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)10.3.136.0/25

network10.3.136.0/25

broadcast10.3.136.127

first host10.3.136.1

last host10.3.136.126

subnet mask255.255.255.128

wildcard0.0.0.127

addresses128

usable hosts126

classA

ipcalc 10.3.136.0/25

address00001010.00000011.10001000.00000000

subnet mask11111111.11111111.11111111.10000000

network00001010.00000011.10001000.00000000

broadcast00001010.00000011.10001000.01111111

green = network part, grey = host part

hex0x0a038800

decimal168003584

reverse dns0.136.3.10.in-addr.arpa

ipv4-mapped::ffff:a03:8800

/25 split into /31 · 64 subnets

close ×

#	network	host range	broadcast
1	10.3.136.0/31	10.3.136.0 – 10.3.136.1	10.3.136.1
2	10.3.136.2/31	10.3.136.2 – 10.3.136.3	10.3.136.3
3	10.3.136.4/31	10.3.136.4 – 10.3.136.5	10.3.136.5
4	10.3.136.6/31	10.3.136.6 – 10.3.136.7	10.3.136.7
5	10.3.136.8/31	10.3.136.8 – 10.3.136.9	10.3.136.9
6	10.3.136.10/31	10.3.136.10 – 10.3.136.11	10.3.136.11
7	10.3.136.12/31	10.3.136.12 – 10.3.136.13	10.3.136.13
8	10.3.136.14/31	10.3.136.14 – 10.3.136.15	10.3.136.15
9	10.3.136.16/31	10.3.136.16 – 10.3.136.17	10.3.136.17
10	10.3.136.18/31	10.3.136.18 – 10.3.136.19	10.3.136.19
11	10.3.136.20/31	10.3.136.20 – 10.3.136.21	10.3.136.21
12	10.3.136.22/31	10.3.136.22 – 10.3.136.23	10.3.136.23
13	10.3.136.24/31	10.3.136.24 – 10.3.136.25	10.3.136.25
14	10.3.136.26/31	10.3.136.26 – 10.3.136.27	10.3.136.27
15	10.3.136.28/31	10.3.136.28 – 10.3.136.29	10.3.136.29
16	10.3.136.30/31	10.3.136.30 – 10.3.136.31	10.3.136.31
17	10.3.136.32/31	10.3.136.32 – 10.3.136.33	10.3.136.33
18	10.3.136.34/31	10.3.136.34 – 10.3.136.35	10.3.136.35
19	10.3.136.36/31	10.3.136.36 – 10.3.136.37	10.3.136.37
20	10.3.136.38/31	10.3.136.38 – 10.3.136.39	10.3.136.39
21	10.3.136.40/31	10.3.136.40 – 10.3.136.41	10.3.136.41
22	10.3.136.42/31	10.3.136.42 – 10.3.136.43	10.3.136.43
23	10.3.136.44/31	10.3.136.44 – 10.3.136.45	10.3.136.45
24	10.3.136.46/31	10.3.136.46 – 10.3.136.47	10.3.136.47
25	10.3.136.48/31	10.3.136.48 – 10.3.136.49	10.3.136.49
26	10.3.136.50/31	10.3.136.50 – 10.3.136.51	10.3.136.51
27	10.3.136.52/31	10.3.136.52 – 10.3.136.53	10.3.136.53
28	10.3.136.54/31	10.3.136.54 – 10.3.136.55	10.3.136.55
29	10.3.136.56/31	10.3.136.56 – 10.3.136.57	10.3.136.57
30	10.3.136.58/31	10.3.136.58 – 10.3.136.59	10.3.136.59
31	10.3.136.60/31	10.3.136.60 – 10.3.136.61	10.3.136.61
32	10.3.136.62/31	10.3.136.62 – 10.3.136.63	10.3.136.63
33	10.3.136.64/31	10.3.136.64 – 10.3.136.65	10.3.136.65
34	10.3.136.66/31	10.3.136.66 – 10.3.136.67	10.3.136.67
35	10.3.136.68/31	10.3.136.68 – 10.3.136.69	10.3.136.69
36	10.3.136.70/31	10.3.136.70 – 10.3.136.71	10.3.136.71
37	10.3.136.72/31	10.3.136.72 – 10.3.136.73	10.3.136.73
38	10.3.136.74/31	10.3.136.74 – 10.3.136.75	10.3.136.75
39	10.3.136.76/31	10.3.136.76 – 10.3.136.77	10.3.136.77
40	10.3.136.78/31	10.3.136.78 – 10.3.136.79	10.3.136.79
41	10.3.136.80/31	10.3.136.80 – 10.3.136.81	10.3.136.81
42	10.3.136.82/31	10.3.136.82 – 10.3.136.83	10.3.136.83
43	10.3.136.84/31	10.3.136.84 – 10.3.136.85	10.3.136.85
44	10.3.136.86/31	10.3.136.86 – 10.3.136.87	10.3.136.87
45	10.3.136.88/31	10.3.136.88 – 10.3.136.89	10.3.136.89
46	10.3.136.90/31	10.3.136.90 – 10.3.136.91	10.3.136.91
47	10.3.136.92/31	10.3.136.92 – 10.3.136.93	10.3.136.93
48	10.3.136.94/31	10.3.136.94 – 10.3.136.95	10.3.136.95
49	10.3.136.96/31	10.3.136.96 – 10.3.136.97	10.3.136.97
50	10.3.136.98/31	10.3.136.98 – 10.3.136.99	10.3.136.99
51	10.3.136.100/31	10.3.136.100 – 10.3.136.101	10.3.136.101
52	10.3.136.102/31	10.3.136.102 – 10.3.136.103	10.3.136.103
53	10.3.136.104/31	10.3.136.104 – 10.3.136.105	10.3.136.105
54	10.3.136.106/31	10.3.136.106 – 10.3.136.107	10.3.136.107
55	10.3.136.108/31	10.3.136.108 – 10.3.136.109	10.3.136.109
56	10.3.136.110/31	10.3.136.110 – 10.3.136.111	10.3.136.111
57	10.3.136.112/31	10.3.136.112 – 10.3.136.113	10.3.136.113
58	10.3.136.114/31	10.3.136.114 – 10.3.136.115	10.3.136.115
59	10.3.136.116/31	10.3.136.116 – 10.3.136.117	10.3.136.117
60	10.3.136.118/31	10.3.136.118 – 10.3.136.119	10.3.136.119
61	10.3.136.120/31	10.3.136.120 – 10.3.136.121	10.3.136.121
62	10.3.136.122/31	10.3.136.122 – 10.3.136.123	10.3.136.123
63	10.3.136.124/31	10.3.136.124 – 10.3.136.125	10.3.136.125
64	10.3.136.126/31	10.3.136.126 – 10.3.136.127	10.3.136.127

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 →