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)10.1.242.0/23

network10.1.242.0/23

broadcast10.1.243.255

first host10.1.242.1

last host10.1.243.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.1.242.0/23

address00001010.00000001.11110010.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000001.11110010.00000000

broadcast00001010.00000001.11110011.11111111

green = network part, grey = host part

hex0x0a01f200

decimal167899648

reverse dns0.242.1.10.in-addr.arpa

ipv4-mapped::ffff:a01:f200

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.1.242.0/29	10.1.242.1 – 10.1.242.6	10.1.242.7
2	10.1.242.8/29	10.1.242.9 – 10.1.242.14	10.1.242.15
3	10.1.242.16/29	10.1.242.17 – 10.1.242.22	10.1.242.23
4	10.1.242.24/29	10.1.242.25 – 10.1.242.30	10.1.242.31
5	10.1.242.32/29	10.1.242.33 – 10.1.242.38	10.1.242.39
6	10.1.242.40/29	10.1.242.41 – 10.1.242.46	10.1.242.47
7	10.1.242.48/29	10.1.242.49 – 10.1.242.54	10.1.242.55
8	10.1.242.56/29	10.1.242.57 – 10.1.242.62	10.1.242.63
9	10.1.242.64/29	10.1.242.65 – 10.1.242.70	10.1.242.71
10	10.1.242.72/29	10.1.242.73 – 10.1.242.78	10.1.242.79
11	10.1.242.80/29	10.1.242.81 – 10.1.242.86	10.1.242.87
12	10.1.242.88/29	10.1.242.89 – 10.1.242.94	10.1.242.95
13	10.1.242.96/29	10.1.242.97 – 10.1.242.102	10.1.242.103
14	10.1.242.104/29	10.1.242.105 – 10.1.242.110	10.1.242.111
15	10.1.242.112/29	10.1.242.113 – 10.1.242.118	10.1.242.119
16	10.1.242.120/29	10.1.242.121 – 10.1.242.126	10.1.242.127
17	10.1.242.128/29	10.1.242.129 – 10.1.242.134	10.1.242.135
18	10.1.242.136/29	10.1.242.137 – 10.1.242.142	10.1.242.143
19	10.1.242.144/29	10.1.242.145 – 10.1.242.150	10.1.242.151
20	10.1.242.152/29	10.1.242.153 – 10.1.242.158	10.1.242.159
21	10.1.242.160/29	10.1.242.161 – 10.1.242.166	10.1.242.167
22	10.1.242.168/29	10.1.242.169 – 10.1.242.174	10.1.242.175
23	10.1.242.176/29	10.1.242.177 – 10.1.242.182	10.1.242.183
24	10.1.242.184/29	10.1.242.185 – 10.1.242.190	10.1.242.191
25	10.1.242.192/29	10.1.242.193 – 10.1.242.198	10.1.242.199
26	10.1.242.200/29	10.1.242.201 – 10.1.242.206	10.1.242.207
27	10.1.242.208/29	10.1.242.209 – 10.1.242.214	10.1.242.215
28	10.1.242.216/29	10.1.242.217 – 10.1.242.222	10.1.242.223
29	10.1.242.224/29	10.1.242.225 – 10.1.242.230	10.1.242.231
30	10.1.242.232/29	10.1.242.233 – 10.1.242.238	10.1.242.239
31	10.1.242.240/29	10.1.242.241 – 10.1.242.246	10.1.242.247
32	10.1.242.248/29	10.1.242.249 – 10.1.242.254	10.1.242.255
33	10.1.243.0/29	10.1.243.1 – 10.1.243.6	10.1.243.7
34	10.1.243.8/29	10.1.243.9 – 10.1.243.14	10.1.243.15
35	10.1.243.16/29	10.1.243.17 – 10.1.243.22	10.1.243.23
36	10.1.243.24/29	10.1.243.25 – 10.1.243.30	10.1.243.31
37	10.1.243.32/29	10.1.243.33 – 10.1.243.38	10.1.243.39
38	10.1.243.40/29	10.1.243.41 – 10.1.243.46	10.1.243.47
39	10.1.243.48/29	10.1.243.49 – 10.1.243.54	10.1.243.55
40	10.1.243.56/29	10.1.243.57 – 10.1.243.62	10.1.243.63
41	10.1.243.64/29	10.1.243.65 – 10.1.243.70	10.1.243.71
42	10.1.243.72/29	10.1.243.73 – 10.1.243.78	10.1.243.79
43	10.1.243.80/29	10.1.243.81 – 10.1.243.86	10.1.243.87
44	10.1.243.88/29	10.1.243.89 – 10.1.243.94	10.1.243.95
45	10.1.243.96/29	10.1.243.97 – 10.1.243.102	10.1.243.103
46	10.1.243.104/29	10.1.243.105 – 10.1.243.110	10.1.243.111
47	10.1.243.112/29	10.1.243.113 – 10.1.243.118	10.1.243.119
48	10.1.243.120/29	10.1.243.121 – 10.1.243.126	10.1.243.127
49	10.1.243.128/29	10.1.243.129 – 10.1.243.134	10.1.243.135
50	10.1.243.136/29	10.1.243.137 – 10.1.243.142	10.1.243.143
51	10.1.243.144/29	10.1.243.145 – 10.1.243.150	10.1.243.151
52	10.1.243.152/29	10.1.243.153 – 10.1.243.158	10.1.243.159
53	10.1.243.160/29	10.1.243.161 – 10.1.243.166	10.1.243.167
54	10.1.243.168/29	10.1.243.169 – 10.1.243.174	10.1.243.175
55	10.1.243.176/29	10.1.243.177 – 10.1.243.182	10.1.243.183
56	10.1.243.184/29	10.1.243.185 – 10.1.243.190	10.1.243.191
57	10.1.243.192/29	10.1.243.193 – 10.1.243.198	10.1.243.199
58	10.1.243.200/29	10.1.243.201 – 10.1.243.206	10.1.243.207
59	10.1.243.208/29	10.1.243.209 – 10.1.243.214	10.1.243.215
60	10.1.243.216/29	10.1.243.217 – 10.1.243.222	10.1.243.223
61	10.1.243.224/29	10.1.243.225 – 10.1.243.230	10.1.243.231
62	10.1.243.232/29	10.1.243.233 – 10.1.243.238	10.1.243.239
63	10.1.243.240/29	10.1.243.241 – 10.1.243.246	10.1.243.247
64	10.1.243.248/29	10.1.243.249 – 10.1.243.254	10.1.243.255

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 →