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)10.3.48.0/21

network10.3.48.0/21

broadcast10.3.55.255

first host10.3.48.1

last host10.3.55.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.3.48.0/21

address00001010.00000011.00110000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000011.00110000.00000000

broadcast00001010.00000011.00110111.11111111

green = network part, grey = host part

hex0x0a033000

decimal167981056

reverse dns0.48.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:3000

/21 split into /28 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.48.0/28	10.3.48.1 – 10.3.48.14	10.3.48.15
2	10.3.48.16/28	10.3.48.17 – 10.3.48.30	10.3.48.31
3	10.3.48.32/28	10.3.48.33 – 10.3.48.46	10.3.48.47
4	10.3.48.48/28	10.3.48.49 – 10.3.48.62	10.3.48.63
5	10.3.48.64/28	10.3.48.65 – 10.3.48.78	10.3.48.79
6	10.3.48.80/28	10.3.48.81 – 10.3.48.94	10.3.48.95
7	10.3.48.96/28	10.3.48.97 – 10.3.48.110	10.3.48.111
8	10.3.48.112/28	10.3.48.113 – 10.3.48.126	10.3.48.127
9	10.3.48.128/28	10.3.48.129 – 10.3.48.142	10.3.48.143
10	10.3.48.144/28	10.3.48.145 – 10.3.48.158	10.3.48.159
11	10.3.48.160/28	10.3.48.161 – 10.3.48.174	10.3.48.175
12	10.3.48.176/28	10.3.48.177 – 10.3.48.190	10.3.48.191
13	10.3.48.192/28	10.3.48.193 – 10.3.48.206	10.3.48.207
14	10.3.48.208/28	10.3.48.209 – 10.3.48.222	10.3.48.223
15	10.3.48.224/28	10.3.48.225 – 10.3.48.238	10.3.48.239
16	10.3.48.240/28	10.3.48.241 – 10.3.48.254	10.3.48.255
17	10.3.49.0/28	10.3.49.1 – 10.3.49.14	10.3.49.15
18	10.3.49.16/28	10.3.49.17 – 10.3.49.30	10.3.49.31
19	10.3.49.32/28	10.3.49.33 – 10.3.49.46	10.3.49.47
20	10.3.49.48/28	10.3.49.49 – 10.3.49.62	10.3.49.63
21	10.3.49.64/28	10.3.49.65 – 10.3.49.78	10.3.49.79
22	10.3.49.80/28	10.3.49.81 – 10.3.49.94	10.3.49.95
23	10.3.49.96/28	10.3.49.97 – 10.3.49.110	10.3.49.111
24	10.3.49.112/28	10.3.49.113 – 10.3.49.126	10.3.49.127
25	10.3.49.128/28	10.3.49.129 – 10.3.49.142	10.3.49.143
26	10.3.49.144/28	10.3.49.145 – 10.3.49.158	10.3.49.159
27	10.3.49.160/28	10.3.49.161 – 10.3.49.174	10.3.49.175
28	10.3.49.176/28	10.3.49.177 – 10.3.49.190	10.3.49.191
29	10.3.49.192/28	10.3.49.193 – 10.3.49.206	10.3.49.207
30	10.3.49.208/28	10.3.49.209 – 10.3.49.222	10.3.49.223
31	10.3.49.224/28	10.3.49.225 – 10.3.49.238	10.3.49.239
32	10.3.49.240/28	10.3.49.241 – 10.3.49.254	10.3.49.255
33	10.3.50.0/28	10.3.50.1 – 10.3.50.14	10.3.50.15
34	10.3.50.16/28	10.3.50.17 – 10.3.50.30	10.3.50.31
35	10.3.50.32/28	10.3.50.33 – 10.3.50.46	10.3.50.47
36	10.3.50.48/28	10.3.50.49 – 10.3.50.62	10.3.50.63
37	10.3.50.64/28	10.3.50.65 – 10.3.50.78	10.3.50.79
38	10.3.50.80/28	10.3.50.81 – 10.3.50.94	10.3.50.95
39	10.3.50.96/28	10.3.50.97 – 10.3.50.110	10.3.50.111
40	10.3.50.112/28	10.3.50.113 – 10.3.50.126	10.3.50.127
41	10.3.50.128/28	10.3.50.129 – 10.3.50.142	10.3.50.143
42	10.3.50.144/28	10.3.50.145 – 10.3.50.158	10.3.50.159
43	10.3.50.160/28	10.3.50.161 – 10.3.50.174	10.3.50.175
44	10.3.50.176/28	10.3.50.177 – 10.3.50.190	10.3.50.191
45	10.3.50.192/28	10.3.50.193 – 10.3.50.206	10.3.50.207
46	10.3.50.208/28	10.3.50.209 – 10.3.50.222	10.3.50.223
47	10.3.50.224/28	10.3.50.225 – 10.3.50.238	10.3.50.239
48	10.3.50.240/28	10.3.50.241 – 10.3.50.254	10.3.50.255
49	10.3.51.0/28	10.3.51.1 – 10.3.51.14	10.3.51.15
50	10.3.51.16/28	10.3.51.17 – 10.3.51.30	10.3.51.31
51	10.3.51.32/28	10.3.51.33 – 10.3.51.46	10.3.51.47
52	10.3.51.48/28	10.3.51.49 – 10.3.51.62	10.3.51.63
53	10.3.51.64/28	10.3.51.65 – 10.3.51.78	10.3.51.79
54	10.3.51.80/28	10.3.51.81 – 10.3.51.94	10.3.51.95
55	10.3.51.96/28	10.3.51.97 – 10.3.51.110	10.3.51.111
56	10.3.51.112/28	10.3.51.113 – 10.3.51.126	10.3.51.127
57	10.3.51.128/28	10.3.51.129 – 10.3.51.142	10.3.51.143
58	10.3.51.144/28	10.3.51.145 – 10.3.51.158	10.3.51.159
59	10.3.51.160/28	10.3.51.161 – 10.3.51.174	10.3.51.175
60	10.3.51.176/28	10.3.51.177 – 10.3.51.190	10.3.51.191
61	10.3.51.192/28	10.3.51.193 – 10.3.51.206	10.3.51.207
62	10.3.51.208/28	10.3.51.209 – 10.3.51.222	10.3.51.223
63	10.3.51.224/28	10.3.51.225 – 10.3.51.238	10.3.51.239
64	10.3.51.240/28	10.3.51.241 – 10.3.51.254	10.3.51.255
65	10.3.52.0/28	10.3.52.1 – 10.3.52.14	10.3.52.15
66	10.3.52.16/28	10.3.52.17 – 10.3.52.30	10.3.52.31
67	10.3.52.32/28	10.3.52.33 – 10.3.52.46	10.3.52.47
68	10.3.52.48/28	10.3.52.49 – 10.3.52.62	10.3.52.63
69	10.3.52.64/28	10.3.52.65 – 10.3.52.78	10.3.52.79
70	10.3.52.80/28	10.3.52.81 – 10.3.52.94	10.3.52.95
71	10.3.52.96/28	10.3.52.97 – 10.3.52.110	10.3.52.111
72	10.3.52.112/28	10.3.52.113 – 10.3.52.126	10.3.52.127
73	10.3.52.128/28	10.3.52.129 – 10.3.52.142	10.3.52.143
74	10.3.52.144/28	10.3.52.145 – 10.3.52.158	10.3.52.159
75	10.3.52.160/28	10.3.52.161 – 10.3.52.174	10.3.52.175
76	10.3.52.176/28	10.3.52.177 – 10.3.52.190	10.3.52.191
77	10.3.52.192/28	10.3.52.193 – 10.3.52.206	10.3.52.207
78	10.3.52.208/28	10.3.52.209 – 10.3.52.222	10.3.52.223
79	10.3.52.224/28	10.3.52.225 – 10.3.52.238	10.3.52.239
80	10.3.52.240/28	10.3.52.241 – 10.3.52.254	10.3.52.255
81	10.3.53.0/28	10.3.53.1 – 10.3.53.14	10.3.53.15
82	10.3.53.16/28	10.3.53.17 – 10.3.53.30	10.3.53.31
83	10.3.53.32/28	10.3.53.33 – 10.3.53.46	10.3.53.47
84	10.3.53.48/28	10.3.53.49 – 10.3.53.62	10.3.53.63
85	10.3.53.64/28	10.3.53.65 – 10.3.53.78	10.3.53.79
86	10.3.53.80/28	10.3.53.81 – 10.3.53.94	10.3.53.95
87	10.3.53.96/28	10.3.53.97 – 10.3.53.110	10.3.53.111
88	10.3.53.112/28	10.3.53.113 – 10.3.53.126	10.3.53.127
89	10.3.53.128/28	10.3.53.129 – 10.3.53.142	10.3.53.143
90	10.3.53.144/28	10.3.53.145 – 10.3.53.158	10.3.53.159
91	10.3.53.160/28	10.3.53.161 – 10.3.53.174	10.3.53.175
92	10.3.53.176/28	10.3.53.177 – 10.3.53.190	10.3.53.191
93	10.3.53.192/28	10.3.53.193 – 10.3.53.206	10.3.53.207
94	10.3.53.208/28	10.3.53.209 – 10.3.53.222	10.3.53.223
95	10.3.53.224/28	10.3.53.225 – 10.3.53.238	10.3.53.239
96	10.3.53.240/28	10.3.53.241 – 10.3.53.254	10.3.53.255
97	10.3.54.0/28	10.3.54.1 – 10.3.54.14	10.3.54.15
98	10.3.54.16/28	10.3.54.17 – 10.3.54.30	10.3.54.31
99	10.3.54.32/28	10.3.54.33 – 10.3.54.46	10.3.54.47
100	10.3.54.48/28	10.3.54.49 – 10.3.54.62	10.3.54.63
101	10.3.54.64/28	10.3.54.65 – 10.3.54.78	10.3.54.79
102	10.3.54.80/28	10.3.54.81 – 10.3.54.94	10.3.54.95
103	10.3.54.96/28	10.3.54.97 – 10.3.54.110	10.3.54.111
104	10.3.54.112/28	10.3.54.113 – 10.3.54.126	10.3.54.127
105	10.3.54.128/28	10.3.54.129 – 10.3.54.142	10.3.54.143
106	10.3.54.144/28	10.3.54.145 – 10.3.54.158	10.3.54.159
107	10.3.54.160/28	10.3.54.161 – 10.3.54.174	10.3.54.175
108	10.3.54.176/28	10.3.54.177 – 10.3.54.190	10.3.54.191
109	10.3.54.192/28	10.3.54.193 – 10.3.54.206	10.3.54.207
110	10.3.54.208/28	10.3.54.209 – 10.3.54.222	10.3.54.223
111	10.3.54.224/28	10.3.54.225 – 10.3.54.238	10.3.54.239
112	10.3.54.240/28	10.3.54.241 – 10.3.54.254	10.3.54.255
113	10.3.55.0/28	10.3.55.1 – 10.3.55.14	10.3.55.15
114	10.3.55.16/28	10.3.55.17 – 10.3.55.30	10.3.55.31
115	10.3.55.32/28	10.3.55.33 – 10.3.55.46	10.3.55.47
116	10.3.55.48/28	10.3.55.49 – 10.3.55.62	10.3.55.63
117	10.3.55.64/28	10.3.55.65 – 10.3.55.78	10.3.55.79
118	10.3.55.80/28	10.3.55.81 – 10.3.55.94	10.3.55.95
119	10.3.55.96/28	10.3.55.97 – 10.3.55.110	10.3.55.111
120	10.3.55.112/28	10.3.55.113 – 10.3.55.126	10.3.55.127
121	10.3.55.128/28	10.3.55.129 – 10.3.55.142	10.3.55.143
122	10.3.55.144/28	10.3.55.145 – 10.3.55.158	10.3.55.159
123	10.3.55.160/28	10.3.55.161 – 10.3.55.174	10.3.55.175
124	10.3.55.176/28	10.3.55.177 – 10.3.55.190	10.3.55.191
125	10.3.55.192/28	10.3.55.193 – 10.3.55.206	10.3.55.207
126	10.3.55.208/28	10.3.55.209 – 10.3.55.222	10.3.55.223
127	10.3.55.224/28	10.3.55.225 – 10.3.55.238	10.3.55.239
128	10.3.55.240/28	10.3.55.241 – 10.3.55.254	10.3.55.255

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 →