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 /26 · 256 subnets

close ×

#	network	host range	broadcast
1	10.21.64.0/26	10.21.64.1 – 10.21.64.62	10.21.64.63
2	10.21.64.64/26	10.21.64.65 – 10.21.64.126	10.21.64.127
3	10.21.64.128/26	10.21.64.129 – 10.21.64.190	10.21.64.191
4	10.21.64.192/26	10.21.64.193 – 10.21.64.254	10.21.64.255
5	10.21.65.0/26	10.21.65.1 – 10.21.65.62	10.21.65.63
6	10.21.65.64/26	10.21.65.65 – 10.21.65.126	10.21.65.127
7	10.21.65.128/26	10.21.65.129 – 10.21.65.190	10.21.65.191
8	10.21.65.192/26	10.21.65.193 – 10.21.65.254	10.21.65.255
9	10.21.66.0/26	10.21.66.1 – 10.21.66.62	10.21.66.63
10	10.21.66.64/26	10.21.66.65 – 10.21.66.126	10.21.66.127
11	10.21.66.128/26	10.21.66.129 – 10.21.66.190	10.21.66.191
12	10.21.66.192/26	10.21.66.193 – 10.21.66.254	10.21.66.255
13	10.21.67.0/26	10.21.67.1 – 10.21.67.62	10.21.67.63
14	10.21.67.64/26	10.21.67.65 – 10.21.67.126	10.21.67.127
15	10.21.67.128/26	10.21.67.129 – 10.21.67.190	10.21.67.191
16	10.21.67.192/26	10.21.67.193 – 10.21.67.254	10.21.67.255
17	10.21.68.0/26	10.21.68.1 – 10.21.68.62	10.21.68.63
18	10.21.68.64/26	10.21.68.65 – 10.21.68.126	10.21.68.127
19	10.21.68.128/26	10.21.68.129 – 10.21.68.190	10.21.68.191
20	10.21.68.192/26	10.21.68.193 – 10.21.68.254	10.21.68.255
21	10.21.69.0/26	10.21.69.1 – 10.21.69.62	10.21.69.63
22	10.21.69.64/26	10.21.69.65 – 10.21.69.126	10.21.69.127
23	10.21.69.128/26	10.21.69.129 – 10.21.69.190	10.21.69.191
24	10.21.69.192/26	10.21.69.193 – 10.21.69.254	10.21.69.255
25	10.21.70.0/26	10.21.70.1 – 10.21.70.62	10.21.70.63
26	10.21.70.64/26	10.21.70.65 – 10.21.70.126	10.21.70.127
27	10.21.70.128/26	10.21.70.129 – 10.21.70.190	10.21.70.191
28	10.21.70.192/26	10.21.70.193 – 10.21.70.254	10.21.70.255
29	10.21.71.0/26	10.21.71.1 – 10.21.71.62	10.21.71.63
30	10.21.71.64/26	10.21.71.65 – 10.21.71.126	10.21.71.127
31	10.21.71.128/26	10.21.71.129 – 10.21.71.190	10.21.71.191
32	10.21.71.192/26	10.21.71.193 – 10.21.71.254	10.21.71.255
33	10.21.72.0/26	10.21.72.1 – 10.21.72.62	10.21.72.63
34	10.21.72.64/26	10.21.72.65 – 10.21.72.126	10.21.72.127
35	10.21.72.128/26	10.21.72.129 – 10.21.72.190	10.21.72.191
36	10.21.72.192/26	10.21.72.193 – 10.21.72.254	10.21.72.255
37	10.21.73.0/26	10.21.73.1 – 10.21.73.62	10.21.73.63
38	10.21.73.64/26	10.21.73.65 – 10.21.73.126	10.21.73.127
39	10.21.73.128/26	10.21.73.129 – 10.21.73.190	10.21.73.191
40	10.21.73.192/26	10.21.73.193 – 10.21.73.254	10.21.73.255
41	10.21.74.0/26	10.21.74.1 – 10.21.74.62	10.21.74.63
42	10.21.74.64/26	10.21.74.65 – 10.21.74.126	10.21.74.127
43	10.21.74.128/26	10.21.74.129 – 10.21.74.190	10.21.74.191
44	10.21.74.192/26	10.21.74.193 – 10.21.74.254	10.21.74.255
45	10.21.75.0/26	10.21.75.1 – 10.21.75.62	10.21.75.63
46	10.21.75.64/26	10.21.75.65 – 10.21.75.126	10.21.75.127
47	10.21.75.128/26	10.21.75.129 – 10.21.75.190	10.21.75.191
48	10.21.75.192/26	10.21.75.193 – 10.21.75.254	10.21.75.255
49	10.21.76.0/26	10.21.76.1 – 10.21.76.62	10.21.76.63
50	10.21.76.64/26	10.21.76.65 – 10.21.76.126	10.21.76.127
51	10.21.76.128/26	10.21.76.129 – 10.21.76.190	10.21.76.191
52	10.21.76.192/26	10.21.76.193 – 10.21.76.254	10.21.76.255
53	10.21.77.0/26	10.21.77.1 – 10.21.77.62	10.21.77.63
54	10.21.77.64/26	10.21.77.65 – 10.21.77.126	10.21.77.127
55	10.21.77.128/26	10.21.77.129 – 10.21.77.190	10.21.77.191
56	10.21.77.192/26	10.21.77.193 – 10.21.77.254	10.21.77.255
57	10.21.78.0/26	10.21.78.1 – 10.21.78.62	10.21.78.63
58	10.21.78.64/26	10.21.78.65 – 10.21.78.126	10.21.78.127
59	10.21.78.128/26	10.21.78.129 – 10.21.78.190	10.21.78.191
60	10.21.78.192/26	10.21.78.193 – 10.21.78.254	10.21.78.255
61	10.21.79.0/26	10.21.79.1 – 10.21.79.62	10.21.79.63
62	10.21.79.64/26	10.21.79.65 – 10.21.79.126	10.21.79.127
63	10.21.79.128/26	10.21.79.129 – 10.21.79.190	10.21.79.191
64	10.21.79.192/26	10.21.79.193 – 10.21.79.254	10.21.79.255
65	10.21.80.0/26	10.21.80.1 – 10.21.80.62	10.21.80.63
66	10.21.80.64/26	10.21.80.65 – 10.21.80.126	10.21.80.127
67	10.21.80.128/26	10.21.80.129 – 10.21.80.190	10.21.80.191
68	10.21.80.192/26	10.21.80.193 – 10.21.80.254	10.21.80.255
69	10.21.81.0/26	10.21.81.1 – 10.21.81.62	10.21.81.63
70	10.21.81.64/26	10.21.81.65 – 10.21.81.126	10.21.81.127
71	10.21.81.128/26	10.21.81.129 – 10.21.81.190	10.21.81.191
72	10.21.81.192/26	10.21.81.193 – 10.21.81.254	10.21.81.255
73	10.21.82.0/26	10.21.82.1 – 10.21.82.62	10.21.82.63
74	10.21.82.64/26	10.21.82.65 – 10.21.82.126	10.21.82.127
75	10.21.82.128/26	10.21.82.129 – 10.21.82.190	10.21.82.191
76	10.21.82.192/26	10.21.82.193 – 10.21.82.254	10.21.82.255
77	10.21.83.0/26	10.21.83.1 – 10.21.83.62	10.21.83.63
78	10.21.83.64/26	10.21.83.65 – 10.21.83.126	10.21.83.127
79	10.21.83.128/26	10.21.83.129 – 10.21.83.190	10.21.83.191
80	10.21.83.192/26	10.21.83.193 – 10.21.83.254	10.21.83.255
81	10.21.84.0/26	10.21.84.1 – 10.21.84.62	10.21.84.63
82	10.21.84.64/26	10.21.84.65 – 10.21.84.126	10.21.84.127
83	10.21.84.128/26	10.21.84.129 – 10.21.84.190	10.21.84.191
84	10.21.84.192/26	10.21.84.193 – 10.21.84.254	10.21.84.255
85	10.21.85.0/26	10.21.85.1 – 10.21.85.62	10.21.85.63
86	10.21.85.64/26	10.21.85.65 – 10.21.85.126	10.21.85.127
87	10.21.85.128/26	10.21.85.129 – 10.21.85.190	10.21.85.191
88	10.21.85.192/26	10.21.85.193 – 10.21.85.254	10.21.85.255
89	10.21.86.0/26	10.21.86.1 – 10.21.86.62	10.21.86.63
90	10.21.86.64/26	10.21.86.65 – 10.21.86.126	10.21.86.127
91	10.21.86.128/26	10.21.86.129 – 10.21.86.190	10.21.86.191
92	10.21.86.192/26	10.21.86.193 – 10.21.86.254	10.21.86.255
93	10.21.87.0/26	10.21.87.1 – 10.21.87.62	10.21.87.63
94	10.21.87.64/26	10.21.87.65 – 10.21.87.126	10.21.87.127
95	10.21.87.128/26	10.21.87.129 – 10.21.87.190	10.21.87.191
96	10.21.87.192/26	10.21.87.193 – 10.21.87.254	10.21.87.255
97	10.21.88.0/26	10.21.88.1 – 10.21.88.62	10.21.88.63
98	10.21.88.64/26	10.21.88.65 – 10.21.88.126	10.21.88.127
99	10.21.88.128/26	10.21.88.129 – 10.21.88.190	10.21.88.191
100	10.21.88.192/26	10.21.88.193 – 10.21.88.254	10.21.88.255
101	10.21.89.0/26	10.21.89.1 – 10.21.89.62	10.21.89.63
102	10.21.89.64/26	10.21.89.65 – 10.21.89.126	10.21.89.127
103	10.21.89.128/26	10.21.89.129 – 10.21.89.190	10.21.89.191
104	10.21.89.192/26	10.21.89.193 – 10.21.89.254	10.21.89.255
105	10.21.90.0/26	10.21.90.1 – 10.21.90.62	10.21.90.63
106	10.21.90.64/26	10.21.90.65 – 10.21.90.126	10.21.90.127
107	10.21.90.128/26	10.21.90.129 – 10.21.90.190	10.21.90.191
108	10.21.90.192/26	10.21.90.193 – 10.21.90.254	10.21.90.255
109	10.21.91.0/26	10.21.91.1 – 10.21.91.62	10.21.91.63
110	10.21.91.64/26	10.21.91.65 – 10.21.91.126	10.21.91.127
111	10.21.91.128/26	10.21.91.129 – 10.21.91.190	10.21.91.191
112	10.21.91.192/26	10.21.91.193 – 10.21.91.254	10.21.91.255
113	10.21.92.0/26	10.21.92.1 – 10.21.92.62	10.21.92.63
114	10.21.92.64/26	10.21.92.65 – 10.21.92.126	10.21.92.127
115	10.21.92.128/26	10.21.92.129 – 10.21.92.190	10.21.92.191
116	10.21.92.192/26	10.21.92.193 – 10.21.92.254	10.21.92.255
117	10.21.93.0/26	10.21.93.1 – 10.21.93.62	10.21.93.63
118	10.21.93.64/26	10.21.93.65 – 10.21.93.126	10.21.93.127
119	10.21.93.128/26	10.21.93.129 – 10.21.93.190	10.21.93.191
120	10.21.93.192/26	10.21.93.193 – 10.21.93.254	10.21.93.255
121	10.21.94.0/26	10.21.94.1 – 10.21.94.62	10.21.94.63
122	10.21.94.64/26	10.21.94.65 – 10.21.94.126	10.21.94.127
123	10.21.94.128/26	10.21.94.129 – 10.21.94.190	10.21.94.191
124	10.21.94.192/26	10.21.94.193 – 10.21.94.254	10.21.94.255
125	10.21.95.0/26	10.21.95.1 – 10.21.95.62	10.21.95.63
126	10.21.95.64/26	10.21.95.65 – 10.21.95.126	10.21.95.127
127	10.21.95.128/26	10.21.95.129 – 10.21.95.190	10.21.95.191
128	10.21.95.192/26	10.21.95.193 – 10.21.95.254	10.21.95.255
129	10.21.96.0/26	10.21.96.1 – 10.21.96.62	10.21.96.63
130	10.21.96.64/26	10.21.96.65 – 10.21.96.126	10.21.96.127
131	10.21.96.128/26	10.21.96.129 – 10.21.96.190	10.21.96.191
132	10.21.96.192/26	10.21.96.193 – 10.21.96.254	10.21.96.255
133	10.21.97.0/26	10.21.97.1 – 10.21.97.62	10.21.97.63
134	10.21.97.64/26	10.21.97.65 – 10.21.97.126	10.21.97.127
135	10.21.97.128/26	10.21.97.129 – 10.21.97.190	10.21.97.191
136	10.21.97.192/26	10.21.97.193 – 10.21.97.254	10.21.97.255
137	10.21.98.0/26	10.21.98.1 – 10.21.98.62	10.21.98.63
138	10.21.98.64/26	10.21.98.65 – 10.21.98.126	10.21.98.127
139	10.21.98.128/26	10.21.98.129 – 10.21.98.190	10.21.98.191
140	10.21.98.192/26	10.21.98.193 – 10.21.98.254	10.21.98.255
141	10.21.99.0/26	10.21.99.1 – 10.21.99.62	10.21.99.63
142	10.21.99.64/26	10.21.99.65 – 10.21.99.126	10.21.99.127
143	10.21.99.128/26	10.21.99.129 – 10.21.99.190	10.21.99.191
144	10.21.99.192/26	10.21.99.193 – 10.21.99.254	10.21.99.255
145	10.21.100.0/26	10.21.100.1 – 10.21.100.62	10.21.100.63
146	10.21.100.64/26	10.21.100.65 – 10.21.100.126	10.21.100.127
147	10.21.100.128/26	10.21.100.129 – 10.21.100.190	10.21.100.191
148	10.21.100.192/26	10.21.100.193 – 10.21.100.254	10.21.100.255
149	10.21.101.0/26	10.21.101.1 – 10.21.101.62	10.21.101.63
150	10.21.101.64/26	10.21.101.65 – 10.21.101.126	10.21.101.127
151	10.21.101.128/26	10.21.101.129 – 10.21.101.190	10.21.101.191
152	10.21.101.192/26	10.21.101.193 – 10.21.101.254	10.21.101.255
153	10.21.102.0/26	10.21.102.1 – 10.21.102.62	10.21.102.63
154	10.21.102.64/26	10.21.102.65 – 10.21.102.126	10.21.102.127
155	10.21.102.128/26	10.21.102.129 – 10.21.102.190	10.21.102.191
156	10.21.102.192/26	10.21.102.193 – 10.21.102.254	10.21.102.255
157	10.21.103.0/26	10.21.103.1 – 10.21.103.62	10.21.103.63
158	10.21.103.64/26	10.21.103.65 – 10.21.103.126	10.21.103.127
159	10.21.103.128/26	10.21.103.129 – 10.21.103.190	10.21.103.191
160	10.21.103.192/26	10.21.103.193 – 10.21.103.254	10.21.103.255
161	10.21.104.0/26	10.21.104.1 – 10.21.104.62	10.21.104.63
162	10.21.104.64/26	10.21.104.65 – 10.21.104.126	10.21.104.127
163	10.21.104.128/26	10.21.104.129 – 10.21.104.190	10.21.104.191
164	10.21.104.192/26	10.21.104.193 – 10.21.104.254	10.21.104.255
165	10.21.105.0/26	10.21.105.1 – 10.21.105.62	10.21.105.63
166	10.21.105.64/26	10.21.105.65 – 10.21.105.126	10.21.105.127
167	10.21.105.128/26	10.21.105.129 – 10.21.105.190	10.21.105.191
168	10.21.105.192/26	10.21.105.193 – 10.21.105.254	10.21.105.255
169	10.21.106.0/26	10.21.106.1 – 10.21.106.62	10.21.106.63
170	10.21.106.64/26	10.21.106.65 – 10.21.106.126	10.21.106.127
171	10.21.106.128/26	10.21.106.129 – 10.21.106.190	10.21.106.191
172	10.21.106.192/26	10.21.106.193 – 10.21.106.254	10.21.106.255
173	10.21.107.0/26	10.21.107.1 – 10.21.107.62	10.21.107.63
174	10.21.107.64/26	10.21.107.65 – 10.21.107.126	10.21.107.127
175	10.21.107.128/26	10.21.107.129 – 10.21.107.190	10.21.107.191
176	10.21.107.192/26	10.21.107.193 – 10.21.107.254	10.21.107.255
177	10.21.108.0/26	10.21.108.1 – 10.21.108.62	10.21.108.63
178	10.21.108.64/26	10.21.108.65 – 10.21.108.126	10.21.108.127
179	10.21.108.128/26	10.21.108.129 – 10.21.108.190	10.21.108.191
180	10.21.108.192/26	10.21.108.193 – 10.21.108.254	10.21.108.255
181	10.21.109.0/26	10.21.109.1 – 10.21.109.62	10.21.109.63
182	10.21.109.64/26	10.21.109.65 – 10.21.109.126	10.21.109.127
183	10.21.109.128/26	10.21.109.129 – 10.21.109.190	10.21.109.191
184	10.21.109.192/26	10.21.109.193 – 10.21.109.254	10.21.109.255
185	10.21.110.0/26	10.21.110.1 – 10.21.110.62	10.21.110.63
186	10.21.110.64/26	10.21.110.65 – 10.21.110.126	10.21.110.127
187	10.21.110.128/26	10.21.110.129 – 10.21.110.190	10.21.110.191
188	10.21.110.192/26	10.21.110.193 – 10.21.110.254	10.21.110.255
189	10.21.111.0/26	10.21.111.1 – 10.21.111.62	10.21.111.63
190	10.21.111.64/26	10.21.111.65 – 10.21.111.126	10.21.111.127
191	10.21.111.128/26	10.21.111.129 – 10.21.111.190	10.21.111.191
192	10.21.111.192/26	10.21.111.193 – 10.21.111.254	10.21.111.255
193	10.21.112.0/26	10.21.112.1 – 10.21.112.62	10.21.112.63
194	10.21.112.64/26	10.21.112.65 – 10.21.112.126	10.21.112.127
195	10.21.112.128/26	10.21.112.129 – 10.21.112.190	10.21.112.191
196	10.21.112.192/26	10.21.112.193 – 10.21.112.254	10.21.112.255
197	10.21.113.0/26	10.21.113.1 – 10.21.113.62	10.21.113.63
198	10.21.113.64/26	10.21.113.65 – 10.21.113.126	10.21.113.127
199	10.21.113.128/26	10.21.113.129 – 10.21.113.190	10.21.113.191
200	10.21.113.192/26	10.21.113.193 – 10.21.113.254	10.21.113.255
201	10.21.114.0/26	10.21.114.1 – 10.21.114.62	10.21.114.63
202	10.21.114.64/26	10.21.114.65 – 10.21.114.126	10.21.114.127
203	10.21.114.128/26	10.21.114.129 – 10.21.114.190	10.21.114.191
204	10.21.114.192/26	10.21.114.193 – 10.21.114.254	10.21.114.255
205	10.21.115.0/26	10.21.115.1 – 10.21.115.62	10.21.115.63
206	10.21.115.64/26	10.21.115.65 – 10.21.115.126	10.21.115.127
207	10.21.115.128/26	10.21.115.129 – 10.21.115.190	10.21.115.191
208	10.21.115.192/26	10.21.115.193 – 10.21.115.254	10.21.115.255
209	10.21.116.0/26	10.21.116.1 – 10.21.116.62	10.21.116.63
210	10.21.116.64/26	10.21.116.65 – 10.21.116.126	10.21.116.127
211	10.21.116.128/26	10.21.116.129 – 10.21.116.190	10.21.116.191
212	10.21.116.192/26	10.21.116.193 – 10.21.116.254	10.21.116.255
213	10.21.117.0/26	10.21.117.1 – 10.21.117.62	10.21.117.63
214	10.21.117.64/26	10.21.117.65 – 10.21.117.126	10.21.117.127
215	10.21.117.128/26	10.21.117.129 – 10.21.117.190	10.21.117.191
216	10.21.117.192/26	10.21.117.193 – 10.21.117.254	10.21.117.255
217	10.21.118.0/26	10.21.118.1 – 10.21.118.62	10.21.118.63
218	10.21.118.64/26	10.21.118.65 – 10.21.118.126	10.21.118.127
219	10.21.118.128/26	10.21.118.129 – 10.21.118.190	10.21.118.191
220	10.21.118.192/26	10.21.118.193 – 10.21.118.254	10.21.118.255
221	10.21.119.0/26	10.21.119.1 – 10.21.119.62	10.21.119.63
222	10.21.119.64/26	10.21.119.65 – 10.21.119.126	10.21.119.127
223	10.21.119.128/26	10.21.119.129 – 10.21.119.190	10.21.119.191
224	10.21.119.192/26	10.21.119.193 – 10.21.119.254	10.21.119.255
225	10.21.120.0/26	10.21.120.1 – 10.21.120.62	10.21.120.63
226	10.21.120.64/26	10.21.120.65 – 10.21.120.126	10.21.120.127
227	10.21.120.128/26	10.21.120.129 – 10.21.120.190	10.21.120.191
228	10.21.120.192/26	10.21.120.193 – 10.21.120.254	10.21.120.255
229	10.21.121.0/26	10.21.121.1 – 10.21.121.62	10.21.121.63
230	10.21.121.64/26	10.21.121.65 – 10.21.121.126	10.21.121.127
231	10.21.121.128/26	10.21.121.129 – 10.21.121.190	10.21.121.191
232	10.21.121.192/26	10.21.121.193 – 10.21.121.254	10.21.121.255
233	10.21.122.0/26	10.21.122.1 – 10.21.122.62	10.21.122.63
234	10.21.122.64/26	10.21.122.65 – 10.21.122.126	10.21.122.127
235	10.21.122.128/26	10.21.122.129 – 10.21.122.190	10.21.122.191
236	10.21.122.192/26	10.21.122.193 – 10.21.122.254	10.21.122.255
237	10.21.123.0/26	10.21.123.1 – 10.21.123.62	10.21.123.63
238	10.21.123.64/26	10.21.123.65 – 10.21.123.126	10.21.123.127
239	10.21.123.128/26	10.21.123.129 – 10.21.123.190	10.21.123.191
240	10.21.123.192/26	10.21.123.193 – 10.21.123.254	10.21.123.255
241	10.21.124.0/26	10.21.124.1 – 10.21.124.62	10.21.124.63
242	10.21.124.64/26	10.21.124.65 – 10.21.124.126	10.21.124.127
243	10.21.124.128/26	10.21.124.129 – 10.21.124.190	10.21.124.191
244	10.21.124.192/26	10.21.124.193 – 10.21.124.254	10.21.124.255
245	10.21.125.0/26	10.21.125.1 – 10.21.125.62	10.21.125.63
246	10.21.125.64/26	10.21.125.65 – 10.21.125.126	10.21.125.127
247	10.21.125.128/26	10.21.125.129 – 10.21.125.190	10.21.125.191
248	10.21.125.192/26	10.21.125.193 – 10.21.125.254	10.21.125.255
249	10.21.126.0/26	10.21.126.1 – 10.21.126.62	10.21.126.63
250	10.21.126.64/26	10.21.126.65 – 10.21.126.126	10.21.126.127
251	10.21.126.128/26	10.21.126.129 – 10.21.126.190	10.21.126.191
252	10.21.126.192/26	10.21.126.193 – 10.21.126.254	10.21.126.255
253	10.21.127.0/26	10.21.127.1 – 10.21.127.62	10.21.127.63
254	10.21.127.64/26	10.21.127.65 – 10.21.127.126	10.21.127.127
255	10.21.127.128/26	10.21.127.129 – 10.21.127.190	10.21.127.191
256	10.21.127.192/26	10.21.127.193 – 10.21.127.254	10.21.127.255

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 →