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)10.3.100.0/23

network10.3.100.0/23

broadcast10.3.101.255

first host10.3.100.1

last host10.3.101.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.3.100.0/23

address00001010.00000011.01100100.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000011.01100100.00000000

broadcast00001010.00000011.01100101.11111111

green = network part, grey = host part

hex0x0a036400

decimal167994368

reverse dns0.100.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:6400

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.100.0/29	10.3.100.1 – 10.3.100.6	10.3.100.7
2	10.3.100.8/29	10.3.100.9 – 10.3.100.14	10.3.100.15
3	10.3.100.16/29	10.3.100.17 – 10.3.100.22	10.3.100.23
4	10.3.100.24/29	10.3.100.25 – 10.3.100.30	10.3.100.31
5	10.3.100.32/29	10.3.100.33 – 10.3.100.38	10.3.100.39
6	10.3.100.40/29	10.3.100.41 – 10.3.100.46	10.3.100.47
7	10.3.100.48/29	10.3.100.49 – 10.3.100.54	10.3.100.55
8	10.3.100.56/29	10.3.100.57 – 10.3.100.62	10.3.100.63
9	10.3.100.64/29	10.3.100.65 – 10.3.100.70	10.3.100.71
10	10.3.100.72/29	10.3.100.73 – 10.3.100.78	10.3.100.79
11	10.3.100.80/29	10.3.100.81 – 10.3.100.86	10.3.100.87
12	10.3.100.88/29	10.3.100.89 – 10.3.100.94	10.3.100.95
13	10.3.100.96/29	10.3.100.97 – 10.3.100.102	10.3.100.103
14	10.3.100.104/29	10.3.100.105 – 10.3.100.110	10.3.100.111
15	10.3.100.112/29	10.3.100.113 – 10.3.100.118	10.3.100.119
16	10.3.100.120/29	10.3.100.121 – 10.3.100.126	10.3.100.127
17	10.3.100.128/29	10.3.100.129 – 10.3.100.134	10.3.100.135
18	10.3.100.136/29	10.3.100.137 – 10.3.100.142	10.3.100.143
19	10.3.100.144/29	10.3.100.145 – 10.3.100.150	10.3.100.151
20	10.3.100.152/29	10.3.100.153 – 10.3.100.158	10.3.100.159
21	10.3.100.160/29	10.3.100.161 – 10.3.100.166	10.3.100.167
22	10.3.100.168/29	10.3.100.169 – 10.3.100.174	10.3.100.175
23	10.3.100.176/29	10.3.100.177 – 10.3.100.182	10.3.100.183
24	10.3.100.184/29	10.3.100.185 – 10.3.100.190	10.3.100.191
25	10.3.100.192/29	10.3.100.193 – 10.3.100.198	10.3.100.199
26	10.3.100.200/29	10.3.100.201 – 10.3.100.206	10.3.100.207
27	10.3.100.208/29	10.3.100.209 – 10.3.100.214	10.3.100.215
28	10.3.100.216/29	10.3.100.217 – 10.3.100.222	10.3.100.223
29	10.3.100.224/29	10.3.100.225 – 10.3.100.230	10.3.100.231
30	10.3.100.232/29	10.3.100.233 – 10.3.100.238	10.3.100.239
31	10.3.100.240/29	10.3.100.241 – 10.3.100.246	10.3.100.247
32	10.3.100.248/29	10.3.100.249 – 10.3.100.254	10.3.100.255
33	10.3.101.0/29	10.3.101.1 – 10.3.101.6	10.3.101.7
34	10.3.101.8/29	10.3.101.9 – 10.3.101.14	10.3.101.15
35	10.3.101.16/29	10.3.101.17 – 10.3.101.22	10.3.101.23
36	10.3.101.24/29	10.3.101.25 – 10.3.101.30	10.3.101.31
37	10.3.101.32/29	10.3.101.33 – 10.3.101.38	10.3.101.39
38	10.3.101.40/29	10.3.101.41 – 10.3.101.46	10.3.101.47
39	10.3.101.48/29	10.3.101.49 – 10.3.101.54	10.3.101.55
40	10.3.101.56/29	10.3.101.57 – 10.3.101.62	10.3.101.63
41	10.3.101.64/29	10.3.101.65 – 10.3.101.70	10.3.101.71
42	10.3.101.72/29	10.3.101.73 – 10.3.101.78	10.3.101.79
43	10.3.101.80/29	10.3.101.81 – 10.3.101.86	10.3.101.87
44	10.3.101.88/29	10.3.101.89 – 10.3.101.94	10.3.101.95
45	10.3.101.96/29	10.3.101.97 – 10.3.101.102	10.3.101.103
46	10.3.101.104/29	10.3.101.105 – 10.3.101.110	10.3.101.111
47	10.3.101.112/29	10.3.101.113 – 10.3.101.118	10.3.101.119
48	10.3.101.120/29	10.3.101.121 – 10.3.101.126	10.3.101.127
49	10.3.101.128/29	10.3.101.129 – 10.3.101.134	10.3.101.135
50	10.3.101.136/29	10.3.101.137 – 10.3.101.142	10.3.101.143
51	10.3.101.144/29	10.3.101.145 – 10.3.101.150	10.3.101.151
52	10.3.101.152/29	10.3.101.153 – 10.3.101.158	10.3.101.159
53	10.3.101.160/29	10.3.101.161 – 10.3.101.166	10.3.101.167
54	10.3.101.168/29	10.3.101.169 – 10.3.101.174	10.3.101.175
55	10.3.101.176/29	10.3.101.177 – 10.3.101.182	10.3.101.183
56	10.3.101.184/29	10.3.101.185 – 10.3.101.190	10.3.101.191
57	10.3.101.192/29	10.3.101.193 – 10.3.101.198	10.3.101.199
58	10.3.101.200/29	10.3.101.201 – 10.3.101.206	10.3.101.207
59	10.3.101.208/29	10.3.101.209 – 10.3.101.214	10.3.101.215
60	10.3.101.216/29	10.3.101.217 – 10.3.101.222	10.3.101.223
61	10.3.101.224/29	10.3.101.225 – 10.3.101.230	10.3.101.231
62	10.3.101.232/29	10.3.101.233 – 10.3.101.238	10.3.101.239
63	10.3.101.240/29	10.3.101.241 – 10.3.101.246	10.3.101.247
64	10.3.101.248/29	10.3.101.249 – 10.3.101.254	10.3.101.255

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 →