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)10.4.88.0/21

network10.4.88.0/21

broadcast10.4.95.255

first host10.4.88.1

last host10.4.95.254

subnet mask255.255.248.0

wildcard0.0.7.255

addresses2,048

usable hosts2,046

classA

ipcalc 10.4.88.0/21

address00001010.00000100.01011000.00000000

subnet mask11111111.11111111.11111000.00000000

network00001010.00000100.01011000.00000000

broadcast00001010.00000100.01011111.11111111

green = network part, grey = host part

hex0x0a045800

decimal168056832

reverse dns0.88.4.10.in-addr.arpa

ipv4-mapped::ffff:a04:5800

/21 split into /28 · 128 subnets

close ×

#	network	host range	broadcast
1	10.4.88.0/28	10.4.88.1 – 10.4.88.14	10.4.88.15
2	10.4.88.16/28	10.4.88.17 – 10.4.88.30	10.4.88.31
3	10.4.88.32/28	10.4.88.33 – 10.4.88.46	10.4.88.47
4	10.4.88.48/28	10.4.88.49 – 10.4.88.62	10.4.88.63
5	10.4.88.64/28	10.4.88.65 – 10.4.88.78	10.4.88.79
6	10.4.88.80/28	10.4.88.81 – 10.4.88.94	10.4.88.95
7	10.4.88.96/28	10.4.88.97 – 10.4.88.110	10.4.88.111
8	10.4.88.112/28	10.4.88.113 – 10.4.88.126	10.4.88.127
9	10.4.88.128/28	10.4.88.129 – 10.4.88.142	10.4.88.143
10	10.4.88.144/28	10.4.88.145 – 10.4.88.158	10.4.88.159
11	10.4.88.160/28	10.4.88.161 – 10.4.88.174	10.4.88.175
12	10.4.88.176/28	10.4.88.177 – 10.4.88.190	10.4.88.191
13	10.4.88.192/28	10.4.88.193 – 10.4.88.206	10.4.88.207
14	10.4.88.208/28	10.4.88.209 – 10.4.88.222	10.4.88.223
15	10.4.88.224/28	10.4.88.225 – 10.4.88.238	10.4.88.239
16	10.4.88.240/28	10.4.88.241 – 10.4.88.254	10.4.88.255
17	10.4.89.0/28	10.4.89.1 – 10.4.89.14	10.4.89.15
18	10.4.89.16/28	10.4.89.17 – 10.4.89.30	10.4.89.31
19	10.4.89.32/28	10.4.89.33 – 10.4.89.46	10.4.89.47
20	10.4.89.48/28	10.4.89.49 – 10.4.89.62	10.4.89.63
21	10.4.89.64/28	10.4.89.65 – 10.4.89.78	10.4.89.79
22	10.4.89.80/28	10.4.89.81 – 10.4.89.94	10.4.89.95
23	10.4.89.96/28	10.4.89.97 – 10.4.89.110	10.4.89.111
24	10.4.89.112/28	10.4.89.113 – 10.4.89.126	10.4.89.127
25	10.4.89.128/28	10.4.89.129 – 10.4.89.142	10.4.89.143
26	10.4.89.144/28	10.4.89.145 – 10.4.89.158	10.4.89.159
27	10.4.89.160/28	10.4.89.161 – 10.4.89.174	10.4.89.175
28	10.4.89.176/28	10.4.89.177 – 10.4.89.190	10.4.89.191
29	10.4.89.192/28	10.4.89.193 – 10.4.89.206	10.4.89.207
30	10.4.89.208/28	10.4.89.209 – 10.4.89.222	10.4.89.223
31	10.4.89.224/28	10.4.89.225 – 10.4.89.238	10.4.89.239
32	10.4.89.240/28	10.4.89.241 – 10.4.89.254	10.4.89.255
33	10.4.90.0/28	10.4.90.1 – 10.4.90.14	10.4.90.15
34	10.4.90.16/28	10.4.90.17 – 10.4.90.30	10.4.90.31
35	10.4.90.32/28	10.4.90.33 – 10.4.90.46	10.4.90.47
36	10.4.90.48/28	10.4.90.49 – 10.4.90.62	10.4.90.63
37	10.4.90.64/28	10.4.90.65 – 10.4.90.78	10.4.90.79
38	10.4.90.80/28	10.4.90.81 – 10.4.90.94	10.4.90.95
39	10.4.90.96/28	10.4.90.97 – 10.4.90.110	10.4.90.111
40	10.4.90.112/28	10.4.90.113 – 10.4.90.126	10.4.90.127
41	10.4.90.128/28	10.4.90.129 – 10.4.90.142	10.4.90.143
42	10.4.90.144/28	10.4.90.145 – 10.4.90.158	10.4.90.159
43	10.4.90.160/28	10.4.90.161 – 10.4.90.174	10.4.90.175
44	10.4.90.176/28	10.4.90.177 – 10.4.90.190	10.4.90.191
45	10.4.90.192/28	10.4.90.193 – 10.4.90.206	10.4.90.207
46	10.4.90.208/28	10.4.90.209 – 10.4.90.222	10.4.90.223
47	10.4.90.224/28	10.4.90.225 – 10.4.90.238	10.4.90.239
48	10.4.90.240/28	10.4.90.241 – 10.4.90.254	10.4.90.255
49	10.4.91.0/28	10.4.91.1 – 10.4.91.14	10.4.91.15
50	10.4.91.16/28	10.4.91.17 – 10.4.91.30	10.4.91.31
51	10.4.91.32/28	10.4.91.33 – 10.4.91.46	10.4.91.47
52	10.4.91.48/28	10.4.91.49 – 10.4.91.62	10.4.91.63
53	10.4.91.64/28	10.4.91.65 – 10.4.91.78	10.4.91.79
54	10.4.91.80/28	10.4.91.81 – 10.4.91.94	10.4.91.95
55	10.4.91.96/28	10.4.91.97 – 10.4.91.110	10.4.91.111
56	10.4.91.112/28	10.4.91.113 – 10.4.91.126	10.4.91.127
57	10.4.91.128/28	10.4.91.129 – 10.4.91.142	10.4.91.143
58	10.4.91.144/28	10.4.91.145 – 10.4.91.158	10.4.91.159
59	10.4.91.160/28	10.4.91.161 – 10.4.91.174	10.4.91.175
60	10.4.91.176/28	10.4.91.177 – 10.4.91.190	10.4.91.191
61	10.4.91.192/28	10.4.91.193 – 10.4.91.206	10.4.91.207
62	10.4.91.208/28	10.4.91.209 – 10.4.91.222	10.4.91.223
63	10.4.91.224/28	10.4.91.225 – 10.4.91.238	10.4.91.239
64	10.4.91.240/28	10.4.91.241 – 10.4.91.254	10.4.91.255
65	10.4.92.0/28	10.4.92.1 – 10.4.92.14	10.4.92.15
66	10.4.92.16/28	10.4.92.17 – 10.4.92.30	10.4.92.31
67	10.4.92.32/28	10.4.92.33 – 10.4.92.46	10.4.92.47
68	10.4.92.48/28	10.4.92.49 – 10.4.92.62	10.4.92.63
69	10.4.92.64/28	10.4.92.65 – 10.4.92.78	10.4.92.79
70	10.4.92.80/28	10.4.92.81 – 10.4.92.94	10.4.92.95
71	10.4.92.96/28	10.4.92.97 – 10.4.92.110	10.4.92.111
72	10.4.92.112/28	10.4.92.113 – 10.4.92.126	10.4.92.127
73	10.4.92.128/28	10.4.92.129 – 10.4.92.142	10.4.92.143
74	10.4.92.144/28	10.4.92.145 – 10.4.92.158	10.4.92.159
75	10.4.92.160/28	10.4.92.161 – 10.4.92.174	10.4.92.175
76	10.4.92.176/28	10.4.92.177 – 10.4.92.190	10.4.92.191
77	10.4.92.192/28	10.4.92.193 – 10.4.92.206	10.4.92.207
78	10.4.92.208/28	10.4.92.209 – 10.4.92.222	10.4.92.223
79	10.4.92.224/28	10.4.92.225 – 10.4.92.238	10.4.92.239
80	10.4.92.240/28	10.4.92.241 – 10.4.92.254	10.4.92.255
81	10.4.93.0/28	10.4.93.1 – 10.4.93.14	10.4.93.15
82	10.4.93.16/28	10.4.93.17 – 10.4.93.30	10.4.93.31
83	10.4.93.32/28	10.4.93.33 – 10.4.93.46	10.4.93.47
84	10.4.93.48/28	10.4.93.49 – 10.4.93.62	10.4.93.63
85	10.4.93.64/28	10.4.93.65 – 10.4.93.78	10.4.93.79
86	10.4.93.80/28	10.4.93.81 – 10.4.93.94	10.4.93.95
87	10.4.93.96/28	10.4.93.97 – 10.4.93.110	10.4.93.111
88	10.4.93.112/28	10.4.93.113 – 10.4.93.126	10.4.93.127
89	10.4.93.128/28	10.4.93.129 – 10.4.93.142	10.4.93.143
90	10.4.93.144/28	10.4.93.145 – 10.4.93.158	10.4.93.159
91	10.4.93.160/28	10.4.93.161 – 10.4.93.174	10.4.93.175
92	10.4.93.176/28	10.4.93.177 – 10.4.93.190	10.4.93.191
93	10.4.93.192/28	10.4.93.193 – 10.4.93.206	10.4.93.207
94	10.4.93.208/28	10.4.93.209 – 10.4.93.222	10.4.93.223
95	10.4.93.224/28	10.4.93.225 – 10.4.93.238	10.4.93.239
96	10.4.93.240/28	10.4.93.241 – 10.4.93.254	10.4.93.255
97	10.4.94.0/28	10.4.94.1 – 10.4.94.14	10.4.94.15
98	10.4.94.16/28	10.4.94.17 – 10.4.94.30	10.4.94.31
99	10.4.94.32/28	10.4.94.33 – 10.4.94.46	10.4.94.47
100	10.4.94.48/28	10.4.94.49 – 10.4.94.62	10.4.94.63
101	10.4.94.64/28	10.4.94.65 – 10.4.94.78	10.4.94.79
102	10.4.94.80/28	10.4.94.81 – 10.4.94.94	10.4.94.95
103	10.4.94.96/28	10.4.94.97 – 10.4.94.110	10.4.94.111
104	10.4.94.112/28	10.4.94.113 – 10.4.94.126	10.4.94.127
105	10.4.94.128/28	10.4.94.129 – 10.4.94.142	10.4.94.143
106	10.4.94.144/28	10.4.94.145 – 10.4.94.158	10.4.94.159
107	10.4.94.160/28	10.4.94.161 – 10.4.94.174	10.4.94.175
108	10.4.94.176/28	10.4.94.177 – 10.4.94.190	10.4.94.191
109	10.4.94.192/28	10.4.94.193 – 10.4.94.206	10.4.94.207
110	10.4.94.208/28	10.4.94.209 – 10.4.94.222	10.4.94.223
111	10.4.94.224/28	10.4.94.225 – 10.4.94.238	10.4.94.239
112	10.4.94.240/28	10.4.94.241 – 10.4.94.254	10.4.94.255
113	10.4.95.0/28	10.4.95.1 – 10.4.95.14	10.4.95.15
114	10.4.95.16/28	10.4.95.17 – 10.4.95.30	10.4.95.31
115	10.4.95.32/28	10.4.95.33 – 10.4.95.46	10.4.95.47
116	10.4.95.48/28	10.4.95.49 – 10.4.95.62	10.4.95.63
117	10.4.95.64/28	10.4.95.65 – 10.4.95.78	10.4.95.79
118	10.4.95.80/28	10.4.95.81 – 10.4.95.94	10.4.95.95
119	10.4.95.96/28	10.4.95.97 – 10.4.95.110	10.4.95.111
120	10.4.95.112/28	10.4.95.113 – 10.4.95.126	10.4.95.127
121	10.4.95.128/28	10.4.95.129 – 10.4.95.142	10.4.95.143
122	10.4.95.144/28	10.4.95.145 – 10.4.95.158	10.4.95.159
123	10.4.95.160/28	10.4.95.161 – 10.4.95.174	10.4.95.175
124	10.4.95.176/28	10.4.95.177 – 10.4.95.190	10.4.95.191
125	10.4.95.192/28	10.4.95.193 – 10.4.95.206	10.4.95.207
126	10.4.95.208/28	10.4.95.209 – 10.4.95.222	10.4.95.223
127	10.4.95.224/28	10.4.95.225 – 10.4.95.238	10.4.95.239
128	10.4.95.240/28	10.4.95.241 – 10.4.95.254	10.4.95.255

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 →