IPv4 Subnet Calculator

Enter an IP with a CIDR prefix or a subnet mask to see its network, broadcast, host range, and host count. You can also split the network into smaller subnets.

Try:192.168.1.10/24 10.0.0.0/8 172.16.5.4/20 203.0.113.9/29

IPv6 calculator →

private IP (RFC 1918)10.21.0.0/16

network10.21.0.0/16

broadcast10.21.255.255

first host10.21.0.1

last host10.21.255.254

subnet mask255.255.0.0

wildcard0.0.255.255

addresses65,536

usable hosts65,534

classA

ipcalc 10.21.0.0/16

address00001010.00010101.00000000.00000000

subnet mask11111111.11111111.00000000.00000000

network00001010.00010101.00000000.00000000

broadcast00001010.00010101.11111111.11111111

green = network part, grey = host part

hex0x0a150000

decimal169148416

reverse dns0.0.21.10.in-addr.arpa

ipv4-mapped::ffff:a15:0

/16 split into /27 · 2,048 subnets

close ×

#	network	host range	broadcast
1	10.21.0.0/27	10.21.0.1 – 10.21.0.30	10.21.0.31
2	10.21.0.32/27	10.21.0.33 – 10.21.0.62	10.21.0.63
3	10.21.0.64/27	10.21.0.65 – 10.21.0.94	10.21.0.95
4	10.21.0.96/27	10.21.0.97 – 10.21.0.126	10.21.0.127
5	10.21.0.128/27	10.21.0.129 – 10.21.0.158	10.21.0.159
6	10.21.0.160/27	10.21.0.161 – 10.21.0.190	10.21.0.191
7	10.21.0.192/27	10.21.0.193 – 10.21.0.222	10.21.0.223
8	10.21.0.224/27	10.21.0.225 – 10.21.0.254	10.21.0.255
9	10.21.1.0/27	10.21.1.1 – 10.21.1.30	10.21.1.31
10	10.21.1.32/27	10.21.1.33 – 10.21.1.62	10.21.1.63
11	10.21.1.64/27	10.21.1.65 – 10.21.1.94	10.21.1.95
12	10.21.1.96/27	10.21.1.97 – 10.21.1.126	10.21.1.127
13	10.21.1.128/27	10.21.1.129 – 10.21.1.158	10.21.1.159
14	10.21.1.160/27	10.21.1.161 – 10.21.1.190	10.21.1.191
15	10.21.1.192/27	10.21.1.193 – 10.21.1.222	10.21.1.223
16	10.21.1.224/27	10.21.1.225 – 10.21.1.254	10.21.1.255
17	10.21.2.0/27	10.21.2.1 – 10.21.2.30	10.21.2.31
18	10.21.2.32/27	10.21.2.33 – 10.21.2.62	10.21.2.63
19	10.21.2.64/27	10.21.2.65 – 10.21.2.94	10.21.2.95
20	10.21.2.96/27	10.21.2.97 – 10.21.2.126	10.21.2.127
21	10.21.2.128/27	10.21.2.129 – 10.21.2.158	10.21.2.159
22	10.21.2.160/27	10.21.2.161 – 10.21.2.190	10.21.2.191
23	10.21.2.192/27	10.21.2.193 – 10.21.2.222	10.21.2.223
24	10.21.2.224/27	10.21.2.225 – 10.21.2.254	10.21.2.255
25	10.21.3.0/27	10.21.3.1 – 10.21.3.30	10.21.3.31
26	10.21.3.32/27	10.21.3.33 – 10.21.3.62	10.21.3.63
27	10.21.3.64/27	10.21.3.65 – 10.21.3.94	10.21.3.95
28	10.21.3.96/27	10.21.3.97 – 10.21.3.126	10.21.3.127
29	10.21.3.128/27	10.21.3.129 – 10.21.3.158	10.21.3.159
30	10.21.3.160/27	10.21.3.161 – 10.21.3.190	10.21.3.191
31	10.21.3.192/27	10.21.3.193 – 10.21.3.222	10.21.3.223
32	10.21.3.224/27	10.21.3.225 – 10.21.3.254	10.21.3.255
33	10.21.4.0/27	10.21.4.1 – 10.21.4.30	10.21.4.31
34	10.21.4.32/27	10.21.4.33 – 10.21.4.62	10.21.4.63
35	10.21.4.64/27	10.21.4.65 – 10.21.4.94	10.21.4.95
36	10.21.4.96/27	10.21.4.97 – 10.21.4.126	10.21.4.127
37	10.21.4.128/27	10.21.4.129 – 10.21.4.158	10.21.4.159
38	10.21.4.160/27	10.21.4.161 – 10.21.4.190	10.21.4.191
39	10.21.4.192/27	10.21.4.193 – 10.21.4.222	10.21.4.223
40	10.21.4.224/27	10.21.4.225 – 10.21.4.254	10.21.4.255
41	10.21.5.0/27	10.21.5.1 – 10.21.5.30	10.21.5.31
42	10.21.5.32/27	10.21.5.33 – 10.21.5.62	10.21.5.63
43	10.21.5.64/27	10.21.5.65 – 10.21.5.94	10.21.5.95
44	10.21.5.96/27	10.21.5.97 – 10.21.5.126	10.21.5.127
45	10.21.5.128/27	10.21.5.129 – 10.21.5.158	10.21.5.159
46	10.21.5.160/27	10.21.5.161 – 10.21.5.190	10.21.5.191
47	10.21.5.192/27	10.21.5.193 – 10.21.5.222	10.21.5.223
48	10.21.5.224/27	10.21.5.225 – 10.21.5.254	10.21.5.255
49	10.21.6.0/27	10.21.6.1 – 10.21.6.30	10.21.6.31
50	10.21.6.32/27	10.21.6.33 – 10.21.6.62	10.21.6.63
51	10.21.6.64/27	10.21.6.65 – 10.21.6.94	10.21.6.95
52	10.21.6.96/27	10.21.6.97 – 10.21.6.126	10.21.6.127
53	10.21.6.128/27	10.21.6.129 – 10.21.6.158	10.21.6.159
54	10.21.6.160/27	10.21.6.161 – 10.21.6.190	10.21.6.191
55	10.21.6.192/27	10.21.6.193 – 10.21.6.222	10.21.6.223
56	10.21.6.224/27	10.21.6.225 – 10.21.6.254	10.21.6.255
57	10.21.7.0/27	10.21.7.1 – 10.21.7.30	10.21.7.31
58	10.21.7.32/27	10.21.7.33 – 10.21.7.62	10.21.7.63
59	10.21.7.64/27	10.21.7.65 – 10.21.7.94	10.21.7.95
60	10.21.7.96/27	10.21.7.97 – 10.21.7.126	10.21.7.127
61	10.21.7.128/27	10.21.7.129 – 10.21.7.158	10.21.7.159
62	10.21.7.160/27	10.21.7.161 – 10.21.7.190	10.21.7.191
63	10.21.7.192/27	10.21.7.193 – 10.21.7.222	10.21.7.223
64	10.21.7.224/27	10.21.7.225 – 10.21.7.254	10.21.7.255
65	10.21.8.0/27	10.21.8.1 – 10.21.8.30	10.21.8.31
66	10.21.8.32/27	10.21.8.33 – 10.21.8.62	10.21.8.63
67	10.21.8.64/27	10.21.8.65 – 10.21.8.94	10.21.8.95
68	10.21.8.96/27	10.21.8.97 – 10.21.8.126	10.21.8.127
69	10.21.8.128/27	10.21.8.129 – 10.21.8.158	10.21.8.159
70	10.21.8.160/27	10.21.8.161 – 10.21.8.190	10.21.8.191
71	10.21.8.192/27	10.21.8.193 – 10.21.8.222	10.21.8.223
72	10.21.8.224/27	10.21.8.225 – 10.21.8.254	10.21.8.255
73	10.21.9.0/27	10.21.9.1 – 10.21.9.30	10.21.9.31
74	10.21.9.32/27	10.21.9.33 – 10.21.9.62	10.21.9.63
75	10.21.9.64/27	10.21.9.65 – 10.21.9.94	10.21.9.95
76	10.21.9.96/27	10.21.9.97 – 10.21.9.126	10.21.9.127
77	10.21.9.128/27	10.21.9.129 – 10.21.9.158	10.21.9.159
78	10.21.9.160/27	10.21.9.161 – 10.21.9.190	10.21.9.191
79	10.21.9.192/27	10.21.9.193 – 10.21.9.222	10.21.9.223
80	10.21.9.224/27	10.21.9.225 – 10.21.9.254	10.21.9.255
81	10.21.10.0/27	10.21.10.1 – 10.21.10.30	10.21.10.31
82	10.21.10.32/27	10.21.10.33 – 10.21.10.62	10.21.10.63
83	10.21.10.64/27	10.21.10.65 – 10.21.10.94	10.21.10.95
84	10.21.10.96/27	10.21.10.97 – 10.21.10.126	10.21.10.127
85	10.21.10.128/27	10.21.10.129 – 10.21.10.158	10.21.10.159
86	10.21.10.160/27	10.21.10.161 – 10.21.10.190	10.21.10.191
87	10.21.10.192/27	10.21.10.193 – 10.21.10.222	10.21.10.223
88	10.21.10.224/27	10.21.10.225 – 10.21.10.254	10.21.10.255
89	10.21.11.0/27	10.21.11.1 – 10.21.11.30	10.21.11.31
90	10.21.11.32/27	10.21.11.33 – 10.21.11.62	10.21.11.63
91	10.21.11.64/27	10.21.11.65 – 10.21.11.94	10.21.11.95
92	10.21.11.96/27	10.21.11.97 – 10.21.11.126	10.21.11.127
93	10.21.11.128/27	10.21.11.129 – 10.21.11.158	10.21.11.159
94	10.21.11.160/27	10.21.11.161 – 10.21.11.190	10.21.11.191
95	10.21.11.192/27	10.21.11.193 – 10.21.11.222	10.21.11.223
96	10.21.11.224/27	10.21.11.225 – 10.21.11.254	10.21.11.255
97	10.21.12.0/27	10.21.12.1 – 10.21.12.30	10.21.12.31
98	10.21.12.32/27	10.21.12.33 – 10.21.12.62	10.21.12.63
99	10.21.12.64/27	10.21.12.65 – 10.21.12.94	10.21.12.95
100	10.21.12.96/27	10.21.12.97 – 10.21.12.126	10.21.12.127
101	10.21.12.128/27	10.21.12.129 – 10.21.12.158	10.21.12.159
102	10.21.12.160/27	10.21.12.161 – 10.21.12.190	10.21.12.191
103	10.21.12.192/27	10.21.12.193 – 10.21.12.222	10.21.12.223
104	10.21.12.224/27	10.21.12.225 – 10.21.12.254	10.21.12.255
105	10.21.13.0/27	10.21.13.1 – 10.21.13.30	10.21.13.31
106	10.21.13.32/27	10.21.13.33 – 10.21.13.62	10.21.13.63
107	10.21.13.64/27	10.21.13.65 – 10.21.13.94	10.21.13.95
108	10.21.13.96/27	10.21.13.97 – 10.21.13.126	10.21.13.127
109	10.21.13.128/27	10.21.13.129 – 10.21.13.158	10.21.13.159
110	10.21.13.160/27	10.21.13.161 – 10.21.13.190	10.21.13.191
111	10.21.13.192/27	10.21.13.193 – 10.21.13.222	10.21.13.223
112	10.21.13.224/27	10.21.13.225 – 10.21.13.254	10.21.13.255
113	10.21.14.0/27	10.21.14.1 – 10.21.14.30	10.21.14.31
114	10.21.14.32/27	10.21.14.33 – 10.21.14.62	10.21.14.63
115	10.21.14.64/27	10.21.14.65 – 10.21.14.94	10.21.14.95
116	10.21.14.96/27	10.21.14.97 – 10.21.14.126	10.21.14.127
117	10.21.14.128/27	10.21.14.129 – 10.21.14.158	10.21.14.159
118	10.21.14.160/27	10.21.14.161 – 10.21.14.190	10.21.14.191
119	10.21.14.192/27	10.21.14.193 – 10.21.14.222	10.21.14.223
120	10.21.14.224/27	10.21.14.225 – 10.21.14.254	10.21.14.255
121	10.21.15.0/27	10.21.15.1 – 10.21.15.30	10.21.15.31
122	10.21.15.32/27	10.21.15.33 – 10.21.15.62	10.21.15.63
123	10.21.15.64/27	10.21.15.65 – 10.21.15.94	10.21.15.95
124	10.21.15.96/27	10.21.15.97 – 10.21.15.126	10.21.15.127
125	10.21.15.128/27	10.21.15.129 – 10.21.15.158	10.21.15.159
126	10.21.15.160/27	10.21.15.161 – 10.21.15.190	10.21.15.191
127	10.21.15.192/27	10.21.15.193 – 10.21.15.222	10.21.15.223
128	10.21.15.224/27	10.21.15.225 – 10.21.15.254	10.21.15.255
129	10.21.16.0/27	10.21.16.1 – 10.21.16.30	10.21.16.31
130	10.21.16.32/27	10.21.16.33 – 10.21.16.62	10.21.16.63
131	10.21.16.64/27	10.21.16.65 – 10.21.16.94	10.21.16.95
132	10.21.16.96/27	10.21.16.97 – 10.21.16.126	10.21.16.127
133	10.21.16.128/27	10.21.16.129 – 10.21.16.158	10.21.16.159
134	10.21.16.160/27	10.21.16.161 – 10.21.16.190	10.21.16.191
135	10.21.16.192/27	10.21.16.193 – 10.21.16.222	10.21.16.223
136	10.21.16.224/27	10.21.16.225 – 10.21.16.254	10.21.16.255
137	10.21.17.0/27	10.21.17.1 – 10.21.17.30	10.21.17.31
138	10.21.17.32/27	10.21.17.33 – 10.21.17.62	10.21.17.63
139	10.21.17.64/27	10.21.17.65 – 10.21.17.94	10.21.17.95
140	10.21.17.96/27	10.21.17.97 – 10.21.17.126	10.21.17.127
141	10.21.17.128/27	10.21.17.129 – 10.21.17.158	10.21.17.159
142	10.21.17.160/27	10.21.17.161 – 10.21.17.190	10.21.17.191
143	10.21.17.192/27	10.21.17.193 – 10.21.17.222	10.21.17.223
144	10.21.17.224/27	10.21.17.225 – 10.21.17.254	10.21.17.255
145	10.21.18.0/27	10.21.18.1 – 10.21.18.30	10.21.18.31
146	10.21.18.32/27	10.21.18.33 – 10.21.18.62	10.21.18.63
147	10.21.18.64/27	10.21.18.65 – 10.21.18.94	10.21.18.95
148	10.21.18.96/27	10.21.18.97 – 10.21.18.126	10.21.18.127
149	10.21.18.128/27	10.21.18.129 – 10.21.18.158	10.21.18.159
150	10.21.18.160/27	10.21.18.161 – 10.21.18.190	10.21.18.191
151	10.21.18.192/27	10.21.18.193 – 10.21.18.222	10.21.18.223
152	10.21.18.224/27	10.21.18.225 – 10.21.18.254	10.21.18.255
153	10.21.19.0/27	10.21.19.1 – 10.21.19.30	10.21.19.31
154	10.21.19.32/27	10.21.19.33 – 10.21.19.62	10.21.19.63
155	10.21.19.64/27	10.21.19.65 – 10.21.19.94	10.21.19.95
156	10.21.19.96/27	10.21.19.97 – 10.21.19.126	10.21.19.127
157	10.21.19.128/27	10.21.19.129 – 10.21.19.158	10.21.19.159
158	10.21.19.160/27	10.21.19.161 – 10.21.19.190	10.21.19.191
159	10.21.19.192/27	10.21.19.193 – 10.21.19.222	10.21.19.223
160	10.21.19.224/27	10.21.19.225 – 10.21.19.254	10.21.19.255
161	10.21.20.0/27	10.21.20.1 – 10.21.20.30	10.21.20.31
162	10.21.20.32/27	10.21.20.33 – 10.21.20.62	10.21.20.63
163	10.21.20.64/27	10.21.20.65 – 10.21.20.94	10.21.20.95
164	10.21.20.96/27	10.21.20.97 – 10.21.20.126	10.21.20.127
165	10.21.20.128/27	10.21.20.129 – 10.21.20.158	10.21.20.159
166	10.21.20.160/27	10.21.20.161 – 10.21.20.190	10.21.20.191
167	10.21.20.192/27	10.21.20.193 – 10.21.20.222	10.21.20.223
168	10.21.20.224/27	10.21.20.225 – 10.21.20.254	10.21.20.255
169	10.21.21.0/27	10.21.21.1 – 10.21.21.30	10.21.21.31
170	10.21.21.32/27	10.21.21.33 – 10.21.21.62	10.21.21.63
171	10.21.21.64/27	10.21.21.65 – 10.21.21.94	10.21.21.95
172	10.21.21.96/27	10.21.21.97 – 10.21.21.126	10.21.21.127
173	10.21.21.128/27	10.21.21.129 – 10.21.21.158	10.21.21.159
174	10.21.21.160/27	10.21.21.161 – 10.21.21.190	10.21.21.191
175	10.21.21.192/27	10.21.21.193 – 10.21.21.222	10.21.21.223
176	10.21.21.224/27	10.21.21.225 – 10.21.21.254	10.21.21.255
177	10.21.22.0/27	10.21.22.1 – 10.21.22.30	10.21.22.31
178	10.21.22.32/27	10.21.22.33 – 10.21.22.62	10.21.22.63
179	10.21.22.64/27	10.21.22.65 – 10.21.22.94	10.21.22.95
180	10.21.22.96/27	10.21.22.97 – 10.21.22.126	10.21.22.127
181	10.21.22.128/27	10.21.22.129 – 10.21.22.158	10.21.22.159
182	10.21.22.160/27	10.21.22.161 – 10.21.22.190	10.21.22.191
183	10.21.22.192/27	10.21.22.193 – 10.21.22.222	10.21.22.223
184	10.21.22.224/27	10.21.22.225 – 10.21.22.254	10.21.22.255
185	10.21.23.0/27	10.21.23.1 – 10.21.23.30	10.21.23.31
186	10.21.23.32/27	10.21.23.33 – 10.21.23.62	10.21.23.63
187	10.21.23.64/27	10.21.23.65 – 10.21.23.94	10.21.23.95
188	10.21.23.96/27	10.21.23.97 – 10.21.23.126	10.21.23.127
189	10.21.23.128/27	10.21.23.129 – 10.21.23.158	10.21.23.159
190	10.21.23.160/27	10.21.23.161 – 10.21.23.190	10.21.23.191
191	10.21.23.192/27	10.21.23.193 – 10.21.23.222	10.21.23.223
192	10.21.23.224/27	10.21.23.225 – 10.21.23.254	10.21.23.255
193	10.21.24.0/27	10.21.24.1 – 10.21.24.30	10.21.24.31
194	10.21.24.32/27	10.21.24.33 – 10.21.24.62	10.21.24.63
195	10.21.24.64/27	10.21.24.65 – 10.21.24.94	10.21.24.95
196	10.21.24.96/27	10.21.24.97 – 10.21.24.126	10.21.24.127
197	10.21.24.128/27	10.21.24.129 – 10.21.24.158	10.21.24.159
198	10.21.24.160/27	10.21.24.161 – 10.21.24.190	10.21.24.191
199	10.21.24.192/27	10.21.24.193 – 10.21.24.222	10.21.24.223
200	10.21.24.224/27	10.21.24.225 – 10.21.24.254	10.21.24.255
201	10.21.25.0/27	10.21.25.1 – 10.21.25.30	10.21.25.31
202	10.21.25.32/27	10.21.25.33 – 10.21.25.62	10.21.25.63
203	10.21.25.64/27	10.21.25.65 – 10.21.25.94	10.21.25.95
204	10.21.25.96/27	10.21.25.97 – 10.21.25.126	10.21.25.127
205	10.21.25.128/27	10.21.25.129 – 10.21.25.158	10.21.25.159
206	10.21.25.160/27	10.21.25.161 – 10.21.25.190	10.21.25.191
207	10.21.25.192/27	10.21.25.193 – 10.21.25.222	10.21.25.223
208	10.21.25.224/27	10.21.25.225 – 10.21.25.254	10.21.25.255
209	10.21.26.0/27	10.21.26.1 – 10.21.26.30	10.21.26.31
210	10.21.26.32/27	10.21.26.33 – 10.21.26.62	10.21.26.63
211	10.21.26.64/27	10.21.26.65 – 10.21.26.94	10.21.26.95
212	10.21.26.96/27	10.21.26.97 – 10.21.26.126	10.21.26.127
213	10.21.26.128/27	10.21.26.129 – 10.21.26.158	10.21.26.159
214	10.21.26.160/27	10.21.26.161 – 10.21.26.190	10.21.26.191
215	10.21.26.192/27	10.21.26.193 – 10.21.26.222	10.21.26.223
216	10.21.26.224/27	10.21.26.225 – 10.21.26.254	10.21.26.255
217	10.21.27.0/27	10.21.27.1 – 10.21.27.30	10.21.27.31
218	10.21.27.32/27	10.21.27.33 – 10.21.27.62	10.21.27.63
219	10.21.27.64/27	10.21.27.65 – 10.21.27.94	10.21.27.95
220	10.21.27.96/27	10.21.27.97 – 10.21.27.126	10.21.27.127
221	10.21.27.128/27	10.21.27.129 – 10.21.27.158	10.21.27.159
222	10.21.27.160/27	10.21.27.161 – 10.21.27.190	10.21.27.191
223	10.21.27.192/27	10.21.27.193 – 10.21.27.222	10.21.27.223
224	10.21.27.224/27	10.21.27.225 – 10.21.27.254	10.21.27.255
225	10.21.28.0/27	10.21.28.1 – 10.21.28.30	10.21.28.31
226	10.21.28.32/27	10.21.28.33 – 10.21.28.62	10.21.28.63
227	10.21.28.64/27	10.21.28.65 – 10.21.28.94	10.21.28.95
228	10.21.28.96/27	10.21.28.97 – 10.21.28.126	10.21.28.127
229	10.21.28.128/27	10.21.28.129 – 10.21.28.158	10.21.28.159
230	10.21.28.160/27	10.21.28.161 – 10.21.28.190	10.21.28.191
231	10.21.28.192/27	10.21.28.193 – 10.21.28.222	10.21.28.223
232	10.21.28.224/27	10.21.28.225 – 10.21.28.254	10.21.28.255
233	10.21.29.0/27	10.21.29.1 – 10.21.29.30	10.21.29.31
234	10.21.29.32/27	10.21.29.33 – 10.21.29.62	10.21.29.63
235	10.21.29.64/27	10.21.29.65 – 10.21.29.94	10.21.29.95
236	10.21.29.96/27	10.21.29.97 – 10.21.29.126	10.21.29.127
237	10.21.29.128/27	10.21.29.129 – 10.21.29.158	10.21.29.159
238	10.21.29.160/27	10.21.29.161 – 10.21.29.190	10.21.29.191
239	10.21.29.192/27	10.21.29.193 – 10.21.29.222	10.21.29.223
240	10.21.29.224/27	10.21.29.225 – 10.21.29.254	10.21.29.255
241	10.21.30.0/27	10.21.30.1 – 10.21.30.30	10.21.30.31
242	10.21.30.32/27	10.21.30.33 – 10.21.30.62	10.21.30.63
243	10.21.30.64/27	10.21.30.65 – 10.21.30.94	10.21.30.95
244	10.21.30.96/27	10.21.30.97 – 10.21.30.126	10.21.30.127
245	10.21.30.128/27	10.21.30.129 – 10.21.30.158	10.21.30.159
246	10.21.30.160/27	10.21.30.161 – 10.21.30.190	10.21.30.191
247	10.21.30.192/27	10.21.30.193 – 10.21.30.222	10.21.30.223
248	10.21.30.224/27	10.21.30.225 – 10.21.30.254	10.21.30.255
249	10.21.31.0/27	10.21.31.1 – 10.21.31.30	10.21.31.31
250	10.21.31.32/27	10.21.31.33 – 10.21.31.62	10.21.31.63
251	10.21.31.64/27	10.21.31.65 – 10.21.31.94	10.21.31.95
252	10.21.31.96/27	10.21.31.97 – 10.21.31.126	10.21.31.127
253	10.21.31.128/27	10.21.31.129 – 10.21.31.158	10.21.31.159
254	10.21.31.160/27	10.21.31.161 – 10.21.31.190	10.21.31.191
255	10.21.31.192/27	10.21.31.193 – 10.21.31.222	10.21.31.223
256	10.21.31.224/27	10.21.31.225 – 10.21.31.254	10.21.31.255

showing 256 of 2,048

01 / table

IPv4 CIDR prefix table.

Click a prefix longer than your network to split it into subnets.

prefix	subnet mask	addresses	hosts	in your /16
/0	0.0.0.0	4,294,967,296	4,294,967,294	-
/1	128.0.0.0	2,147,483,648	2,147,483,646	-
/2	192.0.0.0	1,073,741,824	1,073,741,822	-
/3	224.0.0.0	536,870,912	536,870,910	-
/4	240.0.0.0	268,435,456	268,435,454	-
/5	248.0.0.0	134,217,728	134,217,726	-
/6	252.0.0.0	67,108,864	67,108,862	-
/7	254.0.0.0	33,554,432	33,554,430	-
/8	255.0.0.0	16,777,216	16,777,214	-
/9	255.128.0.0	8,388,608	8,388,606	-
/10	255.192.0.0	4,194,304	4,194,302	-
/11	255.224.0.0	2,097,152	2,097,150	-
/12	255.240.0.0	1,048,576	1,048,574	-
/13	255.248.0.0	524,288	524,286	-
/14	255.252.0.0	262,144	262,142	-
/15	255.254.0.0	131,072	131,070	-
/16	255.255.0.0	65,536	65,534	1
/17	255.255.128.0	32,768	32,766	2 split →
/18	255.255.192.0	16,384	16,382	4 split →
/19	255.255.224.0	8,192	8,190	8 split →
/20	255.255.240.0	4,096	4,094	16 split →
/21	255.255.248.0	2,048	2,046	32 split →
/22	255.255.252.0	1,024	1,022	64 split →
/23	255.255.254.0	512	510	128 split →
/24	255.255.255.0	256	254	256 split →
/25	255.255.255.128	128	126	512 split →
/26	255.255.255.192	64	62	1,024 split →
/27	255.255.255.224	32	30	2,048 split →
/28	255.255.255.240	16	14	4,096 split →
/29	255.255.255.248	8	6	8,192 split →
/30	255.255.255.252	4	2	16,384 split →
/31	255.255.255.254	2	2	32,768 split →
/32	255.255.255.255	1	1	65,536 split →

02 / faq

About this calculator.

How do I use this subnet calculator?

▼

Type an IP address followed by a prefix, like 192.168.1.10/24, or by a subnet mask, like 192.168.1.10 255.255.255.0. Without a prefix it uses /24. Click a row in the table to split the network into smaller subnets.

Why are usable hosts always 2 fewer?

▼

The first address in a subnet is the network address and the last is the broadcast address, so neither can go to a device. The exceptions are /31 (point-to-point links, RFC 3021) and /32 (a single address), which use every address.

Can I use it from a terminal?

▼

Yes. curl 'ipku.in/en/tools/ipv4-subnet-calculator?q=192.168.1.10/24' returns the result as plain text.

Learn how to work it out →