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)10.21.64.0/18

network10.21.64.0/18

broadcast10.21.127.255

first host10.21.64.1

last host10.21.127.254

subnet mask255.255.192.0

wildcard0.0.63.255

addresses16,384

usable hosts16,382

classA

ipcalc 10.21.64.0/18

address00001010.00010101.01000000.00000000

subnet mask11111111.11111111.11000000.00000000

network00001010.00010101.01000000.00000000

broadcast00001010.00010101.01111111.11111111

green = network part, grey = host part

hex0x0a154000

decimal169164800

reverse dns0.64.21.10.in-addr.arpa

ipv4-mapped::ffff:a15:4000

/18 split into /27 · 512 subnets

close ×

#	network	host range	broadcast
1	10.21.64.0/27	10.21.64.1 – 10.21.64.30	10.21.64.31
2	10.21.64.32/27	10.21.64.33 – 10.21.64.62	10.21.64.63
3	10.21.64.64/27	10.21.64.65 – 10.21.64.94	10.21.64.95
4	10.21.64.96/27	10.21.64.97 – 10.21.64.126	10.21.64.127
5	10.21.64.128/27	10.21.64.129 – 10.21.64.158	10.21.64.159
6	10.21.64.160/27	10.21.64.161 – 10.21.64.190	10.21.64.191
7	10.21.64.192/27	10.21.64.193 – 10.21.64.222	10.21.64.223
8	10.21.64.224/27	10.21.64.225 – 10.21.64.254	10.21.64.255
9	10.21.65.0/27	10.21.65.1 – 10.21.65.30	10.21.65.31
10	10.21.65.32/27	10.21.65.33 – 10.21.65.62	10.21.65.63
11	10.21.65.64/27	10.21.65.65 – 10.21.65.94	10.21.65.95
12	10.21.65.96/27	10.21.65.97 – 10.21.65.126	10.21.65.127
13	10.21.65.128/27	10.21.65.129 – 10.21.65.158	10.21.65.159
14	10.21.65.160/27	10.21.65.161 – 10.21.65.190	10.21.65.191
15	10.21.65.192/27	10.21.65.193 – 10.21.65.222	10.21.65.223
16	10.21.65.224/27	10.21.65.225 – 10.21.65.254	10.21.65.255
17	10.21.66.0/27	10.21.66.1 – 10.21.66.30	10.21.66.31
18	10.21.66.32/27	10.21.66.33 – 10.21.66.62	10.21.66.63
19	10.21.66.64/27	10.21.66.65 – 10.21.66.94	10.21.66.95
20	10.21.66.96/27	10.21.66.97 – 10.21.66.126	10.21.66.127
21	10.21.66.128/27	10.21.66.129 – 10.21.66.158	10.21.66.159
22	10.21.66.160/27	10.21.66.161 – 10.21.66.190	10.21.66.191
23	10.21.66.192/27	10.21.66.193 – 10.21.66.222	10.21.66.223
24	10.21.66.224/27	10.21.66.225 – 10.21.66.254	10.21.66.255
25	10.21.67.0/27	10.21.67.1 – 10.21.67.30	10.21.67.31
26	10.21.67.32/27	10.21.67.33 – 10.21.67.62	10.21.67.63
27	10.21.67.64/27	10.21.67.65 – 10.21.67.94	10.21.67.95
28	10.21.67.96/27	10.21.67.97 – 10.21.67.126	10.21.67.127
29	10.21.67.128/27	10.21.67.129 – 10.21.67.158	10.21.67.159
30	10.21.67.160/27	10.21.67.161 – 10.21.67.190	10.21.67.191
31	10.21.67.192/27	10.21.67.193 – 10.21.67.222	10.21.67.223
32	10.21.67.224/27	10.21.67.225 – 10.21.67.254	10.21.67.255
33	10.21.68.0/27	10.21.68.1 – 10.21.68.30	10.21.68.31
34	10.21.68.32/27	10.21.68.33 – 10.21.68.62	10.21.68.63
35	10.21.68.64/27	10.21.68.65 – 10.21.68.94	10.21.68.95
36	10.21.68.96/27	10.21.68.97 – 10.21.68.126	10.21.68.127
37	10.21.68.128/27	10.21.68.129 – 10.21.68.158	10.21.68.159
38	10.21.68.160/27	10.21.68.161 – 10.21.68.190	10.21.68.191
39	10.21.68.192/27	10.21.68.193 – 10.21.68.222	10.21.68.223
40	10.21.68.224/27	10.21.68.225 – 10.21.68.254	10.21.68.255
41	10.21.69.0/27	10.21.69.1 – 10.21.69.30	10.21.69.31
42	10.21.69.32/27	10.21.69.33 – 10.21.69.62	10.21.69.63
43	10.21.69.64/27	10.21.69.65 – 10.21.69.94	10.21.69.95
44	10.21.69.96/27	10.21.69.97 – 10.21.69.126	10.21.69.127
45	10.21.69.128/27	10.21.69.129 – 10.21.69.158	10.21.69.159
46	10.21.69.160/27	10.21.69.161 – 10.21.69.190	10.21.69.191
47	10.21.69.192/27	10.21.69.193 – 10.21.69.222	10.21.69.223
48	10.21.69.224/27	10.21.69.225 – 10.21.69.254	10.21.69.255
49	10.21.70.0/27	10.21.70.1 – 10.21.70.30	10.21.70.31
50	10.21.70.32/27	10.21.70.33 – 10.21.70.62	10.21.70.63
51	10.21.70.64/27	10.21.70.65 – 10.21.70.94	10.21.70.95
52	10.21.70.96/27	10.21.70.97 – 10.21.70.126	10.21.70.127
53	10.21.70.128/27	10.21.70.129 – 10.21.70.158	10.21.70.159
54	10.21.70.160/27	10.21.70.161 – 10.21.70.190	10.21.70.191
55	10.21.70.192/27	10.21.70.193 – 10.21.70.222	10.21.70.223
56	10.21.70.224/27	10.21.70.225 – 10.21.70.254	10.21.70.255
57	10.21.71.0/27	10.21.71.1 – 10.21.71.30	10.21.71.31
58	10.21.71.32/27	10.21.71.33 – 10.21.71.62	10.21.71.63
59	10.21.71.64/27	10.21.71.65 – 10.21.71.94	10.21.71.95
60	10.21.71.96/27	10.21.71.97 – 10.21.71.126	10.21.71.127
61	10.21.71.128/27	10.21.71.129 – 10.21.71.158	10.21.71.159
62	10.21.71.160/27	10.21.71.161 – 10.21.71.190	10.21.71.191
63	10.21.71.192/27	10.21.71.193 – 10.21.71.222	10.21.71.223
64	10.21.71.224/27	10.21.71.225 – 10.21.71.254	10.21.71.255
65	10.21.72.0/27	10.21.72.1 – 10.21.72.30	10.21.72.31
66	10.21.72.32/27	10.21.72.33 – 10.21.72.62	10.21.72.63
67	10.21.72.64/27	10.21.72.65 – 10.21.72.94	10.21.72.95
68	10.21.72.96/27	10.21.72.97 – 10.21.72.126	10.21.72.127
69	10.21.72.128/27	10.21.72.129 – 10.21.72.158	10.21.72.159
70	10.21.72.160/27	10.21.72.161 – 10.21.72.190	10.21.72.191
71	10.21.72.192/27	10.21.72.193 – 10.21.72.222	10.21.72.223
72	10.21.72.224/27	10.21.72.225 – 10.21.72.254	10.21.72.255
73	10.21.73.0/27	10.21.73.1 – 10.21.73.30	10.21.73.31
74	10.21.73.32/27	10.21.73.33 – 10.21.73.62	10.21.73.63
75	10.21.73.64/27	10.21.73.65 – 10.21.73.94	10.21.73.95
76	10.21.73.96/27	10.21.73.97 – 10.21.73.126	10.21.73.127
77	10.21.73.128/27	10.21.73.129 – 10.21.73.158	10.21.73.159
78	10.21.73.160/27	10.21.73.161 – 10.21.73.190	10.21.73.191
79	10.21.73.192/27	10.21.73.193 – 10.21.73.222	10.21.73.223
80	10.21.73.224/27	10.21.73.225 – 10.21.73.254	10.21.73.255
81	10.21.74.0/27	10.21.74.1 – 10.21.74.30	10.21.74.31
82	10.21.74.32/27	10.21.74.33 – 10.21.74.62	10.21.74.63
83	10.21.74.64/27	10.21.74.65 – 10.21.74.94	10.21.74.95
84	10.21.74.96/27	10.21.74.97 – 10.21.74.126	10.21.74.127
85	10.21.74.128/27	10.21.74.129 – 10.21.74.158	10.21.74.159
86	10.21.74.160/27	10.21.74.161 – 10.21.74.190	10.21.74.191
87	10.21.74.192/27	10.21.74.193 – 10.21.74.222	10.21.74.223
88	10.21.74.224/27	10.21.74.225 – 10.21.74.254	10.21.74.255
89	10.21.75.0/27	10.21.75.1 – 10.21.75.30	10.21.75.31
90	10.21.75.32/27	10.21.75.33 – 10.21.75.62	10.21.75.63
91	10.21.75.64/27	10.21.75.65 – 10.21.75.94	10.21.75.95
92	10.21.75.96/27	10.21.75.97 – 10.21.75.126	10.21.75.127
93	10.21.75.128/27	10.21.75.129 – 10.21.75.158	10.21.75.159
94	10.21.75.160/27	10.21.75.161 – 10.21.75.190	10.21.75.191
95	10.21.75.192/27	10.21.75.193 – 10.21.75.222	10.21.75.223
96	10.21.75.224/27	10.21.75.225 – 10.21.75.254	10.21.75.255
97	10.21.76.0/27	10.21.76.1 – 10.21.76.30	10.21.76.31
98	10.21.76.32/27	10.21.76.33 – 10.21.76.62	10.21.76.63
99	10.21.76.64/27	10.21.76.65 – 10.21.76.94	10.21.76.95
100	10.21.76.96/27	10.21.76.97 – 10.21.76.126	10.21.76.127
101	10.21.76.128/27	10.21.76.129 – 10.21.76.158	10.21.76.159
102	10.21.76.160/27	10.21.76.161 – 10.21.76.190	10.21.76.191
103	10.21.76.192/27	10.21.76.193 – 10.21.76.222	10.21.76.223
104	10.21.76.224/27	10.21.76.225 – 10.21.76.254	10.21.76.255
105	10.21.77.0/27	10.21.77.1 – 10.21.77.30	10.21.77.31
106	10.21.77.32/27	10.21.77.33 – 10.21.77.62	10.21.77.63
107	10.21.77.64/27	10.21.77.65 – 10.21.77.94	10.21.77.95
108	10.21.77.96/27	10.21.77.97 – 10.21.77.126	10.21.77.127
109	10.21.77.128/27	10.21.77.129 – 10.21.77.158	10.21.77.159
110	10.21.77.160/27	10.21.77.161 – 10.21.77.190	10.21.77.191
111	10.21.77.192/27	10.21.77.193 – 10.21.77.222	10.21.77.223
112	10.21.77.224/27	10.21.77.225 – 10.21.77.254	10.21.77.255
113	10.21.78.0/27	10.21.78.1 – 10.21.78.30	10.21.78.31
114	10.21.78.32/27	10.21.78.33 – 10.21.78.62	10.21.78.63
115	10.21.78.64/27	10.21.78.65 – 10.21.78.94	10.21.78.95
116	10.21.78.96/27	10.21.78.97 – 10.21.78.126	10.21.78.127
117	10.21.78.128/27	10.21.78.129 – 10.21.78.158	10.21.78.159
118	10.21.78.160/27	10.21.78.161 – 10.21.78.190	10.21.78.191
119	10.21.78.192/27	10.21.78.193 – 10.21.78.222	10.21.78.223
120	10.21.78.224/27	10.21.78.225 – 10.21.78.254	10.21.78.255
121	10.21.79.0/27	10.21.79.1 – 10.21.79.30	10.21.79.31
122	10.21.79.32/27	10.21.79.33 – 10.21.79.62	10.21.79.63
123	10.21.79.64/27	10.21.79.65 – 10.21.79.94	10.21.79.95
124	10.21.79.96/27	10.21.79.97 – 10.21.79.126	10.21.79.127
125	10.21.79.128/27	10.21.79.129 – 10.21.79.158	10.21.79.159
126	10.21.79.160/27	10.21.79.161 – 10.21.79.190	10.21.79.191
127	10.21.79.192/27	10.21.79.193 – 10.21.79.222	10.21.79.223
128	10.21.79.224/27	10.21.79.225 – 10.21.79.254	10.21.79.255
129	10.21.80.0/27	10.21.80.1 – 10.21.80.30	10.21.80.31
130	10.21.80.32/27	10.21.80.33 – 10.21.80.62	10.21.80.63
131	10.21.80.64/27	10.21.80.65 – 10.21.80.94	10.21.80.95
132	10.21.80.96/27	10.21.80.97 – 10.21.80.126	10.21.80.127
133	10.21.80.128/27	10.21.80.129 – 10.21.80.158	10.21.80.159
134	10.21.80.160/27	10.21.80.161 – 10.21.80.190	10.21.80.191
135	10.21.80.192/27	10.21.80.193 – 10.21.80.222	10.21.80.223
136	10.21.80.224/27	10.21.80.225 – 10.21.80.254	10.21.80.255
137	10.21.81.0/27	10.21.81.1 – 10.21.81.30	10.21.81.31
138	10.21.81.32/27	10.21.81.33 – 10.21.81.62	10.21.81.63
139	10.21.81.64/27	10.21.81.65 – 10.21.81.94	10.21.81.95
140	10.21.81.96/27	10.21.81.97 – 10.21.81.126	10.21.81.127
141	10.21.81.128/27	10.21.81.129 – 10.21.81.158	10.21.81.159
142	10.21.81.160/27	10.21.81.161 – 10.21.81.190	10.21.81.191
143	10.21.81.192/27	10.21.81.193 – 10.21.81.222	10.21.81.223
144	10.21.81.224/27	10.21.81.225 – 10.21.81.254	10.21.81.255
145	10.21.82.0/27	10.21.82.1 – 10.21.82.30	10.21.82.31
146	10.21.82.32/27	10.21.82.33 – 10.21.82.62	10.21.82.63
147	10.21.82.64/27	10.21.82.65 – 10.21.82.94	10.21.82.95
148	10.21.82.96/27	10.21.82.97 – 10.21.82.126	10.21.82.127
149	10.21.82.128/27	10.21.82.129 – 10.21.82.158	10.21.82.159
150	10.21.82.160/27	10.21.82.161 – 10.21.82.190	10.21.82.191
151	10.21.82.192/27	10.21.82.193 – 10.21.82.222	10.21.82.223
152	10.21.82.224/27	10.21.82.225 – 10.21.82.254	10.21.82.255
153	10.21.83.0/27	10.21.83.1 – 10.21.83.30	10.21.83.31
154	10.21.83.32/27	10.21.83.33 – 10.21.83.62	10.21.83.63
155	10.21.83.64/27	10.21.83.65 – 10.21.83.94	10.21.83.95
156	10.21.83.96/27	10.21.83.97 – 10.21.83.126	10.21.83.127
157	10.21.83.128/27	10.21.83.129 – 10.21.83.158	10.21.83.159
158	10.21.83.160/27	10.21.83.161 – 10.21.83.190	10.21.83.191
159	10.21.83.192/27	10.21.83.193 – 10.21.83.222	10.21.83.223
160	10.21.83.224/27	10.21.83.225 – 10.21.83.254	10.21.83.255
161	10.21.84.0/27	10.21.84.1 – 10.21.84.30	10.21.84.31
162	10.21.84.32/27	10.21.84.33 – 10.21.84.62	10.21.84.63
163	10.21.84.64/27	10.21.84.65 – 10.21.84.94	10.21.84.95
164	10.21.84.96/27	10.21.84.97 – 10.21.84.126	10.21.84.127
165	10.21.84.128/27	10.21.84.129 – 10.21.84.158	10.21.84.159
166	10.21.84.160/27	10.21.84.161 – 10.21.84.190	10.21.84.191
167	10.21.84.192/27	10.21.84.193 – 10.21.84.222	10.21.84.223
168	10.21.84.224/27	10.21.84.225 – 10.21.84.254	10.21.84.255
169	10.21.85.0/27	10.21.85.1 – 10.21.85.30	10.21.85.31
170	10.21.85.32/27	10.21.85.33 – 10.21.85.62	10.21.85.63
171	10.21.85.64/27	10.21.85.65 – 10.21.85.94	10.21.85.95
172	10.21.85.96/27	10.21.85.97 – 10.21.85.126	10.21.85.127
173	10.21.85.128/27	10.21.85.129 – 10.21.85.158	10.21.85.159
174	10.21.85.160/27	10.21.85.161 – 10.21.85.190	10.21.85.191
175	10.21.85.192/27	10.21.85.193 – 10.21.85.222	10.21.85.223
176	10.21.85.224/27	10.21.85.225 – 10.21.85.254	10.21.85.255
177	10.21.86.0/27	10.21.86.1 – 10.21.86.30	10.21.86.31
178	10.21.86.32/27	10.21.86.33 – 10.21.86.62	10.21.86.63
179	10.21.86.64/27	10.21.86.65 – 10.21.86.94	10.21.86.95
180	10.21.86.96/27	10.21.86.97 – 10.21.86.126	10.21.86.127
181	10.21.86.128/27	10.21.86.129 – 10.21.86.158	10.21.86.159
182	10.21.86.160/27	10.21.86.161 – 10.21.86.190	10.21.86.191
183	10.21.86.192/27	10.21.86.193 – 10.21.86.222	10.21.86.223
184	10.21.86.224/27	10.21.86.225 – 10.21.86.254	10.21.86.255
185	10.21.87.0/27	10.21.87.1 – 10.21.87.30	10.21.87.31
186	10.21.87.32/27	10.21.87.33 – 10.21.87.62	10.21.87.63
187	10.21.87.64/27	10.21.87.65 – 10.21.87.94	10.21.87.95
188	10.21.87.96/27	10.21.87.97 – 10.21.87.126	10.21.87.127
189	10.21.87.128/27	10.21.87.129 – 10.21.87.158	10.21.87.159
190	10.21.87.160/27	10.21.87.161 – 10.21.87.190	10.21.87.191
191	10.21.87.192/27	10.21.87.193 – 10.21.87.222	10.21.87.223
192	10.21.87.224/27	10.21.87.225 – 10.21.87.254	10.21.87.255
193	10.21.88.0/27	10.21.88.1 – 10.21.88.30	10.21.88.31
194	10.21.88.32/27	10.21.88.33 – 10.21.88.62	10.21.88.63
195	10.21.88.64/27	10.21.88.65 – 10.21.88.94	10.21.88.95
196	10.21.88.96/27	10.21.88.97 – 10.21.88.126	10.21.88.127
197	10.21.88.128/27	10.21.88.129 – 10.21.88.158	10.21.88.159
198	10.21.88.160/27	10.21.88.161 – 10.21.88.190	10.21.88.191
199	10.21.88.192/27	10.21.88.193 – 10.21.88.222	10.21.88.223
200	10.21.88.224/27	10.21.88.225 – 10.21.88.254	10.21.88.255
201	10.21.89.0/27	10.21.89.1 – 10.21.89.30	10.21.89.31
202	10.21.89.32/27	10.21.89.33 – 10.21.89.62	10.21.89.63
203	10.21.89.64/27	10.21.89.65 – 10.21.89.94	10.21.89.95
204	10.21.89.96/27	10.21.89.97 – 10.21.89.126	10.21.89.127
205	10.21.89.128/27	10.21.89.129 – 10.21.89.158	10.21.89.159
206	10.21.89.160/27	10.21.89.161 – 10.21.89.190	10.21.89.191
207	10.21.89.192/27	10.21.89.193 – 10.21.89.222	10.21.89.223
208	10.21.89.224/27	10.21.89.225 – 10.21.89.254	10.21.89.255
209	10.21.90.0/27	10.21.90.1 – 10.21.90.30	10.21.90.31
210	10.21.90.32/27	10.21.90.33 – 10.21.90.62	10.21.90.63
211	10.21.90.64/27	10.21.90.65 – 10.21.90.94	10.21.90.95
212	10.21.90.96/27	10.21.90.97 – 10.21.90.126	10.21.90.127
213	10.21.90.128/27	10.21.90.129 – 10.21.90.158	10.21.90.159
214	10.21.90.160/27	10.21.90.161 – 10.21.90.190	10.21.90.191
215	10.21.90.192/27	10.21.90.193 – 10.21.90.222	10.21.90.223
216	10.21.90.224/27	10.21.90.225 – 10.21.90.254	10.21.90.255
217	10.21.91.0/27	10.21.91.1 – 10.21.91.30	10.21.91.31
218	10.21.91.32/27	10.21.91.33 – 10.21.91.62	10.21.91.63
219	10.21.91.64/27	10.21.91.65 – 10.21.91.94	10.21.91.95
220	10.21.91.96/27	10.21.91.97 – 10.21.91.126	10.21.91.127
221	10.21.91.128/27	10.21.91.129 – 10.21.91.158	10.21.91.159
222	10.21.91.160/27	10.21.91.161 – 10.21.91.190	10.21.91.191
223	10.21.91.192/27	10.21.91.193 – 10.21.91.222	10.21.91.223
224	10.21.91.224/27	10.21.91.225 – 10.21.91.254	10.21.91.255
225	10.21.92.0/27	10.21.92.1 – 10.21.92.30	10.21.92.31
226	10.21.92.32/27	10.21.92.33 – 10.21.92.62	10.21.92.63
227	10.21.92.64/27	10.21.92.65 – 10.21.92.94	10.21.92.95
228	10.21.92.96/27	10.21.92.97 – 10.21.92.126	10.21.92.127
229	10.21.92.128/27	10.21.92.129 – 10.21.92.158	10.21.92.159
230	10.21.92.160/27	10.21.92.161 – 10.21.92.190	10.21.92.191
231	10.21.92.192/27	10.21.92.193 – 10.21.92.222	10.21.92.223
232	10.21.92.224/27	10.21.92.225 – 10.21.92.254	10.21.92.255
233	10.21.93.0/27	10.21.93.1 – 10.21.93.30	10.21.93.31
234	10.21.93.32/27	10.21.93.33 – 10.21.93.62	10.21.93.63
235	10.21.93.64/27	10.21.93.65 – 10.21.93.94	10.21.93.95
236	10.21.93.96/27	10.21.93.97 – 10.21.93.126	10.21.93.127
237	10.21.93.128/27	10.21.93.129 – 10.21.93.158	10.21.93.159
238	10.21.93.160/27	10.21.93.161 – 10.21.93.190	10.21.93.191
239	10.21.93.192/27	10.21.93.193 – 10.21.93.222	10.21.93.223
240	10.21.93.224/27	10.21.93.225 – 10.21.93.254	10.21.93.255
241	10.21.94.0/27	10.21.94.1 – 10.21.94.30	10.21.94.31
242	10.21.94.32/27	10.21.94.33 – 10.21.94.62	10.21.94.63
243	10.21.94.64/27	10.21.94.65 – 10.21.94.94	10.21.94.95
244	10.21.94.96/27	10.21.94.97 – 10.21.94.126	10.21.94.127
245	10.21.94.128/27	10.21.94.129 – 10.21.94.158	10.21.94.159
246	10.21.94.160/27	10.21.94.161 – 10.21.94.190	10.21.94.191
247	10.21.94.192/27	10.21.94.193 – 10.21.94.222	10.21.94.223
248	10.21.94.224/27	10.21.94.225 – 10.21.94.254	10.21.94.255
249	10.21.95.0/27	10.21.95.1 – 10.21.95.30	10.21.95.31
250	10.21.95.32/27	10.21.95.33 – 10.21.95.62	10.21.95.63
251	10.21.95.64/27	10.21.95.65 – 10.21.95.94	10.21.95.95
252	10.21.95.96/27	10.21.95.97 – 10.21.95.126	10.21.95.127
253	10.21.95.128/27	10.21.95.129 – 10.21.95.158	10.21.95.159
254	10.21.95.160/27	10.21.95.161 – 10.21.95.190	10.21.95.191
255	10.21.95.192/27	10.21.95.193 – 10.21.95.222	10.21.95.223
256	10.21.95.224/27	10.21.95.225 – 10.21.95.254	10.21.95.255

showing 256 of 512

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 /18
/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	-
/17	255.255.128.0	32,768	32,766	-
/18	255.255.192.0	16,384	16,382	1
/19	255.255.224.0	8,192	8,190	2 split →
/20	255.255.240.0	4,096	4,094	4 split →
/21	255.255.248.0	2,048	2,046	8 split →
/22	255.255.252.0	1,024	1,022	16 split →
/23	255.255.254.0	512	510	32 split →
/24	255.255.255.0	256	254	64 split →
/25	255.255.255.128	128	126	128 split →
/26	255.255.255.192	64	62	256 split →
/27	255.255.255.224	32	30	512 split →
/28	255.255.255.240	16	14	1,024 split →
/29	255.255.255.248	8	6	2,048 split →
/30	255.255.255.252	4	2	4,096 split →
/31	255.255.255.254	2	2	8,192 split →
/32	255.255.255.255	1	1	16,384 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 →