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)10.5.192.0/21

network10.5.192.0/21

broadcast10.5.199.255

first host10.5.192.1

last host10.5.199.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.5.192.0/21

address00001010.00000101.11000000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000101.11000000.00000000

broadcast00001010.00000101.11000111.11111111

green = network part, grey = host part

hex0x0a05c000

decimal168148992

reverse dns0.192.5.10.in-addr.arpa

ipv4-mapped::ffff:a05:c000

/21 split into /28 · 128 subnets

close ×

#	network	host range	broadcast
1	10.5.192.0/28	10.5.192.1 – 10.5.192.14	10.5.192.15
2	10.5.192.16/28	10.5.192.17 – 10.5.192.30	10.5.192.31
3	10.5.192.32/28	10.5.192.33 – 10.5.192.46	10.5.192.47
4	10.5.192.48/28	10.5.192.49 – 10.5.192.62	10.5.192.63
5	10.5.192.64/28	10.5.192.65 – 10.5.192.78	10.5.192.79
6	10.5.192.80/28	10.5.192.81 – 10.5.192.94	10.5.192.95
7	10.5.192.96/28	10.5.192.97 – 10.5.192.110	10.5.192.111
8	10.5.192.112/28	10.5.192.113 – 10.5.192.126	10.5.192.127
9	10.5.192.128/28	10.5.192.129 – 10.5.192.142	10.5.192.143
10	10.5.192.144/28	10.5.192.145 – 10.5.192.158	10.5.192.159
11	10.5.192.160/28	10.5.192.161 – 10.5.192.174	10.5.192.175
12	10.5.192.176/28	10.5.192.177 – 10.5.192.190	10.5.192.191
13	10.5.192.192/28	10.5.192.193 – 10.5.192.206	10.5.192.207
14	10.5.192.208/28	10.5.192.209 – 10.5.192.222	10.5.192.223
15	10.5.192.224/28	10.5.192.225 – 10.5.192.238	10.5.192.239
16	10.5.192.240/28	10.5.192.241 – 10.5.192.254	10.5.192.255
17	10.5.193.0/28	10.5.193.1 – 10.5.193.14	10.5.193.15
18	10.5.193.16/28	10.5.193.17 – 10.5.193.30	10.5.193.31
19	10.5.193.32/28	10.5.193.33 – 10.5.193.46	10.5.193.47
20	10.5.193.48/28	10.5.193.49 – 10.5.193.62	10.5.193.63
21	10.5.193.64/28	10.5.193.65 – 10.5.193.78	10.5.193.79
22	10.5.193.80/28	10.5.193.81 – 10.5.193.94	10.5.193.95
23	10.5.193.96/28	10.5.193.97 – 10.5.193.110	10.5.193.111
24	10.5.193.112/28	10.5.193.113 – 10.5.193.126	10.5.193.127
25	10.5.193.128/28	10.5.193.129 – 10.5.193.142	10.5.193.143
26	10.5.193.144/28	10.5.193.145 – 10.5.193.158	10.5.193.159
27	10.5.193.160/28	10.5.193.161 – 10.5.193.174	10.5.193.175
28	10.5.193.176/28	10.5.193.177 – 10.5.193.190	10.5.193.191
29	10.5.193.192/28	10.5.193.193 – 10.5.193.206	10.5.193.207
30	10.5.193.208/28	10.5.193.209 – 10.5.193.222	10.5.193.223
31	10.5.193.224/28	10.5.193.225 – 10.5.193.238	10.5.193.239
32	10.5.193.240/28	10.5.193.241 – 10.5.193.254	10.5.193.255
33	10.5.194.0/28	10.5.194.1 – 10.5.194.14	10.5.194.15
34	10.5.194.16/28	10.5.194.17 – 10.5.194.30	10.5.194.31
35	10.5.194.32/28	10.5.194.33 – 10.5.194.46	10.5.194.47
36	10.5.194.48/28	10.5.194.49 – 10.5.194.62	10.5.194.63
37	10.5.194.64/28	10.5.194.65 – 10.5.194.78	10.5.194.79
38	10.5.194.80/28	10.5.194.81 – 10.5.194.94	10.5.194.95
39	10.5.194.96/28	10.5.194.97 – 10.5.194.110	10.5.194.111
40	10.5.194.112/28	10.5.194.113 – 10.5.194.126	10.5.194.127
41	10.5.194.128/28	10.5.194.129 – 10.5.194.142	10.5.194.143
42	10.5.194.144/28	10.5.194.145 – 10.5.194.158	10.5.194.159
43	10.5.194.160/28	10.5.194.161 – 10.5.194.174	10.5.194.175
44	10.5.194.176/28	10.5.194.177 – 10.5.194.190	10.5.194.191
45	10.5.194.192/28	10.5.194.193 – 10.5.194.206	10.5.194.207
46	10.5.194.208/28	10.5.194.209 – 10.5.194.222	10.5.194.223
47	10.5.194.224/28	10.5.194.225 – 10.5.194.238	10.5.194.239
48	10.5.194.240/28	10.5.194.241 – 10.5.194.254	10.5.194.255
49	10.5.195.0/28	10.5.195.1 – 10.5.195.14	10.5.195.15
50	10.5.195.16/28	10.5.195.17 – 10.5.195.30	10.5.195.31
51	10.5.195.32/28	10.5.195.33 – 10.5.195.46	10.5.195.47
52	10.5.195.48/28	10.5.195.49 – 10.5.195.62	10.5.195.63
53	10.5.195.64/28	10.5.195.65 – 10.5.195.78	10.5.195.79
54	10.5.195.80/28	10.5.195.81 – 10.5.195.94	10.5.195.95
55	10.5.195.96/28	10.5.195.97 – 10.5.195.110	10.5.195.111
56	10.5.195.112/28	10.5.195.113 – 10.5.195.126	10.5.195.127
57	10.5.195.128/28	10.5.195.129 – 10.5.195.142	10.5.195.143
58	10.5.195.144/28	10.5.195.145 – 10.5.195.158	10.5.195.159
59	10.5.195.160/28	10.5.195.161 – 10.5.195.174	10.5.195.175
60	10.5.195.176/28	10.5.195.177 – 10.5.195.190	10.5.195.191
61	10.5.195.192/28	10.5.195.193 – 10.5.195.206	10.5.195.207
62	10.5.195.208/28	10.5.195.209 – 10.5.195.222	10.5.195.223
63	10.5.195.224/28	10.5.195.225 – 10.5.195.238	10.5.195.239
64	10.5.195.240/28	10.5.195.241 – 10.5.195.254	10.5.195.255
65	10.5.196.0/28	10.5.196.1 – 10.5.196.14	10.5.196.15
66	10.5.196.16/28	10.5.196.17 – 10.5.196.30	10.5.196.31
67	10.5.196.32/28	10.5.196.33 – 10.5.196.46	10.5.196.47
68	10.5.196.48/28	10.5.196.49 – 10.5.196.62	10.5.196.63
69	10.5.196.64/28	10.5.196.65 – 10.5.196.78	10.5.196.79
70	10.5.196.80/28	10.5.196.81 – 10.5.196.94	10.5.196.95
71	10.5.196.96/28	10.5.196.97 – 10.5.196.110	10.5.196.111
72	10.5.196.112/28	10.5.196.113 – 10.5.196.126	10.5.196.127
73	10.5.196.128/28	10.5.196.129 – 10.5.196.142	10.5.196.143
74	10.5.196.144/28	10.5.196.145 – 10.5.196.158	10.5.196.159
75	10.5.196.160/28	10.5.196.161 – 10.5.196.174	10.5.196.175
76	10.5.196.176/28	10.5.196.177 – 10.5.196.190	10.5.196.191
77	10.5.196.192/28	10.5.196.193 – 10.5.196.206	10.5.196.207
78	10.5.196.208/28	10.5.196.209 – 10.5.196.222	10.5.196.223
79	10.5.196.224/28	10.5.196.225 – 10.5.196.238	10.5.196.239
80	10.5.196.240/28	10.5.196.241 – 10.5.196.254	10.5.196.255
81	10.5.197.0/28	10.5.197.1 – 10.5.197.14	10.5.197.15
82	10.5.197.16/28	10.5.197.17 – 10.5.197.30	10.5.197.31
83	10.5.197.32/28	10.5.197.33 – 10.5.197.46	10.5.197.47
84	10.5.197.48/28	10.5.197.49 – 10.5.197.62	10.5.197.63
85	10.5.197.64/28	10.5.197.65 – 10.5.197.78	10.5.197.79
86	10.5.197.80/28	10.5.197.81 – 10.5.197.94	10.5.197.95
87	10.5.197.96/28	10.5.197.97 – 10.5.197.110	10.5.197.111
88	10.5.197.112/28	10.5.197.113 – 10.5.197.126	10.5.197.127
89	10.5.197.128/28	10.5.197.129 – 10.5.197.142	10.5.197.143
90	10.5.197.144/28	10.5.197.145 – 10.5.197.158	10.5.197.159
91	10.5.197.160/28	10.5.197.161 – 10.5.197.174	10.5.197.175
92	10.5.197.176/28	10.5.197.177 – 10.5.197.190	10.5.197.191
93	10.5.197.192/28	10.5.197.193 – 10.5.197.206	10.5.197.207
94	10.5.197.208/28	10.5.197.209 – 10.5.197.222	10.5.197.223
95	10.5.197.224/28	10.5.197.225 – 10.5.197.238	10.5.197.239
96	10.5.197.240/28	10.5.197.241 – 10.5.197.254	10.5.197.255
97	10.5.198.0/28	10.5.198.1 – 10.5.198.14	10.5.198.15
98	10.5.198.16/28	10.5.198.17 – 10.5.198.30	10.5.198.31
99	10.5.198.32/28	10.5.198.33 – 10.5.198.46	10.5.198.47
100	10.5.198.48/28	10.5.198.49 – 10.5.198.62	10.5.198.63
101	10.5.198.64/28	10.5.198.65 – 10.5.198.78	10.5.198.79
102	10.5.198.80/28	10.5.198.81 – 10.5.198.94	10.5.198.95
103	10.5.198.96/28	10.5.198.97 – 10.5.198.110	10.5.198.111
104	10.5.198.112/28	10.5.198.113 – 10.5.198.126	10.5.198.127
105	10.5.198.128/28	10.5.198.129 – 10.5.198.142	10.5.198.143
106	10.5.198.144/28	10.5.198.145 – 10.5.198.158	10.5.198.159
107	10.5.198.160/28	10.5.198.161 – 10.5.198.174	10.5.198.175
108	10.5.198.176/28	10.5.198.177 – 10.5.198.190	10.5.198.191
109	10.5.198.192/28	10.5.198.193 – 10.5.198.206	10.5.198.207
110	10.5.198.208/28	10.5.198.209 – 10.5.198.222	10.5.198.223
111	10.5.198.224/28	10.5.198.225 – 10.5.198.238	10.5.198.239
112	10.5.198.240/28	10.5.198.241 – 10.5.198.254	10.5.198.255
113	10.5.199.0/28	10.5.199.1 – 10.5.199.14	10.5.199.15
114	10.5.199.16/28	10.5.199.17 – 10.5.199.30	10.5.199.31
115	10.5.199.32/28	10.5.199.33 – 10.5.199.46	10.5.199.47
116	10.5.199.48/28	10.5.199.49 – 10.5.199.62	10.5.199.63
117	10.5.199.64/28	10.5.199.65 – 10.5.199.78	10.5.199.79
118	10.5.199.80/28	10.5.199.81 – 10.5.199.94	10.5.199.95
119	10.5.199.96/28	10.5.199.97 – 10.5.199.110	10.5.199.111
120	10.5.199.112/28	10.5.199.113 – 10.5.199.126	10.5.199.127
121	10.5.199.128/28	10.5.199.129 – 10.5.199.142	10.5.199.143
122	10.5.199.144/28	10.5.199.145 – 10.5.199.158	10.5.199.159
123	10.5.199.160/28	10.5.199.161 – 10.5.199.174	10.5.199.175
124	10.5.199.176/28	10.5.199.177 – 10.5.199.190	10.5.199.191
125	10.5.199.192/28	10.5.199.193 – 10.5.199.206	10.5.199.207
126	10.5.199.208/28	10.5.199.209 – 10.5.199.222	10.5.199.223
127	10.5.199.224/28	10.5.199.225 – 10.5.199.238	10.5.199.239
128	10.5.199.240/28	10.5.199.241 – 10.5.199.254	10.5.199.255

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