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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.

Network160.3.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
160.3.0.0
Broadcast address
160.3.63.255
First usable
160.3.0.1
Last usable
160.3.63.254
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
B (default /16)
As numbers
Hex A0030000 · Integer 2684551168 to 2684567551
Reverse DNS zones
0.3.160.in-addr.arpa
1.3.160.in-addr.arpa
2.3.160.in-addr.arpa
3.3.160.in-addr.arpa
4.3.160.in-addr.arpa
5.3.160.in-addr.arpa
6.3.160.in-addr.arpa
7.3.160.in-addr.arpa
8.3.160.in-addr.arpa
9.3.160.in-addr.arpa
10.3.160.in-addr.arpa
11.3.160.in-addr.arpa
12.3.160.in-addr.arpa
13.3.160.in-addr.arpa
14.3.160.in-addr.arpa
15.3.160.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
Address10100000.00000011.00000000.00000000160.3.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network10100000.00000011.00000000.00000000160.3.0.0
Broadcast10100000.00000011.00111111.11111111160.3.63.255
Split into smaller subnets/30
/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)

160.3.0.0/18 makes 4,096 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1160.3.0.0/30160.3.0.1 to 160.3.0.2160.3.0.32
2160.3.0.4/30160.3.0.5 to 160.3.0.6160.3.0.72
3160.3.0.8/30160.3.0.9 to 160.3.0.10160.3.0.112
4160.3.0.12/30160.3.0.13 to 160.3.0.14160.3.0.152
5160.3.0.16/30160.3.0.17 to 160.3.0.18160.3.0.192
6160.3.0.20/30160.3.0.21 to 160.3.0.22160.3.0.232
7160.3.0.24/30160.3.0.25 to 160.3.0.26160.3.0.272
8160.3.0.28/30160.3.0.29 to 160.3.0.30160.3.0.312
9160.3.0.32/30160.3.0.33 to 160.3.0.34160.3.0.352
10160.3.0.36/30160.3.0.37 to 160.3.0.38160.3.0.392
11160.3.0.40/30160.3.0.41 to 160.3.0.42160.3.0.432
12160.3.0.44/30160.3.0.45 to 160.3.0.46160.3.0.472
13160.3.0.48/30160.3.0.49 to 160.3.0.50160.3.0.512
14160.3.0.52/30160.3.0.53 to 160.3.0.54160.3.0.552
15160.3.0.56/30160.3.0.57 to 160.3.0.58160.3.0.592
16160.3.0.60/30160.3.0.61 to 160.3.0.62160.3.0.632
17160.3.0.64/30160.3.0.65 to 160.3.0.66160.3.0.672
18160.3.0.68/30160.3.0.69 to 160.3.0.70160.3.0.712
19160.3.0.72/30160.3.0.73 to 160.3.0.74160.3.0.752
20160.3.0.76/30160.3.0.77 to 160.3.0.78160.3.0.792
21160.3.0.80/30160.3.0.81 to 160.3.0.82160.3.0.832
22160.3.0.84/30160.3.0.85 to 160.3.0.86160.3.0.872
23160.3.0.88/30160.3.0.89 to 160.3.0.90160.3.0.912
24160.3.0.92/30160.3.0.93 to 160.3.0.94160.3.0.952
25160.3.0.96/30160.3.0.97 to 160.3.0.98160.3.0.992
26160.3.0.100/30160.3.0.101 to 160.3.0.102160.3.0.1032
27160.3.0.104/30160.3.0.105 to 160.3.0.106160.3.0.1072
28160.3.0.108/30160.3.0.109 to 160.3.0.110160.3.0.1112
29160.3.0.112/30160.3.0.113 to 160.3.0.114160.3.0.1152
30160.3.0.116/30160.3.0.117 to 160.3.0.118160.3.0.1192
31160.3.0.120/30160.3.0.121 to 160.3.0.122160.3.0.1232
32160.3.0.124/30160.3.0.125 to 160.3.0.126160.3.0.1272
33160.3.0.128/30160.3.0.129 to 160.3.0.130160.3.0.1312
34160.3.0.132/30160.3.0.133 to 160.3.0.134160.3.0.1352
35160.3.0.136/30160.3.0.137 to 160.3.0.138160.3.0.1392
36160.3.0.140/30160.3.0.141 to 160.3.0.142160.3.0.1432
37160.3.0.144/30160.3.0.145 to 160.3.0.146160.3.0.1472
38160.3.0.148/30160.3.0.149 to 160.3.0.150160.3.0.1512
39160.3.0.152/30160.3.0.153 to 160.3.0.154160.3.0.1552
40160.3.0.156/30160.3.0.157 to 160.3.0.158160.3.0.1592
41160.3.0.160/30160.3.0.161 to 160.3.0.162160.3.0.1632
42160.3.0.164/30160.3.0.165 to 160.3.0.166160.3.0.1672
43160.3.0.168/30160.3.0.169 to 160.3.0.170160.3.0.1712
44160.3.0.172/30160.3.0.173 to 160.3.0.174160.3.0.1752
45160.3.0.176/30160.3.0.177 to 160.3.0.178160.3.0.1792
46160.3.0.180/30160.3.0.181 to 160.3.0.182160.3.0.1832
47160.3.0.184/30160.3.0.185 to 160.3.0.186160.3.0.1872
48160.3.0.188/30160.3.0.189 to 160.3.0.190160.3.0.1912
49160.3.0.192/30160.3.0.193 to 160.3.0.194160.3.0.1952
50160.3.0.196/30160.3.0.197 to 160.3.0.198160.3.0.1992
51160.3.0.200/30160.3.0.201 to 160.3.0.202160.3.0.2032
52160.3.0.204/30160.3.0.205 to 160.3.0.206160.3.0.2072
53160.3.0.208/30160.3.0.209 to 160.3.0.210160.3.0.2112
54160.3.0.212/30160.3.0.213 to 160.3.0.214160.3.0.2152
55160.3.0.216/30160.3.0.217 to 160.3.0.218160.3.0.2192
56160.3.0.220/30160.3.0.221 to 160.3.0.222160.3.0.2232
57160.3.0.224/30160.3.0.225 to 160.3.0.226160.3.0.2272
58160.3.0.228/30160.3.0.229 to 160.3.0.230160.3.0.2312
59160.3.0.232/30160.3.0.233 to 160.3.0.234160.3.0.2352
60160.3.0.236/30160.3.0.237 to 160.3.0.238160.3.0.2392
61160.3.0.240/30160.3.0.241 to 160.3.0.242160.3.0.2432
62160.3.0.244/30160.3.0.245 to 160.3.0.246160.3.0.2472
63160.3.0.248/30160.3.0.249 to 160.3.0.250160.3.0.2512
64160.3.0.252/30160.3.0.253 to 160.3.0.254160.3.0.2552
65160.3.1.0/30160.3.1.1 to 160.3.1.2160.3.1.32
66160.3.1.4/30160.3.1.5 to 160.3.1.6160.3.1.72
67160.3.1.8/30160.3.1.9 to 160.3.1.10160.3.1.112
68160.3.1.12/30160.3.1.13 to 160.3.1.14160.3.1.152
69160.3.1.16/30160.3.1.17 to 160.3.1.18160.3.1.192
70160.3.1.20/30160.3.1.21 to 160.3.1.22160.3.1.232
71160.3.1.24/30160.3.1.25 to 160.3.1.26160.3.1.272
72160.3.1.28/30160.3.1.29 to 160.3.1.30160.3.1.312
73160.3.1.32/30160.3.1.33 to 160.3.1.34160.3.1.352
74160.3.1.36/30160.3.1.37 to 160.3.1.38160.3.1.392
75160.3.1.40/30160.3.1.41 to 160.3.1.42160.3.1.432
76160.3.1.44/30160.3.1.45 to 160.3.1.46160.3.1.472
77160.3.1.48/30160.3.1.49 to 160.3.1.50160.3.1.512
78160.3.1.52/30160.3.1.53 to 160.3.1.54160.3.1.552
79160.3.1.56/30160.3.1.57 to 160.3.1.58160.3.1.592
80160.3.1.60/30160.3.1.61 to 160.3.1.62160.3.1.632
81160.3.1.64/30160.3.1.65 to 160.3.1.66160.3.1.672
82160.3.1.68/30160.3.1.69 to 160.3.1.70160.3.1.712
83160.3.1.72/30160.3.1.73 to 160.3.1.74160.3.1.752
84160.3.1.76/30160.3.1.77 to 160.3.1.78160.3.1.792
85160.3.1.80/30160.3.1.81 to 160.3.1.82160.3.1.832
86160.3.1.84/30160.3.1.85 to 160.3.1.86160.3.1.872
87160.3.1.88/30160.3.1.89 to 160.3.1.90160.3.1.912
88160.3.1.92/30160.3.1.93 to 160.3.1.94160.3.1.952
89160.3.1.96/30160.3.1.97 to 160.3.1.98160.3.1.992
90160.3.1.100/30160.3.1.101 to 160.3.1.102160.3.1.1032
91160.3.1.104/30160.3.1.105 to 160.3.1.106160.3.1.1072
92160.3.1.108/30160.3.1.109 to 160.3.1.110160.3.1.1112
93160.3.1.112/30160.3.1.113 to 160.3.1.114160.3.1.1152
94160.3.1.116/30160.3.1.117 to 160.3.1.118160.3.1.1192
95160.3.1.120/30160.3.1.121 to 160.3.1.122160.3.1.1232
96160.3.1.124/30160.3.1.125 to 160.3.1.126160.3.1.1272
97160.3.1.128/30160.3.1.129 to 160.3.1.130160.3.1.1312
98160.3.1.132/30160.3.1.133 to 160.3.1.134160.3.1.1352
99160.3.1.136/30160.3.1.137 to 160.3.1.138160.3.1.1392
100160.3.1.140/30160.3.1.141 to 160.3.1.142160.3.1.1432
101160.3.1.144/30160.3.1.145 to 160.3.1.146160.3.1.1472
102160.3.1.148/30160.3.1.149 to 160.3.1.150160.3.1.1512
103160.3.1.152/30160.3.1.153 to 160.3.1.154160.3.1.1552
104160.3.1.156/30160.3.1.157 to 160.3.1.158160.3.1.1592
105160.3.1.160/30160.3.1.161 to 160.3.1.162160.3.1.1632
106160.3.1.164/30160.3.1.165 to 160.3.1.166160.3.1.1672
107160.3.1.168/30160.3.1.169 to 160.3.1.170160.3.1.1712
108160.3.1.172/30160.3.1.173 to 160.3.1.174160.3.1.1752
109160.3.1.176/30160.3.1.177 to 160.3.1.178160.3.1.1792
110160.3.1.180/30160.3.1.181 to 160.3.1.182160.3.1.1832
111160.3.1.184/30160.3.1.185 to 160.3.1.186160.3.1.1872
112160.3.1.188/30160.3.1.189 to 160.3.1.190160.3.1.1912
113160.3.1.192/30160.3.1.193 to 160.3.1.194160.3.1.1952
114160.3.1.196/30160.3.1.197 to 160.3.1.198160.3.1.1992
115160.3.1.200/30160.3.1.201 to 160.3.1.202160.3.1.2032
116160.3.1.204/30160.3.1.205 to 160.3.1.206160.3.1.2072
117160.3.1.208/30160.3.1.209 to 160.3.1.210160.3.1.2112
118160.3.1.212/30160.3.1.213 to 160.3.1.214160.3.1.2152
119160.3.1.216/30160.3.1.217 to 160.3.1.218160.3.1.2192
120160.3.1.220/30160.3.1.221 to 160.3.1.222160.3.1.2232
121160.3.1.224/30160.3.1.225 to 160.3.1.226160.3.1.2272
122160.3.1.228/30160.3.1.229 to 160.3.1.230160.3.1.2312
123160.3.1.232/30160.3.1.233 to 160.3.1.234160.3.1.2352
124160.3.1.236/30160.3.1.237 to 160.3.1.238160.3.1.2392
125160.3.1.240/30160.3.1.241 to 160.3.1.242160.3.1.2432
126160.3.1.244/30160.3.1.245 to 160.3.1.246160.3.1.2472
127160.3.1.248/30160.3.1.249 to 160.3.1.250160.3.1.2512
128160.3.1.252/30160.3.1.253 to 160.3.1.254160.3.1.2552
129160.3.2.0/30160.3.2.1 to 160.3.2.2160.3.2.32
130160.3.2.4/30160.3.2.5 to 160.3.2.6160.3.2.72
131160.3.2.8/30160.3.2.9 to 160.3.2.10160.3.2.112
132160.3.2.12/30160.3.2.13 to 160.3.2.14160.3.2.152
133160.3.2.16/30160.3.2.17 to 160.3.2.18160.3.2.192
134160.3.2.20/30160.3.2.21 to 160.3.2.22160.3.2.232
135160.3.2.24/30160.3.2.25 to 160.3.2.26160.3.2.272
136160.3.2.28/30160.3.2.29 to 160.3.2.30160.3.2.312
137160.3.2.32/30160.3.2.33 to 160.3.2.34160.3.2.352
138160.3.2.36/30160.3.2.37 to 160.3.2.38160.3.2.392
139160.3.2.40/30160.3.2.41 to 160.3.2.42160.3.2.432
140160.3.2.44/30160.3.2.45 to 160.3.2.46160.3.2.472
141160.3.2.48/30160.3.2.49 to 160.3.2.50160.3.2.512
142160.3.2.52/30160.3.2.53 to 160.3.2.54160.3.2.552
143160.3.2.56/30160.3.2.57 to 160.3.2.58160.3.2.592
144160.3.2.60/30160.3.2.61 to 160.3.2.62160.3.2.632
145160.3.2.64/30160.3.2.65 to 160.3.2.66160.3.2.672
146160.3.2.68/30160.3.2.69 to 160.3.2.70160.3.2.712
147160.3.2.72/30160.3.2.73 to 160.3.2.74160.3.2.752
148160.3.2.76/30160.3.2.77 to 160.3.2.78160.3.2.792
149160.3.2.80/30160.3.2.81 to 160.3.2.82160.3.2.832
150160.3.2.84/30160.3.2.85 to 160.3.2.86160.3.2.872
151160.3.2.88/30160.3.2.89 to 160.3.2.90160.3.2.912
152160.3.2.92/30160.3.2.93 to 160.3.2.94160.3.2.952
153160.3.2.96/30160.3.2.97 to 160.3.2.98160.3.2.992
154160.3.2.100/30160.3.2.101 to 160.3.2.102160.3.2.1032
155160.3.2.104/30160.3.2.105 to 160.3.2.106160.3.2.1072
156160.3.2.108/30160.3.2.109 to 160.3.2.110160.3.2.1112
157160.3.2.112/30160.3.2.113 to 160.3.2.114160.3.2.1152
158160.3.2.116/30160.3.2.117 to 160.3.2.118160.3.2.1192
159160.3.2.120/30160.3.2.121 to 160.3.2.122160.3.2.1232
160160.3.2.124/30160.3.2.125 to 160.3.2.126160.3.2.1272
161160.3.2.128/30160.3.2.129 to 160.3.2.130160.3.2.1312
162160.3.2.132/30160.3.2.133 to 160.3.2.134160.3.2.1352
163160.3.2.136/30160.3.2.137 to 160.3.2.138160.3.2.1392
164160.3.2.140/30160.3.2.141 to 160.3.2.142160.3.2.1432
165160.3.2.144/30160.3.2.145 to 160.3.2.146160.3.2.1472
166160.3.2.148/30160.3.2.149 to 160.3.2.150160.3.2.1512
167160.3.2.152/30160.3.2.153 to 160.3.2.154160.3.2.1552
168160.3.2.156/30160.3.2.157 to 160.3.2.158160.3.2.1592
169160.3.2.160/30160.3.2.161 to 160.3.2.162160.3.2.1632
170160.3.2.164/30160.3.2.165 to 160.3.2.166160.3.2.1672
171160.3.2.168/30160.3.2.169 to 160.3.2.170160.3.2.1712
172160.3.2.172/30160.3.2.173 to 160.3.2.174160.3.2.1752
173160.3.2.176/30160.3.2.177 to 160.3.2.178160.3.2.1792
174160.3.2.180/30160.3.2.181 to 160.3.2.182160.3.2.1832
175160.3.2.184/30160.3.2.185 to 160.3.2.186160.3.2.1872
176160.3.2.188/30160.3.2.189 to 160.3.2.190160.3.2.1912
177160.3.2.192/30160.3.2.193 to 160.3.2.194160.3.2.1952
178160.3.2.196/30160.3.2.197 to 160.3.2.198160.3.2.1992
179160.3.2.200/30160.3.2.201 to 160.3.2.202160.3.2.2032
180160.3.2.204/30160.3.2.205 to 160.3.2.206160.3.2.2072
181160.3.2.208/30160.3.2.209 to 160.3.2.210160.3.2.2112
182160.3.2.212/30160.3.2.213 to 160.3.2.214160.3.2.2152
183160.3.2.216/30160.3.2.217 to 160.3.2.218160.3.2.2192
184160.3.2.220/30160.3.2.221 to 160.3.2.222160.3.2.2232
185160.3.2.224/30160.3.2.225 to 160.3.2.226160.3.2.2272
186160.3.2.228/30160.3.2.229 to 160.3.2.230160.3.2.2312
187160.3.2.232/30160.3.2.233 to 160.3.2.234160.3.2.2352
188160.3.2.236/30160.3.2.237 to 160.3.2.238160.3.2.2392
189160.3.2.240/30160.3.2.241 to 160.3.2.242160.3.2.2432
190160.3.2.244/30160.3.2.245 to 160.3.2.246160.3.2.2472
191160.3.2.248/30160.3.2.249 to 160.3.2.250160.3.2.2512
192160.3.2.252/30160.3.2.253 to 160.3.2.254160.3.2.2552
193160.3.3.0/30160.3.3.1 to 160.3.3.2160.3.3.32
194160.3.3.4/30160.3.3.5 to 160.3.3.6160.3.3.72
195160.3.3.8/30160.3.3.9 to 160.3.3.10160.3.3.112
196160.3.3.12/30160.3.3.13 to 160.3.3.14160.3.3.152
197160.3.3.16/30160.3.3.17 to 160.3.3.18160.3.3.192
198160.3.3.20/30160.3.3.21 to 160.3.3.22160.3.3.232
199160.3.3.24/30160.3.3.25 to 160.3.3.26160.3.3.272
200160.3.3.28/30160.3.3.29 to 160.3.3.30160.3.3.312
201160.3.3.32/30160.3.3.33 to 160.3.3.34160.3.3.352
202160.3.3.36/30160.3.3.37 to 160.3.3.38160.3.3.392
203160.3.3.40/30160.3.3.41 to 160.3.3.42160.3.3.432
204160.3.3.44/30160.3.3.45 to 160.3.3.46160.3.3.472
205160.3.3.48/30160.3.3.49 to 160.3.3.50160.3.3.512
206160.3.3.52/30160.3.3.53 to 160.3.3.54160.3.3.552
207160.3.3.56/30160.3.3.57 to 160.3.3.58160.3.3.592
208160.3.3.60/30160.3.3.61 to 160.3.3.62160.3.3.632
209160.3.3.64/30160.3.3.65 to 160.3.3.66160.3.3.672
210160.3.3.68/30160.3.3.69 to 160.3.3.70160.3.3.712
211160.3.3.72/30160.3.3.73 to 160.3.3.74160.3.3.752
212160.3.3.76/30160.3.3.77 to 160.3.3.78160.3.3.792
213160.3.3.80/30160.3.3.81 to 160.3.3.82160.3.3.832
214160.3.3.84/30160.3.3.85 to 160.3.3.86160.3.3.872
215160.3.3.88/30160.3.3.89 to 160.3.3.90160.3.3.912
216160.3.3.92/30160.3.3.93 to 160.3.3.94160.3.3.952
217160.3.3.96/30160.3.3.97 to 160.3.3.98160.3.3.992
218160.3.3.100/30160.3.3.101 to 160.3.3.102160.3.3.1032
219160.3.3.104/30160.3.3.105 to 160.3.3.106160.3.3.1072
220160.3.3.108/30160.3.3.109 to 160.3.3.110160.3.3.1112
221160.3.3.112/30160.3.3.113 to 160.3.3.114160.3.3.1152
222160.3.3.116/30160.3.3.117 to 160.3.3.118160.3.3.1192
223160.3.3.120/30160.3.3.121 to 160.3.3.122160.3.3.1232
224160.3.3.124/30160.3.3.125 to 160.3.3.126160.3.3.1272
225160.3.3.128/30160.3.3.129 to 160.3.3.130160.3.3.1312
226160.3.3.132/30160.3.3.133 to 160.3.3.134160.3.3.1352
227160.3.3.136/30160.3.3.137 to 160.3.3.138160.3.3.1392
228160.3.3.140/30160.3.3.141 to 160.3.3.142160.3.3.1432
229160.3.3.144/30160.3.3.145 to 160.3.3.146160.3.3.1472
230160.3.3.148/30160.3.3.149 to 160.3.3.150160.3.3.1512
231160.3.3.152/30160.3.3.153 to 160.3.3.154160.3.3.1552
232160.3.3.156/30160.3.3.157 to 160.3.3.158160.3.3.1592
233160.3.3.160/30160.3.3.161 to 160.3.3.162160.3.3.1632
234160.3.3.164/30160.3.3.165 to 160.3.3.166160.3.3.1672
235160.3.3.168/30160.3.3.169 to 160.3.3.170160.3.3.1712
236160.3.3.172/30160.3.3.173 to 160.3.3.174160.3.3.1752
237160.3.3.176/30160.3.3.177 to 160.3.3.178160.3.3.1792
238160.3.3.180/30160.3.3.181 to 160.3.3.182160.3.3.1832
239160.3.3.184/30160.3.3.185 to 160.3.3.186160.3.3.1872
240160.3.3.188/30160.3.3.189 to 160.3.3.190160.3.3.1912
241160.3.3.192/30160.3.3.193 to 160.3.3.194160.3.3.1952
242160.3.3.196/30160.3.3.197 to 160.3.3.198160.3.3.1992
243160.3.3.200/30160.3.3.201 to 160.3.3.202160.3.3.2032
244160.3.3.204/30160.3.3.205 to 160.3.3.206160.3.3.2072
245160.3.3.208/30160.3.3.209 to 160.3.3.210160.3.3.2112
246160.3.3.212/30160.3.3.213 to 160.3.3.214160.3.3.2152
247160.3.3.216/30160.3.3.217 to 160.3.3.218160.3.3.2192
248160.3.3.220/30160.3.3.221 to 160.3.3.222160.3.3.2232
249160.3.3.224/30160.3.3.225 to 160.3.3.226160.3.3.2272
250160.3.3.228/30160.3.3.229 to 160.3.3.230160.3.3.2312
251160.3.3.232/30160.3.3.233 to 160.3.3.234160.3.3.2352
252160.3.3.236/30160.3.3.237 to 160.3.3.238160.3.3.2392
253160.3.3.240/30160.3.3.241 to 160.3.3.242160.3.3.2432
254160.3.3.244/30160.3.3.245 to 160.3.3.246160.3.3.2472
255160.3.3.248/30160.3.3.249 to 160.3.3.250160.3.3.2512
256160.3.3.252/30160.3.3.253 to 160.3.3.254160.3.3.2552

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.