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)10.3.8.0/23

network10.3.8.0/23

broadcast10.3.9.255

first host10.3.8.1

last host10.3.9.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.3.8.0/23

address00001010.00000011.00001000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000011.00001000.00000000

broadcast00001010.00000011.00001001.11111111

green = network part, grey = host part

hex0x0a030800

decimal167970816

reverse dns0.8.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:800

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.8.0/29	10.3.8.1 – 10.3.8.6	10.3.8.7
2	10.3.8.8/29	10.3.8.9 – 10.3.8.14	10.3.8.15
3	10.3.8.16/29	10.3.8.17 – 10.3.8.22	10.3.8.23
4	10.3.8.24/29	10.3.8.25 – 10.3.8.30	10.3.8.31
5	10.3.8.32/29	10.3.8.33 – 10.3.8.38	10.3.8.39
6	10.3.8.40/29	10.3.8.41 – 10.3.8.46	10.3.8.47
7	10.3.8.48/29	10.3.8.49 – 10.3.8.54	10.3.8.55
8	10.3.8.56/29	10.3.8.57 – 10.3.8.62	10.3.8.63
9	10.3.8.64/29	10.3.8.65 – 10.3.8.70	10.3.8.71
10	10.3.8.72/29	10.3.8.73 – 10.3.8.78	10.3.8.79
11	10.3.8.80/29	10.3.8.81 – 10.3.8.86	10.3.8.87
12	10.3.8.88/29	10.3.8.89 – 10.3.8.94	10.3.8.95
13	10.3.8.96/29	10.3.8.97 – 10.3.8.102	10.3.8.103
14	10.3.8.104/29	10.3.8.105 – 10.3.8.110	10.3.8.111
15	10.3.8.112/29	10.3.8.113 – 10.3.8.118	10.3.8.119
16	10.3.8.120/29	10.3.8.121 – 10.3.8.126	10.3.8.127
17	10.3.8.128/29	10.3.8.129 – 10.3.8.134	10.3.8.135
18	10.3.8.136/29	10.3.8.137 – 10.3.8.142	10.3.8.143
19	10.3.8.144/29	10.3.8.145 – 10.3.8.150	10.3.8.151
20	10.3.8.152/29	10.3.8.153 – 10.3.8.158	10.3.8.159
21	10.3.8.160/29	10.3.8.161 – 10.3.8.166	10.3.8.167
22	10.3.8.168/29	10.3.8.169 – 10.3.8.174	10.3.8.175
23	10.3.8.176/29	10.3.8.177 – 10.3.8.182	10.3.8.183
24	10.3.8.184/29	10.3.8.185 – 10.3.8.190	10.3.8.191
25	10.3.8.192/29	10.3.8.193 – 10.3.8.198	10.3.8.199
26	10.3.8.200/29	10.3.8.201 – 10.3.8.206	10.3.8.207
27	10.3.8.208/29	10.3.8.209 – 10.3.8.214	10.3.8.215
28	10.3.8.216/29	10.3.8.217 – 10.3.8.222	10.3.8.223
29	10.3.8.224/29	10.3.8.225 – 10.3.8.230	10.3.8.231
30	10.3.8.232/29	10.3.8.233 – 10.3.8.238	10.3.8.239
31	10.3.8.240/29	10.3.8.241 – 10.3.8.246	10.3.8.247
32	10.3.8.248/29	10.3.8.249 – 10.3.8.254	10.3.8.255
33	10.3.9.0/29	10.3.9.1 – 10.3.9.6	10.3.9.7
34	10.3.9.8/29	10.3.9.9 – 10.3.9.14	10.3.9.15
35	10.3.9.16/29	10.3.9.17 – 10.3.9.22	10.3.9.23
36	10.3.9.24/29	10.3.9.25 – 10.3.9.30	10.3.9.31
37	10.3.9.32/29	10.3.9.33 – 10.3.9.38	10.3.9.39
38	10.3.9.40/29	10.3.9.41 – 10.3.9.46	10.3.9.47
39	10.3.9.48/29	10.3.9.49 – 10.3.9.54	10.3.9.55
40	10.3.9.56/29	10.3.9.57 – 10.3.9.62	10.3.9.63
41	10.3.9.64/29	10.3.9.65 – 10.3.9.70	10.3.9.71
42	10.3.9.72/29	10.3.9.73 – 10.3.9.78	10.3.9.79
43	10.3.9.80/29	10.3.9.81 – 10.3.9.86	10.3.9.87
44	10.3.9.88/29	10.3.9.89 – 10.3.9.94	10.3.9.95
45	10.3.9.96/29	10.3.9.97 – 10.3.9.102	10.3.9.103
46	10.3.9.104/29	10.3.9.105 – 10.3.9.110	10.3.9.111
47	10.3.9.112/29	10.3.9.113 – 10.3.9.118	10.3.9.119
48	10.3.9.120/29	10.3.9.121 – 10.3.9.126	10.3.9.127
49	10.3.9.128/29	10.3.9.129 – 10.3.9.134	10.3.9.135
50	10.3.9.136/29	10.3.9.137 – 10.3.9.142	10.3.9.143
51	10.3.9.144/29	10.3.9.145 – 10.3.9.150	10.3.9.151
52	10.3.9.152/29	10.3.9.153 – 10.3.9.158	10.3.9.159
53	10.3.9.160/29	10.3.9.161 – 10.3.9.166	10.3.9.167
54	10.3.9.168/29	10.3.9.169 – 10.3.9.174	10.3.9.175
55	10.3.9.176/29	10.3.9.177 – 10.3.9.182	10.3.9.183
56	10.3.9.184/29	10.3.9.185 – 10.3.9.190	10.3.9.191
57	10.3.9.192/29	10.3.9.193 – 10.3.9.198	10.3.9.199
58	10.3.9.200/29	10.3.9.201 – 10.3.9.206	10.3.9.207
59	10.3.9.208/29	10.3.9.209 – 10.3.9.214	10.3.9.215
60	10.3.9.216/29	10.3.9.217 – 10.3.9.222	10.3.9.223
61	10.3.9.224/29	10.3.9.225 – 10.3.9.230	10.3.9.231
62	10.3.9.232/29	10.3.9.233 – 10.3.9.238	10.3.9.239
63	10.3.9.240/29	10.3.9.241 – 10.3.9.246	10.3.9.247
64	10.3.9.248/29	10.3.9.249 – 10.3.9.254	10.3.9.255

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 →