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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.

Network248.77.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
248.77.64.0
Broadcast address
248.77.95.255
First usable
248.77.64.1
Last usable
248.77.95.254
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
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F84D4000 · Integer 4165812224 to 4165820415
Reverse DNS zones
64.77.248.in-addr.arpa
65.77.248.in-addr.arpa
66.77.248.in-addr.arpa
67.77.248.in-addr.arpa
68.77.248.in-addr.arpa
69.77.248.in-addr.arpa
70.77.248.in-addr.arpa
71.77.248.in-addr.arpa
72.77.248.in-addr.arpa
73.77.248.in-addr.arpa
74.77.248.in-addr.arpa
75.77.248.in-addr.arpa
76.77.248.in-addr.arpa
77.77.248.in-addr.arpa
78.77.248.in-addr.arpa
79.77.248.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
Address11111000.01001101.01000000.00000000248.77.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network11111000.01001101.01000000.00000000248.77.64.0
Broadcast11111000.01001101.01011111.11111111248.77.95.255
Split into smaller subnets/27
/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)

248.77.64.0/19 makes 256 subnets of /27.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1248.77.64.0/27248.77.64.1 to 248.77.64.30248.77.64.3130
2248.77.64.32/27248.77.64.33 to 248.77.64.62248.77.64.6330
3248.77.64.64/27248.77.64.65 to 248.77.64.94248.77.64.9530
4248.77.64.96/27248.77.64.97 to 248.77.64.126248.77.64.12730
5248.77.64.128/27248.77.64.129 to 248.77.64.158248.77.64.15930
6248.77.64.160/27248.77.64.161 to 248.77.64.190248.77.64.19130
7248.77.64.192/27248.77.64.193 to 248.77.64.222248.77.64.22330
8248.77.64.224/27248.77.64.225 to 248.77.64.254248.77.64.25530
9248.77.65.0/27248.77.65.1 to 248.77.65.30248.77.65.3130
10248.77.65.32/27248.77.65.33 to 248.77.65.62248.77.65.6330
11248.77.65.64/27248.77.65.65 to 248.77.65.94248.77.65.9530
12248.77.65.96/27248.77.65.97 to 248.77.65.126248.77.65.12730
13248.77.65.128/27248.77.65.129 to 248.77.65.158248.77.65.15930
14248.77.65.160/27248.77.65.161 to 248.77.65.190248.77.65.19130
15248.77.65.192/27248.77.65.193 to 248.77.65.222248.77.65.22330
16248.77.65.224/27248.77.65.225 to 248.77.65.254248.77.65.25530
17248.77.66.0/27248.77.66.1 to 248.77.66.30248.77.66.3130
18248.77.66.32/27248.77.66.33 to 248.77.66.62248.77.66.6330
19248.77.66.64/27248.77.66.65 to 248.77.66.94248.77.66.9530
20248.77.66.96/27248.77.66.97 to 248.77.66.126248.77.66.12730
21248.77.66.128/27248.77.66.129 to 248.77.66.158248.77.66.15930
22248.77.66.160/27248.77.66.161 to 248.77.66.190248.77.66.19130
23248.77.66.192/27248.77.66.193 to 248.77.66.222248.77.66.22330
24248.77.66.224/27248.77.66.225 to 248.77.66.254248.77.66.25530
25248.77.67.0/27248.77.67.1 to 248.77.67.30248.77.67.3130
26248.77.67.32/27248.77.67.33 to 248.77.67.62248.77.67.6330
27248.77.67.64/27248.77.67.65 to 248.77.67.94248.77.67.9530
28248.77.67.96/27248.77.67.97 to 248.77.67.126248.77.67.12730
29248.77.67.128/27248.77.67.129 to 248.77.67.158248.77.67.15930
30248.77.67.160/27248.77.67.161 to 248.77.67.190248.77.67.19130
31248.77.67.192/27248.77.67.193 to 248.77.67.222248.77.67.22330
32248.77.67.224/27248.77.67.225 to 248.77.67.254248.77.67.25530
33248.77.68.0/27248.77.68.1 to 248.77.68.30248.77.68.3130
34248.77.68.32/27248.77.68.33 to 248.77.68.62248.77.68.6330
35248.77.68.64/27248.77.68.65 to 248.77.68.94248.77.68.9530
36248.77.68.96/27248.77.68.97 to 248.77.68.126248.77.68.12730
37248.77.68.128/27248.77.68.129 to 248.77.68.158248.77.68.15930
38248.77.68.160/27248.77.68.161 to 248.77.68.190248.77.68.19130
39248.77.68.192/27248.77.68.193 to 248.77.68.222248.77.68.22330
40248.77.68.224/27248.77.68.225 to 248.77.68.254248.77.68.25530
41248.77.69.0/27248.77.69.1 to 248.77.69.30248.77.69.3130
42248.77.69.32/27248.77.69.33 to 248.77.69.62248.77.69.6330
43248.77.69.64/27248.77.69.65 to 248.77.69.94248.77.69.9530
44248.77.69.96/27248.77.69.97 to 248.77.69.126248.77.69.12730
45248.77.69.128/27248.77.69.129 to 248.77.69.158248.77.69.15930
46248.77.69.160/27248.77.69.161 to 248.77.69.190248.77.69.19130
47248.77.69.192/27248.77.69.193 to 248.77.69.222248.77.69.22330
48248.77.69.224/27248.77.69.225 to 248.77.69.254248.77.69.25530
49248.77.70.0/27248.77.70.1 to 248.77.70.30248.77.70.3130
50248.77.70.32/27248.77.70.33 to 248.77.70.62248.77.70.6330
51248.77.70.64/27248.77.70.65 to 248.77.70.94248.77.70.9530
52248.77.70.96/27248.77.70.97 to 248.77.70.126248.77.70.12730
53248.77.70.128/27248.77.70.129 to 248.77.70.158248.77.70.15930
54248.77.70.160/27248.77.70.161 to 248.77.70.190248.77.70.19130
55248.77.70.192/27248.77.70.193 to 248.77.70.222248.77.70.22330
56248.77.70.224/27248.77.70.225 to 248.77.70.254248.77.70.25530
57248.77.71.0/27248.77.71.1 to 248.77.71.30248.77.71.3130
58248.77.71.32/27248.77.71.33 to 248.77.71.62248.77.71.6330
59248.77.71.64/27248.77.71.65 to 248.77.71.94248.77.71.9530
60248.77.71.96/27248.77.71.97 to 248.77.71.126248.77.71.12730
61248.77.71.128/27248.77.71.129 to 248.77.71.158248.77.71.15930
62248.77.71.160/27248.77.71.161 to 248.77.71.190248.77.71.19130
63248.77.71.192/27248.77.71.193 to 248.77.71.222248.77.71.22330
64248.77.71.224/27248.77.71.225 to 248.77.71.254248.77.71.25530
65248.77.72.0/27248.77.72.1 to 248.77.72.30248.77.72.3130
66248.77.72.32/27248.77.72.33 to 248.77.72.62248.77.72.6330
67248.77.72.64/27248.77.72.65 to 248.77.72.94248.77.72.9530
68248.77.72.96/27248.77.72.97 to 248.77.72.126248.77.72.12730
69248.77.72.128/27248.77.72.129 to 248.77.72.158248.77.72.15930
70248.77.72.160/27248.77.72.161 to 248.77.72.190248.77.72.19130
71248.77.72.192/27248.77.72.193 to 248.77.72.222248.77.72.22330
72248.77.72.224/27248.77.72.225 to 248.77.72.254248.77.72.25530
73248.77.73.0/27248.77.73.1 to 248.77.73.30248.77.73.3130
74248.77.73.32/27248.77.73.33 to 248.77.73.62248.77.73.6330
75248.77.73.64/27248.77.73.65 to 248.77.73.94248.77.73.9530
76248.77.73.96/27248.77.73.97 to 248.77.73.126248.77.73.12730
77248.77.73.128/27248.77.73.129 to 248.77.73.158248.77.73.15930
78248.77.73.160/27248.77.73.161 to 248.77.73.190248.77.73.19130
79248.77.73.192/27248.77.73.193 to 248.77.73.222248.77.73.22330
80248.77.73.224/27248.77.73.225 to 248.77.73.254248.77.73.25530
81248.77.74.0/27248.77.74.1 to 248.77.74.30248.77.74.3130
82248.77.74.32/27248.77.74.33 to 248.77.74.62248.77.74.6330
83248.77.74.64/27248.77.74.65 to 248.77.74.94248.77.74.9530
84248.77.74.96/27248.77.74.97 to 248.77.74.126248.77.74.12730
85248.77.74.128/27248.77.74.129 to 248.77.74.158248.77.74.15930
86248.77.74.160/27248.77.74.161 to 248.77.74.190248.77.74.19130
87248.77.74.192/27248.77.74.193 to 248.77.74.222248.77.74.22330
88248.77.74.224/27248.77.74.225 to 248.77.74.254248.77.74.25530
89248.77.75.0/27248.77.75.1 to 248.77.75.30248.77.75.3130
90248.77.75.32/27248.77.75.33 to 248.77.75.62248.77.75.6330
91248.77.75.64/27248.77.75.65 to 248.77.75.94248.77.75.9530
92248.77.75.96/27248.77.75.97 to 248.77.75.126248.77.75.12730
93248.77.75.128/27248.77.75.129 to 248.77.75.158248.77.75.15930
94248.77.75.160/27248.77.75.161 to 248.77.75.190248.77.75.19130
95248.77.75.192/27248.77.75.193 to 248.77.75.222248.77.75.22330
96248.77.75.224/27248.77.75.225 to 248.77.75.254248.77.75.25530
97248.77.76.0/27248.77.76.1 to 248.77.76.30248.77.76.3130
98248.77.76.32/27248.77.76.33 to 248.77.76.62248.77.76.6330
99248.77.76.64/27248.77.76.65 to 248.77.76.94248.77.76.9530
100248.77.76.96/27248.77.76.97 to 248.77.76.126248.77.76.12730
101248.77.76.128/27248.77.76.129 to 248.77.76.158248.77.76.15930
102248.77.76.160/27248.77.76.161 to 248.77.76.190248.77.76.19130
103248.77.76.192/27248.77.76.193 to 248.77.76.222248.77.76.22330
104248.77.76.224/27248.77.76.225 to 248.77.76.254248.77.76.25530
105248.77.77.0/27248.77.77.1 to 248.77.77.30248.77.77.3130
106248.77.77.32/27248.77.77.33 to 248.77.77.62248.77.77.6330
107248.77.77.64/27248.77.77.65 to 248.77.77.94248.77.77.9530
108248.77.77.96/27248.77.77.97 to 248.77.77.126248.77.77.12730
109248.77.77.128/27248.77.77.129 to 248.77.77.158248.77.77.15930
110248.77.77.160/27248.77.77.161 to 248.77.77.190248.77.77.19130
111248.77.77.192/27248.77.77.193 to 248.77.77.222248.77.77.22330
112248.77.77.224/27248.77.77.225 to 248.77.77.254248.77.77.25530
113248.77.78.0/27248.77.78.1 to 248.77.78.30248.77.78.3130
114248.77.78.32/27248.77.78.33 to 248.77.78.62248.77.78.6330
115248.77.78.64/27248.77.78.65 to 248.77.78.94248.77.78.9530
116248.77.78.96/27248.77.78.97 to 248.77.78.126248.77.78.12730
117248.77.78.128/27248.77.78.129 to 248.77.78.158248.77.78.15930
118248.77.78.160/27248.77.78.161 to 248.77.78.190248.77.78.19130
119248.77.78.192/27248.77.78.193 to 248.77.78.222248.77.78.22330
120248.77.78.224/27248.77.78.225 to 248.77.78.254248.77.78.25530
121248.77.79.0/27248.77.79.1 to 248.77.79.30248.77.79.3130
122248.77.79.32/27248.77.79.33 to 248.77.79.62248.77.79.6330
123248.77.79.64/27248.77.79.65 to 248.77.79.94248.77.79.9530
124248.77.79.96/27248.77.79.97 to 248.77.79.126248.77.79.12730
125248.77.79.128/27248.77.79.129 to 248.77.79.158248.77.79.15930
126248.77.79.160/27248.77.79.161 to 248.77.79.190248.77.79.19130
127248.77.79.192/27248.77.79.193 to 248.77.79.222248.77.79.22330
128248.77.79.224/27248.77.79.225 to 248.77.79.254248.77.79.25530
129248.77.80.0/27248.77.80.1 to 248.77.80.30248.77.80.3130
130248.77.80.32/27248.77.80.33 to 248.77.80.62248.77.80.6330
131248.77.80.64/27248.77.80.65 to 248.77.80.94248.77.80.9530
132248.77.80.96/27248.77.80.97 to 248.77.80.126248.77.80.12730
133248.77.80.128/27248.77.80.129 to 248.77.80.158248.77.80.15930
134248.77.80.160/27248.77.80.161 to 248.77.80.190248.77.80.19130
135248.77.80.192/27248.77.80.193 to 248.77.80.222248.77.80.22330
136248.77.80.224/27248.77.80.225 to 248.77.80.254248.77.80.25530
137248.77.81.0/27248.77.81.1 to 248.77.81.30248.77.81.3130
138248.77.81.32/27248.77.81.33 to 248.77.81.62248.77.81.6330
139248.77.81.64/27248.77.81.65 to 248.77.81.94248.77.81.9530
140248.77.81.96/27248.77.81.97 to 248.77.81.126248.77.81.12730
141248.77.81.128/27248.77.81.129 to 248.77.81.158248.77.81.15930
142248.77.81.160/27248.77.81.161 to 248.77.81.190248.77.81.19130
143248.77.81.192/27248.77.81.193 to 248.77.81.222248.77.81.22330
144248.77.81.224/27248.77.81.225 to 248.77.81.254248.77.81.25530
145248.77.82.0/27248.77.82.1 to 248.77.82.30248.77.82.3130
146248.77.82.32/27248.77.82.33 to 248.77.82.62248.77.82.6330
147248.77.82.64/27248.77.82.65 to 248.77.82.94248.77.82.9530
148248.77.82.96/27248.77.82.97 to 248.77.82.126248.77.82.12730
149248.77.82.128/27248.77.82.129 to 248.77.82.158248.77.82.15930
150248.77.82.160/27248.77.82.161 to 248.77.82.190248.77.82.19130
151248.77.82.192/27248.77.82.193 to 248.77.82.222248.77.82.22330
152248.77.82.224/27248.77.82.225 to 248.77.82.254248.77.82.25530
153248.77.83.0/27248.77.83.1 to 248.77.83.30248.77.83.3130
154248.77.83.32/27248.77.83.33 to 248.77.83.62248.77.83.6330
155248.77.83.64/27248.77.83.65 to 248.77.83.94248.77.83.9530
156248.77.83.96/27248.77.83.97 to 248.77.83.126248.77.83.12730
157248.77.83.128/27248.77.83.129 to 248.77.83.158248.77.83.15930
158248.77.83.160/27248.77.83.161 to 248.77.83.190248.77.83.19130
159248.77.83.192/27248.77.83.193 to 248.77.83.222248.77.83.22330
160248.77.83.224/27248.77.83.225 to 248.77.83.254248.77.83.25530
161248.77.84.0/27248.77.84.1 to 248.77.84.30248.77.84.3130
162248.77.84.32/27248.77.84.33 to 248.77.84.62248.77.84.6330
163248.77.84.64/27248.77.84.65 to 248.77.84.94248.77.84.9530
164248.77.84.96/27248.77.84.97 to 248.77.84.126248.77.84.12730
165248.77.84.128/27248.77.84.129 to 248.77.84.158248.77.84.15930
166248.77.84.160/27248.77.84.161 to 248.77.84.190248.77.84.19130
167248.77.84.192/27248.77.84.193 to 248.77.84.222248.77.84.22330
168248.77.84.224/27248.77.84.225 to 248.77.84.254248.77.84.25530
169248.77.85.0/27248.77.85.1 to 248.77.85.30248.77.85.3130
170248.77.85.32/27248.77.85.33 to 248.77.85.62248.77.85.6330
171248.77.85.64/27248.77.85.65 to 248.77.85.94248.77.85.9530
172248.77.85.96/27248.77.85.97 to 248.77.85.126248.77.85.12730
173248.77.85.128/27248.77.85.129 to 248.77.85.158248.77.85.15930
174248.77.85.160/27248.77.85.161 to 248.77.85.190248.77.85.19130
175248.77.85.192/27248.77.85.193 to 248.77.85.222248.77.85.22330
176248.77.85.224/27248.77.85.225 to 248.77.85.254248.77.85.25530
177248.77.86.0/27248.77.86.1 to 248.77.86.30248.77.86.3130
178248.77.86.32/27248.77.86.33 to 248.77.86.62248.77.86.6330
179248.77.86.64/27248.77.86.65 to 248.77.86.94248.77.86.9530
180248.77.86.96/27248.77.86.97 to 248.77.86.126248.77.86.12730
181248.77.86.128/27248.77.86.129 to 248.77.86.158248.77.86.15930
182248.77.86.160/27248.77.86.161 to 248.77.86.190248.77.86.19130
183248.77.86.192/27248.77.86.193 to 248.77.86.222248.77.86.22330
184248.77.86.224/27248.77.86.225 to 248.77.86.254248.77.86.25530
185248.77.87.0/27248.77.87.1 to 248.77.87.30248.77.87.3130
186248.77.87.32/27248.77.87.33 to 248.77.87.62248.77.87.6330
187248.77.87.64/27248.77.87.65 to 248.77.87.94248.77.87.9530
188248.77.87.96/27248.77.87.97 to 248.77.87.126248.77.87.12730
189248.77.87.128/27248.77.87.129 to 248.77.87.158248.77.87.15930
190248.77.87.160/27248.77.87.161 to 248.77.87.190248.77.87.19130
191248.77.87.192/27248.77.87.193 to 248.77.87.222248.77.87.22330
192248.77.87.224/27248.77.87.225 to 248.77.87.254248.77.87.25530
193248.77.88.0/27248.77.88.1 to 248.77.88.30248.77.88.3130
194248.77.88.32/27248.77.88.33 to 248.77.88.62248.77.88.6330
195248.77.88.64/27248.77.88.65 to 248.77.88.94248.77.88.9530
196248.77.88.96/27248.77.88.97 to 248.77.88.126248.77.88.12730
197248.77.88.128/27248.77.88.129 to 248.77.88.158248.77.88.15930
198248.77.88.160/27248.77.88.161 to 248.77.88.190248.77.88.19130
199248.77.88.192/27248.77.88.193 to 248.77.88.222248.77.88.22330
200248.77.88.224/27248.77.88.225 to 248.77.88.254248.77.88.25530
201248.77.89.0/27248.77.89.1 to 248.77.89.30248.77.89.3130
202248.77.89.32/27248.77.89.33 to 248.77.89.62248.77.89.6330
203248.77.89.64/27248.77.89.65 to 248.77.89.94248.77.89.9530
204248.77.89.96/27248.77.89.97 to 248.77.89.126248.77.89.12730
205248.77.89.128/27248.77.89.129 to 248.77.89.158248.77.89.15930
206248.77.89.160/27248.77.89.161 to 248.77.89.190248.77.89.19130
207248.77.89.192/27248.77.89.193 to 248.77.89.222248.77.89.22330
208248.77.89.224/27248.77.89.225 to 248.77.89.254248.77.89.25530
209248.77.90.0/27248.77.90.1 to 248.77.90.30248.77.90.3130
210248.77.90.32/27248.77.90.33 to 248.77.90.62248.77.90.6330
211248.77.90.64/27248.77.90.65 to 248.77.90.94248.77.90.9530
212248.77.90.96/27248.77.90.97 to 248.77.90.126248.77.90.12730
213248.77.90.128/27248.77.90.129 to 248.77.90.158248.77.90.15930
214248.77.90.160/27248.77.90.161 to 248.77.90.190248.77.90.19130
215248.77.90.192/27248.77.90.193 to 248.77.90.222248.77.90.22330
216248.77.90.224/27248.77.90.225 to 248.77.90.254248.77.90.25530
217248.77.91.0/27248.77.91.1 to 248.77.91.30248.77.91.3130
218248.77.91.32/27248.77.91.33 to 248.77.91.62248.77.91.6330
219248.77.91.64/27248.77.91.65 to 248.77.91.94248.77.91.9530
220248.77.91.96/27248.77.91.97 to 248.77.91.126248.77.91.12730
221248.77.91.128/27248.77.91.129 to 248.77.91.158248.77.91.15930
222248.77.91.160/27248.77.91.161 to 248.77.91.190248.77.91.19130
223248.77.91.192/27248.77.91.193 to 248.77.91.222248.77.91.22330
224248.77.91.224/27248.77.91.225 to 248.77.91.254248.77.91.25530
225248.77.92.0/27248.77.92.1 to 248.77.92.30248.77.92.3130
226248.77.92.32/27248.77.92.33 to 248.77.92.62248.77.92.6330
227248.77.92.64/27248.77.92.65 to 248.77.92.94248.77.92.9530
228248.77.92.96/27248.77.92.97 to 248.77.92.126248.77.92.12730
229248.77.92.128/27248.77.92.129 to 248.77.92.158248.77.92.15930
230248.77.92.160/27248.77.92.161 to 248.77.92.190248.77.92.19130
231248.77.92.192/27248.77.92.193 to 248.77.92.222248.77.92.22330
232248.77.92.224/27248.77.92.225 to 248.77.92.254248.77.92.25530
233248.77.93.0/27248.77.93.1 to 248.77.93.30248.77.93.3130
234248.77.93.32/27248.77.93.33 to 248.77.93.62248.77.93.6330
235248.77.93.64/27248.77.93.65 to 248.77.93.94248.77.93.9530
236248.77.93.96/27248.77.93.97 to 248.77.93.126248.77.93.12730
237248.77.93.128/27248.77.93.129 to 248.77.93.158248.77.93.15930
238248.77.93.160/27248.77.93.161 to 248.77.93.190248.77.93.19130
239248.77.93.192/27248.77.93.193 to 248.77.93.222248.77.93.22330
240248.77.93.224/27248.77.93.225 to 248.77.93.254248.77.93.25530
241248.77.94.0/27248.77.94.1 to 248.77.94.30248.77.94.3130
242248.77.94.32/27248.77.94.33 to 248.77.94.62248.77.94.6330
243248.77.94.64/27248.77.94.65 to 248.77.94.94248.77.94.9530
244248.77.94.96/27248.77.94.97 to 248.77.94.126248.77.94.12730
245248.77.94.128/27248.77.94.129 to 248.77.94.158248.77.94.15930
246248.77.94.160/27248.77.94.161 to 248.77.94.190248.77.94.19130
247248.77.94.192/27248.77.94.193 to 248.77.94.222248.77.94.22330
248248.77.94.224/27248.77.94.225 to 248.77.94.254248.77.94.25530
249248.77.95.0/27248.77.95.1 to 248.77.95.30248.77.95.3130
250248.77.95.32/27248.77.95.33 to 248.77.95.62248.77.95.6330
251248.77.95.64/27248.77.95.65 to 248.77.95.94248.77.95.9530
252248.77.95.96/27248.77.95.97 to 248.77.95.126248.77.95.12730
253248.77.95.128/27248.77.95.129 to 248.77.95.158248.77.95.15930
254248.77.95.160/27248.77.95.161 to 248.77.95.190248.77.95.19130
255248.77.95.192/27248.77.95.193 to 248.77.95.222248.77.95.22330
256248.77.95.224/27248.77.95.225 to 248.77.95.254248.77.95.25530

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.