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)10.31.128.0/17

network10.31.128.0/17

broadcast10.31.255.255

first host10.31.128.1

last host10.31.255.254

subnet mask255.255.128.0

wildcard0.0.127.255

addresses32,768

usable hosts32,766

classA

ipcalc 10.31.128.0/17

address00001010.00011111.10000000.00000000

subnet mask11111111.11111111.10000000.00000000

network00001010.00011111.10000000.00000000

broadcast00001010.00011111.11111111.11111111

green = network part, grey = host part

hex0x0a1f8000

decimal169836544

reverse dns0.128.31.10.in-addr.arpa

ipv4-mapped::ffff:a1f:8000

/17 split into /24 · 128 subnets

close ×

#	network	host range	broadcast
1	10.31.128.0/24	10.31.128.1 – 10.31.128.254	10.31.128.255
2	10.31.129.0/24	10.31.129.1 – 10.31.129.254	10.31.129.255
3	10.31.130.0/24	10.31.130.1 – 10.31.130.254	10.31.130.255
4	10.31.131.0/24	10.31.131.1 – 10.31.131.254	10.31.131.255
5	10.31.132.0/24	10.31.132.1 – 10.31.132.254	10.31.132.255
6	10.31.133.0/24	10.31.133.1 – 10.31.133.254	10.31.133.255
7	10.31.134.0/24	10.31.134.1 – 10.31.134.254	10.31.134.255
8	10.31.135.0/24	10.31.135.1 – 10.31.135.254	10.31.135.255
9	10.31.136.0/24	10.31.136.1 – 10.31.136.254	10.31.136.255
10	10.31.137.0/24	10.31.137.1 – 10.31.137.254	10.31.137.255
11	10.31.138.0/24	10.31.138.1 – 10.31.138.254	10.31.138.255
12	10.31.139.0/24	10.31.139.1 – 10.31.139.254	10.31.139.255
13	10.31.140.0/24	10.31.140.1 – 10.31.140.254	10.31.140.255
14	10.31.141.0/24	10.31.141.1 – 10.31.141.254	10.31.141.255
15	10.31.142.0/24	10.31.142.1 – 10.31.142.254	10.31.142.255
16	10.31.143.0/24	10.31.143.1 – 10.31.143.254	10.31.143.255
17	10.31.144.0/24	10.31.144.1 – 10.31.144.254	10.31.144.255
18	10.31.145.0/24	10.31.145.1 – 10.31.145.254	10.31.145.255
19	10.31.146.0/24	10.31.146.1 – 10.31.146.254	10.31.146.255
20	10.31.147.0/24	10.31.147.1 – 10.31.147.254	10.31.147.255
21	10.31.148.0/24	10.31.148.1 – 10.31.148.254	10.31.148.255
22	10.31.149.0/24	10.31.149.1 – 10.31.149.254	10.31.149.255
23	10.31.150.0/24	10.31.150.1 – 10.31.150.254	10.31.150.255
24	10.31.151.0/24	10.31.151.1 – 10.31.151.254	10.31.151.255
25	10.31.152.0/24	10.31.152.1 – 10.31.152.254	10.31.152.255
26	10.31.153.0/24	10.31.153.1 – 10.31.153.254	10.31.153.255
27	10.31.154.0/24	10.31.154.1 – 10.31.154.254	10.31.154.255
28	10.31.155.0/24	10.31.155.1 – 10.31.155.254	10.31.155.255
29	10.31.156.0/24	10.31.156.1 – 10.31.156.254	10.31.156.255
30	10.31.157.0/24	10.31.157.1 – 10.31.157.254	10.31.157.255
31	10.31.158.0/24	10.31.158.1 – 10.31.158.254	10.31.158.255
32	10.31.159.0/24	10.31.159.1 – 10.31.159.254	10.31.159.255
33	10.31.160.0/24	10.31.160.1 – 10.31.160.254	10.31.160.255
34	10.31.161.0/24	10.31.161.1 – 10.31.161.254	10.31.161.255
35	10.31.162.0/24	10.31.162.1 – 10.31.162.254	10.31.162.255
36	10.31.163.0/24	10.31.163.1 – 10.31.163.254	10.31.163.255
37	10.31.164.0/24	10.31.164.1 – 10.31.164.254	10.31.164.255
38	10.31.165.0/24	10.31.165.1 – 10.31.165.254	10.31.165.255
39	10.31.166.0/24	10.31.166.1 – 10.31.166.254	10.31.166.255
40	10.31.167.0/24	10.31.167.1 – 10.31.167.254	10.31.167.255
41	10.31.168.0/24	10.31.168.1 – 10.31.168.254	10.31.168.255
42	10.31.169.0/24	10.31.169.1 – 10.31.169.254	10.31.169.255
43	10.31.170.0/24	10.31.170.1 – 10.31.170.254	10.31.170.255
44	10.31.171.0/24	10.31.171.1 – 10.31.171.254	10.31.171.255
45	10.31.172.0/24	10.31.172.1 – 10.31.172.254	10.31.172.255
46	10.31.173.0/24	10.31.173.1 – 10.31.173.254	10.31.173.255
47	10.31.174.0/24	10.31.174.1 – 10.31.174.254	10.31.174.255
48	10.31.175.0/24	10.31.175.1 – 10.31.175.254	10.31.175.255
49	10.31.176.0/24	10.31.176.1 – 10.31.176.254	10.31.176.255
50	10.31.177.0/24	10.31.177.1 – 10.31.177.254	10.31.177.255
51	10.31.178.0/24	10.31.178.1 – 10.31.178.254	10.31.178.255
52	10.31.179.0/24	10.31.179.1 – 10.31.179.254	10.31.179.255
53	10.31.180.0/24	10.31.180.1 – 10.31.180.254	10.31.180.255
54	10.31.181.0/24	10.31.181.1 – 10.31.181.254	10.31.181.255
55	10.31.182.0/24	10.31.182.1 – 10.31.182.254	10.31.182.255
56	10.31.183.0/24	10.31.183.1 – 10.31.183.254	10.31.183.255
57	10.31.184.0/24	10.31.184.1 – 10.31.184.254	10.31.184.255
58	10.31.185.0/24	10.31.185.1 – 10.31.185.254	10.31.185.255
59	10.31.186.0/24	10.31.186.1 – 10.31.186.254	10.31.186.255
60	10.31.187.0/24	10.31.187.1 – 10.31.187.254	10.31.187.255
61	10.31.188.0/24	10.31.188.1 – 10.31.188.254	10.31.188.255
62	10.31.189.0/24	10.31.189.1 – 10.31.189.254	10.31.189.255
63	10.31.190.0/24	10.31.190.1 – 10.31.190.254	10.31.190.255
64	10.31.191.0/24	10.31.191.1 – 10.31.191.254	10.31.191.255
65	10.31.192.0/24	10.31.192.1 – 10.31.192.254	10.31.192.255
66	10.31.193.0/24	10.31.193.1 – 10.31.193.254	10.31.193.255
67	10.31.194.0/24	10.31.194.1 – 10.31.194.254	10.31.194.255
68	10.31.195.0/24	10.31.195.1 – 10.31.195.254	10.31.195.255
69	10.31.196.0/24	10.31.196.1 – 10.31.196.254	10.31.196.255
70	10.31.197.0/24	10.31.197.1 – 10.31.197.254	10.31.197.255
71	10.31.198.0/24	10.31.198.1 – 10.31.198.254	10.31.198.255
72	10.31.199.0/24	10.31.199.1 – 10.31.199.254	10.31.199.255
73	10.31.200.0/24	10.31.200.1 – 10.31.200.254	10.31.200.255
74	10.31.201.0/24	10.31.201.1 – 10.31.201.254	10.31.201.255
75	10.31.202.0/24	10.31.202.1 – 10.31.202.254	10.31.202.255
76	10.31.203.0/24	10.31.203.1 – 10.31.203.254	10.31.203.255
77	10.31.204.0/24	10.31.204.1 – 10.31.204.254	10.31.204.255
78	10.31.205.0/24	10.31.205.1 – 10.31.205.254	10.31.205.255
79	10.31.206.0/24	10.31.206.1 – 10.31.206.254	10.31.206.255
80	10.31.207.0/24	10.31.207.1 – 10.31.207.254	10.31.207.255
81	10.31.208.0/24	10.31.208.1 – 10.31.208.254	10.31.208.255
82	10.31.209.0/24	10.31.209.1 – 10.31.209.254	10.31.209.255
83	10.31.210.0/24	10.31.210.1 – 10.31.210.254	10.31.210.255
84	10.31.211.0/24	10.31.211.1 – 10.31.211.254	10.31.211.255
85	10.31.212.0/24	10.31.212.1 – 10.31.212.254	10.31.212.255
86	10.31.213.0/24	10.31.213.1 – 10.31.213.254	10.31.213.255
87	10.31.214.0/24	10.31.214.1 – 10.31.214.254	10.31.214.255
88	10.31.215.0/24	10.31.215.1 – 10.31.215.254	10.31.215.255
89	10.31.216.0/24	10.31.216.1 – 10.31.216.254	10.31.216.255
90	10.31.217.0/24	10.31.217.1 – 10.31.217.254	10.31.217.255
91	10.31.218.0/24	10.31.218.1 – 10.31.218.254	10.31.218.255
92	10.31.219.0/24	10.31.219.1 – 10.31.219.254	10.31.219.255
93	10.31.220.0/24	10.31.220.1 – 10.31.220.254	10.31.220.255
94	10.31.221.0/24	10.31.221.1 – 10.31.221.254	10.31.221.255
95	10.31.222.0/24	10.31.222.1 – 10.31.222.254	10.31.222.255
96	10.31.223.0/24	10.31.223.1 – 10.31.223.254	10.31.223.255
97	10.31.224.0/24	10.31.224.1 – 10.31.224.254	10.31.224.255
98	10.31.225.0/24	10.31.225.1 – 10.31.225.254	10.31.225.255
99	10.31.226.0/24	10.31.226.1 – 10.31.226.254	10.31.226.255
100	10.31.227.0/24	10.31.227.1 – 10.31.227.254	10.31.227.255
101	10.31.228.0/24	10.31.228.1 – 10.31.228.254	10.31.228.255
102	10.31.229.0/24	10.31.229.1 – 10.31.229.254	10.31.229.255
103	10.31.230.0/24	10.31.230.1 – 10.31.230.254	10.31.230.255
104	10.31.231.0/24	10.31.231.1 – 10.31.231.254	10.31.231.255
105	10.31.232.0/24	10.31.232.1 – 10.31.232.254	10.31.232.255
106	10.31.233.0/24	10.31.233.1 – 10.31.233.254	10.31.233.255
107	10.31.234.0/24	10.31.234.1 – 10.31.234.254	10.31.234.255
108	10.31.235.0/24	10.31.235.1 – 10.31.235.254	10.31.235.255
109	10.31.236.0/24	10.31.236.1 – 10.31.236.254	10.31.236.255
110	10.31.237.0/24	10.31.237.1 – 10.31.237.254	10.31.237.255
111	10.31.238.0/24	10.31.238.1 – 10.31.238.254	10.31.238.255
112	10.31.239.0/24	10.31.239.1 – 10.31.239.254	10.31.239.255
113	10.31.240.0/24	10.31.240.1 – 10.31.240.254	10.31.240.255
114	10.31.241.0/24	10.31.241.1 – 10.31.241.254	10.31.241.255
115	10.31.242.0/24	10.31.242.1 – 10.31.242.254	10.31.242.255
116	10.31.243.0/24	10.31.243.1 – 10.31.243.254	10.31.243.255
117	10.31.244.0/24	10.31.244.1 – 10.31.244.254	10.31.244.255
118	10.31.245.0/24	10.31.245.1 – 10.31.245.254	10.31.245.255
119	10.31.246.0/24	10.31.246.1 – 10.31.246.254	10.31.246.255
120	10.31.247.0/24	10.31.247.1 – 10.31.247.254	10.31.247.255
121	10.31.248.0/24	10.31.248.1 – 10.31.248.254	10.31.248.255
122	10.31.249.0/24	10.31.249.1 – 10.31.249.254	10.31.249.255
123	10.31.250.0/24	10.31.250.1 – 10.31.250.254	10.31.250.255
124	10.31.251.0/24	10.31.251.1 – 10.31.251.254	10.31.251.255
125	10.31.252.0/24	10.31.252.1 – 10.31.252.254	10.31.252.255
126	10.31.253.0/24	10.31.253.1 – 10.31.253.254	10.31.253.255
127	10.31.254.0/24	10.31.254.1 – 10.31.254.254	10.31.254.255
128	10.31.255.0/24	10.31.255.1 – 10.31.255.254	10.31.255.255

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 /17
/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	1
/18	255.255.192.0	16,384	16,382	2 split →
/19	255.255.224.0	8,192	8,190	4 split →
/20	255.255.240.0	4,096	4,094	8 split →
/21	255.255.248.0	2,048	2,046	16 split →
/22	255.255.252.0	1,024	1,022	32 split →
/23	255.255.254.0	512	510	64 split →
/24	255.255.255.0	256	254	128 split →
/25	255.255.255.128	128	126	256 split →
/26	255.255.255.192	64	62	512 split →
/27	255.255.255.224	32	30	1,024 split →
/28	255.255.255.240	16	14	2,048 split →
/29	255.255.255.248	8	6	4,096 split →
/30	255.255.255.252	4	2	8,192 split →
/31	255.255.255.254	2	2	16,384 split →
/32	255.255.255.255	1	1	32,768 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 →