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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.

Network113.4.64.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
113.4.64.0
Broadcast address
113.4.127.255
First usable
113.4.64.1
Last usable
113.4.127.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
A (default /8)
As numbers
Hex 71044000 · Integer 1896103936 to 1896120319
Reverse DNS zones
64.4.113.in-addr.arpa
65.4.113.in-addr.arpa
66.4.113.in-addr.arpa
67.4.113.in-addr.arpa
68.4.113.in-addr.arpa
69.4.113.in-addr.arpa
70.4.113.in-addr.arpa
71.4.113.in-addr.arpa
72.4.113.in-addr.arpa
73.4.113.in-addr.arpa
74.4.113.in-addr.arpa
75.4.113.in-addr.arpa
76.4.113.in-addr.arpa
77.4.113.in-addr.arpa
78.4.113.in-addr.arpa
79.4.113.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110001.00000100.01000000.00000000113.4.64.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network01110001.00000100.01000000.00000000113.4.64.0
Broadcast01110001.00000100.01111111.11111111113.4.127.255
Split into smaller subnets/29
/19 (2)/20 (4)/21 (8)/22 (16)/23 (32)/24 (64)/25 (128)/26 (256)/27 (512)/28 (1,024)/29 (2,048)/30 (4,096)

113.4.64.0/18 makes 2,048 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1113.4.64.0/29113.4.64.1 to 113.4.64.6113.4.64.76
2113.4.64.8/29113.4.64.9 to 113.4.64.14113.4.64.156
3113.4.64.16/29113.4.64.17 to 113.4.64.22113.4.64.236
4113.4.64.24/29113.4.64.25 to 113.4.64.30113.4.64.316
5113.4.64.32/29113.4.64.33 to 113.4.64.38113.4.64.396
6113.4.64.40/29113.4.64.41 to 113.4.64.46113.4.64.476
7113.4.64.48/29113.4.64.49 to 113.4.64.54113.4.64.556
8113.4.64.56/29113.4.64.57 to 113.4.64.62113.4.64.636
9113.4.64.64/29113.4.64.65 to 113.4.64.70113.4.64.716
10113.4.64.72/29113.4.64.73 to 113.4.64.78113.4.64.796
11113.4.64.80/29113.4.64.81 to 113.4.64.86113.4.64.876
12113.4.64.88/29113.4.64.89 to 113.4.64.94113.4.64.956
13113.4.64.96/29113.4.64.97 to 113.4.64.102113.4.64.1036
14113.4.64.104/29113.4.64.105 to 113.4.64.110113.4.64.1116
15113.4.64.112/29113.4.64.113 to 113.4.64.118113.4.64.1196
16113.4.64.120/29113.4.64.121 to 113.4.64.126113.4.64.1276
17113.4.64.128/29113.4.64.129 to 113.4.64.134113.4.64.1356
18113.4.64.136/29113.4.64.137 to 113.4.64.142113.4.64.1436
19113.4.64.144/29113.4.64.145 to 113.4.64.150113.4.64.1516
20113.4.64.152/29113.4.64.153 to 113.4.64.158113.4.64.1596
21113.4.64.160/29113.4.64.161 to 113.4.64.166113.4.64.1676
22113.4.64.168/29113.4.64.169 to 113.4.64.174113.4.64.1756
23113.4.64.176/29113.4.64.177 to 113.4.64.182113.4.64.1836
24113.4.64.184/29113.4.64.185 to 113.4.64.190113.4.64.1916
25113.4.64.192/29113.4.64.193 to 113.4.64.198113.4.64.1996
26113.4.64.200/29113.4.64.201 to 113.4.64.206113.4.64.2076
27113.4.64.208/29113.4.64.209 to 113.4.64.214113.4.64.2156
28113.4.64.216/29113.4.64.217 to 113.4.64.222113.4.64.2236
29113.4.64.224/29113.4.64.225 to 113.4.64.230113.4.64.2316
30113.4.64.232/29113.4.64.233 to 113.4.64.238113.4.64.2396
31113.4.64.240/29113.4.64.241 to 113.4.64.246113.4.64.2476
32113.4.64.248/29113.4.64.249 to 113.4.64.254113.4.64.2556
33113.4.65.0/29113.4.65.1 to 113.4.65.6113.4.65.76
34113.4.65.8/29113.4.65.9 to 113.4.65.14113.4.65.156
35113.4.65.16/29113.4.65.17 to 113.4.65.22113.4.65.236
36113.4.65.24/29113.4.65.25 to 113.4.65.30113.4.65.316
37113.4.65.32/29113.4.65.33 to 113.4.65.38113.4.65.396
38113.4.65.40/29113.4.65.41 to 113.4.65.46113.4.65.476
39113.4.65.48/29113.4.65.49 to 113.4.65.54113.4.65.556
40113.4.65.56/29113.4.65.57 to 113.4.65.62113.4.65.636
41113.4.65.64/29113.4.65.65 to 113.4.65.70113.4.65.716
42113.4.65.72/29113.4.65.73 to 113.4.65.78113.4.65.796
43113.4.65.80/29113.4.65.81 to 113.4.65.86113.4.65.876
44113.4.65.88/29113.4.65.89 to 113.4.65.94113.4.65.956
45113.4.65.96/29113.4.65.97 to 113.4.65.102113.4.65.1036
46113.4.65.104/29113.4.65.105 to 113.4.65.110113.4.65.1116
47113.4.65.112/29113.4.65.113 to 113.4.65.118113.4.65.1196
48113.4.65.120/29113.4.65.121 to 113.4.65.126113.4.65.1276
49113.4.65.128/29113.4.65.129 to 113.4.65.134113.4.65.1356
50113.4.65.136/29113.4.65.137 to 113.4.65.142113.4.65.1436
51113.4.65.144/29113.4.65.145 to 113.4.65.150113.4.65.1516
52113.4.65.152/29113.4.65.153 to 113.4.65.158113.4.65.1596
53113.4.65.160/29113.4.65.161 to 113.4.65.166113.4.65.1676
54113.4.65.168/29113.4.65.169 to 113.4.65.174113.4.65.1756
55113.4.65.176/29113.4.65.177 to 113.4.65.182113.4.65.1836
56113.4.65.184/29113.4.65.185 to 113.4.65.190113.4.65.1916
57113.4.65.192/29113.4.65.193 to 113.4.65.198113.4.65.1996
58113.4.65.200/29113.4.65.201 to 113.4.65.206113.4.65.2076
59113.4.65.208/29113.4.65.209 to 113.4.65.214113.4.65.2156
60113.4.65.216/29113.4.65.217 to 113.4.65.222113.4.65.2236
61113.4.65.224/29113.4.65.225 to 113.4.65.230113.4.65.2316
62113.4.65.232/29113.4.65.233 to 113.4.65.238113.4.65.2396
63113.4.65.240/29113.4.65.241 to 113.4.65.246113.4.65.2476
64113.4.65.248/29113.4.65.249 to 113.4.65.254113.4.65.2556
65113.4.66.0/29113.4.66.1 to 113.4.66.6113.4.66.76
66113.4.66.8/29113.4.66.9 to 113.4.66.14113.4.66.156
67113.4.66.16/29113.4.66.17 to 113.4.66.22113.4.66.236
68113.4.66.24/29113.4.66.25 to 113.4.66.30113.4.66.316
69113.4.66.32/29113.4.66.33 to 113.4.66.38113.4.66.396
70113.4.66.40/29113.4.66.41 to 113.4.66.46113.4.66.476
71113.4.66.48/29113.4.66.49 to 113.4.66.54113.4.66.556
72113.4.66.56/29113.4.66.57 to 113.4.66.62113.4.66.636
73113.4.66.64/29113.4.66.65 to 113.4.66.70113.4.66.716
74113.4.66.72/29113.4.66.73 to 113.4.66.78113.4.66.796
75113.4.66.80/29113.4.66.81 to 113.4.66.86113.4.66.876
76113.4.66.88/29113.4.66.89 to 113.4.66.94113.4.66.956
77113.4.66.96/29113.4.66.97 to 113.4.66.102113.4.66.1036
78113.4.66.104/29113.4.66.105 to 113.4.66.110113.4.66.1116
79113.4.66.112/29113.4.66.113 to 113.4.66.118113.4.66.1196
80113.4.66.120/29113.4.66.121 to 113.4.66.126113.4.66.1276
81113.4.66.128/29113.4.66.129 to 113.4.66.134113.4.66.1356
82113.4.66.136/29113.4.66.137 to 113.4.66.142113.4.66.1436
83113.4.66.144/29113.4.66.145 to 113.4.66.150113.4.66.1516
84113.4.66.152/29113.4.66.153 to 113.4.66.158113.4.66.1596
85113.4.66.160/29113.4.66.161 to 113.4.66.166113.4.66.1676
86113.4.66.168/29113.4.66.169 to 113.4.66.174113.4.66.1756
87113.4.66.176/29113.4.66.177 to 113.4.66.182113.4.66.1836
88113.4.66.184/29113.4.66.185 to 113.4.66.190113.4.66.1916
89113.4.66.192/29113.4.66.193 to 113.4.66.198113.4.66.1996
90113.4.66.200/29113.4.66.201 to 113.4.66.206113.4.66.2076
91113.4.66.208/29113.4.66.209 to 113.4.66.214113.4.66.2156
92113.4.66.216/29113.4.66.217 to 113.4.66.222113.4.66.2236
93113.4.66.224/29113.4.66.225 to 113.4.66.230113.4.66.2316
94113.4.66.232/29113.4.66.233 to 113.4.66.238113.4.66.2396
95113.4.66.240/29113.4.66.241 to 113.4.66.246113.4.66.2476
96113.4.66.248/29113.4.66.249 to 113.4.66.254113.4.66.2556
97113.4.67.0/29113.4.67.1 to 113.4.67.6113.4.67.76
98113.4.67.8/29113.4.67.9 to 113.4.67.14113.4.67.156
99113.4.67.16/29113.4.67.17 to 113.4.67.22113.4.67.236
100113.4.67.24/29113.4.67.25 to 113.4.67.30113.4.67.316
101113.4.67.32/29113.4.67.33 to 113.4.67.38113.4.67.396
102113.4.67.40/29113.4.67.41 to 113.4.67.46113.4.67.476
103113.4.67.48/29113.4.67.49 to 113.4.67.54113.4.67.556
104113.4.67.56/29113.4.67.57 to 113.4.67.62113.4.67.636
105113.4.67.64/29113.4.67.65 to 113.4.67.70113.4.67.716
106113.4.67.72/29113.4.67.73 to 113.4.67.78113.4.67.796
107113.4.67.80/29113.4.67.81 to 113.4.67.86113.4.67.876
108113.4.67.88/29113.4.67.89 to 113.4.67.94113.4.67.956
109113.4.67.96/29113.4.67.97 to 113.4.67.102113.4.67.1036
110113.4.67.104/29113.4.67.105 to 113.4.67.110113.4.67.1116
111113.4.67.112/29113.4.67.113 to 113.4.67.118113.4.67.1196
112113.4.67.120/29113.4.67.121 to 113.4.67.126113.4.67.1276
113113.4.67.128/29113.4.67.129 to 113.4.67.134113.4.67.1356
114113.4.67.136/29113.4.67.137 to 113.4.67.142113.4.67.1436
115113.4.67.144/29113.4.67.145 to 113.4.67.150113.4.67.1516
116113.4.67.152/29113.4.67.153 to 113.4.67.158113.4.67.1596
117113.4.67.160/29113.4.67.161 to 113.4.67.166113.4.67.1676
118113.4.67.168/29113.4.67.169 to 113.4.67.174113.4.67.1756
119113.4.67.176/29113.4.67.177 to 113.4.67.182113.4.67.1836
120113.4.67.184/29113.4.67.185 to 113.4.67.190113.4.67.1916
121113.4.67.192/29113.4.67.193 to 113.4.67.198113.4.67.1996
122113.4.67.200/29113.4.67.201 to 113.4.67.206113.4.67.2076
123113.4.67.208/29113.4.67.209 to 113.4.67.214113.4.67.2156
124113.4.67.216/29113.4.67.217 to 113.4.67.222113.4.67.2236
125113.4.67.224/29113.4.67.225 to 113.4.67.230113.4.67.2316
126113.4.67.232/29113.4.67.233 to 113.4.67.238113.4.67.2396
127113.4.67.240/29113.4.67.241 to 113.4.67.246113.4.67.2476
128113.4.67.248/29113.4.67.249 to 113.4.67.254113.4.67.2556
129113.4.68.0/29113.4.68.1 to 113.4.68.6113.4.68.76
130113.4.68.8/29113.4.68.9 to 113.4.68.14113.4.68.156
131113.4.68.16/29113.4.68.17 to 113.4.68.22113.4.68.236
132113.4.68.24/29113.4.68.25 to 113.4.68.30113.4.68.316
133113.4.68.32/29113.4.68.33 to 113.4.68.38113.4.68.396
134113.4.68.40/29113.4.68.41 to 113.4.68.46113.4.68.476
135113.4.68.48/29113.4.68.49 to 113.4.68.54113.4.68.556
136113.4.68.56/29113.4.68.57 to 113.4.68.62113.4.68.636
137113.4.68.64/29113.4.68.65 to 113.4.68.70113.4.68.716
138113.4.68.72/29113.4.68.73 to 113.4.68.78113.4.68.796
139113.4.68.80/29113.4.68.81 to 113.4.68.86113.4.68.876
140113.4.68.88/29113.4.68.89 to 113.4.68.94113.4.68.956
141113.4.68.96/29113.4.68.97 to 113.4.68.102113.4.68.1036
142113.4.68.104/29113.4.68.105 to 113.4.68.110113.4.68.1116
143113.4.68.112/29113.4.68.113 to 113.4.68.118113.4.68.1196
144113.4.68.120/29113.4.68.121 to 113.4.68.126113.4.68.1276
145113.4.68.128/29113.4.68.129 to 113.4.68.134113.4.68.1356
146113.4.68.136/29113.4.68.137 to 113.4.68.142113.4.68.1436
147113.4.68.144/29113.4.68.145 to 113.4.68.150113.4.68.1516
148113.4.68.152/29113.4.68.153 to 113.4.68.158113.4.68.1596
149113.4.68.160/29113.4.68.161 to 113.4.68.166113.4.68.1676
150113.4.68.168/29113.4.68.169 to 113.4.68.174113.4.68.1756
151113.4.68.176/29113.4.68.177 to 113.4.68.182113.4.68.1836
152113.4.68.184/29113.4.68.185 to 113.4.68.190113.4.68.1916
153113.4.68.192/29113.4.68.193 to 113.4.68.198113.4.68.1996
154113.4.68.200/29113.4.68.201 to 113.4.68.206113.4.68.2076
155113.4.68.208/29113.4.68.209 to 113.4.68.214113.4.68.2156
156113.4.68.216/29113.4.68.217 to 113.4.68.222113.4.68.2236
157113.4.68.224/29113.4.68.225 to 113.4.68.230113.4.68.2316
158113.4.68.232/29113.4.68.233 to 113.4.68.238113.4.68.2396
159113.4.68.240/29113.4.68.241 to 113.4.68.246113.4.68.2476
160113.4.68.248/29113.4.68.249 to 113.4.68.254113.4.68.2556
161113.4.69.0/29113.4.69.1 to 113.4.69.6113.4.69.76
162113.4.69.8/29113.4.69.9 to 113.4.69.14113.4.69.156
163113.4.69.16/29113.4.69.17 to 113.4.69.22113.4.69.236
164113.4.69.24/29113.4.69.25 to 113.4.69.30113.4.69.316
165113.4.69.32/29113.4.69.33 to 113.4.69.38113.4.69.396
166113.4.69.40/29113.4.69.41 to 113.4.69.46113.4.69.476
167113.4.69.48/29113.4.69.49 to 113.4.69.54113.4.69.556
168113.4.69.56/29113.4.69.57 to 113.4.69.62113.4.69.636
169113.4.69.64/29113.4.69.65 to 113.4.69.70113.4.69.716
170113.4.69.72/29113.4.69.73 to 113.4.69.78113.4.69.796
171113.4.69.80/29113.4.69.81 to 113.4.69.86113.4.69.876
172113.4.69.88/29113.4.69.89 to 113.4.69.94113.4.69.956
173113.4.69.96/29113.4.69.97 to 113.4.69.102113.4.69.1036
174113.4.69.104/29113.4.69.105 to 113.4.69.110113.4.69.1116
175113.4.69.112/29113.4.69.113 to 113.4.69.118113.4.69.1196
176113.4.69.120/29113.4.69.121 to 113.4.69.126113.4.69.1276
177113.4.69.128/29113.4.69.129 to 113.4.69.134113.4.69.1356
178113.4.69.136/29113.4.69.137 to 113.4.69.142113.4.69.1436
179113.4.69.144/29113.4.69.145 to 113.4.69.150113.4.69.1516
180113.4.69.152/29113.4.69.153 to 113.4.69.158113.4.69.1596
181113.4.69.160/29113.4.69.161 to 113.4.69.166113.4.69.1676
182113.4.69.168/29113.4.69.169 to 113.4.69.174113.4.69.1756
183113.4.69.176/29113.4.69.177 to 113.4.69.182113.4.69.1836
184113.4.69.184/29113.4.69.185 to 113.4.69.190113.4.69.1916
185113.4.69.192/29113.4.69.193 to 113.4.69.198113.4.69.1996
186113.4.69.200/29113.4.69.201 to 113.4.69.206113.4.69.2076
187113.4.69.208/29113.4.69.209 to 113.4.69.214113.4.69.2156
188113.4.69.216/29113.4.69.217 to 113.4.69.222113.4.69.2236
189113.4.69.224/29113.4.69.225 to 113.4.69.230113.4.69.2316
190113.4.69.232/29113.4.69.233 to 113.4.69.238113.4.69.2396
191113.4.69.240/29113.4.69.241 to 113.4.69.246113.4.69.2476
192113.4.69.248/29113.4.69.249 to 113.4.69.254113.4.69.2556
193113.4.70.0/29113.4.70.1 to 113.4.70.6113.4.70.76
194113.4.70.8/29113.4.70.9 to 113.4.70.14113.4.70.156
195113.4.70.16/29113.4.70.17 to 113.4.70.22113.4.70.236
196113.4.70.24/29113.4.70.25 to 113.4.70.30113.4.70.316
197113.4.70.32/29113.4.70.33 to 113.4.70.38113.4.70.396
198113.4.70.40/29113.4.70.41 to 113.4.70.46113.4.70.476
199113.4.70.48/29113.4.70.49 to 113.4.70.54113.4.70.556
200113.4.70.56/29113.4.70.57 to 113.4.70.62113.4.70.636
201113.4.70.64/29113.4.70.65 to 113.4.70.70113.4.70.716
202113.4.70.72/29113.4.70.73 to 113.4.70.78113.4.70.796
203113.4.70.80/29113.4.70.81 to 113.4.70.86113.4.70.876
204113.4.70.88/29113.4.70.89 to 113.4.70.94113.4.70.956
205113.4.70.96/29113.4.70.97 to 113.4.70.102113.4.70.1036
206113.4.70.104/29113.4.70.105 to 113.4.70.110113.4.70.1116
207113.4.70.112/29113.4.70.113 to 113.4.70.118113.4.70.1196
208113.4.70.120/29113.4.70.121 to 113.4.70.126113.4.70.1276
209113.4.70.128/29113.4.70.129 to 113.4.70.134113.4.70.1356
210113.4.70.136/29113.4.70.137 to 113.4.70.142113.4.70.1436
211113.4.70.144/29113.4.70.145 to 113.4.70.150113.4.70.1516
212113.4.70.152/29113.4.70.153 to 113.4.70.158113.4.70.1596
213113.4.70.160/29113.4.70.161 to 113.4.70.166113.4.70.1676
214113.4.70.168/29113.4.70.169 to 113.4.70.174113.4.70.1756
215113.4.70.176/29113.4.70.177 to 113.4.70.182113.4.70.1836
216113.4.70.184/29113.4.70.185 to 113.4.70.190113.4.70.1916
217113.4.70.192/29113.4.70.193 to 113.4.70.198113.4.70.1996
218113.4.70.200/29113.4.70.201 to 113.4.70.206113.4.70.2076
219113.4.70.208/29113.4.70.209 to 113.4.70.214113.4.70.2156
220113.4.70.216/29113.4.70.217 to 113.4.70.222113.4.70.2236
221113.4.70.224/29113.4.70.225 to 113.4.70.230113.4.70.2316
222113.4.70.232/29113.4.70.233 to 113.4.70.238113.4.70.2396
223113.4.70.240/29113.4.70.241 to 113.4.70.246113.4.70.2476
224113.4.70.248/29113.4.70.249 to 113.4.70.254113.4.70.2556
225113.4.71.0/29113.4.71.1 to 113.4.71.6113.4.71.76
226113.4.71.8/29113.4.71.9 to 113.4.71.14113.4.71.156
227113.4.71.16/29113.4.71.17 to 113.4.71.22113.4.71.236
228113.4.71.24/29113.4.71.25 to 113.4.71.30113.4.71.316
229113.4.71.32/29113.4.71.33 to 113.4.71.38113.4.71.396
230113.4.71.40/29113.4.71.41 to 113.4.71.46113.4.71.476
231113.4.71.48/29113.4.71.49 to 113.4.71.54113.4.71.556
232113.4.71.56/29113.4.71.57 to 113.4.71.62113.4.71.636
233113.4.71.64/29113.4.71.65 to 113.4.71.70113.4.71.716
234113.4.71.72/29113.4.71.73 to 113.4.71.78113.4.71.796
235113.4.71.80/29113.4.71.81 to 113.4.71.86113.4.71.876
236113.4.71.88/29113.4.71.89 to 113.4.71.94113.4.71.956
237113.4.71.96/29113.4.71.97 to 113.4.71.102113.4.71.1036
238113.4.71.104/29113.4.71.105 to 113.4.71.110113.4.71.1116
239113.4.71.112/29113.4.71.113 to 113.4.71.118113.4.71.1196
240113.4.71.120/29113.4.71.121 to 113.4.71.126113.4.71.1276
241113.4.71.128/29113.4.71.129 to 113.4.71.134113.4.71.1356
242113.4.71.136/29113.4.71.137 to 113.4.71.142113.4.71.1436
243113.4.71.144/29113.4.71.145 to 113.4.71.150113.4.71.1516
244113.4.71.152/29113.4.71.153 to 113.4.71.158113.4.71.1596
245113.4.71.160/29113.4.71.161 to 113.4.71.166113.4.71.1676
246113.4.71.168/29113.4.71.169 to 113.4.71.174113.4.71.1756
247113.4.71.176/29113.4.71.177 to 113.4.71.182113.4.71.1836
248113.4.71.184/29113.4.71.185 to 113.4.71.190113.4.71.1916
249113.4.71.192/29113.4.71.193 to 113.4.71.198113.4.71.1996
250113.4.71.200/29113.4.71.201 to 113.4.71.206113.4.71.2076
251113.4.71.208/29113.4.71.209 to 113.4.71.214113.4.71.2156
252113.4.71.216/29113.4.71.217 to 113.4.71.222113.4.71.2236
253113.4.71.224/29113.4.71.225 to 113.4.71.230113.4.71.2316
254113.4.71.232/29113.4.71.233 to 113.4.71.238113.4.71.2396
255113.4.71.240/29113.4.71.241 to 113.4.71.246113.4.71.2476
256113.4.71.248/29113.4.71.249 to 113.4.71.254113.4.71.2556

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.