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)10.3.0.0/23

network10.3.0.0/23

broadcast10.3.1.255

first host10.3.0.1

last host10.3.1.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.3.0.0/23

address00001010.00000011.00000000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000011.00000000.00000000

broadcast00001010.00000011.00000001.11111111

green = network part, grey = host part

hex0x0a030000

decimal167968768

reverse dns0.0.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:0

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.0.0/29	10.3.0.1 – 10.3.0.6	10.3.0.7
2	10.3.0.8/29	10.3.0.9 – 10.3.0.14	10.3.0.15
3	10.3.0.16/29	10.3.0.17 – 10.3.0.22	10.3.0.23
4	10.3.0.24/29	10.3.0.25 – 10.3.0.30	10.3.0.31
5	10.3.0.32/29	10.3.0.33 – 10.3.0.38	10.3.0.39
6	10.3.0.40/29	10.3.0.41 – 10.3.0.46	10.3.0.47
7	10.3.0.48/29	10.3.0.49 – 10.3.0.54	10.3.0.55
8	10.3.0.56/29	10.3.0.57 – 10.3.0.62	10.3.0.63
9	10.3.0.64/29	10.3.0.65 – 10.3.0.70	10.3.0.71
10	10.3.0.72/29	10.3.0.73 – 10.3.0.78	10.3.0.79
11	10.3.0.80/29	10.3.0.81 – 10.3.0.86	10.3.0.87
12	10.3.0.88/29	10.3.0.89 – 10.3.0.94	10.3.0.95
13	10.3.0.96/29	10.3.0.97 – 10.3.0.102	10.3.0.103
14	10.3.0.104/29	10.3.0.105 – 10.3.0.110	10.3.0.111
15	10.3.0.112/29	10.3.0.113 – 10.3.0.118	10.3.0.119
16	10.3.0.120/29	10.3.0.121 – 10.3.0.126	10.3.0.127
17	10.3.0.128/29	10.3.0.129 – 10.3.0.134	10.3.0.135
18	10.3.0.136/29	10.3.0.137 – 10.3.0.142	10.3.0.143
19	10.3.0.144/29	10.3.0.145 – 10.3.0.150	10.3.0.151
20	10.3.0.152/29	10.3.0.153 – 10.3.0.158	10.3.0.159
21	10.3.0.160/29	10.3.0.161 – 10.3.0.166	10.3.0.167
22	10.3.0.168/29	10.3.0.169 – 10.3.0.174	10.3.0.175
23	10.3.0.176/29	10.3.0.177 – 10.3.0.182	10.3.0.183
24	10.3.0.184/29	10.3.0.185 – 10.3.0.190	10.3.0.191
25	10.3.0.192/29	10.3.0.193 – 10.3.0.198	10.3.0.199
26	10.3.0.200/29	10.3.0.201 – 10.3.0.206	10.3.0.207
27	10.3.0.208/29	10.3.0.209 – 10.3.0.214	10.3.0.215
28	10.3.0.216/29	10.3.0.217 – 10.3.0.222	10.3.0.223
29	10.3.0.224/29	10.3.0.225 – 10.3.0.230	10.3.0.231
30	10.3.0.232/29	10.3.0.233 – 10.3.0.238	10.3.0.239
31	10.3.0.240/29	10.3.0.241 – 10.3.0.246	10.3.0.247
32	10.3.0.248/29	10.3.0.249 – 10.3.0.254	10.3.0.255
33	10.3.1.0/29	10.3.1.1 – 10.3.1.6	10.3.1.7
34	10.3.1.8/29	10.3.1.9 – 10.3.1.14	10.3.1.15
35	10.3.1.16/29	10.3.1.17 – 10.3.1.22	10.3.1.23
36	10.3.1.24/29	10.3.1.25 – 10.3.1.30	10.3.1.31
37	10.3.1.32/29	10.3.1.33 – 10.3.1.38	10.3.1.39
38	10.3.1.40/29	10.3.1.41 – 10.3.1.46	10.3.1.47
39	10.3.1.48/29	10.3.1.49 – 10.3.1.54	10.3.1.55
40	10.3.1.56/29	10.3.1.57 – 10.3.1.62	10.3.1.63
41	10.3.1.64/29	10.3.1.65 – 10.3.1.70	10.3.1.71
42	10.3.1.72/29	10.3.1.73 – 10.3.1.78	10.3.1.79
43	10.3.1.80/29	10.3.1.81 – 10.3.1.86	10.3.1.87
44	10.3.1.88/29	10.3.1.89 – 10.3.1.94	10.3.1.95
45	10.3.1.96/29	10.3.1.97 – 10.3.1.102	10.3.1.103
46	10.3.1.104/29	10.3.1.105 – 10.3.1.110	10.3.1.111
47	10.3.1.112/29	10.3.1.113 – 10.3.1.118	10.3.1.119
48	10.3.1.120/29	10.3.1.121 – 10.3.1.126	10.3.1.127
49	10.3.1.128/29	10.3.1.129 – 10.3.1.134	10.3.1.135
50	10.3.1.136/29	10.3.1.137 – 10.3.1.142	10.3.1.143
51	10.3.1.144/29	10.3.1.145 – 10.3.1.150	10.3.1.151
52	10.3.1.152/29	10.3.1.153 – 10.3.1.158	10.3.1.159
53	10.3.1.160/29	10.3.1.161 – 10.3.1.166	10.3.1.167
54	10.3.1.168/29	10.3.1.169 – 10.3.1.174	10.3.1.175
55	10.3.1.176/29	10.3.1.177 – 10.3.1.182	10.3.1.183
56	10.3.1.184/29	10.3.1.185 – 10.3.1.190	10.3.1.191
57	10.3.1.192/29	10.3.1.193 – 10.3.1.198	10.3.1.199
58	10.3.1.200/29	10.3.1.201 – 10.3.1.206	10.3.1.207
59	10.3.1.208/29	10.3.1.209 – 10.3.1.214	10.3.1.215
60	10.3.1.216/29	10.3.1.217 – 10.3.1.222	10.3.1.223
61	10.3.1.224/29	10.3.1.225 – 10.3.1.230	10.3.1.231
62	10.3.1.232/29	10.3.1.233 – 10.3.1.238	10.3.1.239
63	10.3.1.240/29	10.3.1.241 – 10.3.1.246	10.3.1.247
64	10.3.1.248/29	10.3.1.249 – 10.3.1.254	10.3.1.255

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 →