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)10.166.4.0/23

network10.166.4.0/23

broadcast10.166.5.255

first host10.166.4.1

last host10.166.5.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.166.4.0/23

address00001010.10100110.00000100.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.10100110.00000100.00000000

broadcast00001010.10100110.00000101.11111111

green = network part, grey = host part

hex0x0aa60400

decimal178652160

reverse dns0.4.166.10.in-addr.arpa

ipv4-mapped::ffff:aa6:400

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.166.4.0/29	10.166.4.1 – 10.166.4.6	10.166.4.7
2	10.166.4.8/29	10.166.4.9 – 10.166.4.14	10.166.4.15
3	10.166.4.16/29	10.166.4.17 – 10.166.4.22	10.166.4.23
4	10.166.4.24/29	10.166.4.25 – 10.166.4.30	10.166.4.31
5	10.166.4.32/29	10.166.4.33 – 10.166.4.38	10.166.4.39
6	10.166.4.40/29	10.166.4.41 – 10.166.4.46	10.166.4.47
7	10.166.4.48/29	10.166.4.49 – 10.166.4.54	10.166.4.55
8	10.166.4.56/29	10.166.4.57 – 10.166.4.62	10.166.4.63
9	10.166.4.64/29	10.166.4.65 – 10.166.4.70	10.166.4.71
10	10.166.4.72/29	10.166.4.73 – 10.166.4.78	10.166.4.79
11	10.166.4.80/29	10.166.4.81 – 10.166.4.86	10.166.4.87
12	10.166.4.88/29	10.166.4.89 – 10.166.4.94	10.166.4.95
13	10.166.4.96/29	10.166.4.97 – 10.166.4.102	10.166.4.103
14	10.166.4.104/29	10.166.4.105 – 10.166.4.110	10.166.4.111
15	10.166.4.112/29	10.166.4.113 – 10.166.4.118	10.166.4.119
16	10.166.4.120/29	10.166.4.121 – 10.166.4.126	10.166.4.127
17	10.166.4.128/29	10.166.4.129 – 10.166.4.134	10.166.4.135
18	10.166.4.136/29	10.166.4.137 – 10.166.4.142	10.166.4.143
19	10.166.4.144/29	10.166.4.145 – 10.166.4.150	10.166.4.151
20	10.166.4.152/29	10.166.4.153 – 10.166.4.158	10.166.4.159
21	10.166.4.160/29	10.166.4.161 – 10.166.4.166	10.166.4.167
22	10.166.4.168/29	10.166.4.169 – 10.166.4.174	10.166.4.175
23	10.166.4.176/29	10.166.4.177 – 10.166.4.182	10.166.4.183
24	10.166.4.184/29	10.166.4.185 – 10.166.4.190	10.166.4.191
25	10.166.4.192/29	10.166.4.193 – 10.166.4.198	10.166.4.199
26	10.166.4.200/29	10.166.4.201 – 10.166.4.206	10.166.4.207
27	10.166.4.208/29	10.166.4.209 – 10.166.4.214	10.166.4.215
28	10.166.4.216/29	10.166.4.217 – 10.166.4.222	10.166.4.223
29	10.166.4.224/29	10.166.4.225 – 10.166.4.230	10.166.4.231
30	10.166.4.232/29	10.166.4.233 – 10.166.4.238	10.166.4.239
31	10.166.4.240/29	10.166.4.241 – 10.166.4.246	10.166.4.247
32	10.166.4.248/29	10.166.4.249 – 10.166.4.254	10.166.4.255
33	10.166.5.0/29	10.166.5.1 – 10.166.5.6	10.166.5.7
34	10.166.5.8/29	10.166.5.9 – 10.166.5.14	10.166.5.15
35	10.166.5.16/29	10.166.5.17 – 10.166.5.22	10.166.5.23
36	10.166.5.24/29	10.166.5.25 – 10.166.5.30	10.166.5.31
37	10.166.5.32/29	10.166.5.33 – 10.166.5.38	10.166.5.39
38	10.166.5.40/29	10.166.5.41 – 10.166.5.46	10.166.5.47
39	10.166.5.48/29	10.166.5.49 – 10.166.5.54	10.166.5.55
40	10.166.5.56/29	10.166.5.57 – 10.166.5.62	10.166.5.63
41	10.166.5.64/29	10.166.5.65 – 10.166.5.70	10.166.5.71
42	10.166.5.72/29	10.166.5.73 – 10.166.5.78	10.166.5.79
43	10.166.5.80/29	10.166.5.81 – 10.166.5.86	10.166.5.87
44	10.166.5.88/29	10.166.5.89 – 10.166.5.94	10.166.5.95
45	10.166.5.96/29	10.166.5.97 – 10.166.5.102	10.166.5.103
46	10.166.5.104/29	10.166.5.105 – 10.166.5.110	10.166.5.111
47	10.166.5.112/29	10.166.5.113 – 10.166.5.118	10.166.5.119
48	10.166.5.120/29	10.166.5.121 – 10.166.5.126	10.166.5.127
49	10.166.5.128/29	10.166.5.129 – 10.166.5.134	10.166.5.135
50	10.166.5.136/29	10.166.5.137 – 10.166.5.142	10.166.5.143
51	10.166.5.144/29	10.166.5.145 – 10.166.5.150	10.166.5.151
52	10.166.5.152/29	10.166.5.153 – 10.166.5.158	10.166.5.159
53	10.166.5.160/29	10.166.5.161 – 10.166.5.166	10.166.5.167
54	10.166.5.168/29	10.166.5.169 – 10.166.5.174	10.166.5.175
55	10.166.5.176/29	10.166.5.177 – 10.166.5.182	10.166.5.183
56	10.166.5.184/29	10.166.5.185 – 10.166.5.190	10.166.5.191
57	10.166.5.192/29	10.166.5.193 – 10.166.5.198	10.166.5.199
58	10.166.5.200/29	10.166.5.201 – 10.166.5.206	10.166.5.207
59	10.166.5.208/29	10.166.5.209 – 10.166.5.214	10.166.5.215
60	10.166.5.216/29	10.166.5.217 – 10.166.5.222	10.166.5.223
61	10.166.5.224/29	10.166.5.225 – 10.166.5.230	10.166.5.231
62	10.166.5.232/29	10.166.5.233 – 10.166.5.238	10.166.5.239
63	10.166.5.240/29	10.166.5.241 – 10.166.5.246	10.166.5.247
64	10.166.5.248/29	10.166.5.249 – 10.166.5.254	10.166.5.255

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 /23
/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	-
/22	255.255.252.0	1,024	1,022	-
/23	255.255.254.0	512	510	1
/24	255.255.255.0	256	254	2 split →
/25	255.255.255.128	128	126	4 split →
/26	255.255.255.192	64	62	8 split →
/27	255.255.255.224	32	30	16 split →
/28	255.255.255.240	16	14	32 split →
/29	255.255.255.248	8	6	64 split →
/30	255.255.255.252	4	2	128 split →
/31	255.255.255.254	2	2	256 split →
/32	255.255.255.255	1	1	512 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 →