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)10.2.24.0/21

network10.2.24.0/21

broadcast10.2.31.255

first host10.2.24.1

last host10.2.31.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.2.24.0/21

address00001010.00000010.00011000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000010.00011000.00000000

broadcast00001010.00000010.00011111.11111111

green = network part, grey = host part

hex0x0a021800

decimal167909376

reverse dns0.24.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:1800

/21 split into /28 · 128 subnets

close ×

#	network	host range	broadcast
1	10.2.24.0/28	10.2.24.1 – 10.2.24.14	10.2.24.15
2	10.2.24.16/28	10.2.24.17 – 10.2.24.30	10.2.24.31
3	10.2.24.32/28	10.2.24.33 – 10.2.24.46	10.2.24.47
4	10.2.24.48/28	10.2.24.49 – 10.2.24.62	10.2.24.63
5	10.2.24.64/28	10.2.24.65 – 10.2.24.78	10.2.24.79
6	10.2.24.80/28	10.2.24.81 – 10.2.24.94	10.2.24.95
7	10.2.24.96/28	10.2.24.97 – 10.2.24.110	10.2.24.111
8	10.2.24.112/28	10.2.24.113 – 10.2.24.126	10.2.24.127
9	10.2.24.128/28	10.2.24.129 – 10.2.24.142	10.2.24.143
10	10.2.24.144/28	10.2.24.145 – 10.2.24.158	10.2.24.159
11	10.2.24.160/28	10.2.24.161 – 10.2.24.174	10.2.24.175
12	10.2.24.176/28	10.2.24.177 – 10.2.24.190	10.2.24.191
13	10.2.24.192/28	10.2.24.193 – 10.2.24.206	10.2.24.207
14	10.2.24.208/28	10.2.24.209 – 10.2.24.222	10.2.24.223
15	10.2.24.224/28	10.2.24.225 – 10.2.24.238	10.2.24.239
16	10.2.24.240/28	10.2.24.241 – 10.2.24.254	10.2.24.255
17	10.2.25.0/28	10.2.25.1 – 10.2.25.14	10.2.25.15
18	10.2.25.16/28	10.2.25.17 – 10.2.25.30	10.2.25.31
19	10.2.25.32/28	10.2.25.33 – 10.2.25.46	10.2.25.47
20	10.2.25.48/28	10.2.25.49 – 10.2.25.62	10.2.25.63
21	10.2.25.64/28	10.2.25.65 – 10.2.25.78	10.2.25.79
22	10.2.25.80/28	10.2.25.81 – 10.2.25.94	10.2.25.95
23	10.2.25.96/28	10.2.25.97 – 10.2.25.110	10.2.25.111
24	10.2.25.112/28	10.2.25.113 – 10.2.25.126	10.2.25.127
25	10.2.25.128/28	10.2.25.129 – 10.2.25.142	10.2.25.143
26	10.2.25.144/28	10.2.25.145 – 10.2.25.158	10.2.25.159
27	10.2.25.160/28	10.2.25.161 – 10.2.25.174	10.2.25.175
28	10.2.25.176/28	10.2.25.177 – 10.2.25.190	10.2.25.191
29	10.2.25.192/28	10.2.25.193 – 10.2.25.206	10.2.25.207
30	10.2.25.208/28	10.2.25.209 – 10.2.25.222	10.2.25.223
31	10.2.25.224/28	10.2.25.225 – 10.2.25.238	10.2.25.239
32	10.2.25.240/28	10.2.25.241 – 10.2.25.254	10.2.25.255
33	10.2.26.0/28	10.2.26.1 – 10.2.26.14	10.2.26.15
34	10.2.26.16/28	10.2.26.17 – 10.2.26.30	10.2.26.31
35	10.2.26.32/28	10.2.26.33 – 10.2.26.46	10.2.26.47
36	10.2.26.48/28	10.2.26.49 – 10.2.26.62	10.2.26.63
37	10.2.26.64/28	10.2.26.65 – 10.2.26.78	10.2.26.79
38	10.2.26.80/28	10.2.26.81 – 10.2.26.94	10.2.26.95
39	10.2.26.96/28	10.2.26.97 – 10.2.26.110	10.2.26.111
40	10.2.26.112/28	10.2.26.113 – 10.2.26.126	10.2.26.127
41	10.2.26.128/28	10.2.26.129 – 10.2.26.142	10.2.26.143
42	10.2.26.144/28	10.2.26.145 – 10.2.26.158	10.2.26.159
43	10.2.26.160/28	10.2.26.161 – 10.2.26.174	10.2.26.175
44	10.2.26.176/28	10.2.26.177 – 10.2.26.190	10.2.26.191
45	10.2.26.192/28	10.2.26.193 – 10.2.26.206	10.2.26.207
46	10.2.26.208/28	10.2.26.209 – 10.2.26.222	10.2.26.223
47	10.2.26.224/28	10.2.26.225 – 10.2.26.238	10.2.26.239
48	10.2.26.240/28	10.2.26.241 – 10.2.26.254	10.2.26.255
49	10.2.27.0/28	10.2.27.1 – 10.2.27.14	10.2.27.15
50	10.2.27.16/28	10.2.27.17 – 10.2.27.30	10.2.27.31
51	10.2.27.32/28	10.2.27.33 – 10.2.27.46	10.2.27.47
52	10.2.27.48/28	10.2.27.49 – 10.2.27.62	10.2.27.63
53	10.2.27.64/28	10.2.27.65 – 10.2.27.78	10.2.27.79
54	10.2.27.80/28	10.2.27.81 – 10.2.27.94	10.2.27.95
55	10.2.27.96/28	10.2.27.97 – 10.2.27.110	10.2.27.111
56	10.2.27.112/28	10.2.27.113 – 10.2.27.126	10.2.27.127
57	10.2.27.128/28	10.2.27.129 – 10.2.27.142	10.2.27.143
58	10.2.27.144/28	10.2.27.145 – 10.2.27.158	10.2.27.159
59	10.2.27.160/28	10.2.27.161 – 10.2.27.174	10.2.27.175
60	10.2.27.176/28	10.2.27.177 – 10.2.27.190	10.2.27.191
61	10.2.27.192/28	10.2.27.193 – 10.2.27.206	10.2.27.207
62	10.2.27.208/28	10.2.27.209 – 10.2.27.222	10.2.27.223
63	10.2.27.224/28	10.2.27.225 – 10.2.27.238	10.2.27.239
64	10.2.27.240/28	10.2.27.241 – 10.2.27.254	10.2.27.255
65	10.2.28.0/28	10.2.28.1 – 10.2.28.14	10.2.28.15
66	10.2.28.16/28	10.2.28.17 – 10.2.28.30	10.2.28.31
67	10.2.28.32/28	10.2.28.33 – 10.2.28.46	10.2.28.47
68	10.2.28.48/28	10.2.28.49 – 10.2.28.62	10.2.28.63
69	10.2.28.64/28	10.2.28.65 – 10.2.28.78	10.2.28.79
70	10.2.28.80/28	10.2.28.81 – 10.2.28.94	10.2.28.95
71	10.2.28.96/28	10.2.28.97 – 10.2.28.110	10.2.28.111
72	10.2.28.112/28	10.2.28.113 – 10.2.28.126	10.2.28.127
73	10.2.28.128/28	10.2.28.129 – 10.2.28.142	10.2.28.143
74	10.2.28.144/28	10.2.28.145 – 10.2.28.158	10.2.28.159
75	10.2.28.160/28	10.2.28.161 – 10.2.28.174	10.2.28.175
76	10.2.28.176/28	10.2.28.177 – 10.2.28.190	10.2.28.191
77	10.2.28.192/28	10.2.28.193 – 10.2.28.206	10.2.28.207
78	10.2.28.208/28	10.2.28.209 – 10.2.28.222	10.2.28.223
79	10.2.28.224/28	10.2.28.225 – 10.2.28.238	10.2.28.239
80	10.2.28.240/28	10.2.28.241 – 10.2.28.254	10.2.28.255
81	10.2.29.0/28	10.2.29.1 – 10.2.29.14	10.2.29.15
82	10.2.29.16/28	10.2.29.17 – 10.2.29.30	10.2.29.31
83	10.2.29.32/28	10.2.29.33 – 10.2.29.46	10.2.29.47
84	10.2.29.48/28	10.2.29.49 – 10.2.29.62	10.2.29.63
85	10.2.29.64/28	10.2.29.65 – 10.2.29.78	10.2.29.79
86	10.2.29.80/28	10.2.29.81 – 10.2.29.94	10.2.29.95
87	10.2.29.96/28	10.2.29.97 – 10.2.29.110	10.2.29.111
88	10.2.29.112/28	10.2.29.113 – 10.2.29.126	10.2.29.127
89	10.2.29.128/28	10.2.29.129 – 10.2.29.142	10.2.29.143
90	10.2.29.144/28	10.2.29.145 – 10.2.29.158	10.2.29.159
91	10.2.29.160/28	10.2.29.161 – 10.2.29.174	10.2.29.175
92	10.2.29.176/28	10.2.29.177 – 10.2.29.190	10.2.29.191
93	10.2.29.192/28	10.2.29.193 – 10.2.29.206	10.2.29.207
94	10.2.29.208/28	10.2.29.209 – 10.2.29.222	10.2.29.223
95	10.2.29.224/28	10.2.29.225 – 10.2.29.238	10.2.29.239
96	10.2.29.240/28	10.2.29.241 – 10.2.29.254	10.2.29.255
97	10.2.30.0/28	10.2.30.1 – 10.2.30.14	10.2.30.15
98	10.2.30.16/28	10.2.30.17 – 10.2.30.30	10.2.30.31
99	10.2.30.32/28	10.2.30.33 – 10.2.30.46	10.2.30.47
100	10.2.30.48/28	10.2.30.49 – 10.2.30.62	10.2.30.63
101	10.2.30.64/28	10.2.30.65 – 10.2.30.78	10.2.30.79
102	10.2.30.80/28	10.2.30.81 – 10.2.30.94	10.2.30.95
103	10.2.30.96/28	10.2.30.97 – 10.2.30.110	10.2.30.111
104	10.2.30.112/28	10.2.30.113 – 10.2.30.126	10.2.30.127
105	10.2.30.128/28	10.2.30.129 – 10.2.30.142	10.2.30.143
106	10.2.30.144/28	10.2.30.145 – 10.2.30.158	10.2.30.159
107	10.2.30.160/28	10.2.30.161 – 10.2.30.174	10.2.30.175
108	10.2.30.176/28	10.2.30.177 – 10.2.30.190	10.2.30.191
109	10.2.30.192/28	10.2.30.193 – 10.2.30.206	10.2.30.207
110	10.2.30.208/28	10.2.30.209 – 10.2.30.222	10.2.30.223
111	10.2.30.224/28	10.2.30.225 – 10.2.30.238	10.2.30.239
112	10.2.30.240/28	10.2.30.241 – 10.2.30.254	10.2.30.255
113	10.2.31.0/28	10.2.31.1 – 10.2.31.14	10.2.31.15
114	10.2.31.16/28	10.2.31.17 – 10.2.31.30	10.2.31.31
115	10.2.31.32/28	10.2.31.33 – 10.2.31.46	10.2.31.47
116	10.2.31.48/28	10.2.31.49 – 10.2.31.62	10.2.31.63
117	10.2.31.64/28	10.2.31.65 – 10.2.31.78	10.2.31.79
118	10.2.31.80/28	10.2.31.81 – 10.2.31.94	10.2.31.95
119	10.2.31.96/28	10.2.31.97 – 10.2.31.110	10.2.31.111
120	10.2.31.112/28	10.2.31.113 – 10.2.31.126	10.2.31.127
121	10.2.31.128/28	10.2.31.129 – 10.2.31.142	10.2.31.143
122	10.2.31.144/28	10.2.31.145 – 10.2.31.158	10.2.31.159
123	10.2.31.160/28	10.2.31.161 – 10.2.31.174	10.2.31.175
124	10.2.31.176/28	10.2.31.177 – 10.2.31.190	10.2.31.191
125	10.2.31.192/28	10.2.31.193 – 10.2.31.206	10.2.31.207
126	10.2.31.208/28	10.2.31.209 – 10.2.31.222	10.2.31.223
127	10.2.31.224/28	10.2.31.225 – 10.2.31.238	10.2.31.239
128	10.2.31.240/28	10.2.31.241 – 10.2.31.254	10.2.31.255

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 →