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)10.2.240.0/23

network10.2.240.0/23

broadcast10.2.241.255

first host10.2.240.1

last host10.2.241.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.2.240.0/23

address00001010.00000010.11110000.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.00000010.11110000.00000000

broadcast00001010.00000010.11110001.11111111

green = network part, grey = host part

hex0x0a02f000

decimal167964672

reverse dns0.240.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:f000

/23 split into /29 · 64 subnets

close ×

#	network	host range	broadcast
1	10.2.240.0/29	10.2.240.1 – 10.2.240.6	10.2.240.7
2	10.2.240.8/29	10.2.240.9 – 10.2.240.14	10.2.240.15
3	10.2.240.16/29	10.2.240.17 – 10.2.240.22	10.2.240.23
4	10.2.240.24/29	10.2.240.25 – 10.2.240.30	10.2.240.31
5	10.2.240.32/29	10.2.240.33 – 10.2.240.38	10.2.240.39
6	10.2.240.40/29	10.2.240.41 – 10.2.240.46	10.2.240.47
7	10.2.240.48/29	10.2.240.49 – 10.2.240.54	10.2.240.55
8	10.2.240.56/29	10.2.240.57 – 10.2.240.62	10.2.240.63
9	10.2.240.64/29	10.2.240.65 – 10.2.240.70	10.2.240.71
10	10.2.240.72/29	10.2.240.73 – 10.2.240.78	10.2.240.79
11	10.2.240.80/29	10.2.240.81 – 10.2.240.86	10.2.240.87
12	10.2.240.88/29	10.2.240.89 – 10.2.240.94	10.2.240.95
13	10.2.240.96/29	10.2.240.97 – 10.2.240.102	10.2.240.103
14	10.2.240.104/29	10.2.240.105 – 10.2.240.110	10.2.240.111
15	10.2.240.112/29	10.2.240.113 – 10.2.240.118	10.2.240.119
16	10.2.240.120/29	10.2.240.121 – 10.2.240.126	10.2.240.127
17	10.2.240.128/29	10.2.240.129 – 10.2.240.134	10.2.240.135
18	10.2.240.136/29	10.2.240.137 – 10.2.240.142	10.2.240.143
19	10.2.240.144/29	10.2.240.145 – 10.2.240.150	10.2.240.151
20	10.2.240.152/29	10.2.240.153 – 10.2.240.158	10.2.240.159
21	10.2.240.160/29	10.2.240.161 – 10.2.240.166	10.2.240.167
22	10.2.240.168/29	10.2.240.169 – 10.2.240.174	10.2.240.175
23	10.2.240.176/29	10.2.240.177 – 10.2.240.182	10.2.240.183
24	10.2.240.184/29	10.2.240.185 – 10.2.240.190	10.2.240.191
25	10.2.240.192/29	10.2.240.193 – 10.2.240.198	10.2.240.199
26	10.2.240.200/29	10.2.240.201 – 10.2.240.206	10.2.240.207
27	10.2.240.208/29	10.2.240.209 – 10.2.240.214	10.2.240.215
28	10.2.240.216/29	10.2.240.217 – 10.2.240.222	10.2.240.223
29	10.2.240.224/29	10.2.240.225 – 10.2.240.230	10.2.240.231
30	10.2.240.232/29	10.2.240.233 – 10.2.240.238	10.2.240.239
31	10.2.240.240/29	10.2.240.241 – 10.2.240.246	10.2.240.247
32	10.2.240.248/29	10.2.240.249 – 10.2.240.254	10.2.240.255
33	10.2.241.0/29	10.2.241.1 – 10.2.241.6	10.2.241.7
34	10.2.241.8/29	10.2.241.9 – 10.2.241.14	10.2.241.15
35	10.2.241.16/29	10.2.241.17 – 10.2.241.22	10.2.241.23
36	10.2.241.24/29	10.2.241.25 – 10.2.241.30	10.2.241.31
37	10.2.241.32/29	10.2.241.33 – 10.2.241.38	10.2.241.39
38	10.2.241.40/29	10.2.241.41 – 10.2.241.46	10.2.241.47
39	10.2.241.48/29	10.2.241.49 – 10.2.241.54	10.2.241.55
40	10.2.241.56/29	10.2.241.57 – 10.2.241.62	10.2.241.63
41	10.2.241.64/29	10.2.241.65 – 10.2.241.70	10.2.241.71
42	10.2.241.72/29	10.2.241.73 – 10.2.241.78	10.2.241.79
43	10.2.241.80/29	10.2.241.81 – 10.2.241.86	10.2.241.87
44	10.2.241.88/29	10.2.241.89 – 10.2.241.94	10.2.241.95
45	10.2.241.96/29	10.2.241.97 – 10.2.241.102	10.2.241.103
46	10.2.241.104/29	10.2.241.105 – 10.2.241.110	10.2.241.111
47	10.2.241.112/29	10.2.241.113 – 10.2.241.118	10.2.241.119
48	10.2.241.120/29	10.2.241.121 – 10.2.241.126	10.2.241.127
49	10.2.241.128/29	10.2.241.129 – 10.2.241.134	10.2.241.135
50	10.2.241.136/29	10.2.241.137 – 10.2.241.142	10.2.241.143
51	10.2.241.144/29	10.2.241.145 – 10.2.241.150	10.2.241.151
52	10.2.241.152/29	10.2.241.153 – 10.2.241.158	10.2.241.159
53	10.2.241.160/29	10.2.241.161 – 10.2.241.166	10.2.241.167
54	10.2.241.168/29	10.2.241.169 – 10.2.241.174	10.2.241.175
55	10.2.241.176/29	10.2.241.177 – 10.2.241.182	10.2.241.183
56	10.2.241.184/29	10.2.241.185 – 10.2.241.190	10.2.241.191
57	10.2.241.192/29	10.2.241.193 – 10.2.241.198	10.2.241.199
58	10.2.241.200/29	10.2.241.201 – 10.2.241.206	10.2.241.207
59	10.2.241.208/29	10.2.241.209 – 10.2.241.214	10.2.241.215
60	10.2.241.216/29	10.2.241.217 – 10.2.241.222	10.2.241.223
61	10.2.241.224/29	10.2.241.225 – 10.2.241.230	10.2.241.231
62	10.2.241.232/29	10.2.241.233 – 10.2.241.238	10.2.241.239
63	10.2.241.240/29	10.2.241.241 – 10.2.241.246	10.2.241.247
64	10.2.241.248/29	10.2.241.249 – 10.2.241.254	10.2.241.255

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 →