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)10.3.136.0/23

network10.3.136.0/23

broadcast10.3.137.255

first host10.3.136.1

last host10.3.137.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.3.136.0/23

address00001010.00000011.10001000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000011.10001000.00000000

broadcast00001010.00000011.10001001.11111111

green = network part, grey = host part

hex0x0a038800

decimal168003584

reverse dns0.136.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:8800

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.136.0/29	10.3.136.1 – 10.3.136.6	10.3.136.7
2	10.3.136.8/29	10.3.136.9 – 10.3.136.14	10.3.136.15
3	10.3.136.16/29	10.3.136.17 – 10.3.136.22	10.3.136.23
4	10.3.136.24/29	10.3.136.25 – 10.3.136.30	10.3.136.31
5	10.3.136.32/29	10.3.136.33 – 10.3.136.38	10.3.136.39
6	10.3.136.40/29	10.3.136.41 – 10.3.136.46	10.3.136.47
7	10.3.136.48/29	10.3.136.49 – 10.3.136.54	10.3.136.55
8	10.3.136.56/29	10.3.136.57 – 10.3.136.62	10.3.136.63
9	10.3.136.64/29	10.3.136.65 – 10.3.136.70	10.3.136.71
10	10.3.136.72/29	10.3.136.73 – 10.3.136.78	10.3.136.79
11	10.3.136.80/29	10.3.136.81 – 10.3.136.86	10.3.136.87
12	10.3.136.88/29	10.3.136.89 – 10.3.136.94	10.3.136.95
13	10.3.136.96/29	10.3.136.97 – 10.3.136.102	10.3.136.103
14	10.3.136.104/29	10.3.136.105 – 10.3.136.110	10.3.136.111
15	10.3.136.112/29	10.3.136.113 – 10.3.136.118	10.3.136.119
16	10.3.136.120/29	10.3.136.121 – 10.3.136.126	10.3.136.127
17	10.3.136.128/29	10.3.136.129 – 10.3.136.134	10.3.136.135
18	10.3.136.136/29	10.3.136.137 – 10.3.136.142	10.3.136.143
19	10.3.136.144/29	10.3.136.145 – 10.3.136.150	10.3.136.151
20	10.3.136.152/29	10.3.136.153 – 10.3.136.158	10.3.136.159
21	10.3.136.160/29	10.3.136.161 – 10.3.136.166	10.3.136.167
22	10.3.136.168/29	10.3.136.169 – 10.3.136.174	10.3.136.175
23	10.3.136.176/29	10.3.136.177 – 10.3.136.182	10.3.136.183
24	10.3.136.184/29	10.3.136.185 – 10.3.136.190	10.3.136.191
25	10.3.136.192/29	10.3.136.193 – 10.3.136.198	10.3.136.199
26	10.3.136.200/29	10.3.136.201 – 10.3.136.206	10.3.136.207
27	10.3.136.208/29	10.3.136.209 – 10.3.136.214	10.3.136.215
28	10.3.136.216/29	10.3.136.217 – 10.3.136.222	10.3.136.223
29	10.3.136.224/29	10.3.136.225 – 10.3.136.230	10.3.136.231
30	10.3.136.232/29	10.3.136.233 – 10.3.136.238	10.3.136.239
31	10.3.136.240/29	10.3.136.241 – 10.3.136.246	10.3.136.247
32	10.3.136.248/29	10.3.136.249 – 10.3.136.254	10.3.136.255
33	10.3.137.0/29	10.3.137.1 – 10.3.137.6	10.3.137.7
34	10.3.137.8/29	10.3.137.9 – 10.3.137.14	10.3.137.15
35	10.3.137.16/29	10.3.137.17 – 10.3.137.22	10.3.137.23
36	10.3.137.24/29	10.3.137.25 – 10.3.137.30	10.3.137.31
37	10.3.137.32/29	10.3.137.33 – 10.3.137.38	10.3.137.39
38	10.3.137.40/29	10.3.137.41 – 10.3.137.46	10.3.137.47
39	10.3.137.48/29	10.3.137.49 – 10.3.137.54	10.3.137.55
40	10.3.137.56/29	10.3.137.57 – 10.3.137.62	10.3.137.63
41	10.3.137.64/29	10.3.137.65 – 10.3.137.70	10.3.137.71
42	10.3.137.72/29	10.3.137.73 – 10.3.137.78	10.3.137.79
43	10.3.137.80/29	10.3.137.81 – 10.3.137.86	10.3.137.87
44	10.3.137.88/29	10.3.137.89 – 10.3.137.94	10.3.137.95
45	10.3.137.96/29	10.3.137.97 – 10.3.137.102	10.3.137.103
46	10.3.137.104/29	10.3.137.105 – 10.3.137.110	10.3.137.111
47	10.3.137.112/29	10.3.137.113 – 10.3.137.118	10.3.137.119
48	10.3.137.120/29	10.3.137.121 – 10.3.137.126	10.3.137.127
49	10.3.137.128/29	10.3.137.129 – 10.3.137.134	10.3.137.135
50	10.3.137.136/29	10.3.137.137 – 10.3.137.142	10.3.137.143
51	10.3.137.144/29	10.3.137.145 – 10.3.137.150	10.3.137.151
52	10.3.137.152/29	10.3.137.153 – 10.3.137.158	10.3.137.159
53	10.3.137.160/29	10.3.137.161 – 10.3.137.166	10.3.137.167
54	10.3.137.168/29	10.3.137.169 – 10.3.137.174	10.3.137.175
55	10.3.137.176/29	10.3.137.177 – 10.3.137.182	10.3.137.183
56	10.3.137.184/29	10.3.137.185 – 10.3.137.190	10.3.137.191
57	10.3.137.192/29	10.3.137.193 – 10.3.137.198	10.3.137.199
58	10.3.137.200/29	10.3.137.201 – 10.3.137.206	10.3.137.207
59	10.3.137.208/29	10.3.137.209 – 10.3.137.214	10.3.137.215
60	10.3.137.216/29	10.3.137.217 – 10.3.137.222	10.3.137.223
61	10.3.137.224/29	10.3.137.225 – 10.3.137.230	10.3.137.231
62	10.3.137.232/29	10.3.137.233 – 10.3.137.238	10.3.137.239
63	10.3.137.240/29	10.3.137.241 – 10.3.137.246	10.3.137.247
64	10.3.137.248/29	10.3.137.249 – 10.3.137.254	10.3.137.255

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 →