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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.

Network172.26.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
172.26.64.0
Broadcast address
172.26.95.255
First usable
172.26.64.1
Last usable
172.26.95.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Private (RFC 1918) 172.16.0.0/12
Office and home networks; not routed on the internet
Old class
B (default /16)
As numbers
Hex AC1A4000 · Integer 2887401472 to 2887409663
Reverse DNS zones
64.26.172.in-addr.arpa
65.26.172.in-addr.arpa
66.26.172.in-addr.arpa
67.26.172.in-addr.arpa
68.26.172.in-addr.arpa
69.26.172.in-addr.arpa
70.26.172.in-addr.arpa
71.26.172.in-addr.arpa
72.26.172.in-addr.arpa
73.26.172.in-addr.arpa
74.26.172.in-addr.arpa
75.26.172.in-addr.arpa
76.26.172.in-addr.arpa
77.26.172.in-addr.arpa
78.26.172.in-addr.arpa
79.26.172.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10101100.00011010.01000000.00000000172.26.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network10101100.00011010.01000000.00000000172.26.64.0
Broadcast10101100.00011010.01011111.11111111172.26.95.255
Split into smaller subnets/29
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

172.26.64.0/19 makes 1,024 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1172.26.64.0/29172.26.64.1 to 172.26.64.6172.26.64.76
2172.26.64.8/29172.26.64.9 to 172.26.64.14172.26.64.156
3172.26.64.16/29172.26.64.17 to 172.26.64.22172.26.64.236
4172.26.64.24/29172.26.64.25 to 172.26.64.30172.26.64.316
5172.26.64.32/29172.26.64.33 to 172.26.64.38172.26.64.396
6172.26.64.40/29172.26.64.41 to 172.26.64.46172.26.64.476
7172.26.64.48/29172.26.64.49 to 172.26.64.54172.26.64.556
8172.26.64.56/29172.26.64.57 to 172.26.64.62172.26.64.636
9172.26.64.64/29172.26.64.65 to 172.26.64.70172.26.64.716
10172.26.64.72/29172.26.64.73 to 172.26.64.78172.26.64.796
11172.26.64.80/29172.26.64.81 to 172.26.64.86172.26.64.876
12172.26.64.88/29172.26.64.89 to 172.26.64.94172.26.64.956
13172.26.64.96/29172.26.64.97 to 172.26.64.102172.26.64.1036
14172.26.64.104/29172.26.64.105 to 172.26.64.110172.26.64.1116
15172.26.64.112/29172.26.64.113 to 172.26.64.118172.26.64.1196
16172.26.64.120/29172.26.64.121 to 172.26.64.126172.26.64.1276
17172.26.64.128/29172.26.64.129 to 172.26.64.134172.26.64.1356
18172.26.64.136/29172.26.64.137 to 172.26.64.142172.26.64.1436
19172.26.64.144/29172.26.64.145 to 172.26.64.150172.26.64.1516
20172.26.64.152/29172.26.64.153 to 172.26.64.158172.26.64.1596
21172.26.64.160/29172.26.64.161 to 172.26.64.166172.26.64.1676
22172.26.64.168/29172.26.64.169 to 172.26.64.174172.26.64.1756
23172.26.64.176/29172.26.64.177 to 172.26.64.182172.26.64.1836
24172.26.64.184/29172.26.64.185 to 172.26.64.190172.26.64.1916
25172.26.64.192/29172.26.64.193 to 172.26.64.198172.26.64.1996
26172.26.64.200/29172.26.64.201 to 172.26.64.206172.26.64.2076
27172.26.64.208/29172.26.64.209 to 172.26.64.214172.26.64.2156
28172.26.64.216/29172.26.64.217 to 172.26.64.222172.26.64.2236
29172.26.64.224/29172.26.64.225 to 172.26.64.230172.26.64.2316
30172.26.64.232/29172.26.64.233 to 172.26.64.238172.26.64.2396
31172.26.64.240/29172.26.64.241 to 172.26.64.246172.26.64.2476
32172.26.64.248/29172.26.64.249 to 172.26.64.254172.26.64.2556
33172.26.65.0/29172.26.65.1 to 172.26.65.6172.26.65.76
34172.26.65.8/29172.26.65.9 to 172.26.65.14172.26.65.156
35172.26.65.16/29172.26.65.17 to 172.26.65.22172.26.65.236
36172.26.65.24/29172.26.65.25 to 172.26.65.30172.26.65.316
37172.26.65.32/29172.26.65.33 to 172.26.65.38172.26.65.396
38172.26.65.40/29172.26.65.41 to 172.26.65.46172.26.65.476
39172.26.65.48/29172.26.65.49 to 172.26.65.54172.26.65.556
40172.26.65.56/29172.26.65.57 to 172.26.65.62172.26.65.636
41172.26.65.64/29172.26.65.65 to 172.26.65.70172.26.65.716
42172.26.65.72/29172.26.65.73 to 172.26.65.78172.26.65.796
43172.26.65.80/29172.26.65.81 to 172.26.65.86172.26.65.876
44172.26.65.88/29172.26.65.89 to 172.26.65.94172.26.65.956
45172.26.65.96/29172.26.65.97 to 172.26.65.102172.26.65.1036
46172.26.65.104/29172.26.65.105 to 172.26.65.110172.26.65.1116
47172.26.65.112/29172.26.65.113 to 172.26.65.118172.26.65.1196
48172.26.65.120/29172.26.65.121 to 172.26.65.126172.26.65.1276
49172.26.65.128/29172.26.65.129 to 172.26.65.134172.26.65.1356
50172.26.65.136/29172.26.65.137 to 172.26.65.142172.26.65.1436
51172.26.65.144/29172.26.65.145 to 172.26.65.150172.26.65.1516
52172.26.65.152/29172.26.65.153 to 172.26.65.158172.26.65.1596
53172.26.65.160/29172.26.65.161 to 172.26.65.166172.26.65.1676
54172.26.65.168/29172.26.65.169 to 172.26.65.174172.26.65.1756
55172.26.65.176/29172.26.65.177 to 172.26.65.182172.26.65.1836
56172.26.65.184/29172.26.65.185 to 172.26.65.190172.26.65.1916
57172.26.65.192/29172.26.65.193 to 172.26.65.198172.26.65.1996
58172.26.65.200/29172.26.65.201 to 172.26.65.206172.26.65.2076
59172.26.65.208/29172.26.65.209 to 172.26.65.214172.26.65.2156
60172.26.65.216/29172.26.65.217 to 172.26.65.222172.26.65.2236
61172.26.65.224/29172.26.65.225 to 172.26.65.230172.26.65.2316
62172.26.65.232/29172.26.65.233 to 172.26.65.238172.26.65.2396
63172.26.65.240/29172.26.65.241 to 172.26.65.246172.26.65.2476
64172.26.65.248/29172.26.65.249 to 172.26.65.254172.26.65.2556
65172.26.66.0/29172.26.66.1 to 172.26.66.6172.26.66.76
66172.26.66.8/29172.26.66.9 to 172.26.66.14172.26.66.156
67172.26.66.16/29172.26.66.17 to 172.26.66.22172.26.66.236
68172.26.66.24/29172.26.66.25 to 172.26.66.30172.26.66.316
69172.26.66.32/29172.26.66.33 to 172.26.66.38172.26.66.396
70172.26.66.40/29172.26.66.41 to 172.26.66.46172.26.66.476
71172.26.66.48/29172.26.66.49 to 172.26.66.54172.26.66.556
72172.26.66.56/29172.26.66.57 to 172.26.66.62172.26.66.636
73172.26.66.64/29172.26.66.65 to 172.26.66.70172.26.66.716
74172.26.66.72/29172.26.66.73 to 172.26.66.78172.26.66.796
75172.26.66.80/29172.26.66.81 to 172.26.66.86172.26.66.876
76172.26.66.88/29172.26.66.89 to 172.26.66.94172.26.66.956
77172.26.66.96/29172.26.66.97 to 172.26.66.102172.26.66.1036
78172.26.66.104/29172.26.66.105 to 172.26.66.110172.26.66.1116
79172.26.66.112/29172.26.66.113 to 172.26.66.118172.26.66.1196
80172.26.66.120/29172.26.66.121 to 172.26.66.126172.26.66.1276
81172.26.66.128/29172.26.66.129 to 172.26.66.134172.26.66.1356
82172.26.66.136/29172.26.66.137 to 172.26.66.142172.26.66.1436
83172.26.66.144/29172.26.66.145 to 172.26.66.150172.26.66.1516
84172.26.66.152/29172.26.66.153 to 172.26.66.158172.26.66.1596
85172.26.66.160/29172.26.66.161 to 172.26.66.166172.26.66.1676
86172.26.66.168/29172.26.66.169 to 172.26.66.174172.26.66.1756
87172.26.66.176/29172.26.66.177 to 172.26.66.182172.26.66.1836
88172.26.66.184/29172.26.66.185 to 172.26.66.190172.26.66.1916
89172.26.66.192/29172.26.66.193 to 172.26.66.198172.26.66.1996
90172.26.66.200/29172.26.66.201 to 172.26.66.206172.26.66.2076
91172.26.66.208/29172.26.66.209 to 172.26.66.214172.26.66.2156
92172.26.66.216/29172.26.66.217 to 172.26.66.222172.26.66.2236
93172.26.66.224/29172.26.66.225 to 172.26.66.230172.26.66.2316
94172.26.66.232/29172.26.66.233 to 172.26.66.238172.26.66.2396
95172.26.66.240/29172.26.66.241 to 172.26.66.246172.26.66.2476
96172.26.66.248/29172.26.66.249 to 172.26.66.254172.26.66.2556
97172.26.67.0/29172.26.67.1 to 172.26.67.6172.26.67.76
98172.26.67.8/29172.26.67.9 to 172.26.67.14172.26.67.156
99172.26.67.16/29172.26.67.17 to 172.26.67.22172.26.67.236
100172.26.67.24/29172.26.67.25 to 172.26.67.30172.26.67.316
101172.26.67.32/29172.26.67.33 to 172.26.67.38172.26.67.396
102172.26.67.40/29172.26.67.41 to 172.26.67.46172.26.67.476
103172.26.67.48/29172.26.67.49 to 172.26.67.54172.26.67.556
104172.26.67.56/29172.26.67.57 to 172.26.67.62172.26.67.636
105172.26.67.64/29172.26.67.65 to 172.26.67.70172.26.67.716
106172.26.67.72/29172.26.67.73 to 172.26.67.78172.26.67.796
107172.26.67.80/29172.26.67.81 to 172.26.67.86172.26.67.876
108172.26.67.88/29172.26.67.89 to 172.26.67.94172.26.67.956
109172.26.67.96/29172.26.67.97 to 172.26.67.102172.26.67.1036
110172.26.67.104/29172.26.67.105 to 172.26.67.110172.26.67.1116
111172.26.67.112/29172.26.67.113 to 172.26.67.118172.26.67.1196
112172.26.67.120/29172.26.67.121 to 172.26.67.126172.26.67.1276
113172.26.67.128/29172.26.67.129 to 172.26.67.134172.26.67.1356
114172.26.67.136/29172.26.67.137 to 172.26.67.142172.26.67.1436
115172.26.67.144/29172.26.67.145 to 172.26.67.150172.26.67.1516
116172.26.67.152/29172.26.67.153 to 172.26.67.158172.26.67.1596
117172.26.67.160/29172.26.67.161 to 172.26.67.166172.26.67.1676
118172.26.67.168/29172.26.67.169 to 172.26.67.174172.26.67.1756
119172.26.67.176/29172.26.67.177 to 172.26.67.182172.26.67.1836
120172.26.67.184/29172.26.67.185 to 172.26.67.190172.26.67.1916
121172.26.67.192/29172.26.67.193 to 172.26.67.198172.26.67.1996
122172.26.67.200/29172.26.67.201 to 172.26.67.206172.26.67.2076
123172.26.67.208/29172.26.67.209 to 172.26.67.214172.26.67.2156
124172.26.67.216/29172.26.67.217 to 172.26.67.222172.26.67.2236
125172.26.67.224/29172.26.67.225 to 172.26.67.230172.26.67.2316
126172.26.67.232/29172.26.67.233 to 172.26.67.238172.26.67.2396
127172.26.67.240/29172.26.67.241 to 172.26.67.246172.26.67.2476
128172.26.67.248/29172.26.67.249 to 172.26.67.254172.26.67.2556
129172.26.68.0/29172.26.68.1 to 172.26.68.6172.26.68.76
130172.26.68.8/29172.26.68.9 to 172.26.68.14172.26.68.156
131172.26.68.16/29172.26.68.17 to 172.26.68.22172.26.68.236
132172.26.68.24/29172.26.68.25 to 172.26.68.30172.26.68.316
133172.26.68.32/29172.26.68.33 to 172.26.68.38172.26.68.396
134172.26.68.40/29172.26.68.41 to 172.26.68.46172.26.68.476
135172.26.68.48/29172.26.68.49 to 172.26.68.54172.26.68.556
136172.26.68.56/29172.26.68.57 to 172.26.68.62172.26.68.636
137172.26.68.64/29172.26.68.65 to 172.26.68.70172.26.68.716
138172.26.68.72/29172.26.68.73 to 172.26.68.78172.26.68.796
139172.26.68.80/29172.26.68.81 to 172.26.68.86172.26.68.876
140172.26.68.88/29172.26.68.89 to 172.26.68.94172.26.68.956
141172.26.68.96/29172.26.68.97 to 172.26.68.102172.26.68.1036
142172.26.68.104/29172.26.68.105 to 172.26.68.110172.26.68.1116
143172.26.68.112/29172.26.68.113 to 172.26.68.118172.26.68.1196
144172.26.68.120/29172.26.68.121 to 172.26.68.126172.26.68.1276
145172.26.68.128/29172.26.68.129 to 172.26.68.134172.26.68.1356
146172.26.68.136/29172.26.68.137 to 172.26.68.142172.26.68.1436
147172.26.68.144/29172.26.68.145 to 172.26.68.150172.26.68.1516
148172.26.68.152/29172.26.68.153 to 172.26.68.158172.26.68.1596
149172.26.68.160/29172.26.68.161 to 172.26.68.166172.26.68.1676
150172.26.68.168/29172.26.68.169 to 172.26.68.174172.26.68.1756
151172.26.68.176/29172.26.68.177 to 172.26.68.182172.26.68.1836
152172.26.68.184/29172.26.68.185 to 172.26.68.190172.26.68.1916
153172.26.68.192/29172.26.68.193 to 172.26.68.198172.26.68.1996
154172.26.68.200/29172.26.68.201 to 172.26.68.206172.26.68.2076
155172.26.68.208/29172.26.68.209 to 172.26.68.214172.26.68.2156
156172.26.68.216/29172.26.68.217 to 172.26.68.222172.26.68.2236
157172.26.68.224/29172.26.68.225 to 172.26.68.230172.26.68.2316
158172.26.68.232/29172.26.68.233 to 172.26.68.238172.26.68.2396
159172.26.68.240/29172.26.68.241 to 172.26.68.246172.26.68.2476
160172.26.68.248/29172.26.68.249 to 172.26.68.254172.26.68.2556
161172.26.69.0/29172.26.69.1 to 172.26.69.6172.26.69.76
162172.26.69.8/29172.26.69.9 to 172.26.69.14172.26.69.156
163172.26.69.16/29172.26.69.17 to 172.26.69.22172.26.69.236
164172.26.69.24/29172.26.69.25 to 172.26.69.30172.26.69.316
165172.26.69.32/29172.26.69.33 to 172.26.69.38172.26.69.396
166172.26.69.40/29172.26.69.41 to 172.26.69.46172.26.69.476
167172.26.69.48/29172.26.69.49 to 172.26.69.54172.26.69.556
168172.26.69.56/29172.26.69.57 to 172.26.69.62172.26.69.636
169172.26.69.64/29172.26.69.65 to 172.26.69.70172.26.69.716
170172.26.69.72/29172.26.69.73 to 172.26.69.78172.26.69.796
171172.26.69.80/29172.26.69.81 to 172.26.69.86172.26.69.876
172172.26.69.88/29172.26.69.89 to 172.26.69.94172.26.69.956
173172.26.69.96/29172.26.69.97 to 172.26.69.102172.26.69.1036
174172.26.69.104/29172.26.69.105 to 172.26.69.110172.26.69.1116
175172.26.69.112/29172.26.69.113 to 172.26.69.118172.26.69.1196
176172.26.69.120/29172.26.69.121 to 172.26.69.126172.26.69.1276
177172.26.69.128/29172.26.69.129 to 172.26.69.134172.26.69.1356
178172.26.69.136/29172.26.69.137 to 172.26.69.142172.26.69.1436
179172.26.69.144/29172.26.69.145 to 172.26.69.150172.26.69.1516
180172.26.69.152/29172.26.69.153 to 172.26.69.158172.26.69.1596
181172.26.69.160/29172.26.69.161 to 172.26.69.166172.26.69.1676
182172.26.69.168/29172.26.69.169 to 172.26.69.174172.26.69.1756
183172.26.69.176/29172.26.69.177 to 172.26.69.182172.26.69.1836
184172.26.69.184/29172.26.69.185 to 172.26.69.190172.26.69.1916
185172.26.69.192/29172.26.69.193 to 172.26.69.198172.26.69.1996
186172.26.69.200/29172.26.69.201 to 172.26.69.206172.26.69.2076
187172.26.69.208/29172.26.69.209 to 172.26.69.214172.26.69.2156
188172.26.69.216/29172.26.69.217 to 172.26.69.222172.26.69.2236
189172.26.69.224/29172.26.69.225 to 172.26.69.230172.26.69.2316
190172.26.69.232/29172.26.69.233 to 172.26.69.238172.26.69.2396
191172.26.69.240/29172.26.69.241 to 172.26.69.246172.26.69.2476
192172.26.69.248/29172.26.69.249 to 172.26.69.254172.26.69.2556
193172.26.70.0/29172.26.70.1 to 172.26.70.6172.26.70.76
194172.26.70.8/29172.26.70.9 to 172.26.70.14172.26.70.156
195172.26.70.16/29172.26.70.17 to 172.26.70.22172.26.70.236
196172.26.70.24/29172.26.70.25 to 172.26.70.30172.26.70.316
197172.26.70.32/29172.26.70.33 to 172.26.70.38172.26.70.396
198172.26.70.40/29172.26.70.41 to 172.26.70.46172.26.70.476
199172.26.70.48/29172.26.70.49 to 172.26.70.54172.26.70.556
200172.26.70.56/29172.26.70.57 to 172.26.70.62172.26.70.636
201172.26.70.64/29172.26.70.65 to 172.26.70.70172.26.70.716
202172.26.70.72/29172.26.70.73 to 172.26.70.78172.26.70.796
203172.26.70.80/29172.26.70.81 to 172.26.70.86172.26.70.876
204172.26.70.88/29172.26.70.89 to 172.26.70.94172.26.70.956
205172.26.70.96/29172.26.70.97 to 172.26.70.102172.26.70.1036
206172.26.70.104/29172.26.70.105 to 172.26.70.110172.26.70.1116
207172.26.70.112/29172.26.70.113 to 172.26.70.118172.26.70.1196
208172.26.70.120/29172.26.70.121 to 172.26.70.126172.26.70.1276
209172.26.70.128/29172.26.70.129 to 172.26.70.134172.26.70.1356
210172.26.70.136/29172.26.70.137 to 172.26.70.142172.26.70.1436
211172.26.70.144/29172.26.70.145 to 172.26.70.150172.26.70.1516
212172.26.70.152/29172.26.70.153 to 172.26.70.158172.26.70.1596
213172.26.70.160/29172.26.70.161 to 172.26.70.166172.26.70.1676
214172.26.70.168/29172.26.70.169 to 172.26.70.174172.26.70.1756
215172.26.70.176/29172.26.70.177 to 172.26.70.182172.26.70.1836
216172.26.70.184/29172.26.70.185 to 172.26.70.190172.26.70.1916
217172.26.70.192/29172.26.70.193 to 172.26.70.198172.26.70.1996
218172.26.70.200/29172.26.70.201 to 172.26.70.206172.26.70.2076
219172.26.70.208/29172.26.70.209 to 172.26.70.214172.26.70.2156
220172.26.70.216/29172.26.70.217 to 172.26.70.222172.26.70.2236
221172.26.70.224/29172.26.70.225 to 172.26.70.230172.26.70.2316
222172.26.70.232/29172.26.70.233 to 172.26.70.238172.26.70.2396
223172.26.70.240/29172.26.70.241 to 172.26.70.246172.26.70.2476
224172.26.70.248/29172.26.70.249 to 172.26.70.254172.26.70.2556
225172.26.71.0/29172.26.71.1 to 172.26.71.6172.26.71.76
226172.26.71.8/29172.26.71.9 to 172.26.71.14172.26.71.156
227172.26.71.16/29172.26.71.17 to 172.26.71.22172.26.71.236
228172.26.71.24/29172.26.71.25 to 172.26.71.30172.26.71.316
229172.26.71.32/29172.26.71.33 to 172.26.71.38172.26.71.396
230172.26.71.40/29172.26.71.41 to 172.26.71.46172.26.71.476
231172.26.71.48/29172.26.71.49 to 172.26.71.54172.26.71.556
232172.26.71.56/29172.26.71.57 to 172.26.71.62172.26.71.636
233172.26.71.64/29172.26.71.65 to 172.26.71.70172.26.71.716
234172.26.71.72/29172.26.71.73 to 172.26.71.78172.26.71.796
235172.26.71.80/29172.26.71.81 to 172.26.71.86172.26.71.876
236172.26.71.88/29172.26.71.89 to 172.26.71.94172.26.71.956
237172.26.71.96/29172.26.71.97 to 172.26.71.102172.26.71.1036
238172.26.71.104/29172.26.71.105 to 172.26.71.110172.26.71.1116
239172.26.71.112/29172.26.71.113 to 172.26.71.118172.26.71.1196
240172.26.71.120/29172.26.71.121 to 172.26.71.126172.26.71.1276
241172.26.71.128/29172.26.71.129 to 172.26.71.134172.26.71.1356
242172.26.71.136/29172.26.71.137 to 172.26.71.142172.26.71.1436
243172.26.71.144/29172.26.71.145 to 172.26.71.150172.26.71.1516
244172.26.71.152/29172.26.71.153 to 172.26.71.158172.26.71.1596
245172.26.71.160/29172.26.71.161 to 172.26.71.166172.26.71.1676
246172.26.71.168/29172.26.71.169 to 172.26.71.174172.26.71.1756
247172.26.71.176/29172.26.71.177 to 172.26.71.182172.26.71.1836
248172.26.71.184/29172.26.71.185 to 172.26.71.190172.26.71.1916
249172.26.71.192/29172.26.71.193 to 172.26.71.198172.26.71.1996
250172.26.71.200/29172.26.71.201 to 172.26.71.206172.26.71.2076
251172.26.71.208/29172.26.71.209 to 172.26.71.214172.26.71.2156
252172.26.71.216/29172.26.71.217 to 172.26.71.222172.26.71.2236
253172.26.71.224/29172.26.71.225 to 172.26.71.230172.26.71.2316
254172.26.71.232/29172.26.71.233 to 172.26.71.238172.26.71.2396
255172.26.71.240/29172.26.71.241 to 172.26.71.246172.26.71.2476
256172.26.71.248/29172.26.71.249 to 172.26.71.254172.26.71.2556

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.