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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.

Network230.167.32.0/20
Usable hosts4,094
Subnet mask255.255.240.0
Addresses4,096
Network address
230.167.32.0
Broadcast address
230.167.47.255
First usable
230.167.32.1
Last usable
230.167.47.254
Usable hosts
4,094 (4,096 less the network and broadcast addresses)
Subnet mask
255.255.240.0
Wildcard mask
0.0.15.255 (Cisco ACLs, OSPF)
Prefix length
/20
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E6A72000 · Integer 3869712384 to 3869716479
Reverse DNS zones
32.167.230.in-addr.arpa
33.167.230.in-addr.arpa
34.167.230.in-addr.arpa
35.167.230.in-addr.arpa
36.167.230.in-addr.arpa
37.167.230.in-addr.arpa
38.167.230.in-addr.arpa
39.167.230.in-addr.arpa
40.167.230.in-addr.arpa
41.167.230.in-addr.arpa
42.167.230.in-addr.arpa
43.167.230.in-addr.arpa
44.167.230.in-addr.arpa
45.167.230.in-addr.arpa
46.167.230.in-addr.arpa
47.167.230.in-addr.arpa
/20 is not on a 8-bit boundary, so it takes 16 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11100110.10100111.00100000.00000000230.167.32.0
Subnet mask11111111.11111111.11110000.00000000255.255.240.0
Network11100110.10100111.00100000.00000000230.167.32.0
Broadcast11100110.10100111.00101111.11111111230.167.47.255
Split into smaller subnets/29
/21 (2)/22 (4)/23 (8)/24 (16)/25 (32)/26 (64)/27 (128)/28 (256)/29 (512)/30 (1,024)/31 (2,048)/32 (4,096)

230.167.32.0/20 makes 512 subnets of /29; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1230.167.32.0/29230.167.32.1 to 230.167.32.6230.167.32.76
2230.167.32.8/29230.167.32.9 to 230.167.32.14230.167.32.156
3230.167.32.16/29230.167.32.17 to 230.167.32.22230.167.32.236
4230.167.32.24/29230.167.32.25 to 230.167.32.30230.167.32.316
5230.167.32.32/29230.167.32.33 to 230.167.32.38230.167.32.396
6230.167.32.40/29230.167.32.41 to 230.167.32.46230.167.32.476
7230.167.32.48/29230.167.32.49 to 230.167.32.54230.167.32.556
8230.167.32.56/29230.167.32.57 to 230.167.32.62230.167.32.636
9230.167.32.64/29230.167.32.65 to 230.167.32.70230.167.32.716
10230.167.32.72/29230.167.32.73 to 230.167.32.78230.167.32.796
11230.167.32.80/29230.167.32.81 to 230.167.32.86230.167.32.876
12230.167.32.88/29230.167.32.89 to 230.167.32.94230.167.32.956
13230.167.32.96/29230.167.32.97 to 230.167.32.102230.167.32.1036
14230.167.32.104/29230.167.32.105 to 230.167.32.110230.167.32.1116
15230.167.32.112/29230.167.32.113 to 230.167.32.118230.167.32.1196
16230.167.32.120/29230.167.32.121 to 230.167.32.126230.167.32.1276
17230.167.32.128/29230.167.32.129 to 230.167.32.134230.167.32.1356
18230.167.32.136/29230.167.32.137 to 230.167.32.142230.167.32.1436
19230.167.32.144/29230.167.32.145 to 230.167.32.150230.167.32.1516
20230.167.32.152/29230.167.32.153 to 230.167.32.158230.167.32.1596
21230.167.32.160/29230.167.32.161 to 230.167.32.166230.167.32.1676
22230.167.32.168/29230.167.32.169 to 230.167.32.174230.167.32.1756
23230.167.32.176/29230.167.32.177 to 230.167.32.182230.167.32.1836
24230.167.32.184/29230.167.32.185 to 230.167.32.190230.167.32.1916
25230.167.32.192/29230.167.32.193 to 230.167.32.198230.167.32.1996
26230.167.32.200/29230.167.32.201 to 230.167.32.206230.167.32.2076
27230.167.32.208/29230.167.32.209 to 230.167.32.214230.167.32.2156
28230.167.32.216/29230.167.32.217 to 230.167.32.222230.167.32.2236
29230.167.32.224/29230.167.32.225 to 230.167.32.230230.167.32.2316
30230.167.32.232/29230.167.32.233 to 230.167.32.238230.167.32.2396
31230.167.32.240/29230.167.32.241 to 230.167.32.246230.167.32.2476
32230.167.32.248/29230.167.32.249 to 230.167.32.254230.167.32.2556
33230.167.33.0/29230.167.33.1 to 230.167.33.6230.167.33.76
34230.167.33.8/29230.167.33.9 to 230.167.33.14230.167.33.156
35230.167.33.16/29230.167.33.17 to 230.167.33.22230.167.33.236
36230.167.33.24/29230.167.33.25 to 230.167.33.30230.167.33.316
37230.167.33.32/29230.167.33.33 to 230.167.33.38230.167.33.396
38230.167.33.40/29230.167.33.41 to 230.167.33.46230.167.33.476
39230.167.33.48/29230.167.33.49 to 230.167.33.54230.167.33.556
40230.167.33.56/29230.167.33.57 to 230.167.33.62230.167.33.636
41230.167.33.64/29230.167.33.65 to 230.167.33.70230.167.33.716
42230.167.33.72/29230.167.33.73 to 230.167.33.78230.167.33.796
43230.167.33.80/29230.167.33.81 to 230.167.33.86230.167.33.876
44230.167.33.88/29230.167.33.89 to 230.167.33.94230.167.33.956
45230.167.33.96/29230.167.33.97 to 230.167.33.102230.167.33.1036
46230.167.33.104/29230.167.33.105 to 230.167.33.110230.167.33.1116
47230.167.33.112/29230.167.33.113 to 230.167.33.118230.167.33.1196
48230.167.33.120/29230.167.33.121 to 230.167.33.126230.167.33.1276
49230.167.33.128/29230.167.33.129 to 230.167.33.134230.167.33.1356
50230.167.33.136/29230.167.33.137 to 230.167.33.142230.167.33.1436
51230.167.33.144/29230.167.33.145 to 230.167.33.150230.167.33.1516
52230.167.33.152/29230.167.33.153 to 230.167.33.158230.167.33.1596
53230.167.33.160/29230.167.33.161 to 230.167.33.166230.167.33.1676
54230.167.33.168/29230.167.33.169 to 230.167.33.174230.167.33.1756
55230.167.33.176/29230.167.33.177 to 230.167.33.182230.167.33.1836
56230.167.33.184/29230.167.33.185 to 230.167.33.190230.167.33.1916
57230.167.33.192/29230.167.33.193 to 230.167.33.198230.167.33.1996
58230.167.33.200/29230.167.33.201 to 230.167.33.206230.167.33.2076
59230.167.33.208/29230.167.33.209 to 230.167.33.214230.167.33.2156
60230.167.33.216/29230.167.33.217 to 230.167.33.222230.167.33.2236
61230.167.33.224/29230.167.33.225 to 230.167.33.230230.167.33.2316
62230.167.33.232/29230.167.33.233 to 230.167.33.238230.167.33.2396
63230.167.33.240/29230.167.33.241 to 230.167.33.246230.167.33.2476
64230.167.33.248/29230.167.33.249 to 230.167.33.254230.167.33.2556
65230.167.34.0/29230.167.34.1 to 230.167.34.6230.167.34.76
66230.167.34.8/29230.167.34.9 to 230.167.34.14230.167.34.156
67230.167.34.16/29230.167.34.17 to 230.167.34.22230.167.34.236
68230.167.34.24/29230.167.34.25 to 230.167.34.30230.167.34.316
69230.167.34.32/29230.167.34.33 to 230.167.34.38230.167.34.396
70230.167.34.40/29230.167.34.41 to 230.167.34.46230.167.34.476
71230.167.34.48/29230.167.34.49 to 230.167.34.54230.167.34.556
72230.167.34.56/29230.167.34.57 to 230.167.34.62230.167.34.636
73230.167.34.64/29230.167.34.65 to 230.167.34.70230.167.34.716
74230.167.34.72/29230.167.34.73 to 230.167.34.78230.167.34.796
75230.167.34.80/29230.167.34.81 to 230.167.34.86230.167.34.876
76230.167.34.88/29230.167.34.89 to 230.167.34.94230.167.34.956
77230.167.34.96/29230.167.34.97 to 230.167.34.102230.167.34.1036
78230.167.34.104/29230.167.34.105 to 230.167.34.110230.167.34.1116
79230.167.34.112/29230.167.34.113 to 230.167.34.118230.167.34.1196
80230.167.34.120/29230.167.34.121 to 230.167.34.126230.167.34.1276
81230.167.34.128/29230.167.34.129 to 230.167.34.134230.167.34.1356
82230.167.34.136/29230.167.34.137 to 230.167.34.142230.167.34.1436
83230.167.34.144/29230.167.34.145 to 230.167.34.150230.167.34.1516
84230.167.34.152/29230.167.34.153 to 230.167.34.158230.167.34.1596
85230.167.34.160/29230.167.34.161 to 230.167.34.166230.167.34.1676
86230.167.34.168/29230.167.34.169 to 230.167.34.174230.167.34.1756
87230.167.34.176/29230.167.34.177 to 230.167.34.182230.167.34.1836
88230.167.34.184/29230.167.34.185 to 230.167.34.190230.167.34.1916
89230.167.34.192/29230.167.34.193 to 230.167.34.198230.167.34.1996
90230.167.34.200/29230.167.34.201 to 230.167.34.206230.167.34.2076
91230.167.34.208/29230.167.34.209 to 230.167.34.214230.167.34.2156
92230.167.34.216/29230.167.34.217 to 230.167.34.222230.167.34.2236
93230.167.34.224/29230.167.34.225 to 230.167.34.230230.167.34.2316
94230.167.34.232/29230.167.34.233 to 230.167.34.238230.167.34.2396
95230.167.34.240/29230.167.34.241 to 230.167.34.246230.167.34.2476
96230.167.34.248/29230.167.34.249 to 230.167.34.254230.167.34.2556
97230.167.35.0/29230.167.35.1 to 230.167.35.6230.167.35.76
98230.167.35.8/29230.167.35.9 to 230.167.35.14230.167.35.156
99230.167.35.16/29230.167.35.17 to 230.167.35.22230.167.35.236
100230.167.35.24/29230.167.35.25 to 230.167.35.30230.167.35.316
101230.167.35.32/29230.167.35.33 to 230.167.35.38230.167.35.396
102230.167.35.40/29230.167.35.41 to 230.167.35.46230.167.35.476
103230.167.35.48/29230.167.35.49 to 230.167.35.54230.167.35.556
104230.167.35.56/29230.167.35.57 to 230.167.35.62230.167.35.636
105230.167.35.64/29230.167.35.65 to 230.167.35.70230.167.35.716
106230.167.35.72/29230.167.35.73 to 230.167.35.78230.167.35.796
107230.167.35.80/29230.167.35.81 to 230.167.35.86230.167.35.876
108230.167.35.88/29230.167.35.89 to 230.167.35.94230.167.35.956
109230.167.35.96/29230.167.35.97 to 230.167.35.102230.167.35.1036
110230.167.35.104/29230.167.35.105 to 230.167.35.110230.167.35.1116
111230.167.35.112/29230.167.35.113 to 230.167.35.118230.167.35.1196
112230.167.35.120/29230.167.35.121 to 230.167.35.126230.167.35.1276
113230.167.35.128/29230.167.35.129 to 230.167.35.134230.167.35.1356
114230.167.35.136/29230.167.35.137 to 230.167.35.142230.167.35.1436
115230.167.35.144/29230.167.35.145 to 230.167.35.150230.167.35.1516
116230.167.35.152/29230.167.35.153 to 230.167.35.158230.167.35.1596
117230.167.35.160/29230.167.35.161 to 230.167.35.166230.167.35.1676
118230.167.35.168/29230.167.35.169 to 230.167.35.174230.167.35.1756
119230.167.35.176/29230.167.35.177 to 230.167.35.182230.167.35.1836
120230.167.35.184/29230.167.35.185 to 230.167.35.190230.167.35.1916
121230.167.35.192/29230.167.35.193 to 230.167.35.198230.167.35.1996
122230.167.35.200/29230.167.35.201 to 230.167.35.206230.167.35.2076
123230.167.35.208/29230.167.35.209 to 230.167.35.214230.167.35.2156
124230.167.35.216/29230.167.35.217 to 230.167.35.222230.167.35.2236
125230.167.35.224/29230.167.35.225 to 230.167.35.230230.167.35.2316
126230.167.35.232/29230.167.35.233 to 230.167.35.238230.167.35.2396
127230.167.35.240/29230.167.35.241 to 230.167.35.246230.167.35.2476
128230.167.35.248/29230.167.35.249 to 230.167.35.254230.167.35.2556
129230.167.36.0/29230.167.36.1 to 230.167.36.6230.167.36.76
130230.167.36.8/29230.167.36.9 to 230.167.36.14230.167.36.156
131230.167.36.16/29230.167.36.17 to 230.167.36.22230.167.36.236
132230.167.36.24/29230.167.36.25 to 230.167.36.30230.167.36.316
133230.167.36.32/29230.167.36.33 to 230.167.36.38230.167.36.396
134230.167.36.40/29230.167.36.41 to 230.167.36.46230.167.36.476
135230.167.36.48/29230.167.36.49 to 230.167.36.54230.167.36.556
136230.167.36.56/29230.167.36.57 to 230.167.36.62230.167.36.636
137230.167.36.64/29230.167.36.65 to 230.167.36.70230.167.36.716
138230.167.36.72/29230.167.36.73 to 230.167.36.78230.167.36.796
139230.167.36.80/29230.167.36.81 to 230.167.36.86230.167.36.876
140230.167.36.88/29230.167.36.89 to 230.167.36.94230.167.36.956
141230.167.36.96/29230.167.36.97 to 230.167.36.102230.167.36.1036
142230.167.36.104/29230.167.36.105 to 230.167.36.110230.167.36.1116
143230.167.36.112/29230.167.36.113 to 230.167.36.118230.167.36.1196
144230.167.36.120/29230.167.36.121 to 230.167.36.126230.167.36.1276
145230.167.36.128/29230.167.36.129 to 230.167.36.134230.167.36.1356
146230.167.36.136/29230.167.36.137 to 230.167.36.142230.167.36.1436
147230.167.36.144/29230.167.36.145 to 230.167.36.150230.167.36.1516
148230.167.36.152/29230.167.36.153 to 230.167.36.158230.167.36.1596
149230.167.36.160/29230.167.36.161 to 230.167.36.166230.167.36.1676
150230.167.36.168/29230.167.36.169 to 230.167.36.174230.167.36.1756
151230.167.36.176/29230.167.36.177 to 230.167.36.182230.167.36.1836
152230.167.36.184/29230.167.36.185 to 230.167.36.190230.167.36.1916
153230.167.36.192/29230.167.36.193 to 230.167.36.198230.167.36.1996
154230.167.36.200/29230.167.36.201 to 230.167.36.206230.167.36.2076
155230.167.36.208/29230.167.36.209 to 230.167.36.214230.167.36.2156
156230.167.36.216/29230.167.36.217 to 230.167.36.222230.167.36.2236
157230.167.36.224/29230.167.36.225 to 230.167.36.230230.167.36.2316
158230.167.36.232/29230.167.36.233 to 230.167.36.238230.167.36.2396
159230.167.36.240/29230.167.36.241 to 230.167.36.246230.167.36.2476
160230.167.36.248/29230.167.36.249 to 230.167.36.254230.167.36.2556
161230.167.37.0/29230.167.37.1 to 230.167.37.6230.167.37.76
162230.167.37.8/29230.167.37.9 to 230.167.37.14230.167.37.156
163230.167.37.16/29230.167.37.17 to 230.167.37.22230.167.37.236
164230.167.37.24/29230.167.37.25 to 230.167.37.30230.167.37.316
165230.167.37.32/29230.167.37.33 to 230.167.37.38230.167.37.396
166230.167.37.40/29230.167.37.41 to 230.167.37.46230.167.37.476
167230.167.37.48/29230.167.37.49 to 230.167.37.54230.167.37.556
168230.167.37.56/29230.167.37.57 to 230.167.37.62230.167.37.636
169230.167.37.64/29230.167.37.65 to 230.167.37.70230.167.37.716
170230.167.37.72/29230.167.37.73 to 230.167.37.78230.167.37.796
171230.167.37.80/29230.167.37.81 to 230.167.37.86230.167.37.876
172230.167.37.88/29230.167.37.89 to 230.167.37.94230.167.37.956
173230.167.37.96/29230.167.37.97 to 230.167.37.102230.167.37.1036
174230.167.37.104/29230.167.37.105 to 230.167.37.110230.167.37.1116
175230.167.37.112/29230.167.37.113 to 230.167.37.118230.167.37.1196
176230.167.37.120/29230.167.37.121 to 230.167.37.126230.167.37.1276
177230.167.37.128/29230.167.37.129 to 230.167.37.134230.167.37.1356
178230.167.37.136/29230.167.37.137 to 230.167.37.142230.167.37.1436
179230.167.37.144/29230.167.37.145 to 230.167.37.150230.167.37.1516
180230.167.37.152/29230.167.37.153 to 230.167.37.158230.167.37.1596
181230.167.37.160/29230.167.37.161 to 230.167.37.166230.167.37.1676
182230.167.37.168/29230.167.37.169 to 230.167.37.174230.167.37.1756
183230.167.37.176/29230.167.37.177 to 230.167.37.182230.167.37.1836
184230.167.37.184/29230.167.37.185 to 230.167.37.190230.167.37.1916
185230.167.37.192/29230.167.37.193 to 230.167.37.198230.167.37.1996
186230.167.37.200/29230.167.37.201 to 230.167.37.206230.167.37.2076
187230.167.37.208/29230.167.37.209 to 230.167.37.214230.167.37.2156
188230.167.37.216/29230.167.37.217 to 230.167.37.222230.167.37.2236
189230.167.37.224/29230.167.37.225 to 230.167.37.230230.167.37.2316
190230.167.37.232/29230.167.37.233 to 230.167.37.238230.167.37.2396
191230.167.37.240/29230.167.37.241 to 230.167.37.246230.167.37.2476
192230.167.37.248/29230.167.37.249 to 230.167.37.254230.167.37.2556
193230.167.38.0/29230.167.38.1 to 230.167.38.6230.167.38.76
194230.167.38.8/29230.167.38.9 to 230.167.38.14230.167.38.156
195230.167.38.16/29230.167.38.17 to 230.167.38.22230.167.38.236
196230.167.38.24/29230.167.38.25 to 230.167.38.30230.167.38.316
197230.167.38.32/29230.167.38.33 to 230.167.38.38230.167.38.396
198230.167.38.40/29230.167.38.41 to 230.167.38.46230.167.38.476
199230.167.38.48/29230.167.38.49 to 230.167.38.54230.167.38.556
200230.167.38.56/29230.167.38.57 to 230.167.38.62230.167.38.636
201230.167.38.64/29230.167.38.65 to 230.167.38.70230.167.38.716
202230.167.38.72/29230.167.38.73 to 230.167.38.78230.167.38.796
203230.167.38.80/29230.167.38.81 to 230.167.38.86230.167.38.876
204230.167.38.88/29230.167.38.89 to 230.167.38.94230.167.38.956
205230.167.38.96/29230.167.38.97 to 230.167.38.102230.167.38.1036
206230.167.38.104/29230.167.38.105 to 230.167.38.110230.167.38.1116
207230.167.38.112/29230.167.38.113 to 230.167.38.118230.167.38.1196
208230.167.38.120/29230.167.38.121 to 230.167.38.126230.167.38.1276
209230.167.38.128/29230.167.38.129 to 230.167.38.134230.167.38.1356
210230.167.38.136/29230.167.38.137 to 230.167.38.142230.167.38.1436
211230.167.38.144/29230.167.38.145 to 230.167.38.150230.167.38.1516
212230.167.38.152/29230.167.38.153 to 230.167.38.158230.167.38.1596
213230.167.38.160/29230.167.38.161 to 230.167.38.166230.167.38.1676
214230.167.38.168/29230.167.38.169 to 230.167.38.174230.167.38.1756
215230.167.38.176/29230.167.38.177 to 230.167.38.182230.167.38.1836
216230.167.38.184/29230.167.38.185 to 230.167.38.190230.167.38.1916
217230.167.38.192/29230.167.38.193 to 230.167.38.198230.167.38.1996
218230.167.38.200/29230.167.38.201 to 230.167.38.206230.167.38.2076
219230.167.38.208/29230.167.38.209 to 230.167.38.214230.167.38.2156
220230.167.38.216/29230.167.38.217 to 230.167.38.222230.167.38.2236
221230.167.38.224/29230.167.38.225 to 230.167.38.230230.167.38.2316
222230.167.38.232/29230.167.38.233 to 230.167.38.238230.167.38.2396
223230.167.38.240/29230.167.38.241 to 230.167.38.246230.167.38.2476
224230.167.38.248/29230.167.38.249 to 230.167.38.254230.167.38.2556
225230.167.39.0/29230.167.39.1 to 230.167.39.6230.167.39.76
226230.167.39.8/29230.167.39.9 to 230.167.39.14230.167.39.156
227230.167.39.16/29230.167.39.17 to 230.167.39.22230.167.39.236
228230.167.39.24/29230.167.39.25 to 230.167.39.30230.167.39.316
229230.167.39.32/29230.167.39.33 to 230.167.39.38230.167.39.396
230230.167.39.40/29230.167.39.41 to 230.167.39.46230.167.39.476
231230.167.39.48/29230.167.39.49 to 230.167.39.54230.167.39.556
232230.167.39.56/29230.167.39.57 to 230.167.39.62230.167.39.636
233230.167.39.64/29230.167.39.65 to 230.167.39.70230.167.39.716
234230.167.39.72/29230.167.39.73 to 230.167.39.78230.167.39.796
235230.167.39.80/29230.167.39.81 to 230.167.39.86230.167.39.876
236230.167.39.88/29230.167.39.89 to 230.167.39.94230.167.39.956
237230.167.39.96/29230.167.39.97 to 230.167.39.102230.167.39.1036
238230.167.39.104/29230.167.39.105 to 230.167.39.110230.167.39.1116
239230.167.39.112/29230.167.39.113 to 230.167.39.118230.167.39.1196
240230.167.39.120/29230.167.39.121 to 230.167.39.126230.167.39.1276
241230.167.39.128/29230.167.39.129 to 230.167.39.134230.167.39.1356
242230.167.39.136/29230.167.39.137 to 230.167.39.142230.167.39.1436
243230.167.39.144/29230.167.39.145 to 230.167.39.150230.167.39.1516
244230.167.39.152/29230.167.39.153 to 230.167.39.158230.167.39.1596
245230.167.39.160/29230.167.39.161 to 230.167.39.166230.167.39.1676
246230.167.39.168/29230.167.39.169 to 230.167.39.174230.167.39.1756
247230.167.39.176/29230.167.39.177 to 230.167.39.182230.167.39.1836
248230.167.39.184/29230.167.39.185 to 230.167.39.190230.167.39.1916
249230.167.39.192/29230.167.39.193 to 230.167.39.198230.167.39.1996
250230.167.39.200/29230.167.39.201 to 230.167.39.206230.167.39.2076
251230.167.39.208/29230.167.39.209 to 230.167.39.214230.167.39.2156
252230.167.39.216/29230.167.39.217 to 230.167.39.222230.167.39.2236
253230.167.39.224/29230.167.39.225 to 230.167.39.230230.167.39.2316
254230.167.39.232/29230.167.39.233 to 230.167.39.238230.167.39.2396
255230.167.39.240/29230.167.39.241 to 230.167.39.246230.167.39.2476
256230.167.39.248/29230.167.39.249 to 230.167.39.254230.167.39.2556

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.