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)10.3.166.0/23

network10.3.166.0/23

broadcast10.3.167.255

first host10.3.166.1

last host10.3.167.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.3.166.0/23

address00001010.00000011.10100110.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000011.10100110.00000000

broadcast00001010.00000011.10100111.11111111

green = network part, grey = host part

hex0x0a03a600

decimal168011264

reverse dns0.166.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:a600

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.166.0/29	10.3.166.1 – 10.3.166.6	10.3.166.7
2	10.3.166.8/29	10.3.166.9 – 10.3.166.14	10.3.166.15
3	10.3.166.16/29	10.3.166.17 – 10.3.166.22	10.3.166.23
4	10.3.166.24/29	10.3.166.25 – 10.3.166.30	10.3.166.31
5	10.3.166.32/29	10.3.166.33 – 10.3.166.38	10.3.166.39
6	10.3.166.40/29	10.3.166.41 – 10.3.166.46	10.3.166.47
7	10.3.166.48/29	10.3.166.49 – 10.3.166.54	10.3.166.55
8	10.3.166.56/29	10.3.166.57 – 10.3.166.62	10.3.166.63
9	10.3.166.64/29	10.3.166.65 – 10.3.166.70	10.3.166.71
10	10.3.166.72/29	10.3.166.73 – 10.3.166.78	10.3.166.79
11	10.3.166.80/29	10.3.166.81 – 10.3.166.86	10.3.166.87
12	10.3.166.88/29	10.3.166.89 – 10.3.166.94	10.3.166.95
13	10.3.166.96/29	10.3.166.97 – 10.3.166.102	10.3.166.103
14	10.3.166.104/29	10.3.166.105 – 10.3.166.110	10.3.166.111
15	10.3.166.112/29	10.3.166.113 – 10.3.166.118	10.3.166.119
16	10.3.166.120/29	10.3.166.121 – 10.3.166.126	10.3.166.127
17	10.3.166.128/29	10.3.166.129 – 10.3.166.134	10.3.166.135
18	10.3.166.136/29	10.3.166.137 – 10.3.166.142	10.3.166.143
19	10.3.166.144/29	10.3.166.145 – 10.3.166.150	10.3.166.151
20	10.3.166.152/29	10.3.166.153 – 10.3.166.158	10.3.166.159
21	10.3.166.160/29	10.3.166.161 – 10.3.166.166	10.3.166.167
22	10.3.166.168/29	10.3.166.169 – 10.3.166.174	10.3.166.175
23	10.3.166.176/29	10.3.166.177 – 10.3.166.182	10.3.166.183
24	10.3.166.184/29	10.3.166.185 – 10.3.166.190	10.3.166.191
25	10.3.166.192/29	10.3.166.193 – 10.3.166.198	10.3.166.199
26	10.3.166.200/29	10.3.166.201 – 10.3.166.206	10.3.166.207
27	10.3.166.208/29	10.3.166.209 – 10.3.166.214	10.3.166.215
28	10.3.166.216/29	10.3.166.217 – 10.3.166.222	10.3.166.223
29	10.3.166.224/29	10.3.166.225 – 10.3.166.230	10.3.166.231
30	10.3.166.232/29	10.3.166.233 – 10.3.166.238	10.3.166.239
31	10.3.166.240/29	10.3.166.241 – 10.3.166.246	10.3.166.247
32	10.3.166.248/29	10.3.166.249 – 10.3.166.254	10.3.166.255
33	10.3.167.0/29	10.3.167.1 – 10.3.167.6	10.3.167.7
34	10.3.167.8/29	10.3.167.9 – 10.3.167.14	10.3.167.15
35	10.3.167.16/29	10.3.167.17 – 10.3.167.22	10.3.167.23
36	10.3.167.24/29	10.3.167.25 – 10.3.167.30	10.3.167.31
37	10.3.167.32/29	10.3.167.33 – 10.3.167.38	10.3.167.39
38	10.3.167.40/29	10.3.167.41 – 10.3.167.46	10.3.167.47
39	10.3.167.48/29	10.3.167.49 – 10.3.167.54	10.3.167.55
40	10.3.167.56/29	10.3.167.57 – 10.3.167.62	10.3.167.63
41	10.3.167.64/29	10.3.167.65 – 10.3.167.70	10.3.167.71
42	10.3.167.72/29	10.3.167.73 – 10.3.167.78	10.3.167.79
43	10.3.167.80/29	10.3.167.81 – 10.3.167.86	10.3.167.87
44	10.3.167.88/29	10.3.167.89 – 10.3.167.94	10.3.167.95
45	10.3.167.96/29	10.3.167.97 – 10.3.167.102	10.3.167.103
46	10.3.167.104/29	10.3.167.105 – 10.3.167.110	10.3.167.111
47	10.3.167.112/29	10.3.167.113 – 10.3.167.118	10.3.167.119
48	10.3.167.120/29	10.3.167.121 – 10.3.167.126	10.3.167.127
49	10.3.167.128/29	10.3.167.129 – 10.3.167.134	10.3.167.135
50	10.3.167.136/29	10.3.167.137 – 10.3.167.142	10.3.167.143
51	10.3.167.144/29	10.3.167.145 – 10.3.167.150	10.3.167.151
52	10.3.167.152/29	10.3.167.153 – 10.3.167.158	10.3.167.159
53	10.3.167.160/29	10.3.167.161 – 10.3.167.166	10.3.167.167
54	10.3.167.168/29	10.3.167.169 – 10.3.167.174	10.3.167.175
55	10.3.167.176/29	10.3.167.177 – 10.3.167.182	10.3.167.183
56	10.3.167.184/29	10.3.167.185 – 10.3.167.190	10.3.167.191
57	10.3.167.192/29	10.3.167.193 – 10.3.167.198	10.3.167.199
58	10.3.167.200/29	10.3.167.201 – 10.3.167.206	10.3.167.207
59	10.3.167.208/29	10.3.167.209 – 10.3.167.214	10.3.167.215
60	10.3.167.216/29	10.3.167.217 – 10.3.167.222	10.3.167.223
61	10.3.167.224/29	10.3.167.225 – 10.3.167.230	10.3.167.231
62	10.3.167.232/29	10.3.167.233 – 10.3.167.238	10.3.167.239
63	10.3.167.240/29	10.3.167.241 – 10.3.167.246	10.3.167.247
64	10.3.167.248/29	10.3.167.249 – 10.3.167.254	10.3.167.255

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 →