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)10.63.1.0/25

network10.63.1.0/25

broadcast10.63.1.127

first host10.63.1.1

last host10.63.1.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.63.1.0/25

address00001010.00111111.00000001.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00111111.00000001.00000000

broadcast00001010.00111111.00000001.01111111

green = network part, grey = host part

hex0x0a3f0100

decimal171901184

reverse dns0.1.63.10.in-addr.arpa

ipv4-mapped::ffff:a3f:100

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.63.1.0/31	10.63.1.0 – 10.63.1.1	10.63.1.1
2	10.63.1.2/31	10.63.1.2 – 10.63.1.3	10.63.1.3
3	10.63.1.4/31	10.63.1.4 – 10.63.1.5	10.63.1.5
4	10.63.1.6/31	10.63.1.6 – 10.63.1.7	10.63.1.7
5	10.63.1.8/31	10.63.1.8 – 10.63.1.9	10.63.1.9
6	10.63.1.10/31	10.63.1.10 – 10.63.1.11	10.63.1.11
7	10.63.1.12/31	10.63.1.12 – 10.63.1.13	10.63.1.13
8	10.63.1.14/31	10.63.1.14 – 10.63.1.15	10.63.1.15
9	10.63.1.16/31	10.63.1.16 – 10.63.1.17	10.63.1.17
10	10.63.1.18/31	10.63.1.18 – 10.63.1.19	10.63.1.19
11	10.63.1.20/31	10.63.1.20 – 10.63.1.21	10.63.1.21
12	10.63.1.22/31	10.63.1.22 – 10.63.1.23	10.63.1.23
13	10.63.1.24/31	10.63.1.24 – 10.63.1.25	10.63.1.25
14	10.63.1.26/31	10.63.1.26 – 10.63.1.27	10.63.1.27
15	10.63.1.28/31	10.63.1.28 – 10.63.1.29	10.63.1.29
16	10.63.1.30/31	10.63.1.30 – 10.63.1.31	10.63.1.31
17	10.63.1.32/31	10.63.1.32 – 10.63.1.33	10.63.1.33
18	10.63.1.34/31	10.63.1.34 – 10.63.1.35	10.63.1.35
19	10.63.1.36/31	10.63.1.36 – 10.63.1.37	10.63.1.37
20	10.63.1.38/31	10.63.1.38 – 10.63.1.39	10.63.1.39
21	10.63.1.40/31	10.63.1.40 – 10.63.1.41	10.63.1.41
22	10.63.1.42/31	10.63.1.42 – 10.63.1.43	10.63.1.43
23	10.63.1.44/31	10.63.1.44 – 10.63.1.45	10.63.1.45
24	10.63.1.46/31	10.63.1.46 – 10.63.1.47	10.63.1.47
25	10.63.1.48/31	10.63.1.48 – 10.63.1.49	10.63.1.49
26	10.63.1.50/31	10.63.1.50 – 10.63.1.51	10.63.1.51
27	10.63.1.52/31	10.63.1.52 – 10.63.1.53	10.63.1.53
28	10.63.1.54/31	10.63.1.54 – 10.63.1.55	10.63.1.55
29	10.63.1.56/31	10.63.1.56 – 10.63.1.57	10.63.1.57
30	10.63.1.58/31	10.63.1.58 – 10.63.1.59	10.63.1.59
31	10.63.1.60/31	10.63.1.60 – 10.63.1.61	10.63.1.61
32	10.63.1.62/31	10.63.1.62 – 10.63.1.63	10.63.1.63
33	10.63.1.64/31	10.63.1.64 – 10.63.1.65	10.63.1.65
34	10.63.1.66/31	10.63.1.66 – 10.63.1.67	10.63.1.67
35	10.63.1.68/31	10.63.1.68 – 10.63.1.69	10.63.1.69
36	10.63.1.70/31	10.63.1.70 – 10.63.1.71	10.63.1.71
37	10.63.1.72/31	10.63.1.72 – 10.63.1.73	10.63.1.73
38	10.63.1.74/31	10.63.1.74 – 10.63.1.75	10.63.1.75
39	10.63.1.76/31	10.63.1.76 – 10.63.1.77	10.63.1.77
40	10.63.1.78/31	10.63.1.78 – 10.63.1.79	10.63.1.79
41	10.63.1.80/31	10.63.1.80 – 10.63.1.81	10.63.1.81
42	10.63.1.82/31	10.63.1.82 – 10.63.1.83	10.63.1.83
43	10.63.1.84/31	10.63.1.84 – 10.63.1.85	10.63.1.85
44	10.63.1.86/31	10.63.1.86 – 10.63.1.87	10.63.1.87
45	10.63.1.88/31	10.63.1.88 – 10.63.1.89	10.63.1.89
46	10.63.1.90/31	10.63.1.90 – 10.63.1.91	10.63.1.91
47	10.63.1.92/31	10.63.1.92 – 10.63.1.93	10.63.1.93
48	10.63.1.94/31	10.63.1.94 – 10.63.1.95	10.63.1.95
49	10.63.1.96/31	10.63.1.96 – 10.63.1.97	10.63.1.97
50	10.63.1.98/31	10.63.1.98 – 10.63.1.99	10.63.1.99
51	10.63.1.100/31	10.63.1.100 – 10.63.1.101	10.63.1.101
52	10.63.1.102/31	10.63.1.102 – 10.63.1.103	10.63.1.103
53	10.63.1.104/31	10.63.1.104 – 10.63.1.105	10.63.1.105
54	10.63.1.106/31	10.63.1.106 – 10.63.1.107	10.63.1.107
55	10.63.1.108/31	10.63.1.108 – 10.63.1.109	10.63.1.109
56	10.63.1.110/31	10.63.1.110 – 10.63.1.111	10.63.1.111
57	10.63.1.112/31	10.63.1.112 – 10.63.1.113	10.63.1.113
58	10.63.1.114/31	10.63.1.114 – 10.63.1.115	10.63.1.115
59	10.63.1.116/31	10.63.1.116 – 10.63.1.117	10.63.1.117
60	10.63.1.118/31	10.63.1.118 – 10.63.1.119	10.63.1.119
61	10.63.1.120/31	10.63.1.120 – 10.63.1.121	10.63.1.121
62	10.63.1.122/31	10.63.1.122 – 10.63.1.123	10.63.1.123
63	10.63.1.124/31	10.63.1.124 – 10.63.1.125	10.63.1.125
64	10.63.1.126/31	10.63.1.126 – 10.63.1.127	10.63.1.127

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 →