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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.

Network149.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
149.0.0.0
Broadcast address
149.63.255.255
First usable
149.0.0.1
Last usable
149.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
B (default /16)
As numbers
Hex 95000000 · Integer 2499805184 to 2503999487
Reverse DNS zones
0.149.in-addr.arpa
1.149.in-addr.arpa
2.149.in-addr.arpa
3.149.in-addr.arpa
4.149.in-addr.arpa
5.149.in-addr.arpa
6.149.in-addr.arpa
7.149.in-addr.arpa
8.149.in-addr.arpa
9.149.in-addr.arpa
10.149.in-addr.arpa
11.149.in-addr.arpa
12.149.in-addr.arpa
13.149.in-addr.arpa
14.149.in-addr.arpa
15.149.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010101.00000000.00000000.00000000149.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network10010101.00000000.00000000.00000000149.0.0.0
Broadcast10010101.00111111.11111111.11111111149.63.255.255
Split into smaller subnets/19
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

149.0.0.0/10 makes 512 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1149.0.0.0/19149.0.0.1 to 149.0.31.254149.0.31.2558,190
2149.0.32.0/19149.0.32.1 to 149.0.63.254149.0.63.2558,190
3149.0.64.0/19149.0.64.1 to 149.0.95.254149.0.95.2558,190
4149.0.96.0/19149.0.96.1 to 149.0.127.254149.0.127.2558,190
5149.0.128.0/19149.0.128.1 to 149.0.159.254149.0.159.2558,190
6149.0.160.0/19149.0.160.1 to 149.0.191.254149.0.191.2558,190
7149.0.192.0/19149.0.192.1 to 149.0.223.254149.0.223.2558,190
8149.0.224.0/19149.0.224.1 to 149.0.255.254149.0.255.2558,190
9149.1.0.0/19149.1.0.1 to 149.1.31.254149.1.31.2558,190
10149.1.32.0/19149.1.32.1 to 149.1.63.254149.1.63.2558,190
11149.1.64.0/19149.1.64.1 to 149.1.95.254149.1.95.2558,190
12149.1.96.0/19149.1.96.1 to 149.1.127.254149.1.127.2558,190
13149.1.128.0/19149.1.128.1 to 149.1.159.254149.1.159.2558,190
14149.1.160.0/19149.1.160.1 to 149.1.191.254149.1.191.2558,190
15149.1.192.0/19149.1.192.1 to 149.1.223.254149.1.223.2558,190
16149.1.224.0/19149.1.224.1 to 149.1.255.254149.1.255.2558,190
17149.2.0.0/19149.2.0.1 to 149.2.31.254149.2.31.2558,190
18149.2.32.0/19149.2.32.1 to 149.2.63.254149.2.63.2558,190
19149.2.64.0/19149.2.64.1 to 149.2.95.254149.2.95.2558,190
20149.2.96.0/19149.2.96.1 to 149.2.127.254149.2.127.2558,190
21149.2.128.0/19149.2.128.1 to 149.2.159.254149.2.159.2558,190
22149.2.160.0/19149.2.160.1 to 149.2.191.254149.2.191.2558,190
23149.2.192.0/19149.2.192.1 to 149.2.223.254149.2.223.2558,190
24149.2.224.0/19149.2.224.1 to 149.2.255.254149.2.255.2558,190
25149.3.0.0/19149.3.0.1 to 149.3.31.254149.3.31.2558,190
26149.3.32.0/19149.3.32.1 to 149.3.63.254149.3.63.2558,190
27149.3.64.0/19149.3.64.1 to 149.3.95.254149.3.95.2558,190
28149.3.96.0/19149.3.96.1 to 149.3.127.254149.3.127.2558,190
29149.3.128.0/19149.3.128.1 to 149.3.159.254149.3.159.2558,190
30149.3.160.0/19149.3.160.1 to 149.3.191.254149.3.191.2558,190
31149.3.192.0/19149.3.192.1 to 149.3.223.254149.3.223.2558,190
32149.3.224.0/19149.3.224.1 to 149.3.255.254149.3.255.2558,190
33149.4.0.0/19149.4.0.1 to 149.4.31.254149.4.31.2558,190
34149.4.32.0/19149.4.32.1 to 149.4.63.254149.4.63.2558,190
35149.4.64.0/19149.4.64.1 to 149.4.95.254149.4.95.2558,190
36149.4.96.0/19149.4.96.1 to 149.4.127.254149.4.127.2558,190
37149.4.128.0/19149.4.128.1 to 149.4.159.254149.4.159.2558,190
38149.4.160.0/19149.4.160.1 to 149.4.191.254149.4.191.2558,190
39149.4.192.0/19149.4.192.1 to 149.4.223.254149.4.223.2558,190
40149.4.224.0/19149.4.224.1 to 149.4.255.254149.4.255.2558,190
41149.5.0.0/19149.5.0.1 to 149.5.31.254149.5.31.2558,190
42149.5.32.0/19149.5.32.1 to 149.5.63.254149.5.63.2558,190
43149.5.64.0/19149.5.64.1 to 149.5.95.254149.5.95.2558,190
44149.5.96.0/19149.5.96.1 to 149.5.127.254149.5.127.2558,190
45149.5.128.0/19149.5.128.1 to 149.5.159.254149.5.159.2558,190
46149.5.160.0/19149.5.160.1 to 149.5.191.254149.5.191.2558,190
47149.5.192.0/19149.5.192.1 to 149.5.223.254149.5.223.2558,190
48149.5.224.0/19149.5.224.1 to 149.5.255.254149.5.255.2558,190
49149.6.0.0/19149.6.0.1 to 149.6.31.254149.6.31.2558,190
50149.6.32.0/19149.6.32.1 to 149.6.63.254149.6.63.2558,190
51149.6.64.0/19149.6.64.1 to 149.6.95.254149.6.95.2558,190
52149.6.96.0/19149.6.96.1 to 149.6.127.254149.6.127.2558,190
53149.6.128.0/19149.6.128.1 to 149.6.159.254149.6.159.2558,190
54149.6.160.0/19149.6.160.1 to 149.6.191.254149.6.191.2558,190
55149.6.192.0/19149.6.192.1 to 149.6.223.254149.6.223.2558,190
56149.6.224.0/19149.6.224.1 to 149.6.255.254149.6.255.2558,190
57149.7.0.0/19149.7.0.1 to 149.7.31.254149.7.31.2558,190
58149.7.32.0/19149.7.32.1 to 149.7.63.254149.7.63.2558,190
59149.7.64.0/19149.7.64.1 to 149.7.95.254149.7.95.2558,190
60149.7.96.0/19149.7.96.1 to 149.7.127.254149.7.127.2558,190
61149.7.128.0/19149.7.128.1 to 149.7.159.254149.7.159.2558,190
62149.7.160.0/19149.7.160.1 to 149.7.191.254149.7.191.2558,190
63149.7.192.0/19149.7.192.1 to 149.7.223.254149.7.223.2558,190
64149.7.224.0/19149.7.224.1 to 149.7.255.254149.7.255.2558,190
65149.8.0.0/19149.8.0.1 to 149.8.31.254149.8.31.2558,190
66149.8.32.0/19149.8.32.1 to 149.8.63.254149.8.63.2558,190
67149.8.64.0/19149.8.64.1 to 149.8.95.254149.8.95.2558,190
68149.8.96.0/19149.8.96.1 to 149.8.127.254149.8.127.2558,190
69149.8.128.0/19149.8.128.1 to 149.8.159.254149.8.159.2558,190
70149.8.160.0/19149.8.160.1 to 149.8.191.254149.8.191.2558,190
71149.8.192.0/19149.8.192.1 to 149.8.223.254149.8.223.2558,190
72149.8.224.0/19149.8.224.1 to 149.8.255.254149.8.255.2558,190
73149.9.0.0/19149.9.0.1 to 149.9.31.254149.9.31.2558,190
74149.9.32.0/19149.9.32.1 to 149.9.63.254149.9.63.2558,190
75149.9.64.0/19149.9.64.1 to 149.9.95.254149.9.95.2558,190
76149.9.96.0/19149.9.96.1 to 149.9.127.254149.9.127.2558,190
77149.9.128.0/19149.9.128.1 to 149.9.159.254149.9.159.2558,190
78149.9.160.0/19149.9.160.1 to 149.9.191.254149.9.191.2558,190
79149.9.192.0/19149.9.192.1 to 149.9.223.254149.9.223.2558,190
80149.9.224.0/19149.9.224.1 to 149.9.255.254149.9.255.2558,190
81149.10.0.0/19149.10.0.1 to 149.10.31.254149.10.31.2558,190
82149.10.32.0/19149.10.32.1 to 149.10.63.254149.10.63.2558,190
83149.10.64.0/19149.10.64.1 to 149.10.95.254149.10.95.2558,190
84149.10.96.0/19149.10.96.1 to 149.10.127.254149.10.127.2558,190
85149.10.128.0/19149.10.128.1 to 149.10.159.254149.10.159.2558,190
86149.10.160.0/19149.10.160.1 to 149.10.191.254149.10.191.2558,190
87149.10.192.0/19149.10.192.1 to 149.10.223.254149.10.223.2558,190
88149.10.224.0/19149.10.224.1 to 149.10.255.254149.10.255.2558,190
89149.11.0.0/19149.11.0.1 to 149.11.31.254149.11.31.2558,190
90149.11.32.0/19149.11.32.1 to 149.11.63.254149.11.63.2558,190
91149.11.64.0/19149.11.64.1 to 149.11.95.254149.11.95.2558,190
92149.11.96.0/19149.11.96.1 to 149.11.127.254149.11.127.2558,190
93149.11.128.0/19149.11.128.1 to 149.11.159.254149.11.159.2558,190
94149.11.160.0/19149.11.160.1 to 149.11.191.254149.11.191.2558,190
95149.11.192.0/19149.11.192.1 to 149.11.223.254149.11.223.2558,190
96149.11.224.0/19149.11.224.1 to 149.11.255.254149.11.255.2558,190
97149.12.0.0/19149.12.0.1 to 149.12.31.254149.12.31.2558,190
98149.12.32.0/19149.12.32.1 to 149.12.63.254149.12.63.2558,190
99149.12.64.0/19149.12.64.1 to 149.12.95.254149.12.95.2558,190
100149.12.96.0/19149.12.96.1 to 149.12.127.254149.12.127.2558,190
101149.12.128.0/19149.12.128.1 to 149.12.159.254149.12.159.2558,190
102149.12.160.0/19149.12.160.1 to 149.12.191.254149.12.191.2558,190
103149.12.192.0/19149.12.192.1 to 149.12.223.254149.12.223.2558,190
104149.12.224.0/19149.12.224.1 to 149.12.255.254149.12.255.2558,190
105149.13.0.0/19149.13.0.1 to 149.13.31.254149.13.31.2558,190
106149.13.32.0/19149.13.32.1 to 149.13.63.254149.13.63.2558,190
107149.13.64.0/19149.13.64.1 to 149.13.95.254149.13.95.2558,190
108149.13.96.0/19149.13.96.1 to 149.13.127.254149.13.127.2558,190
109149.13.128.0/19149.13.128.1 to 149.13.159.254149.13.159.2558,190
110149.13.160.0/19149.13.160.1 to 149.13.191.254149.13.191.2558,190
111149.13.192.0/19149.13.192.1 to 149.13.223.254149.13.223.2558,190
112149.13.224.0/19149.13.224.1 to 149.13.255.254149.13.255.2558,190
113149.14.0.0/19149.14.0.1 to 149.14.31.254149.14.31.2558,190
114149.14.32.0/19149.14.32.1 to 149.14.63.254149.14.63.2558,190
115149.14.64.0/19149.14.64.1 to 149.14.95.254149.14.95.2558,190
116149.14.96.0/19149.14.96.1 to 149.14.127.254149.14.127.2558,190
117149.14.128.0/19149.14.128.1 to 149.14.159.254149.14.159.2558,190
118149.14.160.0/19149.14.160.1 to 149.14.191.254149.14.191.2558,190
119149.14.192.0/19149.14.192.1 to 149.14.223.254149.14.223.2558,190
120149.14.224.0/19149.14.224.1 to 149.14.255.254149.14.255.2558,190
121149.15.0.0/19149.15.0.1 to 149.15.31.254149.15.31.2558,190
122149.15.32.0/19149.15.32.1 to 149.15.63.254149.15.63.2558,190
123149.15.64.0/19149.15.64.1 to 149.15.95.254149.15.95.2558,190
124149.15.96.0/19149.15.96.1 to 149.15.127.254149.15.127.2558,190
125149.15.128.0/19149.15.128.1 to 149.15.159.254149.15.159.2558,190
126149.15.160.0/19149.15.160.1 to 149.15.191.254149.15.191.2558,190
127149.15.192.0/19149.15.192.1 to 149.15.223.254149.15.223.2558,190
128149.15.224.0/19149.15.224.1 to 149.15.255.254149.15.255.2558,190
129149.16.0.0/19149.16.0.1 to 149.16.31.254149.16.31.2558,190
130149.16.32.0/19149.16.32.1 to 149.16.63.254149.16.63.2558,190
131149.16.64.0/19149.16.64.1 to 149.16.95.254149.16.95.2558,190
132149.16.96.0/19149.16.96.1 to 149.16.127.254149.16.127.2558,190
133149.16.128.0/19149.16.128.1 to 149.16.159.254149.16.159.2558,190
134149.16.160.0/19149.16.160.1 to 149.16.191.254149.16.191.2558,190
135149.16.192.0/19149.16.192.1 to 149.16.223.254149.16.223.2558,190
136149.16.224.0/19149.16.224.1 to 149.16.255.254149.16.255.2558,190
137149.17.0.0/19149.17.0.1 to 149.17.31.254149.17.31.2558,190
138149.17.32.0/19149.17.32.1 to 149.17.63.254149.17.63.2558,190
139149.17.64.0/19149.17.64.1 to 149.17.95.254149.17.95.2558,190
140149.17.96.0/19149.17.96.1 to 149.17.127.254149.17.127.2558,190
141149.17.128.0/19149.17.128.1 to 149.17.159.254149.17.159.2558,190
142149.17.160.0/19149.17.160.1 to 149.17.191.254149.17.191.2558,190
143149.17.192.0/19149.17.192.1 to 149.17.223.254149.17.223.2558,190
144149.17.224.0/19149.17.224.1 to 149.17.255.254149.17.255.2558,190
145149.18.0.0/19149.18.0.1 to 149.18.31.254149.18.31.2558,190
146149.18.32.0/19149.18.32.1 to 149.18.63.254149.18.63.2558,190
147149.18.64.0/19149.18.64.1 to 149.18.95.254149.18.95.2558,190
148149.18.96.0/19149.18.96.1 to 149.18.127.254149.18.127.2558,190
149149.18.128.0/19149.18.128.1 to 149.18.159.254149.18.159.2558,190
150149.18.160.0/19149.18.160.1 to 149.18.191.254149.18.191.2558,190
151149.18.192.0/19149.18.192.1 to 149.18.223.254149.18.223.2558,190
152149.18.224.0/19149.18.224.1 to 149.18.255.254149.18.255.2558,190
153149.19.0.0/19149.19.0.1 to 149.19.31.254149.19.31.2558,190
154149.19.32.0/19149.19.32.1 to 149.19.63.254149.19.63.2558,190
155149.19.64.0/19149.19.64.1 to 149.19.95.254149.19.95.2558,190
156149.19.96.0/19149.19.96.1 to 149.19.127.254149.19.127.2558,190
157149.19.128.0/19149.19.128.1 to 149.19.159.254149.19.159.2558,190
158149.19.160.0/19149.19.160.1 to 149.19.191.254149.19.191.2558,190
159149.19.192.0/19149.19.192.1 to 149.19.223.254149.19.223.2558,190
160149.19.224.0/19149.19.224.1 to 149.19.255.254149.19.255.2558,190
161149.20.0.0/19149.20.0.1 to 149.20.31.254149.20.31.2558,190
162149.20.32.0/19149.20.32.1 to 149.20.63.254149.20.63.2558,190
163149.20.64.0/19149.20.64.1 to 149.20.95.254149.20.95.2558,190
164149.20.96.0/19149.20.96.1 to 149.20.127.254149.20.127.2558,190
165149.20.128.0/19149.20.128.1 to 149.20.159.254149.20.159.2558,190
166149.20.160.0/19149.20.160.1 to 149.20.191.254149.20.191.2558,190
167149.20.192.0/19149.20.192.1 to 149.20.223.254149.20.223.2558,190
168149.20.224.0/19149.20.224.1 to 149.20.255.254149.20.255.2558,190
169149.21.0.0/19149.21.0.1 to 149.21.31.254149.21.31.2558,190
170149.21.32.0/19149.21.32.1 to 149.21.63.254149.21.63.2558,190
171149.21.64.0/19149.21.64.1 to 149.21.95.254149.21.95.2558,190
172149.21.96.0/19149.21.96.1 to 149.21.127.254149.21.127.2558,190
173149.21.128.0/19149.21.128.1 to 149.21.159.254149.21.159.2558,190
174149.21.160.0/19149.21.160.1 to 149.21.191.254149.21.191.2558,190
175149.21.192.0/19149.21.192.1 to 149.21.223.254149.21.223.2558,190
176149.21.224.0/19149.21.224.1 to 149.21.255.254149.21.255.2558,190
177149.22.0.0/19149.22.0.1 to 149.22.31.254149.22.31.2558,190
178149.22.32.0/19149.22.32.1 to 149.22.63.254149.22.63.2558,190
179149.22.64.0/19149.22.64.1 to 149.22.95.254149.22.95.2558,190
180149.22.96.0/19149.22.96.1 to 149.22.127.254149.22.127.2558,190
181149.22.128.0/19149.22.128.1 to 149.22.159.254149.22.159.2558,190
182149.22.160.0/19149.22.160.1 to 149.22.191.254149.22.191.2558,190
183149.22.192.0/19149.22.192.1 to 149.22.223.254149.22.223.2558,190
184149.22.224.0/19149.22.224.1 to 149.22.255.254149.22.255.2558,190
185149.23.0.0/19149.23.0.1 to 149.23.31.254149.23.31.2558,190
186149.23.32.0/19149.23.32.1 to 149.23.63.254149.23.63.2558,190
187149.23.64.0/19149.23.64.1 to 149.23.95.254149.23.95.2558,190
188149.23.96.0/19149.23.96.1 to 149.23.127.254149.23.127.2558,190
189149.23.128.0/19149.23.128.1 to 149.23.159.254149.23.159.2558,190
190149.23.160.0/19149.23.160.1 to 149.23.191.254149.23.191.2558,190
191149.23.192.0/19149.23.192.1 to 149.23.223.254149.23.223.2558,190
192149.23.224.0/19149.23.224.1 to 149.23.255.254149.23.255.2558,190
193149.24.0.0/19149.24.0.1 to 149.24.31.254149.24.31.2558,190
194149.24.32.0/19149.24.32.1 to 149.24.63.254149.24.63.2558,190
195149.24.64.0/19149.24.64.1 to 149.24.95.254149.24.95.2558,190
196149.24.96.0/19149.24.96.1 to 149.24.127.254149.24.127.2558,190
197149.24.128.0/19149.24.128.1 to 149.24.159.254149.24.159.2558,190
198149.24.160.0/19149.24.160.1 to 149.24.191.254149.24.191.2558,190
199149.24.192.0/19149.24.192.1 to 149.24.223.254149.24.223.2558,190
200149.24.224.0/19149.24.224.1 to 149.24.255.254149.24.255.2558,190
201149.25.0.0/19149.25.0.1 to 149.25.31.254149.25.31.2558,190
202149.25.32.0/19149.25.32.1 to 149.25.63.254149.25.63.2558,190
203149.25.64.0/19149.25.64.1 to 149.25.95.254149.25.95.2558,190
204149.25.96.0/19149.25.96.1 to 149.25.127.254149.25.127.2558,190
205149.25.128.0/19149.25.128.1 to 149.25.159.254149.25.159.2558,190
206149.25.160.0/19149.25.160.1 to 149.25.191.254149.25.191.2558,190
207149.25.192.0/19149.25.192.1 to 149.25.223.254149.25.223.2558,190
208149.25.224.0/19149.25.224.1 to 149.25.255.254149.25.255.2558,190
209149.26.0.0/19149.26.0.1 to 149.26.31.254149.26.31.2558,190
210149.26.32.0/19149.26.32.1 to 149.26.63.254149.26.63.2558,190
211149.26.64.0/19149.26.64.1 to 149.26.95.254149.26.95.2558,190
212149.26.96.0/19149.26.96.1 to 149.26.127.254149.26.127.2558,190
213149.26.128.0/19149.26.128.1 to 149.26.159.254149.26.159.2558,190
214149.26.160.0/19149.26.160.1 to 149.26.191.254149.26.191.2558,190
215149.26.192.0/19149.26.192.1 to 149.26.223.254149.26.223.2558,190
216149.26.224.0/19149.26.224.1 to 149.26.255.254149.26.255.2558,190
217149.27.0.0/19149.27.0.1 to 149.27.31.254149.27.31.2558,190
218149.27.32.0/19149.27.32.1 to 149.27.63.254149.27.63.2558,190
219149.27.64.0/19149.27.64.1 to 149.27.95.254149.27.95.2558,190
220149.27.96.0/19149.27.96.1 to 149.27.127.254149.27.127.2558,190
221149.27.128.0/19149.27.128.1 to 149.27.159.254149.27.159.2558,190
222149.27.160.0/19149.27.160.1 to 149.27.191.254149.27.191.2558,190
223149.27.192.0/19149.27.192.1 to 149.27.223.254149.27.223.2558,190
224149.27.224.0/19149.27.224.1 to 149.27.255.254149.27.255.2558,190
225149.28.0.0/19149.28.0.1 to 149.28.31.254149.28.31.2558,190
226149.28.32.0/19149.28.32.1 to 149.28.63.254149.28.63.2558,190
227149.28.64.0/19149.28.64.1 to 149.28.95.254149.28.95.2558,190
228149.28.96.0/19149.28.96.1 to 149.28.127.254149.28.127.2558,190
229149.28.128.0/19149.28.128.1 to 149.28.159.254149.28.159.2558,190
230149.28.160.0/19149.28.160.1 to 149.28.191.254149.28.191.2558,190
231149.28.192.0/19149.28.192.1 to 149.28.223.254149.28.223.2558,190
232149.28.224.0/19149.28.224.1 to 149.28.255.254149.28.255.2558,190
233149.29.0.0/19149.29.0.1 to 149.29.31.254149.29.31.2558,190
234149.29.32.0/19149.29.32.1 to 149.29.63.254149.29.63.2558,190
235149.29.64.0/19149.29.64.1 to 149.29.95.254149.29.95.2558,190
236149.29.96.0/19149.29.96.1 to 149.29.127.254149.29.127.2558,190
237149.29.128.0/19149.29.128.1 to 149.29.159.254149.29.159.2558,190
238149.29.160.0/19149.29.160.1 to 149.29.191.254149.29.191.2558,190
239149.29.192.0/19149.29.192.1 to 149.29.223.254149.29.223.2558,190
240149.29.224.0/19149.29.224.1 to 149.29.255.254149.29.255.2558,190
241149.30.0.0/19149.30.0.1 to 149.30.31.254149.30.31.2558,190
242149.30.32.0/19149.30.32.1 to 149.30.63.254149.30.63.2558,190
243149.30.64.0/19149.30.64.1 to 149.30.95.254149.30.95.2558,190
244149.30.96.0/19149.30.96.1 to 149.30.127.254149.30.127.2558,190
245149.30.128.0/19149.30.128.1 to 149.30.159.254149.30.159.2558,190
246149.30.160.0/19149.30.160.1 to 149.30.191.254149.30.191.2558,190
247149.30.192.0/19149.30.192.1 to 149.30.223.254149.30.223.2558,190
248149.30.224.0/19149.30.224.1 to 149.30.255.254149.30.255.2558,190
249149.31.0.0/19149.31.0.1 to 149.31.31.254149.31.31.2558,190
250149.31.32.0/19149.31.32.1 to 149.31.63.254149.31.63.2558,190
251149.31.64.0/19149.31.64.1 to 149.31.95.254149.31.95.2558,190
252149.31.96.0/19149.31.96.1 to 149.31.127.254149.31.127.2558,190
253149.31.128.0/19149.31.128.1 to 149.31.159.254149.31.159.2558,190
254149.31.160.0/19149.31.160.1 to 149.31.191.254149.31.191.2558,190
255149.31.192.0/19149.31.192.1 to 149.31.223.254149.31.223.2558,190
256149.31.224.0/19149.31.224.1 to 149.31.255.254149.31.255.2558,190

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.