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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.

Network232.7.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
232.7.0.0
Broadcast address
232.7.255.255
First usable
232.7.0.1
Last usable
232.7.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E8070000 · Integer 3892772864 to 3892838399
Reverse DNS zone
7.232.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101000.00000111..00000000.00000000232.7.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network11101000.00000111..00000000.00000000232.7.0.0
Broadcast11101000.00000111..11111111.11111111232.7.255.255
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

232.7.0.0/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1232.7.0.0/28232.7.0.1 to 232.7.0.14232.7.0.1514
2232.7.0.16/28232.7.0.17 to 232.7.0.30232.7.0.3114
3232.7.0.32/28232.7.0.33 to 232.7.0.46232.7.0.4714
4232.7.0.48/28232.7.0.49 to 232.7.0.62232.7.0.6314
5232.7.0.64/28232.7.0.65 to 232.7.0.78232.7.0.7914
6232.7.0.80/28232.7.0.81 to 232.7.0.94232.7.0.9514
7232.7.0.96/28232.7.0.97 to 232.7.0.110232.7.0.11114
8232.7.0.112/28232.7.0.113 to 232.7.0.126232.7.0.12714
9232.7.0.128/28232.7.0.129 to 232.7.0.142232.7.0.14314
10232.7.0.144/28232.7.0.145 to 232.7.0.158232.7.0.15914
11232.7.0.160/28232.7.0.161 to 232.7.0.174232.7.0.17514
12232.7.0.176/28232.7.0.177 to 232.7.0.190232.7.0.19114
13232.7.0.192/28232.7.0.193 to 232.7.0.206232.7.0.20714
14232.7.0.208/28232.7.0.209 to 232.7.0.222232.7.0.22314
15232.7.0.224/28232.7.0.225 to 232.7.0.238232.7.0.23914
16232.7.0.240/28232.7.0.241 to 232.7.0.254232.7.0.25514
17232.7.1.0/28232.7.1.1 to 232.7.1.14232.7.1.1514
18232.7.1.16/28232.7.1.17 to 232.7.1.30232.7.1.3114
19232.7.1.32/28232.7.1.33 to 232.7.1.46232.7.1.4714
20232.7.1.48/28232.7.1.49 to 232.7.1.62232.7.1.6314
21232.7.1.64/28232.7.1.65 to 232.7.1.78232.7.1.7914
22232.7.1.80/28232.7.1.81 to 232.7.1.94232.7.1.9514
23232.7.1.96/28232.7.1.97 to 232.7.1.110232.7.1.11114
24232.7.1.112/28232.7.1.113 to 232.7.1.126232.7.1.12714
25232.7.1.128/28232.7.1.129 to 232.7.1.142232.7.1.14314
26232.7.1.144/28232.7.1.145 to 232.7.1.158232.7.1.15914
27232.7.1.160/28232.7.1.161 to 232.7.1.174232.7.1.17514
28232.7.1.176/28232.7.1.177 to 232.7.1.190232.7.1.19114
29232.7.1.192/28232.7.1.193 to 232.7.1.206232.7.1.20714
30232.7.1.208/28232.7.1.209 to 232.7.1.222232.7.1.22314
31232.7.1.224/28232.7.1.225 to 232.7.1.238232.7.1.23914
32232.7.1.240/28232.7.1.241 to 232.7.1.254232.7.1.25514
33232.7.2.0/28232.7.2.1 to 232.7.2.14232.7.2.1514
34232.7.2.16/28232.7.2.17 to 232.7.2.30232.7.2.3114
35232.7.2.32/28232.7.2.33 to 232.7.2.46232.7.2.4714
36232.7.2.48/28232.7.2.49 to 232.7.2.62232.7.2.6314
37232.7.2.64/28232.7.2.65 to 232.7.2.78232.7.2.7914
38232.7.2.80/28232.7.2.81 to 232.7.2.94232.7.2.9514
39232.7.2.96/28232.7.2.97 to 232.7.2.110232.7.2.11114
40232.7.2.112/28232.7.2.113 to 232.7.2.126232.7.2.12714
41232.7.2.128/28232.7.2.129 to 232.7.2.142232.7.2.14314
42232.7.2.144/28232.7.2.145 to 232.7.2.158232.7.2.15914
43232.7.2.160/28232.7.2.161 to 232.7.2.174232.7.2.17514
44232.7.2.176/28232.7.2.177 to 232.7.2.190232.7.2.19114
45232.7.2.192/28232.7.2.193 to 232.7.2.206232.7.2.20714
46232.7.2.208/28232.7.2.209 to 232.7.2.222232.7.2.22314
47232.7.2.224/28232.7.2.225 to 232.7.2.238232.7.2.23914
48232.7.2.240/28232.7.2.241 to 232.7.2.254232.7.2.25514
49232.7.3.0/28232.7.3.1 to 232.7.3.14232.7.3.1514
50232.7.3.16/28232.7.3.17 to 232.7.3.30232.7.3.3114
51232.7.3.32/28232.7.3.33 to 232.7.3.46232.7.3.4714
52232.7.3.48/28232.7.3.49 to 232.7.3.62232.7.3.6314
53232.7.3.64/28232.7.3.65 to 232.7.3.78232.7.3.7914
54232.7.3.80/28232.7.3.81 to 232.7.3.94232.7.3.9514
55232.7.3.96/28232.7.3.97 to 232.7.3.110232.7.3.11114
56232.7.3.112/28232.7.3.113 to 232.7.3.126232.7.3.12714
57232.7.3.128/28232.7.3.129 to 232.7.3.142232.7.3.14314
58232.7.3.144/28232.7.3.145 to 232.7.3.158232.7.3.15914
59232.7.3.160/28232.7.3.161 to 232.7.3.174232.7.3.17514
60232.7.3.176/28232.7.3.177 to 232.7.3.190232.7.3.19114
61232.7.3.192/28232.7.3.193 to 232.7.3.206232.7.3.20714
62232.7.3.208/28232.7.3.209 to 232.7.3.222232.7.3.22314
63232.7.3.224/28232.7.3.225 to 232.7.3.238232.7.3.23914
64232.7.3.240/28232.7.3.241 to 232.7.3.254232.7.3.25514
65232.7.4.0/28232.7.4.1 to 232.7.4.14232.7.4.1514
66232.7.4.16/28232.7.4.17 to 232.7.4.30232.7.4.3114
67232.7.4.32/28232.7.4.33 to 232.7.4.46232.7.4.4714
68232.7.4.48/28232.7.4.49 to 232.7.4.62232.7.4.6314
69232.7.4.64/28232.7.4.65 to 232.7.4.78232.7.4.7914
70232.7.4.80/28232.7.4.81 to 232.7.4.94232.7.4.9514
71232.7.4.96/28232.7.4.97 to 232.7.4.110232.7.4.11114
72232.7.4.112/28232.7.4.113 to 232.7.4.126232.7.4.12714
73232.7.4.128/28232.7.4.129 to 232.7.4.142232.7.4.14314
74232.7.4.144/28232.7.4.145 to 232.7.4.158232.7.4.15914
75232.7.4.160/28232.7.4.161 to 232.7.4.174232.7.4.17514
76232.7.4.176/28232.7.4.177 to 232.7.4.190232.7.4.19114
77232.7.4.192/28232.7.4.193 to 232.7.4.206232.7.4.20714
78232.7.4.208/28232.7.4.209 to 232.7.4.222232.7.4.22314
79232.7.4.224/28232.7.4.225 to 232.7.4.238232.7.4.23914
80232.7.4.240/28232.7.4.241 to 232.7.4.254232.7.4.25514
81232.7.5.0/28232.7.5.1 to 232.7.5.14232.7.5.1514
82232.7.5.16/28232.7.5.17 to 232.7.5.30232.7.5.3114
83232.7.5.32/28232.7.5.33 to 232.7.5.46232.7.5.4714
84232.7.5.48/28232.7.5.49 to 232.7.5.62232.7.5.6314
85232.7.5.64/28232.7.5.65 to 232.7.5.78232.7.5.7914
86232.7.5.80/28232.7.5.81 to 232.7.5.94232.7.5.9514
87232.7.5.96/28232.7.5.97 to 232.7.5.110232.7.5.11114
88232.7.5.112/28232.7.5.113 to 232.7.5.126232.7.5.12714
89232.7.5.128/28232.7.5.129 to 232.7.5.142232.7.5.14314
90232.7.5.144/28232.7.5.145 to 232.7.5.158232.7.5.15914
91232.7.5.160/28232.7.5.161 to 232.7.5.174232.7.5.17514
92232.7.5.176/28232.7.5.177 to 232.7.5.190232.7.5.19114
93232.7.5.192/28232.7.5.193 to 232.7.5.206232.7.5.20714
94232.7.5.208/28232.7.5.209 to 232.7.5.222232.7.5.22314
95232.7.5.224/28232.7.5.225 to 232.7.5.238232.7.5.23914
96232.7.5.240/28232.7.5.241 to 232.7.5.254232.7.5.25514
97232.7.6.0/28232.7.6.1 to 232.7.6.14232.7.6.1514
98232.7.6.16/28232.7.6.17 to 232.7.6.30232.7.6.3114
99232.7.6.32/28232.7.6.33 to 232.7.6.46232.7.6.4714
100232.7.6.48/28232.7.6.49 to 232.7.6.62232.7.6.6314
101232.7.6.64/28232.7.6.65 to 232.7.6.78232.7.6.7914
102232.7.6.80/28232.7.6.81 to 232.7.6.94232.7.6.9514
103232.7.6.96/28232.7.6.97 to 232.7.6.110232.7.6.11114
104232.7.6.112/28232.7.6.113 to 232.7.6.126232.7.6.12714
105232.7.6.128/28232.7.6.129 to 232.7.6.142232.7.6.14314
106232.7.6.144/28232.7.6.145 to 232.7.6.158232.7.6.15914
107232.7.6.160/28232.7.6.161 to 232.7.6.174232.7.6.17514
108232.7.6.176/28232.7.6.177 to 232.7.6.190232.7.6.19114
109232.7.6.192/28232.7.6.193 to 232.7.6.206232.7.6.20714
110232.7.6.208/28232.7.6.209 to 232.7.6.222232.7.6.22314
111232.7.6.224/28232.7.6.225 to 232.7.6.238232.7.6.23914
112232.7.6.240/28232.7.6.241 to 232.7.6.254232.7.6.25514
113232.7.7.0/28232.7.7.1 to 232.7.7.14232.7.7.1514
114232.7.7.16/28232.7.7.17 to 232.7.7.30232.7.7.3114
115232.7.7.32/28232.7.7.33 to 232.7.7.46232.7.7.4714
116232.7.7.48/28232.7.7.49 to 232.7.7.62232.7.7.6314
117232.7.7.64/28232.7.7.65 to 232.7.7.78232.7.7.7914
118232.7.7.80/28232.7.7.81 to 232.7.7.94232.7.7.9514
119232.7.7.96/28232.7.7.97 to 232.7.7.110232.7.7.11114
120232.7.7.112/28232.7.7.113 to 232.7.7.126232.7.7.12714
121232.7.7.128/28232.7.7.129 to 232.7.7.142232.7.7.14314
122232.7.7.144/28232.7.7.145 to 232.7.7.158232.7.7.15914
123232.7.7.160/28232.7.7.161 to 232.7.7.174232.7.7.17514
124232.7.7.176/28232.7.7.177 to 232.7.7.190232.7.7.19114
125232.7.7.192/28232.7.7.193 to 232.7.7.206232.7.7.20714
126232.7.7.208/28232.7.7.209 to 232.7.7.222232.7.7.22314
127232.7.7.224/28232.7.7.225 to 232.7.7.238232.7.7.23914
128232.7.7.240/28232.7.7.241 to 232.7.7.254232.7.7.25514
129232.7.8.0/28232.7.8.1 to 232.7.8.14232.7.8.1514
130232.7.8.16/28232.7.8.17 to 232.7.8.30232.7.8.3114
131232.7.8.32/28232.7.8.33 to 232.7.8.46232.7.8.4714
132232.7.8.48/28232.7.8.49 to 232.7.8.62232.7.8.6314
133232.7.8.64/28232.7.8.65 to 232.7.8.78232.7.8.7914
134232.7.8.80/28232.7.8.81 to 232.7.8.94232.7.8.9514
135232.7.8.96/28232.7.8.97 to 232.7.8.110232.7.8.11114
136232.7.8.112/28232.7.8.113 to 232.7.8.126232.7.8.12714
137232.7.8.128/28232.7.8.129 to 232.7.8.142232.7.8.14314
138232.7.8.144/28232.7.8.145 to 232.7.8.158232.7.8.15914
139232.7.8.160/28232.7.8.161 to 232.7.8.174232.7.8.17514
140232.7.8.176/28232.7.8.177 to 232.7.8.190232.7.8.19114
141232.7.8.192/28232.7.8.193 to 232.7.8.206232.7.8.20714
142232.7.8.208/28232.7.8.209 to 232.7.8.222232.7.8.22314
143232.7.8.224/28232.7.8.225 to 232.7.8.238232.7.8.23914
144232.7.8.240/28232.7.8.241 to 232.7.8.254232.7.8.25514
145232.7.9.0/28232.7.9.1 to 232.7.9.14232.7.9.1514
146232.7.9.16/28232.7.9.17 to 232.7.9.30232.7.9.3114
147232.7.9.32/28232.7.9.33 to 232.7.9.46232.7.9.4714
148232.7.9.48/28232.7.9.49 to 232.7.9.62232.7.9.6314
149232.7.9.64/28232.7.9.65 to 232.7.9.78232.7.9.7914
150232.7.9.80/28232.7.9.81 to 232.7.9.94232.7.9.9514
151232.7.9.96/28232.7.9.97 to 232.7.9.110232.7.9.11114
152232.7.9.112/28232.7.9.113 to 232.7.9.126232.7.9.12714
153232.7.9.128/28232.7.9.129 to 232.7.9.142232.7.9.14314
154232.7.9.144/28232.7.9.145 to 232.7.9.158232.7.9.15914
155232.7.9.160/28232.7.9.161 to 232.7.9.174232.7.9.17514
156232.7.9.176/28232.7.9.177 to 232.7.9.190232.7.9.19114
157232.7.9.192/28232.7.9.193 to 232.7.9.206232.7.9.20714
158232.7.9.208/28232.7.9.209 to 232.7.9.222232.7.9.22314
159232.7.9.224/28232.7.9.225 to 232.7.9.238232.7.9.23914
160232.7.9.240/28232.7.9.241 to 232.7.9.254232.7.9.25514
161232.7.10.0/28232.7.10.1 to 232.7.10.14232.7.10.1514
162232.7.10.16/28232.7.10.17 to 232.7.10.30232.7.10.3114
163232.7.10.32/28232.7.10.33 to 232.7.10.46232.7.10.4714
164232.7.10.48/28232.7.10.49 to 232.7.10.62232.7.10.6314
165232.7.10.64/28232.7.10.65 to 232.7.10.78232.7.10.7914
166232.7.10.80/28232.7.10.81 to 232.7.10.94232.7.10.9514
167232.7.10.96/28232.7.10.97 to 232.7.10.110232.7.10.11114
168232.7.10.112/28232.7.10.113 to 232.7.10.126232.7.10.12714
169232.7.10.128/28232.7.10.129 to 232.7.10.142232.7.10.14314
170232.7.10.144/28232.7.10.145 to 232.7.10.158232.7.10.15914
171232.7.10.160/28232.7.10.161 to 232.7.10.174232.7.10.17514
172232.7.10.176/28232.7.10.177 to 232.7.10.190232.7.10.19114
173232.7.10.192/28232.7.10.193 to 232.7.10.206232.7.10.20714
174232.7.10.208/28232.7.10.209 to 232.7.10.222232.7.10.22314
175232.7.10.224/28232.7.10.225 to 232.7.10.238232.7.10.23914
176232.7.10.240/28232.7.10.241 to 232.7.10.254232.7.10.25514
177232.7.11.0/28232.7.11.1 to 232.7.11.14232.7.11.1514
178232.7.11.16/28232.7.11.17 to 232.7.11.30232.7.11.3114
179232.7.11.32/28232.7.11.33 to 232.7.11.46232.7.11.4714
180232.7.11.48/28232.7.11.49 to 232.7.11.62232.7.11.6314
181232.7.11.64/28232.7.11.65 to 232.7.11.78232.7.11.7914
182232.7.11.80/28232.7.11.81 to 232.7.11.94232.7.11.9514
183232.7.11.96/28232.7.11.97 to 232.7.11.110232.7.11.11114
184232.7.11.112/28232.7.11.113 to 232.7.11.126232.7.11.12714
185232.7.11.128/28232.7.11.129 to 232.7.11.142232.7.11.14314
186232.7.11.144/28232.7.11.145 to 232.7.11.158232.7.11.15914
187232.7.11.160/28232.7.11.161 to 232.7.11.174232.7.11.17514
188232.7.11.176/28232.7.11.177 to 232.7.11.190232.7.11.19114
189232.7.11.192/28232.7.11.193 to 232.7.11.206232.7.11.20714
190232.7.11.208/28232.7.11.209 to 232.7.11.222232.7.11.22314
191232.7.11.224/28232.7.11.225 to 232.7.11.238232.7.11.23914
192232.7.11.240/28232.7.11.241 to 232.7.11.254232.7.11.25514
193232.7.12.0/28232.7.12.1 to 232.7.12.14232.7.12.1514
194232.7.12.16/28232.7.12.17 to 232.7.12.30232.7.12.3114
195232.7.12.32/28232.7.12.33 to 232.7.12.46232.7.12.4714
196232.7.12.48/28232.7.12.49 to 232.7.12.62232.7.12.6314
197232.7.12.64/28232.7.12.65 to 232.7.12.78232.7.12.7914
198232.7.12.80/28232.7.12.81 to 232.7.12.94232.7.12.9514
199232.7.12.96/28232.7.12.97 to 232.7.12.110232.7.12.11114
200232.7.12.112/28232.7.12.113 to 232.7.12.126232.7.12.12714
201232.7.12.128/28232.7.12.129 to 232.7.12.142232.7.12.14314
202232.7.12.144/28232.7.12.145 to 232.7.12.158232.7.12.15914
203232.7.12.160/28232.7.12.161 to 232.7.12.174232.7.12.17514
204232.7.12.176/28232.7.12.177 to 232.7.12.190232.7.12.19114
205232.7.12.192/28232.7.12.193 to 232.7.12.206232.7.12.20714
206232.7.12.208/28232.7.12.209 to 232.7.12.222232.7.12.22314
207232.7.12.224/28232.7.12.225 to 232.7.12.238232.7.12.23914
208232.7.12.240/28232.7.12.241 to 232.7.12.254232.7.12.25514
209232.7.13.0/28232.7.13.1 to 232.7.13.14232.7.13.1514
210232.7.13.16/28232.7.13.17 to 232.7.13.30232.7.13.3114
211232.7.13.32/28232.7.13.33 to 232.7.13.46232.7.13.4714
212232.7.13.48/28232.7.13.49 to 232.7.13.62232.7.13.6314
213232.7.13.64/28232.7.13.65 to 232.7.13.78232.7.13.7914
214232.7.13.80/28232.7.13.81 to 232.7.13.94232.7.13.9514
215232.7.13.96/28232.7.13.97 to 232.7.13.110232.7.13.11114
216232.7.13.112/28232.7.13.113 to 232.7.13.126232.7.13.12714
217232.7.13.128/28232.7.13.129 to 232.7.13.142232.7.13.14314
218232.7.13.144/28232.7.13.145 to 232.7.13.158232.7.13.15914
219232.7.13.160/28232.7.13.161 to 232.7.13.174232.7.13.17514
220232.7.13.176/28232.7.13.177 to 232.7.13.190232.7.13.19114
221232.7.13.192/28232.7.13.193 to 232.7.13.206232.7.13.20714
222232.7.13.208/28232.7.13.209 to 232.7.13.222232.7.13.22314
223232.7.13.224/28232.7.13.225 to 232.7.13.238232.7.13.23914
224232.7.13.240/28232.7.13.241 to 232.7.13.254232.7.13.25514
225232.7.14.0/28232.7.14.1 to 232.7.14.14232.7.14.1514
226232.7.14.16/28232.7.14.17 to 232.7.14.30232.7.14.3114
227232.7.14.32/28232.7.14.33 to 232.7.14.46232.7.14.4714
228232.7.14.48/28232.7.14.49 to 232.7.14.62232.7.14.6314
229232.7.14.64/28232.7.14.65 to 232.7.14.78232.7.14.7914
230232.7.14.80/28232.7.14.81 to 232.7.14.94232.7.14.9514
231232.7.14.96/28232.7.14.97 to 232.7.14.110232.7.14.11114
232232.7.14.112/28232.7.14.113 to 232.7.14.126232.7.14.12714
233232.7.14.128/28232.7.14.129 to 232.7.14.142232.7.14.14314
234232.7.14.144/28232.7.14.145 to 232.7.14.158232.7.14.15914
235232.7.14.160/28232.7.14.161 to 232.7.14.174232.7.14.17514
236232.7.14.176/28232.7.14.177 to 232.7.14.190232.7.14.19114
237232.7.14.192/28232.7.14.193 to 232.7.14.206232.7.14.20714
238232.7.14.208/28232.7.14.209 to 232.7.14.222232.7.14.22314
239232.7.14.224/28232.7.14.225 to 232.7.14.238232.7.14.23914
240232.7.14.240/28232.7.14.241 to 232.7.14.254232.7.14.25514
241232.7.15.0/28232.7.15.1 to 232.7.15.14232.7.15.1514
242232.7.15.16/28232.7.15.17 to 232.7.15.30232.7.15.3114
243232.7.15.32/28232.7.15.33 to 232.7.15.46232.7.15.4714
244232.7.15.48/28232.7.15.49 to 232.7.15.62232.7.15.6314
245232.7.15.64/28232.7.15.65 to 232.7.15.78232.7.15.7914
246232.7.15.80/28232.7.15.81 to 232.7.15.94232.7.15.9514
247232.7.15.96/28232.7.15.97 to 232.7.15.110232.7.15.11114
248232.7.15.112/28232.7.15.113 to 232.7.15.126232.7.15.12714
249232.7.15.128/28232.7.15.129 to 232.7.15.142232.7.15.14314
250232.7.15.144/28232.7.15.145 to 232.7.15.158232.7.15.15914
251232.7.15.160/28232.7.15.161 to 232.7.15.174232.7.15.17514
252232.7.15.176/28232.7.15.177 to 232.7.15.190232.7.15.19114
253232.7.15.192/28232.7.15.193 to 232.7.15.206232.7.15.20714
254232.7.15.208/28232.7.15.209 to 232.7.15.222232.7.15.22314
255232.7.15.224/28232.7.15.225 to 232.7.15.238232.7.15.23914
256232.7.15.240/28232.7.15.241 to 232.7.15.254232.7.15.25514

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.