159.254107.21.159.2558,190
174107.21.160.0/19107.21.160.1 to 107.21.191.254107.21.191.2558,190
175107.21.192.0/19107.21.192.1 to 107.21.223.254107.21.223.2558,190
176107.21.224.0/19107.21.224.1 to 107.21.255.254107.21.255.2558,190
177107.22.0.0/19107.22.0.1 to 107.22.31.254107.22.31.2558,190
178107.22.32.0/19107.22.32.1 to 107.22.63.254107.22.63.2558,190
179107.22.64.0/19107.22.64.1 to 107.22.95.254107.22.95.2558,190
180107.22.96.0/19107.22.96.1 to 107.22.127.254107.22.127.2558,190
181107.22.128.0/19107.22.128.1 to 107.22.159.254107.22.159.2558,190
182107.22.160.0/19107.22.160.1 to 107.22.191.254107.22.191.2558,190
183107.22.192.0/19107.22.192.1 to 107.22.223.254107.22.223.2558,190
184107.22.224.0/19107.22.224.1 to 107.22.255.254107.22.255.2558,190
185107.23.0.0/19107.23.0.1 to 107.23.31.254107.23.31.2558,190
186107.23.32.0/19107.23.32.1 to 107.23.63.254107.23.63.2558,190
187107.23.64.0/19107.23.64.1 to 107.23.95.254107.23.95.2558,190
188107.23.96.0/19107.23.96.1 to 107.23.127.254107.23.127.2558,190
189107.23.128.0/19107.23.128.1 to 107.23.159.254107.23.159.2558,190
190107.23.160.0/19107.23.160.1 to 107.23.191.254107.23.191.2558,190
191107.23.192.0/19107.23.192.1 to 107.23.223.254107.23.223.2558,190
192107.23.224.0/19107.23.224.1 to 107.23.255.254107.23.255.2558,190
193107.24.0.0/19107.24.0.1 to 107.24.31.254107.24.31.2558,190
194107.24.32.0/19107.24.32.1 to 107.24.63.254107.24.63.2558,190
195107.24.64.0/19107.24.64.1 to 107.24.95.254107.24.95.2558,190
196107.24.96.0/19107.24.96.1 to 107.24.127.254107.24.127.2558,190
197107.24.128.0/19107.24.128.1 to 107.24.159.254107.24.159.2558,190
198107.24.160.0/19107.24.160.1 to 107.24.191.254107.24.191.2558,190
199107.24.192.0/19107.24.192.1 to 107.24.223.254107.24.223.2558,190
200107.24.224.0/19107.24.224.1 to 107.24.255.254107.24.255.2558,190
201107.25.0.0/19107.25.0.1 to 107.25.31.254107.25.31.2558,190
202107.25.32.0/19107.25.32.1 to 107.25.63.254107.25.63.2558,190
203107.25.64.0/19107.25.64.1 to 107.25.95.254107.25.95.2558,190
204107.25.96.0/19107.25.96.1 to 107.25.127.254107.25.127.2558,190
205107.25.128.0/19107.25.128.1 to 107.25.159.254107.25.159.2558,190
206107.25.160.0/19107.25.160.1 to 107.25.191.254107.25.191.2558,190
207107.25.192.0/19107.25.192.1 to 107.25.223.254107.25.223.2558,190
208107.25.224.0/19107.25.224.1 to 107.25.255.254107.25.255.2558,190
209107.26.0.0/19107.26.0.1 to 107.26.31.254107.26.31.2558,190
210107.26.32.0/19107.26.32.1 to 107.26.63.254107.26.63.2558,190
211107.26.64.0/19107.26.64.1 to 107.26.95.254107.26.95.2558,190
212107.26.96.0/19107.26.96.1 to 107.26.127.254107.26.127.2558,190
213107.26.128.0/19107.26.128.1 to 107.26.159.254107.26.159.2558,190
214107.26.160.0/19107.26.160.1 to 107.26.191.254107.26.191.2558,190
215107.26.192.0/19107.26.192.1 to 107.26.223.254107.26.223.2558,190
216107.26.224.0/19107.26.224.1 to 107.26.255.254107.26.255.2558,190
217107.27.0.0/19107.27.0.1 to 107.27.31.254107.27.31.2558,190
218107.27.32.0/19107.27.32.1 to 107.27.63.254107.27.63.2558,190
219107.27.64.0/19107.27.64.1 to 107.27.95.254107.27.95.2558,190
220107.27.96.0/19107.27.96.1 to 107.27.127.254107.27.127.2558,190
221107.27.128.0/19107.27.128.1 to 107.27.159.254107.27.159.2558,190
222107.27.160.0/19107.27.160.1 to 107.27.191.254107.27.191.2558,190
223107.27.192.0/19107.27.192.1 to 107.27.223.254107.27.223.2558,190
224107.27.224.0/19107.27.224.1 to 107.27.255.254107.27.255.2558,190
225107.28.0.0/19107.28.0.1 to 107.28.31.254107.28.31.2558,190
226107.28.32.0/19107.28.32.1 to 107.28.63.254107.28.63.2558,190
227107.28.64.0/19107.28.64.1 to 107.28.95.254107.28.95.2558,190
228107.28.96.0/19107.28.96.1 to 107.28.127.254107.28.127.2558,190
229107.28.128.0/19107.28.128.1 to 107.28.159.254107.28.159.2558,190
230107.28.160.0/19107.28.160.1 to 107.28.191.254107.28.191.2558,190
231107.28.192.0/19107.28.192.1 to 107.28.223.254107.28.223.2558,190
232107.28.224.0/19107.28.224.1 to 107.28.255.254107.28.255.2558,190
233107.29.0.0/19107.29.0.1 to 107.29.31.254107.29.31.2558,190
234107.29.32.0/19107.29.32.1 to 107.29.63.254107.29.63.2558,190
235107.29.64.0/19107.29.64.1 to 107.29.95.254107.29.95.2558,190
236107.29.96.0/19107.29.96.1 to 107.29.127.254107.29.127.2558,190
237107.29.128.0/19107.29.128.1 to 107.29.159.254107.29.159.2558,190
238107.29.160.0/19107.29.160.1 to 107.29.191.254107.29.191.2558,190
239107.29.192.0/19107.29.192.1 to 107.29.223.254107.29.223.2558,190
240107.29.224.0/19107.29.224.1 to 107.29.255.254107.29.255.2558,190
241107.30.0.0/19107.30.0.1 to 107.30.31.254107.30.31.2558,190
242107.30.32.0/19107.30.32.1 to 107.30.63.254107.30.63.2558,190
243107.30.64.0/19107.30.64.1 to 107.30.95.254107.30.95.2558,190
244107.30.96.0/19107.30.96.1 to 107.30.127.254107.30.127.2558,190
245107.30.128.0/19107.30.128.1 to 107.30.159.254107.30.159.2558,190
246107.30.160.0/19107.30.160.1 to 107.30.191.254107.30.191.2558,190
247107.30.192.0/19107.30.192.1 to 107.30.223.254107.30.223.2558,190
248107.30.224.0/19107.30.224.1 to 107.30.255.254107.30.255.2558,190
249107.31.0.0/19107.31.0.1 to 107.31.31.254107.31.31.2558,190
250107.31.32.0/19107.31.32.1 to 107.31.63.254107.31.63.2558,190
251107.31.64.0/19107.31.64.1 to 107.31.95.254107.31.95.2558,190
252107.31.96.0/19107.31.96.1 to 107.31.127.254107.31.127.2558,190
253107.31.128.0/19107.31.128.1 to 107.31.159.254107.31.159.2558,190
254107.31.160.0/19107.31.160.1 to 107.31.191.254107.31.191.2558,190
255107.31.192.0/19107.31.192.1 to 107.31.223.254107.31.223.2558,190
256107.31.224.0/19107.31.224.1 to 107.31.255.254107.31.255.2558,190

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.