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)10.2.176.0/21

network10.2.176.0/21

broadcast10.2.183.255

first host10.2.176.1

last host10.2.183.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.2.176.0/21

address00001010.00000010.10110000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000010.10110000.00000000

broadcast00001010.00000010.10110111.11111111

green = network part, grey = host part

hex0x0a02b000

decimal167948288

reverse dns0.176.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:b000

/21 split into /28 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.176.0/28	10.2.176.1 – 10.2.176.14	10.2.176.15
2	10.2.176.16/28	10.2.176.17 – 10.2.176.30	10.2.176.31
3	10.2.176.32/28	10.2.176.33 – 10.2.176.46	10.2.176.47
4	10.2.176.48/28	10.2.176.49 – 10.2.176.62	10.2.176.63
5	10.2.176.64/28	10.2.176.65 – 10.2.176.78	10.2.176.79
6	10.2.176.80/28	10.2.176.81 – 10.2.176.94	10.2.176.95
7	10.2.176.96/28	10.2.176.97 – 10.2.176.110	10.2.176.111
8	10.2.176.112/28	10.2.176.113 – 10.2.176.126	10.2.176.127
9	10.2.176.128/28	10.2.176.129 – 10.2.176.142	10.2.176.143
10	10.2.176.144/28	10.2.176.145 – 10.2.176.158	10.2.176.159
11	10.2.176.160/28	10.2.176.161 – 10.2.176.174	10.2.176.175
12	10.2.176.176/28	10.2.176.177 – 10.2.176.190	10.2.176.191
13	10.2.176.192/28	10.2.176.193 – 10.2.176.206	10.2.176.207
14	10.2.176.208/28	10.2.176.209 – 10.2.176.222	10.2.176.223
15	10.2.176.224/28	10.2.176.225 – 10.2.176.238	10.2.176.239
16	10.2.176.240/28	10.2.176.241 – 10.2.176.254	10.2.176.255
17	10.2.177.0/28	10.2.177.1 – 10.2.177.14	10.2.177.15
18	10.2.177.16/28	10.2.177.17 – 10.2.177.30	10.2.177.31
19	10.2.177.32/28	10.2.177.33 – 10.2.177.46	10.2.177.47
20	10.2.177.48/28	10.2.177.49 – 10.2.177.62	10.2.177.63
21	10.2.177.64/28	10.2.177.65 – 10.2.177.78	10.2.177.79
22	10.2.177.80/28	10.2.177.81 – 10.2.177.94	10.2.177.95
23	10.2.177.96/28	10.2.177.97 – 10.2.177.110	10.2.177.111
24	10.2.177.112/28	10.2.177.113 – 10.2.177.126	10.2.177.127
25	10.2.177.128/28	10.2.177.129 – 10.2.177.142	10.2.177.143
26	10.2.177.144/28	10.2.177.145 – 10.2.177.158	10.2.177.159
27	10.2.177.160/28	10.2.177.161 – 10.2.177.174	10.2.177.175
28	10.2.177.176/28	10.2.177.177 – 10.2.177.190	10.2.177.191
29	10.2.177.192/28	10.2.177.193 – 10.2.177.206	10.2.177.207
30	10.2.177.208/28	10.2.177.209 – 10.2.177.222	10.2.177.223
31	10.2.177.224/28	10.2.177.225 – 10.2.177.238	10.2.177.239
32	10.2.177.240/28	10.2.177.241 – 10.2.177.254	10.2.177.255
33	10.2.178.0/28	10.2.178.1 – 10.2.178.14	10.2.178.15
34	10.2.178.16/28	10.2.178.17 – 10.2.178.30	10.2.178.31
35	10.2.178.32/28	10.2.178.33 – 10.2.178.46	10.2.178.47
36	10.2.178.48/28	10.2.178.49 – 10.2.178.62	10.2.178.63
37	10.2.178.64/28	10.2.178.65 – 10.2.178.78	10.2.178.79
38	10.2.178.80/28	10.2.178.81 – 10.2.178.94	10.2.178.95
39	10.2.178.96/28	10.2.178.97 – 10.2.178.110	10.2.178.111
40	10.2.178.112/28	10.2.178.113 – 10.2.178.126	10.2.178.127
41	10.2.178.128/28	10.2.178.129 – 10.2.178.142	10.2.178.143
42	10.2.178.144/28	10.2.178.145 – 10.2.178.158	10.2.178.159
43	10.2.178.160/28	10.2.178.161 – 10.2.178.174	10.2.178.175
44	10.2.178.176/28	10.2.178.177 – 10.2.178.190	10.2.178.191
45	10.2.178.192/28	10.2.178.193 – 10.2.178.206	10.2.178.207
46	10.2.178.208/28	10.2.178.209 – 10.2.178.222	10.2.178.223
47	10.2.178.224/28	10.2.178.225 – 10.2.178.238	10.2.178.239
48	10.2.178.240/28	10.2.178.241 – 10.2.178.254	10.2.178.255
49	10.2.179.0/28	10.2.179.1 – 10.2.179.14	10.2.179.15
50	10.2.179.16/28	10.2.179.17 – 10.2.179.30	10.2.179.31
51	10.2.179.32/28	10.2.179.33 – 10.2.179.46	10.2.179.47
52	10.2.179.48/28	10.2.179.49 – 10.2.179.62	10.2.179.63
53	10.2.179.64/28	10.2.179.65 – 10.2.179.78	10.2.179.79
54	10.2.179.80/28	10.2.179.81 – 10.2.179.94	10.2.179.95
55	10.2.179.96/28	10.2.179.97 – 10.2.179.110	10.2.179.111
56	10.2.179.112/28	10.2.179.113 – 10.2.179.126	10.2.179.127
57	10.2.179.128/28	10.2.179.129 – 10.2.179.142	10.2.179.143
58	10.2.179.144/28	10.2.179.145 – 10.2.179.158	10.2.179.159
59	10.2.179.160/28	10.2.179.161 – 10.2.179.174	10.2.179.175
60	10.2.179.176/28	10.2.179.177 – 10.2.179.190	10.2.179.191
61	10.2.179.192/28	10.2.179.193 – 10.2.179.206	10.2.179.207
62	10.2.179.208/28	10.2.179.209 – 10.2.179.222	10.2.179.223
63	10.2.179.224/28	10.2.179.225 – 10.2.179.238	10.2.179.239
64	10.2.179.240/28	10.2.179.241 – 10.2.179.254	10.2.179.255
65	10.2.180.0/28	10.2.180.1 – 10.2.180.14	10.2.180.15
66	10.2.180.16/28	10.2.180.17 – 10.2.180.30	10.2.180.31
67	10.2.180.32/28	10.2.180.33 – 10.2.180.46	10.2.180.47
68	10.2.180.48/28	10.2.180.49 – 10.2.180.62	10.2.180.63
69	10.2.180.64/28	10.2.180.65 – 10.2.180.78	10.2.180.79
70	10.2.180.80/28	10.2.180.81 – 10.2.180.94	10.2.180.95
71	10.2.180.96/28	10.2.180.97 – 10.2.180.110	10.2.180.111
72	10.2.180.112/28	10.2.180.113 – 10.2.180.126	10.2.180.127
73	10.2.180.128/28	10.2.180.129 – 10.2.180.142	10.2.180.143
74	10.2.180.144/28	10.2.180.145 – 10.2.180.158	10.2.180.159
75	10.2.180.160/28	10.2.180.161 – 10.2.180.174	10.2.180.175
76	10.2.180.176/28	10.2.180.177 – 10.2.180.190	10.2.180.191
77	10.2.180.192/28	10.2.180.193 – 10.2.180.206	10.2.180.207
78	10.2.180.208/28	10.2.180.209 – 10.2.180.222	10.2.180.223
79	10.2.180.224/28	10.2.180.225 – 10.2.180.238	10.2.180.239
80	10.2.180.240/28	10.2.180.241 – 10.2.180.254	10.2.180.255
81	10.2.181.0/28	10.2.181.1 – 10.2.181.14	10.2.181.15
82	10.2.181.16/28	10.2.181.17 – 10.2.181.30	10.2.181.31
83	10.2.181.32/28	10.2.181.33 – 10.2.181.46	10.2.181.47
84	10.2.181.48/28	10.2.181.49 – 10.2.181.62	10.2.181.63
85	10.2.181.64/28	10.2.181.65 – 10.2.181.78	10.2.181.79
86	10.2.181.80/28	10.2.181.81 – 10.2.181.94	10.2.181.95
87	10.2.181.96/28	10.2.181.97 – 10.2.181.110	10.2.181.111
88	10.2.181.112/28	10.2.181.113 – 10.2.181.126	10.2.181.127
89	10.2.181.128/28	10.2.181.129 – 10.2.181.142	10.2.181.143
90	10.2.181.144/28	10.2.181.145 – 10.2.181.158	10.2.181.159
91	10.2.181.160/28	10.2.181.161 – 10.2.181.174	10.2.181.175
92	10.2.181.176/28	10.2.181.177 – 10.2.181.190	10.2.181.191
93	10.2.181.192/28	10.2.181.193 – 10.2.181.206	10.2.181.207
94	10.2.181.208/28	10.2.181.209 – 10.2.181.222	10.2.181.223
95	10.2.181.224/28	10.2.181.225 – 10.2.181.238	10.2.181.239
96	10.2.181.240/28	10.2.181.241 – 10.2.181.254	10.2.181.255
97	10.2.182.0/28	10.2.182.1 – 10.2.182.14	10.2.182.15
98	10.2.182.16/28	10.2.182.17 – 10.2.182.30	10.2.182.31
99	10.2.182.32/28	10.2.182.33 – 10.2.182.46	10.2.182.47
100	10.2.182.48/28	10.2.182.49 – 10.2.182.62	10.2.182.63
101	10.2.182.64/28	10.2.182.65 – 10.2.182.78	10.2.182.79
102	10.2.182.80/28	10.2.182.81 – 10.2.182.94	10.2.182.95
103	10.2.182.96/28	10.2.182.97 – 10.2.182.110	10.2.182.111
104	10.2.182.112/28	10.2.182.113 – 10.2.182.126	10.2.182.127
105	10.2.182.128/28	10.2.182.129 – 10.2.182.142	10.2.182.143
106	10.2.182.144/28	10.2.182.145 – 10.2.182.158	10.2.182.159
107	10.2.182.160/28	10.2.182.161 – 10.2.182.174	10.2.182.175
108	10.2.182.176/28	10.2.182.177 – 10.2.182.190	10.2.182.191
109	10.2.182.192/28	10.2.182.193 – 10.2.182.206	10.2.182.207
110	10.2.182.208/28	10.2.182.209 – 10.2.182.222	10.2.182.223
111	10.2.182.224/28	10.2.182.225 – 10.2.182.238	10.2.182.239
112	10.2.182.240/28	10.2.182.241 – 10.2.182.254	10.2.182.255
113	10.2.183.0/28	10.2.183.1 – 10.2.183.14	10.2.183.15
114	10.2.183.16/28	10.2.183.17 – 10.2.183.30	10.2.183.31
115	10.2.183.32/28	10.2.183.33 – 10.2.183.46	10.2.183.47
116	10.2.183.48/28	10.2.183.49 – 10.2.183.62	10.2.183.63
117	10.2.183.64/28	10.2.183.65 – 10.2.183.78	10.2.183.79
118	10.2.183.80/28	10.2.183.81 – 10.2.183.94	10.2.183.95
119	10.2.183.96/28	10.2.183.97 – 10.2.183.110	10.2.183.111
120	10.2.183.112/28	10.2.183.113 – 10.2.183.126	10.2.183.127
121	10.2.183.128/28	10.2.183.129 – 10.2.183.142	10.2.183.143
122	10.2.183.144/28	10.2.183.145 – 10.2.183.158	10.2.183.159
123	10.2.183.160/28	10.2.183.161 – 10.2.183.174	10.2.183.175
124	10.2.183.176/28	10.2.183.177 – 10.2.183.190	10.2.183.191
125	10.2.183.192/28	10.2.183.193 – 10.2.183.206	10.2.183.207
126	10.2.183.208/28	10.2.183.209 – 10.2.183.222	10.2.183.223
127	10.2.183.224/28	10.2.183.225 – 10.2.183.238	10.2.183.239
128	10.2.183.240/28	10.2.183.241 – 10.2.183.254	10.2.183.255

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 →