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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.

Network211.64.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
211.64.0.0
Broadcast address
211.127.255.255
First usable
211.64.0.1
Last usable
211.127.255.254
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
C (default /24)
As numbers
Hex D3400000 · Integer 3544186880 to 3548381183
Reverse DNS zones
64.211.in-addr.arpa
65.211.in-addr.arpa
66.211.in-addr.arpa
67.211.in-addr.arpa
68.211.in-addr.arpa
69.211.in-addr.arpa
70.211.in-addr.arpa
71.211.in-addr.arpa
72.211.in-addr.arpa
73.211.in-addr.arpa
74.211.in-addr.arpa
75.211.in-addr.arpa
76.211.in-addr.arpa
77.211.in-addr.arpa
78.211.in-addr.arpa
79.211.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
Address11010011.01000000.00000000.00000000211.64.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network11010011.01000000.00000000.00000000211.64.0.0
Broadcast11010011.01111111.11111111.11111111211.127.255.255
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)

211.64.0.0/10 makes 512 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1211.64.0.0/19211.64.0.1 to 211.64.31.254211.64.31.2558,190
2211.64.32.0/19211.64.32.1 to 211.64.63.254211.64.63.2558,190
3211.64.64.0/19211.64.64.1 to 211.64.95.254211.64.95.2558,190
4211.64.96.0/19211.64.96.1 to 211.64.127.254211.64.127.2558,190
5211.64.128.0/19211.64.128.1 to 211.64.159.254211.64.159.2558,190
6211.64.160.0/19211.64.160.1 to 211.64.191.254211.64.191.2558,190
7211.64.192.0/19211.64.192.1 to 211.64.223.254211.64.223.2558,190
8211.64.224.0/19211.64.224.1 to 211.64.255.254211.64.255.2558,190
9211.65.0.0/19211.65.0.1 to 211.65.31.254211.65.31.2558,190
10211.65.32.0/19211.65.32.1 to 211.65.63.254211.65.63.2558,190
11211.65.64.0/19211.65.64.1 to 211.65.95.254211.65.95.2558,190
12211.65.96.0/19211.65.96.1 to 211.65.127.254211.65.127.2558,190
13211.65.128.0/19211.65.128.1 to 211.65.159.254211.65.159.2558,190
14211.65.160.0/19211.65.160.1 to 211.65.191.254211.65.191.2558,190
15211.65.192.0/19211.65.192.1 to 211.65.223.254211.65.223.2558,190
16211.65.224.0/19211.65.224.1 to 211.65.255.254211.65.255.2558,190
17211.66.0.0/19211.66.0.1 to 211.66.31.254211.66.31.2558,190
18211.66.32.0/19211.66.32.1 to 211.66.63.254211.66.63.2558,190
19211.66.64.0/19211.66.64.1 to 211.66.95.254211.66.95.2558,190
20211.66.96.0/19211.66.96.1 to 211.66.127.254211.66.127.2558,190
21211.66.128.0/19211.66.128.1 to 211.66.159.254211.66.159.2558,190
22211.66.160.0/19211.66.160.1 to 211.66.191.254211.66.191.2558,190
23211.66.192.0/19211.66.192.1 to 211.66.223.254211.66.223.2558,190
24211.66.224.0/19211.66.224.1 to 211.66.255.254211.66.255.2558,190
25211.67.0.0/19211.67.0.1 to 211.67.31.254211.67.31.2558,190
26211.67.32.0/19211.67.32.1 to 211.67.63.254211.67.63.2558,190
27211.67.64.0/19211.67.64.1 to 211.67.95.254211.67.95.2558,190
28211.67.96.0/19211.67.96.1 to 211.67.127.254211.67.127.2558,190
29211.67.128.0/19211.67.128.1 to 211.67.159.254211.67.159.2558,190
30211.67.160.0/19211.67.160.1 to 211.67.191.254211.67.191.2558,190
31211.67.192.0/19211.67.192.1 to 211.67.223.254211.67.223.2558,190
32211.67.224.0/19211.67.224.1 to 211.67.255.254211.67.255.2558,190
33211.68.0.0/19211.68.0.1 to 211.68.31.254211.68.31.2558,190
34211.68.32.0/19211.68.32.1 to 211.68.63.254211.68.63.2558,190
35211.68.64.0/19211.68.64.1 to 211.68.95.254211.68.95.2558,190
36211.68.96.0/19211.68.96.1 to 211.68.127.254211.68.127.2558,190
37211.68.128.0/19211.68.128.1 to 211.68.159.254211.68.159.2558,190
38211.68.160.0/19211.68.160.1 to 211.68.191.254211.68.191.2558,190
39211.68.192.0/19211.68.192.1 to 211.68.223.254211.68.223.2558,190
40211.68.224.0/19211.68.224.1 to 211.68.255.254211.68.255.2558,190
41211.69.0.0/19211.69.0.1 to 211.69.31.254211.69.31.2558,190
42211.69.32.0/19211.69.32.1 to 211.69.63.254211.69.63.2558,190
43211.69.64.0/19211.69.64.1 to 211.69.95.254211.69.95.2558,190
44211.69.96.0/19211.69.96.1 to 211.69.127.254211.69.127.2558,190
45211.69.128.0/19211.69.128.1 to 211.69.159.254211.69.159.2558,190
46211.69.160.0/19211.69.160.1 to 211.69.191.254211.69.191.2558,190
47211.69.192.0/19211.69.192.1 to 211.69.223.254211.69.223.2558,190
48211.69.224.0/19211.69.224.1 to 211.69.255.254211.69.255.2558,190
49211.70.0.0/19211.70.0.1 to 211.70.31.254211.70.31.2558,190
50211.70.32.0/19211.70.32.1 to 211.70.63.254211.70.63.2558,190
51211.70.64.0/19211.70.64.1 to 211.70.95.254211.70.95.2558,190
52211.70.96.0/19211.70.96.1 to 211.70.127.254211.70.127.2558,190
53211.70.128.0/19211.70.128.1 to 211.70.159.254211.70.159.2558,190
54211.70.160.0/19211.70.160.1 to 211.70.191.254211.70.191.2558,190
55211.70.192.0/19211.70.192.1 to 211.70.223.254211.70.223.2558,190
56211.70.224.0/19211.70.224.1 to 211.70.255.254211.70.255.2558,190
57211.71.0.0/19211.71.0.1 to 211.71.31.254211.71.31.2558,190
58211.71.32.0/19211.71.32.1 to 211.71.63.254211.71.63.2558,190
59211.71.64.0/19211.71.64.1 to 211.71.95.254211.71.95.2558,190
60211.71.96.0/19211.71.96.1 to 211.71.127.254211.71.127.2558,190
61211.71.128.0/19211.71.128.1 to 211.71.159.254211.71.159.2558,190
62211.71.160.0/19211.71.160.1 to 211.71.191.254211.71.191.2558,190
63211.71.192.0/19211.71.192.1 to 211.71.223.254211.71.223.2558,190
64211.71.224.0/19211.71.224.1 to 211.71.255.254211.71.255.2558,190
65211.72.0.0/19211.72.0.1 to 211.72.31.254211.72.31.2558,190
66211.72.32.0/19211.72.32.1 to 211.72.63.254211.72.63.2558,190
67211.72.64.0/19211.72.64.1 to 211.72.95.254211.72.95.2558,190
68211.72.96.0/19211.72.96.1 to 211.72.127.254211.72.127.2558,190
69211.72.128.0/19211.72.128.1 to 211.72.159.254211.72.159.2558,190
70211.72.160.0/19211.72.160.1 to 211.72.191.254211.72.191.2558,190
71211.72.192.0/19211.72.192.1 to 211.72.223.254211.72.223.2558,190
72211.72.224.0/19211.72.224.1 to 211.72.255.254211.72.255.2558,190
73211.73.0.0/19211.73.0.1 to 211.73.31.254211.73.31.2558,190
74211.73.32.0/19211.73.32.1 to 211.73.63.254211.73.63.2558,190
75211.73.64.0/19211.73.64.1 to 211.73.95.254211.73.95.2558,190
76211.73.96.0/19211.73.96.1 to 211.73.127.254211.73.127.2558,190
77211.73.128.0/19211.73.128.1 to 211.73.159.254211.73.159.2558,190
78211.73.160.0/19211.73.160.1 to 211.73.191.254211.73.191.2558,190
79211.73.192.0/19211.73.192.1 to 211.73.223.254211.73.223.2558,190
80211.73.224.0/19211.73.224.1 to 211.73.255.254211.73.255.2558,190
81211.74.0.0/19211.74.0.1 to 211.74.31.254211.74.31.2558,190
82211.74.32.0/19211.74.32.1 to 211.74.63.254211.74.63.2558,190
83211.74.64.0/19211.74.64.1 to 211.74.95.254211.74.95.2558,190
84211.74.96.0/19211.74.96.1 to 211.74.127.254211.74.127.2558,190
85211.74.128.0/19211.74.128.1 to 211.74.159.254211.74.159.2558,190
86211.74.160.0/19211.74.160.1 to 211.74.191.254211.74.191.2558,190
87211.74.192.0/19211.74.192.1 to 211.74.223.254211.74.223.2558,190
88211.74.224.0/19211.74.224.1 to 211.74.255.254211.74.255.2558,190
89211.75.0.0/19211.75.0.1 to 211.75.31.254211.75.31.2558,190
90211.75.32.0/19211.75.32.1 to 211.75.63.254211.75.63.2558,190
91211.75.64.0/19211.75.64.1 to 211.75.95.254211.75.95.2558,190
92211.75.96.0/19211.75.96.1 to 211.75.127.254211.75.127.2558,190
93211.75.128.0/19211.75.128.1 to 211.75.159.254211.75.159.2558,190
94211.75.160.0/19211.75.160.1 to 211.75.191.254211.75.191.2558,190
95211.75.192.0/19211.75.192.1 to 211.75.223.254211.75.223.2558,190
96211.75.224.0/19211.75.224.1 to 211.75.255.254211.75.255.2558,190
97211.76.0.0/19211.76.0.1 to 211.76.31.254211.76.31.2558,190
98211.76.32.0/19211.76.32.1 to 211.76.63.254211.76.63.2558,190
99211.76.64.0/19211.76.64.1 to 211.76.95.254211.76.95.2558,190
100211.76.96.0/19211.76.96.1 to 211.76.127.254211.76.127.2558,190
101211.76.128.0/19211.76.128.1 to 211.76.159.254211.76.159.2558,190
102211.76.160.0/19211.76.160.1 to 211.76.191.254211.76.191.2558,190
103211.76.192.0/19211.76.192.1 to 211.76.223.254211.76.223.2558,190
104211.76.224.0/19211.76.224.1 to 211.76.255.254211.76.255.2558,190
105211.77.0.0/19211.77.0.1 to 211.77.31.254211.77.31.2558,190
106211.77.32.0/19211.77.32.1 to 211.77.63.254211.77.63.2558,190
107211.77.64.0/19211.77.64.1 to 211.77.95.254211.77.95.2558,190
108211.77.96.0/19211.77.96.1 to 211.77.127.254211.77.127.2558,190
109211.77.128.0/19211.77.128.1 to 211.77.159.254211.77.159.2558,190
110211.77.160.0/19211.77.160.1 to 211.77.191.254211.77.191.2558,190
111211.77.192.0/19211.77.192.1 to 211.77.223.254211.77.223.2558,190
112211.77.224.0/19211.77.224.1 to 211.77.255.254211.77.255.2558,190
113211.78.0.0/19211.78.0.1 to 211.78.31.254211.78.31.2558,190
114211.78.32.0/19211.78.32.1 to 211.78.63.254211.78.63.2558,190
115211.78.64.0/19211.78.64.1 to 211.78.95.254211.78.95.2558,190
116211.78.96.0/19211.78.96.1 to 211.78.127.254211.78.127.2558,190
117211.78.128.0/19211.78.128.1 to 211.78.159.254211.78.159.2558,190
118211.78.160.0/19211.78.160.1 to 211.78.191.254211.78.191.2558,190
119211.78.192.0/19211.78.192.1 to 211.78.223.254211.78.223.2558,190
120211.78.224.0/19211.78.224.1 to 211.78.255.254211.78.255.2558,190
121211.79.0.0/19211.79.0.1 to 211.79.31.254211.79.31.2558,190
122211.79.32.0/19211.79.32.1 to 211.79.63.254211.79.63.2558,190
123211.79.64.0/19211.79.64.1 to 211.79.95.254211.79.95.2558,190
124211.79.96.0/19211.79.96.1 to 211.79.127.254211.79.127.2558,190
125211.79.128.0/19211.79.128.1 to 211.79.159.254211.79.159.2558,190
126211.79.160.0/19211.79.160.1 to 211.79.191.254211.79.191.2558,190
127211.79.192.0/19211.79.192.1 to 211.79.223.254211.79.223.2558,190
128211.79.224.0/19211.79.224.1 to 211.79.255.254211.79.255.2558,190
129211.80.0.0/19211.80.0.1 to 211.80.31.254211.80.31.2558,190
130211.80.32.0/19211.80.32.1 to 211.80.63.254211.80.63.2558,190
131211.80.64.0/19211.80.64.1 to 211.80.95.254211.80.95.2558,190
132211.80.96.0/19211.80.96.1 to 211.80.127.254211.80.127.2558,190
133211.80.128.0/19211.80.128.1 to 211.80.159.254211.80.159.2558,190
134211.80.160.0/19211.80.160.1 to 211.80.191.254211.80.191.2558,190
135211.80.192.0/19211.80.192.1 to 211.80.223.254211.80.223.2558,190
136211.80.224.0/19211.80.224.1 to 211.80.255.254211.80.255.2558,190
137211.81.0.0/19211.81.0.1 to 211.81.31.254211.81.31.2558,190
138211.81.32.0/19211.81.32.1 to 211.81.63.254211.81.63.2558,190
139211.81.64.0/19211.81.64.1 to 211.81.95.254211.81.95.2558,190
140211.81.96.0/19211.81.96.1 to 211.81.127.254211.81.127.2558,190
141211.81.128.0/19211.81.128.1 to 211.81.159.254211.81.159.2558,190
142211.81.160.0/19211.81.160.1 to 211.81.191.254211.81.191.2558,190
143211.81.192.0/19211.81.192.1 to 211.81.223.254211.81.223.2558,190
144211.81.224.0/19211.81.224.1 to 211.81.255.254211.81.255.2558,190
145211.82.0.0/19211.82.0.1 to 211.82.31.254211.82.31.2558,190
146211.82.32.0/19211.82.32.1 to 211.82.63.254211.82.63.2558,190
147211.82.64.0/19211.82.64.1 to 211.82.95.254211.82.95.2558,190
148211.82.96.0/19211.82.96.1 to 211.82.127.254211.82.127.2558,190
149211.82.128.0/19211.82.128.1 to 211.82.159.254211.82.159.2558,190
150211.82.160.0/19211.82.160.1 to 211.82.191.254211.82.191.2558,190
151211.82.192.0/19211.82.192.1 to 211.82.223.254211.82.223.2558,190
152211.82.224.0/19211.82.224.1 to 211.82.255.254211.82.255.2558,190
153211.83.0.0/19211.83.0.1 to 211.83.31.254211.83.31.2558,190
154211.83.32.0/19211.83.32.1 to 211.83.63.254211.83.63.2558,190
155211.83.64.0/19211.83.64.1 to 211.83.95.254211.83.95.2558,190
156211.83.96.0/19211.83.96.1 to 211.83.127.254211.83.127.2558,190
157211.83.128.0/19211.83.128.1 to 211.83.159.254211.83.159.2558,190
158211.83.160.0/19211.83.160.1 to 211.83.191.254211.83.191.2558,190
159211.83.192.0/19211.83.192.1 to 211.83.223.254211.83.223.2558,190
160211.83.224.0/19211.83.224.1 to 211.83.255.254211.83.255.2558,190
161211.84.0.0/19211.84.0.1 to 211.84.31.254211.84.31.2558,190
162211.84.32.0/19211.84.32.1 to 211.84.63.254211.84.63.2558,190
163211.84.64.0/19211.84.64.1 to 211.84.95.254211.84.95.2558,190
164211.84.96.0/19211.84.96.1 to 211.84.127.254211.84.127.2558,190
165211.84.128.0/19211.84.128.1 to 211.84.159.254211.84.159.2558,190
166211.84.160.0/19211.84.160.1 to 211.84.191.254211.84.191.2558,190
167211.84.192.0/19211.84.192.1 to 211.84.223.254211.84.223.2558,190
168211.84.224.0/19211.84.224.1 to 211.84.255.254211.84.255.2558,190
169211.85.0.0/19211.85.0.1 to 211.85.31.254211.85.31.2558,190
170211.85.32.0/19211.85.32.1 to 211.85.63.254211.85.63.2558,190
171211.85.64.0/19211.85.64.1 to 211.85.95.254211.85.95.2558,190
172211.85.96.0/19211.85.96.1 to 211.85.127.254211.85.127.2558,190
173211.85.128.0/19211.85.128.1 to 211.85.159.254211.85.159.2558,190
174211.85.160.0/19211.85.160.1 to 211.85.191.254211.85.191.2558,190
175211.85.192.0/19211.85.192.1 to 211.85.223.254211.85.223.2558,190
176211.85.224.0/19211.85.224.1 to 211.85.255.254211.85.255.2558,190
177211.86.0.0/19211.86.0.1 to 211.86.31.254211.86.31.2558,190
178211.86.32.0/19211.86.32.1 to 211.86.63.254211.86.63.2558,190
179211.86.64.0/19211.86.64.1 to 211.86.95.254211.86.95.2558,190
180211.86.96.0/19211.86.96.1 to 211.86.127.254211.86.127.2558,190
181211.86.128.0/19211.86.128.1 to 211.86.159.254211.86.159.2558,190
182211.86.160.0/19211.86.160.1 to 211.86.191.254211.86.191.2558,190
183211.86.192.0/19211.86.192.1 to 211.86.223.254211.86.223.2558,190
184211.86.224.0/19211.86.224.1 to 211.86.255.254211.86.255.2558,190
185211.87.0.0/19211.87.0.1 to 211.87.31.254211.87.31.2558,190
186211.87.32.0/19211.87.32.1 to 211.87.63.254211.87.63.2558,190
187211.87.64.0/19211.87.64.1 to 211.87.95.254211.87.95.2558,190
188211.87.96.0/19211.87.96.1 to 211.87.127.254211.87.127.2558,190
189211.87.128.0/19211.87.128.1 to 211.87.159.254211.87.159.2558,190
190211.87.160.0/19211.87.160.1 to 211.87.191.254211.87.191.2558,190
191211.87.192.0/19211.87.192.1 to 211.87.223.254211.87.223.2558,190
192211.87.224.0/19211.87.224.1 to 211.87.255.254211.87.255.2558,190
193211.88.0.0/19211.88.0.1 to 211.88.31.254211.88.31.2558,190
194211.88.32.0/19211.88.32.1 to 211.88.63.254211.88.63.2558,190
195211.88.64.0/19211.88.64.1 to 211.88.95.254211.88.95.2558,190
196211.88.96.0/19211.88.96.1 to 211.88.127.254211.88.127.2558,190
197211.88.128.0/19211.88.128.1 to 211.88.159.254211.88.159.2558,190
198211.88.160.0/19211.88.160.1 to 211.88.191.254211.88.191.2558,190
199211.88.192.0/19211.88.192.1 to 211.88.223.254211.88.223.2558,190
200211.88.224.0/19211.88.224.1 to 211.88.255.254211.88.255.2558,190
201211.89.0.0/19211.89.0.1 to 211.89.31.254211.89.31.2558,190
202211.89.32.0/19211.89.32.1 to 211.89.63.254211.89.63.2558,190
203211.89.64.0/19211.89.64.1 to 211.89.95.254211.89.95.2558,190
204211.89.96.0/19211.89.96.1 to 211.89.127.254211.89.127.2558,190
205211.89.128.0/19211.89.128.1 to 211.89.159.254211.89.159.2558,190
206211.89.160.0/19211.89.160.1 to 211.89.191.254211.89.191.2558,190
207211.89.192.0/19211.89.192.1 to 211.89.223.254211.89.223.2558,190
208211.89.224.0/19211.89.224.1 to 211.89.255.254211.89.255.2558,190
209211.90.0.0/19211.90.0.1 to 211.90.31.254211.90.31.2558,190
210211.90.32.0/19211.90.32.1 to 211.90.63.254211.90.63.2558,190
211211.90.64.0/19211.90.64.1 to 211.90.95.254211.90.95.2558,190
212211.90.96.0/19211.90.96.1 to 211.90.127.254211.90.127.2558,190
213211.90.128.0/19211.90.128.1 to 211.90.159.254211.90.159.2558,190
214211.90.160.0/19211.90.160.1 to 211.90.191.254211.90.191.2558,190
215211.90.192.0/19211.90.192.1 to 211.90.223.254211.90.223.2558,190
216211.90.224.0/19211.90.224.1 to 211.90.255.254211.90.255.2558,190
217211.91.0.0/19211.91.0.1 to 211.91.31.254211.91.31.2558,190
218211.91.32.0/19211.91.32.1 to 211.91.63.254211.91.63.2558,190
219211.91.64.0/19211.91.64.1 to 211.91.95.254211.91.95.2558,190
220211.91.96.0/19211.91.96.1 to 211.91.127.254211.91.127.2558,190
221211.91.128.0/19211.91.128.1 to 211.91.159.254211.91.159.2558,190
222211.91.160.0/19211.91.160.1 to 211.91.191.254211.91.191.2558,190
223211.91.192.0/19211.91.192.1 to 211.91.223.254211.91.223.2558,190
224211.91.224.0/19211.91.224.1 to 211.91.255.254211.91.255.2558,190
225211.92.0.0/19211.92.0.1 to 211.92.31.254211.92.31.2558,190
226211.92.32.0/19211.92.32.1 to 211.92.63.254211.92.63.2558,190
227211.92.64.0/19211.92.64.1 to 211.92.95.254211.92.95.2558,190
228211.92.96.0/19211.92.96.1 to 211.92.127.254211.92.127.2558,190
229211.92.128.0/19211.92.128.1 to 211.92.159.254211.92.159.2558,190
230211.92.160.0/19211.92.160.1 to 211.92.191.254211.92.191.2558,190
231211.92.192.0/19211.92.192.1 to 211.92.223.254211.92.223.2558,190
232211.92.224.0/19211.92.224.1 to 211.92.255.254211.92.255.2558,190
233211.93.0.0/19211.93.0.1 to 211.93.31.254211.93.31.2558,190
234211.93.32.0/19211.93.32.1 to 211.93.63.254211.93.63.2558,190
235211.93.64.0/19211.93.64.1 to 211.93.95.254211.93.95.2558,190
236211.93.96.0/19211.93.96.1 to 211.93.127.254211.93.127.2558,190
237211.93.128.0/19211.93.128.1 to 211.93.159.254211.93.159.2558,190
238211.93.160.0/19211.93.160.1 to 211.93.191.254211.93.191.2558,190
239211.93.192.0/19211.93.192.1 to 211.93.223.254211.93.223.2558,190
240211.93.224.0/19211.93.224.1 to 211.93.255.254211.93.255.2558,190
241211.94.0.0/19211.94.0.1 to 211.94.31.254211.94.31.2558,190
242211.94.32.0/19211.94.32.1 to 211.94.63.254211.94.63.2558,190
243211.94.64.0/19211.94.64.1 to 211.94.95.254211.94.95.2558,190
244211.94.96.0/19211.94.96.1 to 211.94.127.254211.94.127.2558,190
245211.94.128.0/19211.94.128.1 to 211.94.159.254211.94.159.2558,190
246211.94.160.0/19211.94.160.1 to 211.94.191.254211.94.191.2558,190
247211.94.192.0/19211.94.192.1 to 211.94.223.254211.94.223.2558,190
248211.94.224.0/19211.94.224.1 to 211.94.255.254211.94.255.2558,190
249211.95.0.0/19211.95.0.1 to 211.95.31.254211.95.31.2558,190
250211.95.32.0/19211.95.32.1 to 211.95.63.254211.95.63.2558,190
251211.95.64.0/19211.95.64.1 to 211.95.95.254211.95.95.2558,190
252211.95.96.0/19211.95.96.1 to 211.95.127.254211.95.127.2558,190
253211.95.128.0/19211.95.128.1 to 211.95.159.254211.95.159.2558,190
254211.95.160.0/19211.95.160.1 to 211.95.191.254211.95.191.2558,190
255211.95.192.0/19211.95.192.1 to 211.95.223.254211.95.223.2558,190
256211.95.224.0/19211.95.224.1 to 211.95.255.254211.95.255.2558,190

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.