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)10.8.3.0/25

network10.8.3.0/25

broadcast10.8.3.127

first host10.8.3.1

last host10.8.3.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.8.3.0/25

address00001010.00001000.00000011.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00001000.00000011.00000000

broadcast00001010.00001000.00000011.01111111

green = network part, grey = host part

hex0x0a080300

decimal168297216

reverse dns0.3.8.10.in-addr.arpa

ipv4-mapped::ffff:a08:300

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.8.3.0/31	10.8.3.0 – 10.8.3.1	10.8.3.1
2	10.8.3.2/31	10.8.3.2 – 10.8.3.3	10.8.3.3
3	10.8.3.4/31	10.8.3.4 – 10.8.3.5	10.8.3.5
4	10.8.3.6/31	10.8.3.6 – 10.8.3.7	10.8.3.7
5	10.8.3.8/31	10.8.3.8 – 10.8.3.9	10.8.3.9
6	10.8.3.10/31	10.8.3.10 – 10.8.3.11	10.8.3.11
7	10.8.3.12/31	10.8.3.12 – 10.8.3.13	10.8.3.13
8	10.8.3.14/31	10.8.3.14 – 10.8.3.15	10.8.3.15
9	10.8.3.16/31	10.8.3.16 – 10.8.3.17	10.8.3.17
10	10.8.3.18/31	10.8.3.18 – 10.8.3.19	10.8.3.19
11	10.8.3.20/31	10.8.3.20 – 10.8.3.21	10.8.3.21
12	10.8.3.22/31	10.8.3.22 – 10.8.3.23	10.8.3.23
13	10.8.3.24/31	10.8.3.24 – 10.8.3.25	10.8.3.25
14	10.8.3.26/31	10.8.3.26 – 10.8.3.27	10.8.3.27
15	10.8.3.28/31	10.8.3.28 – 10.8.3.29	10.8.3.29
16	10.8.3.30/31	10.8.3.30 – 10.8.3.31	10.8.3.31
17	10.8.3.32/31	10.8.3.32 – 10.8.3.33	10.8.3.33
18	10.8.3.34/31	10.8.3.34 – 10.8.3.35	10.8.3.35
19	10.8.3.36/31	10.8.3.36 – 10.8.3.37	10.8.3.37
20	10.8.3.38/31	10.8.3.38 – 10.8.3.39	10.8.3.39
21	10.8.3.40/31	10.8.3.40 – 10.8.3.41	10.8.3.41
22	10.8.3.42/31	10.8.3.42 – 10.8.3.43	10.8.3.43
23	10.8.3.44/31	10.8.3.44 – 10.8.3.45	10.8.3.45
24	10.8.3.46/31	10.8.3.46 – 10.8.3.47	10.8.3.47
25	10.8.3.48/31	10.8.3.48 – 10.8.3.49	10.8.3.49
26	10.8.3.50/31	10.8.3.50 – 10.8.3.51	10.8.3.51
27	10.8.3.52/31	10.8.3.52 – 10.8.3.53	10.8.3.53
28	10.8.3.54/31	10.8.3.54 – 10.8.3.55	10.8.3.55
29	10.8.3.56/31	10.8.3.56 – 10.8.3.57	10.8.3.57
30	10.8.3.58/31	10.8.3.58 – 10.8.3.59	10.8.3.59
31	10.8.3.60/31	10.8.3.60 – 10.8.3.61	10.8.3.61
32	10.8.3.62/31	10.8.3.62 – 10.8.3.63	10.8.3.63
33	10.8.3.64/31	10.8.3.64 – 10.8.3.65	10.8.3.65
34	10.8.3.66/31	10.8.3.66 – 10.8.3.67	10.8.3.67
35	10.8.3.68/31	10.8.3.68 – 10.8.3.69	10.8.3.69
36	10.8.3.70/31	10.8.3.70 – 10.8.3.71	10.8.3.71
37	10.8.3.72/31	10.8.3.72 – 10.8.3.73	10.8.3.73
38	10.8.3.74/31	10.8.3.74 – 10.8.3.75	10.8.3.75
39	10.8.3.76/31	10.8.3.76 – 10.8.3.77	10.8.3.77
40	10.8.3.78/31	10.8.3.78 – 10.8.3.79	10.8.3.79
41	10.8.3.80/31	10.8.3.80 – 10.8.3.81	10.8.3.81
42	10.8.3.82/31	10.8.3.82 – 10.8.3.83	10.8.3.83
43	10.8.3.84/31	10.8.3.84 – 10.8.3.85	10.8.3.85
44	10.8.3.86/31	10.8.3.86 – 10.8.3.87	10.8.3.87
45	10.8.3.88/31	10.8.3.88 – 10.8.3.89	10.8.3.89
46	10.8.3.90/31	10.8.3.90 – 10.8.3.91	10.8.3.91
47	10.8.3.92/31	10.8.3.92 – 10.8.3.93	10.8.3.93
48	10.8.3.94/31	10.8.3.94 – 10.8.3.95	10.8.3.95
49	10.8.3.96/31	10.8.3.96 – 10.8.3.97	10.8.3.97
50	10.8.3.98/31	10.8.3.98 – 10.8.3.99	10.8.3.99
51	10.8.3.100/31	10.8.3.100 – 10.8.3.101	10.8.3.101
52	10.8.3.102/31	10.8.3.102 – 10.8.3.103	10.8.3.103
53	10.8.3.104/31	10.8.3.104 – 10.8.3.105	10.8.3.105
54	10.8.3.106/31	10.8.3.106 – 10.8.3.107	10.8.3.107
55	10.8.3.108/31	10.8.3.108 – 10.8.3.109	10.8.3.109
56	10.8.3.110/31	10.8.3.110 – 10.8.3.111	10.8.3.111
57	10.8.3.112/31	10.8.3.112 – 10.8.3.113	10.8.3.113
58	10.8.3.114/31	10.8.3.114 – 10.8.3.115	10.8.3.115
59	10.8.3.116/31	10.8.3.116 – 10.8.3.117	10.8.3.117
60	10.8.3.118/31	10.8.3.118 – 10.8.3.119	10.8.3.119
61	10.8.3.120/31	10.8.3.120 – 10.8.3.121	10.8.3.121
62	10.8.3.122/31	10.8.3.122 – 10.8.3.123	10.8.3.123
63	10.8.3.124/31	10.8.3.124 – 10.8.3.125	10.8.3.125
64	10.8.3.126/31	10.8.3.126 – 10.8.3.127	10.8.3.127

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 /25
/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	-
/24	255.255.255.0	256	254	-
/25	255.255.255.128	128	126	1
/26	255.255.255.192	64	62	2 split →
/27	255.255.255.224	32	30	4 split →
/28	255.255.255.240	16	14	8 split →
/29	255.255.255.248	8	6	16 split →
/30	255.255.255.252	4	2	32 split →
/31	255.255.255.254	2	2	64 split →
/32	255.255.255.255	1	1	128 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 →