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)10.131.65.0/25

network10.131.65.0/25

broadcast10.131.65.127

first host10.131.65.1

last host10.131.65.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.131.65.0/25

address00001010.10000011.01000001.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.10000011.01000001.00000000

broadcast00001010.10000011.01000001.01111111

green = network part, grey = host part

hex0x0a834100

decimal176374016

reverse dns0.65.131.10.in-addr.arpa

ipv4-mapped::ffff:a83:4100

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.131.65.0/31	10.131.65.0 – 10.131.65.1	10.131.65.1
2	10.131.65.2/31	10.131.65.2 – 10.131.65.3	10.131.65.3
3	10.131.65.4/31	10.131.65.4 – 10.131.65.5	10.131.65.5
4	10.131.65.6/31	10.131.65.6 – 10.131.65.7	10.131.65.7
5	10.131.65.8/31	10.131.65.8 – 10.131.65.9	10.131.65.9
6	10.131.65.10/31	10.131.65.10 – 10.131.65.11	10.131.65.11
7	10.131.65.12/31	10.131.65.12 – 10.131.65.13	10.131.65.13
8	10.131.65.14/31	10.131.65.14 – 10.131.65.15	10.131.65.15
9	10.131.65.16/31	10.131.65.16 – 10.131.65.17	10.131.65.17
10	10.131.65.18/31	10.131.65.18 – 10.131.65.19	10.131.65.19
11	10.131.65.20/31	10.131.65.20 – 10.131.65.21	10.131.65.21
12	10.131.65.22/31	10.131.65.22 – 10.131.65.23	10.131.65.23
13	10.131.65.24/31	10.131.65.24 – 10.131.65.25	10.131.65.25
14	10.131.65.26/31	10.131.65.26 – 10.131.65.27	10.131.65.27
15	10.131.65.28/31	10.131.65.28 – 10.131.65.29	10.131.65.29
16	10.131.65.30/31	10.131.65.30 – 10.131.65.31	10.131.65.31
17	10.131.65.32/31	10.131.65.32 – 10.131.65.33	10.131.65.33
18	10.131.65.34/31	10.131.65.34 – 10.131.65.35	10.131.65.35
19	10.131.65.36/31	10.131.65.36 – 10.131.65.37	10.131.65.37
20	10.131.65.38/31	10.131.65.38 – 10.131.65.39	10.131.65.39
21	10.131.65.40/31	10.131.65.40 – 10.131.65.41	10.131.65.41
22	10.131.65.42/31	10.131.65.42 – 10.131.65.43	10.131.65.43
23	10.131.65.44/31	10.131.65.44 – 10.131.65.45	10.131.65.45
24	10.131.65.46/31	10.131.65.46 – 10.131.65.47	10.131.65.47
25	10.131.65.48/31	10.131.65.48 – 10.131.65.49	10.131.65.49
26	10.131.65.50/31	10.131.65.50 – 10.131.65.51	10.131.65.51
27	10.131.65.52/31	10.131.65.52 – 10.131.65.53	10.131.65.53
28	10.131.65.54/31	10.131.65.54 – 10.131.65.55	10.131.65.55
29	10.131.65.56/31	10.131.65.56 – 10.131.65.57	10.131.65.57
30	10.131.65.58/31	10.131.65.58 – 10.131.65.59	10.131.65.59
31	10.131.65.60/31	10.131.65.60 – 10.131.65.61	10.131.65.61
32	10.131.65.62/31	10.131.65.62 – 10.131.65.63	10.131.65.63
33	10.131.65.64/31	10.131.65.64 – 10.131.65.65	10.131.65.65
34	10.131.65.66/31	10.131.65.66 – 10.131.65.67	10.131.65.67
35	10.131.65.68/31	10.131.65.68 – 10.131.65.69	10.131.65.69
36	10.131.65.70/31	10.131.65.70 – 10.131.65.71	10.131.65.71
37	10.131.65.72/31	10.131.65.72 – 10.131.65.73	10.131.65.73
38	10.131.65.74/31	10.131.65.74 – 10.131.65.75	10.131.65.75
39	10.131.65.76/31	10.131.65.76 – 10.131.65.77	10.131.65.77
40	10.131.65.78/31	10.131.65.78 – 10.131.65.79	10.131.65.79
41	10.131.65.80/31	10.131.65.80 – 10.131.65.81	10.131.65.81
42	10.131.65.82/31	10.131.65.82 – 10.131.65.83	10.131.65.83
43	10.131.65.84/31	10.131.65.84 – 10.131.65.85	10.131.65.85
44	10.131.65.86/31	10.131.65.86 – 10.131.65.87	10.131.65.87
45	10.131.65.88/31	10.131.65.88 – 10.131.65.89	10.131.65.89
46	10.131.65.90/31	10.131.65.90 – 10.131.65.91	10.131.65.91
47	10.131.65.92/31	10.131.65.92 – 10.131.65.93	10.131.65.93
48	10.131.65.94/31	10.131.65.94 – 10.131.65.95	10.131.65.95
49	10.131.65.96/31	10.131.65.96 – 10.131.65.97	10.131.65.97
50	10.131.65.98/31	10.131.65.98 – 10.131.65.99	10.131.65.99
51	10.131.65.100/31	10.131.65.100 – 10.131.65.101	10.131.65.101
52	10.131.65.102/31	10.131.65.102 – 10.131.65.103	10.131.65.103
53	10.131.65.104/31	10.131.65.104 – 10.131.65.105	10.131.65.105
54	10.131.65.106/31	10.131.65.106 – 10.131.65.107	10.131.65.107
55	10.131.65.108/31	10.131.65.108 – 10.131.65.109	10.131.65.109
56	10.131.65.110/31	10.131.65.110 – 10.131.65.111	10.131.65.111
57	10.131.65.112/31	10.131.65.112 – 10.131.65.113	10.131.65.113
58	10.131.65.114/31	10.131.65.114 – 10.131.65.115	10.131.65.115
59	10.131.65.116/31	10.131.65.116 – 10.131.65.117	10.131.65.117
60	10.131.65.118/31	10.131.65.118 – 10.131.65.119	10.131.65.119
61	10.131.65.120/31	10.131.65.120 – 10.131.65.121	10.131.65.121
62	10.131.65.122/31	10.131.65.122 – 10.131.65.123	10.131.65.123
63	10.131.65.124/31	10.131.65.124 – 10.131.65.125	10.131.65.125
64	10.131.65.126/31	10.131.65.126 – 10.131.65.127	10.131.65.127

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 →