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)10.2.245.0/25

network10.2.245.0/25

broadcast10.2.245.127

first host10.2.245.1

last host10.2.245.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.2.245.0/25

address00001010.00000010.11110101.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000010.11110101.00000000

broadcast00001010.00000010.11110101.01111111

green = network part, grey = host part

hex0x0a02f500

decimal167965952

reverse dns0.245.2.10.in-addr.arpa

ipv4-mapped::ffff:a02:f500

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.2.245.0/31	10.2.245.0 – 10.2.245.1	10.2.245.1
2	10.2.245.2/31	10.2.245.2 – 10.2.245.3	10.2.245.3
3	10.2.245.4/31	10.2.245.4 – 10.2.245.5	10.2.245.5
4	10.2.245.6/31	10.2.245.6 – 10.2.245.7	10.2.245.7
5	10.2.245.8/31	10.2.245.8 – 10.2.245.9	10.2.245.9
6	10.2.245.10/31	10.2.245.10 – 10.2.245.11	10.2.245.11
7	10.2.245.12/31	10.2.245.12 – 10.2.245.13	10.2.245.13
8	10.2.245.14/31	10.2.245.14 – 10.2.245.15	10.2.245.15
9	10.2.245.16/31	10.2.245.16 – 10.2.245.17	10.2.245.17
10	10.2.245.18/31	10.2.245.18 – 10.2.245.19	10.2.245.19
11	10.2.245.20/31	10.2.245.20 – 10.2.245.21	10.2.245.21
12	10.2.245.22/31	10.2.245.22 – 10.2.245.23	10.2.245.23
13	10.2.245.24/31	10.2.245.24 – 10.2.245.25	10.2.245.25
14	10.2.245.26/31	10.2.245.26 – 10.2.245.27	10.2.245.27
15	10.2.245.28/31	10.2.245.28 – 10.2.245.29	10.2.245.29
16	10.2.245.30/31	10.2.245.30 – 10.2.245.31	10.2.245.31
17	10.2.245.32/31	10.2.245.32 – 10.2.245.33	10.2.245.33
18	10.2.245.34/31	10.2.245.34 – 10.2.245.35	10.2.245.35
19	10.2.245.36/31	10.2.245.36 – 10.2.245.37	10.2.245.37
20	10.2.245.38/31	10.2.245.38 – 10.2.245.39	10.2.245.39
21	10.2.245.40/31	10.2.245.40 – 10.2.245.41	10.2.245.41
22	10.2.245.42/31	10.2.245.42 – 10.2.245.43	10.2.245.43
23	10.2.245.44/31	10.2.245.44 – 10.2.245.45	10.2.245.45
24	10.2.245.46/31	10.2.245.46 – 10.2.245.47	10.2.245.47
25	10.2.245.48/31	10.2.245.48 – 10.2.245.49	10.2.245.49
26	10.2.245.50/31	10.2.245.50 – 10.2.245.51	10.2.245.51
27	10.2.245.52/31	10.2.245.52 – 10.2.245.53	10.2.245.53
28	10.2.245.54/31	10.2.245.54 – 10.2.245.55	10.2.245.55
29	10.2.245.56/31	10.2.245.56 – 10.2.245.57	10.2.245.57
30	10.2.245.58/31	10.2.245.58 – 10.2.245.59	10.2.245.59
31	10.2.245.60/31	10.2.245.60 – 10.2.245.61	10.2.245.61
32	10.2.245.62/31	10.2.245.62 – 10.2.245.63	10.2.245.63
33	10.2.245.64/31	10.2.245.64 – 10.2.245.65	10.2.245.65
34	10.2.245.66/31	10.2.245.66 – 10.2.245.67	10.2.245.67
35	10.2.245.68/31	10.2.245.68 – 10.2.245.69	10.2.245.69
36	10.2.245.70/31	10.2.245.70 – 10.2.245.71	10.2.245.71
37	10.2.245.72/31	10.2.245.72 – 10.2.245.73	10.2.245.73
38	10.2.245.74/31	10.2.245.74 – 10.2.245.75	10.2.245.75
39	10.2.245.76/31	10.2.245.76 – 10.2.245.77	10.2.245.77
40	10.2.245.78/31	10.2.245.78 – 10.2.245.79	10.2.245.79
41	10.2.245.80/31	10.2.245.80 – 10.2.245.81	10.2.245.81
42	10.2.245.82/31	10.2.245.82 – 10.2.245.83	10.2.245.83
43	10.2.245.84/31	10.2.245.84 – 10.2.245.85	10.2.245.85
44	10.2.245.86/31	10.2.245.86 – 10.2.245.87	10.2.245.87
45	10.2.245.88/31	10.2.245.88 – 10.2.245.89	10.2.245.89
46	10.2.245.90/31	10.2.245.90 – 10.2.245.91	10.2.245.91
47	10.2.245.92/31	10.2.245.92 – 10.2.245.93	10.2.245.93
48	10.2.245.94/31	10.2.245.94 – 10.2.245.95	10.2.245.95
49	10.2.245.96/31	10.2.245.96 – 10.2.245.97	10.2.245.97
50	10.2.245.98/31	10.2.245.98 – 10.2.245.99	10.2.245.99
51	10.2.245.100/31	10.2.245.100 – 10.2.245.101	10.2.245.101
52	10.2.245.102/31	10.2.245.102 – 10.2.245.103	10.2.245.103
53	10.2.245.104/31	10.2.245.104 – 10.2.245.105	10.2.245.105
54	10.2.245.106/31	10.2.245.106 – 10.2.245.107	10.2.245.107
55	10.2.245.108/31	10.2.245.108 – 10.2.245.109	10.2.245.109
56	10.2.245.110/31	10.2.245.110 – 10.2.245.111	10.2.245.111
57	10.2.245.112/31	10.2.245.112 – 10.2.245.113	10.2.245.113
58	10.2.245.114/31	10.2.245.114 – 10.2.245.115	10.2.245.115
59	10.2.245.116/31	10.2.245.116 – 10.2.245.117	10.2.245.117
60	10.2.245.118/31	10.2.245.118 – 10.2.245.119	10.2.245.119
61	10.2.245.120/31	10.2.245.120 – 10.2.245.121	10.2.245.121
62	10.2.245.122/31	10.2.245.122 – 10.2.245.123	10.2.245.123
63	10.2.245.124/31	10.2.245.124 – 10.2.245.125	10.2.245.125
64	10.2.245.126/31	10.2.245.126 – 10.2.245.127	10.2.245.127

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 →