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)10.3.152.0/21

network10.3.152.0/21

broadcast10.3.159.255

first host10.3.152.1

last host10.3.159.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.3.152.0/21

address00001010.00000011.10011000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000011.10011000.00000000

broadcast00001010.00000011.10011111.11111111

green = network part, grey = host part

hex0x0a039800

decimal168007680

reverse dns0.152.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:9800

/21 split into /28 · 128 subnets

close ×

#	network	host range	broadcast
1	10.3.152.0/28	10.3.152.1 – 10.3.152.14	10.3.152.15
2	10.3.152.16/28	10.3.152.17 – 10.3.152.30	10.3.152.31
3	10.3.152.32/28	10.3.152.33 – 10.3.152.46	10.3.152.47
4	10.3.152.48/28	10.3.152.49 – 10.3.152.62	10.3.152.63
5	10.3.152.64/28	10.3.152.65 – 10.3.152.78	10.3.152.79
6	10.3.152.80/28	10.3.152.81 – 10.3.152.94	10.3.152.95
7	10.3.152.96/28	10.3.152.97 – 10.3.152.110	10.3.152.111
8	10.3.152.112/28	10.3.152.113 – 10.3.152.126	10.3.152.127
9	10.3.152.128/28	10.3.152.129 – 10.3.152.142	10.3.152.143
10	10.3.152.144/28	10.3.152.145 – 10.3.152.158	10.3.152.159
11	10.3.152.160/28	10.3.152.161 – 10.3.152.174	10.3.152.175
12	10.3.152.176/28	10.3.152.177 – 10.3.152.190	10.3.152.191
13	10.3.152.192/28	10.3.152.193 – 10.3.152.206	10.3.152.207
14	10.3.152.208/28	10.3.152.209 – 10.3.152.222	10.3.152.223
15	10.3.152.224/28	10.3.152.225 – 10.3.152.238	10.3.152.239
16	10.3.152.240/28	10.3.152.241 – 10.3.152.254	10.3.152.255
17	10.3.153.0/28	10.3.153.1 – 10.3.153.14	10.3.153.15
18	10.3.153.16/28	10.3.153.17 – 10.3.153.30	10.3.153.31
19	10.3.153.32/28	10.3.153.33 – 10.3.153.46	10.3.153.47
20	10.3.153.48/28	10.3.153.49 – 10.3.153.62	10.3.153.63
21	10.3.153.64/28	10.3.153.65 – 10.3.153.78	10.3.153.79
22	10.3.153.80/28	10.3.153.81 – 10.3.153.94	10.3.153.95
23	10.3.153.96/28	10.3.153.97 – 10.3.153.110	10.3.153.111
24	10.3.153.112/28	10.3.153.113 – 10.3.153.126	10.3.153.127
25	10.3.153.128/28	10.3.153.129 – 10.3.153.142	10.3.153.143
26	10.3.153.144/28	10.3.153.145 – 10.3.153.158	10.3.153.159
27	10.3.153.160/28	10.3.153.161 – 10.3.153.174	10.3.153.175
28	10.3.153.176/28	10.3.153.177 – 10.3.153.190	10.3.153.191
29	10.3.153.192/28	10.3.153.193 – 10.3.153.206	10.3.153.207
30	10.3.153.208/28	10.3.153.209 – 10.3.153.222	10.3.153.223
31	10.3.153.224/28	10.3.153.225 – 10.3.153.238	10.3.153.239
32	10.3.153.240/28	10.3.153.241 – 10.3.153.254	10.3.153.255
33	10.3.154.0/28	10.3.154.1 – 10.3.154.14	10.3.154.15
34	10.3.154.16/28	10.3.154.17 – 10.3.154.30	10.3.154.31
35	10.3.154.32/28	10.3.154.33 – 10.3.154.46	10.3.154.47
36	10.3.154.48/28	10.3.154.49 – 10.3.154.62	10.3.154.63
37	10.3.154.64/28	10.3.154.65 – 10.3.154.78	10.3.154.79
38	10.3.154.80/28	10.3.154.81 – 10.3.154.94	10.3.154.95
39	10.3.154.96/28	10.3.154.97 – 10.3.154.110	10.3.154.111
40	10.3.154.112/28	10.3.154.113 – 10.3.154.126	10.3.154.127
41	10.3.154.128/28	10.3.154.129 – 10.3.154.142	10.3.154.143
42	10.3.154.144/28	10.3.154.145 – 10.3.154.158	10.3.154.159
43	10.3.154.160/28	10.3.154.161 – 10.3.154.174	10.3.154.175
44	10.3.154.176/28	10.3.154.177 – 10.3.154.190	10.3.154.191
45	10.3.154.192/28	10.3.154.193 – 10.3.154.206	10.3.154.207
46	10.3.154.208/28	10.3.154.209 – 10.3.154.222	10.3.154.223
47	10.3.154.224/28	10.3.154.225 – 10.3.154.238	10.3.154.239
48	10.3.154.240/28	10.3.154.241 – 10.3.154.254	10.3.154.255
49	10.3.155.0/28	10.3.155.1 – 10.3.155.14	10.3.155.15
50	10.3.155.16/28	10.3.155.17 – 10.3.155.30	10.3.155.31
51	10.3.155.32/28	10.3.155.33 – 10.3.155.46	10.3.155.47
52	10.3.155.48/28	10.3.155.49 – 10.3.155.62	10.3.155.63
53	10.3.155.64/28	10.3.155.65 – 10.3.155.78	10.3.155.79
54	10.3.155.80/28	10.3.155.81 – 10.3.155.94	10.3.155.95
55	10.3.155.96/28	10.3.155.97 – 10.3.155.110	10.3.155.111
56	10.3.155.112/28	10.3.155.113 – 10.3.155.126	10.3.155.127
57	10.3.155.128/28	10.3.155.129 – 10.3.155.142	10.3.155.143
58	10.3.155.144/28	10.3.155.145 – 10.3.155.158	10.3.155.159
59	10.3.155.160/28	10.3.155.161 – 10.3.155.174	10.3.155.175
60	10.3.155.176/28	10.3.155.177 – 10.3.155.190	10.3.155.191
61	10.3.155.192/28	10.3.155.193 – 10.3.155.206	10.3.155.207
62	10.3.155.208/28	10.3.155.209 – 10.3.155.222	10.3.155.223
63	10.3.155.224/28	10.3.155.225 – 10.3.155.238	10.3.155.239
64	10.3.155.240/28	10.3.155.241 – 10.3.155.254	10.3.155.255
65	10.3.156.0/28	10.3.156.1 – 10.3.156.14	10.3.156.15
66	10.3.156.16/28	10.3.156.17 – 10.3.156.30	10.3.156.31
67	10.3.156.32/28	10.3.156.33 – 10.3.156.46	10.3.156.47
68	10.3.156.48/28	10.3.156.49 – 10.3.156.62	10.3.156.63
69	10.3.156.64/28	10.3.156.65 – 10.3.156.78	10.3.156.79
70	10.3.156.80/28	10.3.156.81 – 10.3.156.94	10.3.156.95
71	10.3.156.96/28	10.3.156.97 – 10.3.156.110	10.3.156.111
72	10.3.156.112/28	10.3.156.113 – 10.3.156.126	10.3.156.127
73	10.3.156.128/28	10.3.156.129 – 10.3.156.142	10.3.156.143
74	10.3.156.144/28	10.3.156.145 – 10.3.156.158	10.3.156.159
75	10.3.156.160/28	10.3.156.161 – 10.3.156.174	10.3.156.175
76	10.3.156.176/28	10.3.156.177 – 10.3.156.190	10.3.156.191
77	10.3.156.192/28	10.3.156.193 – 10.3.156.206	10.3.156.207
78	10.3.156.208/28	10.3.156.209 – 10.3.156.222	10.3.156.223
79	10.3.156.224/28	10.3.156.225 – 10.3.156.238	10.3.156.239
80	10.3.156.240/28	10.3.156.241 – 10.3.156.254	10.3.156.255
81	10.3.157.0/28	10.3.157.1 – 10.3.157.14	10.3.157.15
82	10.3.157.16/28	10.3.157.17 – 10.3.157.30	10.3.157.31
83	10.3.157.32/28	10.3.157.33 – 10.3.157.46	10.3.157.47
84	10.3.157.48/28	10.3.157.49 – 10.3.157.62	10.3.157.63
85	10.3.157.64/28	10.3.157.65 – 10.3.157.78	10.3.157.79
86	10.3.157.80/28	10.3.157.81 – 10.3.157.94	10.3.157.95
87	10.3.157.96/28	10.3.157.97 – 10.3.157.110	10.3.157.111
88	10.3.157.112/28	10.3.157.113 – 10.3.157.126	10.3.157.127
89	10.3.157.128/28	10.3.157.129 – 10.3.157.142	10.3.157.143
90	10.3.157.144/28	10.3.157.145 – 10.3.157.158	10.3.157.159
91	10.3.157.160/28	10.3.157.161 – 10.3.157.174	10.3.157.175
92	10.3.157.176/28	10.3.157.177 – 10.3.157.190	10.3.157.191
93	10.3.157.192/28	10.3.157.193 – 10.3.157.206	10.3.157.207
94	10.3.157.208/28	10.3.157.209 – 10.3.157.222	10.3.157.223
95	10.3.157.224/28	10.3.157.225 – 10.3.157.238	10.3.157.239
96	10.3.157.240/28	10.3.157.241 – 10.3.157.254	10.3.157.255
97	10.3.158.0/28	10.3.158.1 – 10.3.158.14	10.3.158.15
98	10.3.158.16/28	10.3.158.17 – 10.3.158.30	10.3.158.31
99	10.3.158.32/28	10.3.158.33 – 10.3.158.46	10.3.158.47
100	10.3.158.48/28	10.3.158.49 – 10.3.158.62	10.3.158.63
101	10.3.158.64/28	10.3.158.65 – 10.3.158.78	10.3.158.79
102	10.3.158.80/28	10.3.158.81 – 10.3.158.94	10.3.158.95
103	10.3.158.96/28	10.3.158.97 – 10.3.158.110	10.3.158.111
104	10.3.158.112/28	10.3.158.113 – 10.3.158.126	10.3.158.127
105	10.3.158.128/28	10.3.158.129 – 10.3.158.142	10.3.158.143
106	10.3.158.144/28	10.3.158.145 – 10.3.158.158	10.3.158.159
107	10.3.158.160/28	10.3.158.161 – 10.3.158.174	10.3.158.175
108	10.3.158.176/28	10.3.158.177 – 10.3.158.190	10.3.158.191
109	10.3.158.192/28	10.3.158.193 – 10.3.158.206	10.3.158.207
110	10.3.158.208/28	10.3.158.209 – 10.3.158.222	10.3.158.223
111	10.3.158.224/28	10.3.158.225 – 10.3.158.238	10.3.158.239
112	10.3.158.240/28	10.3.158.241 – 10.3.158.254	10.3.158.255
113	10.3.159.0/28	10.3.159.1 – 10.3.159.14	10.3.159.15
114	10.3.159.16/28	10.3.159.17 – 10.3.159.30	10.3.159.31
115	10.3.159.32/28	10.3.159.33 – 10.3.159.46	10.3.159.47
116	10.3.159.48/28	10.3.159.49 – 10.3.159.62	10.3.159.63
117	10.3.159.64/28	10.3.159.65 – 10.3.159.78	10.3.159.79
118	10.3.159.80/28	10.3.159.81 – 10.3.159.94	10.3.159.95
119	10.3.159.96/28	10.3.159.97 – 10.3.159.110	10.3.159.111
120	10.3.159.112/28	10.3.159.113 – 10.3.159.126	10.3.159.127
121	10.3.159.128/28	10.3.159.129 – 10.3.159.142	10.3.159.143
122	10.3.159.144/28	10.3.159.145 – 10.3.159.158	10.3.159.159
123	10.3.159.160/28	10.3.159.161 – 10.3.159.174	10.3.159.175
124	10.3.159.176/28	10.3.159.177 – 10.3.159.190	10.3.159.191
125	10.3.159.192/28	10.3.159.193 – 10.3.159.206	10.3.159.207
126	10.3.159.208/28	10.3.159.209 – 10.3.159.222	10.3.159.223
127	10.3.159.224/28	10.3.159.225 – 10.3.159.238	10.3.159.239
128	10.3.159.240/28	10.3.159.241 – 10.3.159.254	10.3.159.255

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 →