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)10.2.158.0/23

network10.2.158.0/23

broadcast10.2.159.255

first host10.2.158.1

last host10.2.159.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.2.158.0/23

address00001010.00000010.10011110.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000010.10011110.00000000

broadcast00001010.00000010.10011111.11111111

green = network part, grey = host part

hex0x0a029e00

decimal167943680

reverse dns0.158.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:9e00

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.2.158.0/29	10.2.158.1 – 10.2.158.6	10.2.158.7
2	10.2.158.8/29	10.2.158.9 – 10.2.158.14	10.2.158.15
3	10.2.158.16/29	10.2.158.17 – 10.2.158.22	10.2.158.23
4	10.2.158.24/29	10.2.158.25 – 10.2.158.30	10.2.158.31
5	10.2.158.32/29	10.2.158.33 – 10.2.158.38	10.2.158.39
6	10.2.158.40/29	10.2.158.41 – 10.2.158.46	10.2.158.47
7	10.2.158.48/29	10.2.158.49 – 10.2.158.54	10.2.158.55
8	10.2.158.56/29	10.2.158.57 – 10.2.158.62	10.2.158.63
9	10.2.158.64/29	10.2.158.65 – 10.2.158.70	10.2.158.71
10	10.2.158.72/29	10.2.158.73 – 10.2.158.78	10.2.158.79
11	10.2.158.80/29	10.2.158.81 – 10.2.158.86	10.2.158.87
12	10.2.158.88/29	10.2.158.89 – 10.2.158.94	10.2.158.95
13	10.2.158.96/29	10.2.158.97 – 10.2.158.102	10.2.158.103
14	10.2.158.104/29	10.2.158.105 – 10.2.158.110	10.2.158.111
15	10.2.158.112/29	10.2.158.113 – 10.2.158.118	10.2.158.119
16	10.2.158.120/29	10.2.158.121 – 10.2.158.126	10.2.158.127
17	10.2.158.128/29	10.2.158.129 – 10.2.158.134	10.2.158.135
18	10.2.158.136/29	10.2.158.137 – 10.2.158.142	10.2.158.143
19	10.2.158.144/29	10.2.158.145 – 10.2.158.150	10.2.158.151
20	10.2.158.152/29	10.2.158.153 – 10.2.158.158	10.2.158.159
21	10.2.158.160/29	10.2.158.161 – 10.2.158.166	10.2.158.167
22	10.2.158.168/29	10.2.158.169 – 10.2.158.174	10.2.158.175
23	10.2.158.176/29	10.2.158.177 – 10.2.158.182	10.2.158.183
24	10.2.158.184/29	10.2.158.185 – 10.2.158.190	10.2.158.191
25	10.2.158.192/29	10.2.158.193 – 10.2.158.198	10.2.158.199
26	10.2.158.200/29	10.2.158.201 – 10.2.158.206	10.2.158.207
27	10.2.158.208/29	10.2.158.209 – 10.2.158.214	10.2.158.215
28	10.2.158.216/29	10.2.158.217 – 10.2.158.222	10.2.158.223
29	10.2.158.224/29	10.2.158.225 – 10.2.158.230	10.2.158.231
30	10.2.158.232/29	10.2.158.233 – 10.2.158.238	10.2.158.239
31	10.2.158.240/29	10.2.158.241 – 10.2.158.246	10.2.158.247
32	10.2.158.248/29	10.2.158.249 – 10.2.158.254	10.2.158.255
33	10.2.159.0/29	10.2.159.1 – 10.2.159.6	10.2.159.7
34	10.2.159.8/29	10.2.159.9 – 10.2.159.14	10.2.159.15
35	10.2.159.16/29	10.2.159.17 – 10.2.159.22	10.2.159.23
36	10.2.159.24/29	10.2.159.25 – 10.2.159.30	10.2.159.31
37	10.2.159.32/29	10.2.159.33 – 10.2.159.38	10.2.159.39
38	10.2.159.40/29	10.2.159.41 – 10.2.159.46	10.2.159.47
39	10.2.159.48/29	10.2.159.49 – 10.2.159.54	10.2.159.55
40	10.2.159.56/29	10.2.159.57 – 10.2.159.62	10.2.159.63
41	10.2.159.64/29	10.2.159.65 – 10.2.159.70	10.2.159.71
42	10.2.159.72/29	10.2.159.73 – 10.2.159.78	10.2.159.79
43	10.2.159.80/29	10.2.159.81 – 10.2.159.86	10.2.159.87
44	10.2.159.88/29	10.2.159.89 – 10.2.159.94	10.2.159.95
45	10.2.159.96/29	10.2.159.97 – 10.2.159.102	10.2.159.103
46	10.2.159.104/29	10.2.159.105 – 10.2.159.110	10.2.159.111
47	10.2.159.112/29	10.2.159.113 – 10.2.159.118	10.2.159.119
48	10.2.159.120/29	10.2.159.121 – 10.2.159.126	10.2.159.127
49	10.2.159.128/29	10.2.159.129 – 10.2.159.134	10.2.159.135
50	10.2.159.136/29	10.2.159.137 – 10.2.159.142	10.2.159.143
51	10.2.159.144/29	10.2.159.145 – 10.2.159.150	10.2.159.151
52	10.2.159.152/29	10.2.159.153 – 10.2.159.158	10.2.159.159
53	10.2.159.160/29	10.2.159.161 – 10.2.159.166	10.2.159.167
54	10.2.159.168/29	10.2.159.169 – 10.2.159.174	10.2.159.175
55	10.2.159.176/29	10.2.159.177 – 10.2.159.182	10.2.159.183
56	10.2.159.184/29	10.2.159.185 – 10.2.159.190	10.2.159.191
57	10.2.159.192/29	10.2.159.193 – 10.2.159.198	10.2.159.199
58	10.2.159.200/29	10.2.159.201 – 10.2.159.206	10.2.159.207
59	10.2.159.208/29	10.2.159.209 – 10.2.159.214	10.2.159.215
60	10.2.159.216/29	10.2.159.217 – 10.2.159.222	10.2.159.223
61	10.2.159.224/29	10.2.159.225 – 10.2.159.230	10.2.159.231
62	10.2.159.232/29	10.2.159.233 – 10.2.159.238	10.2.159.239
63	10.2.159.240/29	10.2.159.241 – 10.2.159.246	10.2.159.247
64	10.2.159.248/29	10.2.159.249 – 10.2.159.254	10.2.159.255

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 /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 →