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)10.128.78.0/23

network10.128.78.0/23

broadcast10.128.79.255

first host10.128.78.1

last host10.128.79.254

subnet mask255.255.254.0

wildcard0.0.1.255

addresses512

usable hosts510

classA

ipcalc 10.128.78.0/23

address00001010.10000000.01001110.00000000

subnet mask11111111.11111111.11111110.00000000

network00001010.10000000.01001110.00000000

broadcast00001010.10000000.01001111.11111111

green = network part, grey = host part

hex0x0a804e00

decimal176180736

reverse dns0.78.128.10.in-addr.arpa

ipv4-mapped::ffff:a80:4e00

/23 split into /30 · 128 subnets

close ×

#	network	host range	broadcast
1	10.128.78.0/30	10.128.78.1 – 10.128.78.2	10.128.78.3
2	10.128.78.4/30	10.128.78.5 – 10.128.78.6	10.128.78.7
3	10.128.78.8/30	10.128.78.9 – 10.128.78.10	10.128.78.11
4	10.128.78.12/30	10.128.78.13 – 10.128.78.14	10.128.78.15
5	10.128.78.16/30	10.128.78.17 – 10.128.78.18	10.128.78.19
6	10.128.78.20/30	10.128.78.21 – 10.128.78.22	10.128.78.23
7	10.128.78.24/30	10.128.78.25 – 10.128.78.26	10.128.78.27
8	10.128.78.28/30	10.128.78.29 – 10.128.78.30	10.128.78.31
9	10.128.78.32/30	10.128.78.33 – 10.128.78.34	10.128.78.35
10	10.128.78.36/30	10.128.78.37 – 10.128.78.38	10.128.78.39
11	10.128.78.40/30	10.128.78.41 – 10.128.78.42	10.128.78.43
12	10.128.78.44/30	10.128.78.45 – 10.128.78.46	10.128.78.47
13	10.128.78.48/30	10.128.78.49 – 10.128.78.50	10.128.78.51
14	10.128.78.52/30	10.128.78.53 – 10.128.78.54	10.128.78.55
15	10.128.78.56/30	10.128.78.57 – 10.128.78.58	10.128.78.59
16	10.128.78.60/30	10.128.78.61 – 10.128.78.62	10.128.78.63
17	10.128.78.64/30	10.128.78.65 – 10.128.78.66	10.128.78.67
18	10.128.78.68/30	10.128.78.69 – 10.128.78.70	10.128.78.71
19	10.128.78.72/30	10.128.78.73 – 10.128.78.74	10.128.78.75
20	10.128.78.76/30	10.128.78.77 – 10.128.78.78	10.128.78.79
21	10.128.78.80/30	10.128.78.81 – 10.128.78.82	10.128.78.83
22	10.128.78.84/30	10.128.78.85 – 10.128.78.86	10.128.78.87
23	10.128.78.88/30	10.128.78.89 – 10.128.78.90	10.128.78.91
24	10.128.78.92/30	10.128.78.93 – 10.128.78.94	10.128.78.95
25	10.128.78.96/30	10.128.78.97 – 10.128.78.98	10.128.78.99
26	10.128.78.100/30	10.128.78.101 – 10.128.78.102	10.128.78.103
27	10.128.78.104/30	10.128.78.105 – 10.128.78.106	10.128.78.107
28	10.128.78.108/30	10.128.78.109 – 10.128.78.110	10.128.78.111
29	10.128.78.112/30	10.128.78.113 – 10.128.78.114	10.128.78.115
30	10.128.78.116/30	10.128.78.117 – 10.128.78.118	10.128.78.119
31	10.128.78.120/30	10.128.78.121 – 10.128.78.122	10.128.78.123
32	10.128.78.124/30	10.128.78.125 – 10.128.78.126	10.128.78.127
33	10.128.78.128/30	10.128.78.129 – 10.128.78.130	10.128.78.131
34	10.128.78.132/30	10.128.78.133 – 10.128.78.134	10.128.78.135
35	10.128.78.136/30	10.128.78.137 – 10.128.78.138	10.128.78.139
36	10.128.78.140/30	10.128.78.141 – 10.128.78.142	10.128.78.143
37	10.128.78.144/30	10.128.78.145 – 10.128.78.146	10.128.78.147
38	10.128.78.148/30	10.128.78.149 – 10.128.78.150	10.128.78.151
39	10.128.78.152/30	10.128.78.153 – 10.128.78.154	10.128.78.155
40	10.128.78.156/30	10.128.78.157 – 10.128.78.158	10.128.78.159
41	10.128.78.160/30	10.128.78.161 – 10.128.78.162	10.128.78.163
42	10.128.78.164/30	10.128.78.165 – 10.128.78.166	10.128.78.167
43	10.128.78.168/30	10.128.78.169 – 10.128.78.170	10.128.78.171
44	10.128.78.172/30	10.128.78.173 – 10.128.78.174	10.128.78.175
45	10.128.78.176/30	10.128.78.177 – 10.128.78.178	10.128.78.179
46	10.128.78.180/30	10.128.78.181 – 10.128.78.182	10.128.78.183
47	10.128.78.184/30	10.128.78.185 – 10.128.78.186	10.128.78.187
48	10.128.78.188/30	10.128.78.189 – 10.128.78.190	10.128.78.191
49	10.128.78.192/30	10.128.78.193 – 10.128.78.194	10.128.78.195
50	10.128.78.196/30	10.128.78.197 – 10.128.78.198	10.128.78.199
51	10.128.78.200/30	10.128.78.201 – 10.128.78.202	10.128.78.203
52	10.128.78.204/30	10.128.78.205 – 10.128.78.206	10.128.78.207
53	10.128.78.208/30	10.128.78.209 – 10.128.78.210	10.128.78.211
54	10.128.78.212/30	10.128.78.213 – 10.128.78.214	10.128.78.215
55	10.128.78.216/30	10.128.78.217 – 10.128.78.218	10.128.78.219
56	10.128.78.220/30	10.128.78.221 – 10.128.78.222	10.128.78.223
57	10.128.78.224/30	10.128.78.225 – 10.128.78.226	10.128.78.227
58	10.128.78.228/30	10.128.78.229 – 10.128.78.230	10.128.78.231
59	10.128.78.232/30	10.128.78.233 – 10.128.78.234	10.128.78.235
60	10.128.78.236/30	10.128.78.237 – 10.128.78.238	10.128.78.239
61	10.128.78.240/30	10.128.78.241 – 10.128.78.242	10.128.78.243
62	10.128.78.244/30	10.128.78.245 – 10.128.78.246	10.128.78.247
63	10.128.78.248/30	10.128.78.249 – 10.128.78.250	10.128.78.251
64	10.128.78.252/30	10.128.78.253 – 10.128.78.254	10.128.78.255
65	10.128.79.0/30	10.128.79.1 – 10.128.79.2	10.128.79.3
66	10.128.79.4/30	10.128.79.5 – 10.128.79.6	10.128.79.7
67	10.128.79.8/30	10.128.79.9 – 10.128.79.10	10.128.79.11
68	10.128.79.12/30	10.128.79.13 – 10.128.79.14	10.128.79.15
69	10.128.79.16/30	10.128.79.17 – 10.128.79.18	10.128.79.19
70	10.128.79.20/30	10.128.79.21 – 10.128.79.22	10.128.79.23
71	10.128.79.24/30	10.128.79.25 – 10.128.79.26	10.128.79.27
72	10.128.79.28/30	10.128.79.29 – 10.128.79.30	10.128.79.31
73	10.128.79.32/30	10.128.79.33 – 10.128.79.34	10.128.79.35
74	10.128.79.36/30	10.128.79.37 – 10.128.79.38	10.128.79.39
75	10.128.79.40/30	10.128.79.41 – 10.128.79.42	10.128.79.43
76	10.128.79.44/30	10.128.79.45 – 10.128.79.46	10.128.79.47
77	10.128.79.48/30	10.128.79.49 – 10.128.79.50	10.128.79.51
78	10.128.79.52/30	10.128.79.53 – 10.128.79.54	10.128.79.55
79	10.128.79.56/30	10.128.79.57 – 10.128.79.58	10.128.79.59
80	10.128.79.60/30	10.128.79.61 – 10.128.79.62	10.128.79.63
81	10.128.79.64/30	10.128.79.65 – 10.128.79.66	10.128.79.67
82	10.128.79.68/30	10.128.79.69 – 10.128.79.70	10.128.79.71
83	10.128.79.72/30	10.128.79.73 – 10.128.79.74	10.128.79.75
84	10.128.79.76/30	10.128.79.77 – 10.128.79.78	10.128.79.79
85	10.128.79.80/30	10.128.79.81 – 10.128.79.82	10.128.79.83
86	10.128.79.84/30	10.128.79.85 – 10.128.79.86	10.128.79.87
87	10.128.79.88/30	10.128.79.89 – 10.128.79.90	10.128.79.91
88	10.128.79.92/30	10.128.79.93 – 10.128.79.94	10.128.79.95
89	10.128.79.96/30	10.128.79.97 – 10.128.79.98	10.128.79.99
90	10.128.79.100/30	10.128.79.101 – 10.128.79.102	10.128.79.103
91	10.128.79.104/30	10.128.79.105 – 10.128.79.106	10.128.79.107
92	10.128.79.108/30	10.128.79.109 – 10.128.79.110	10.128.79.111
93	10.128.79.112/30	10.128.79.113 – 10.128.79.114	10.128.79.115
94	10.128.79.116/30	10.128.79.117 – 10.128.79.118	10.128.79.119
95	10.128.79.120/30	10.128.79.121 – 10.128.79.122	10.128.79.123
96	10.128.79.124/30	10.128.79.125 – 10.128.79.126	10.128.79.127
97	10.128.79.128/30	10.128.79.129 – 10.128.79.130	10.128.79.131
98	10.128.79.132/30	10.128.79.133 – 10.128.79.134	10.128.79.135
99	10.128.79.136/30	10.128.79.137 – 10.128.79.138	10.128.79.139
100	10.128.79.140/30	10.128.79.141 – 10.128.79.142	10.128.79.143
101	10.128.79.144/30	10.128.79.145 – 10.128.79.146	10.128.79.147
102	10.128.79.148/30	10.128.79.149 – 10.128.79.150	10.128.79.151
103	10.128.79.152/30	10.128.79.153 – 10.128.79.154	10.128.79.155
104	10.128.79.156/30	10.128.79.157 – 10.128.79.158	10.128.79.159
105	10.128.79.160/30	10.128.79.161 – 10.128.79.162	10.128.79.163
106	10.128.79.164/30	10.128.79.165 – 10.128.79.166	10.128.79.167
107	10.128.79.168/30	10.128.79.169 – 10.128.79.170	10.128.79.171
108	10.128.79.172/30	10.128.79.173 – 10.128.79.174	10.128.79.175
109	10.128.79.176/30	10.128.79.177 – 10.128.79.178	10.128.79.179
110	10.128.79.180/30	10.128.79.181 – 10.128.79.182	10.128.79.183
111	10.128.79.184/30	10.128.79.185 – 10.128.79.186	10.128.79.187
112	10.128.79.188/30	10.128.79.189 – 10.128.79.190	10.128.79.191
113	10.128.79.192/30	10.128.79.193 – 10.128.79.194	10.128.79.195
114	10.128.79.196/30	10.128.79.197 – 10.128.79.198	10.128.79.199
115	10.128.79.200/30	10.128.79.201 – 10.128.79.202	10.128.79.203
116	10.128.79.204/30	10.128.79.205 – 10.128.79.206	10.128.79.207
117	10.128.79.208/30	10.128.79.209 – 10.128.79.210	10.128.79.211
118	10.128.79.212/30	10.128.79.213 – 10.128.79.214	10.128.79.215
119	10.128.79.216/30	10.128.79.217 – 10.128.79.218	10.128.79.219
120	10.128.79.220/30	10.128.79.221 – 10.128.79.222	10.128.79.223
121	10.128.79.224/30	10.128.79.225 – 10.128.79.226	10.128.79.227
122	10.128.79.228/30	10.128.79.229 – 10.128.79.230	10.128.79.231
123	10.128.79.232/30	10.128.79.233 – 10.128.79.234	10.128.79.235
124	10.128.79.236/30	10.128.79.237 – 10.128.79.238	10.128.79.239
125	10.128.79.240/30	10.128.79.241 – 10.128.79.242	10.128.79.243
126	10.128.79.244/30	10.128.79.245 – 10.128.79.246	10.128.79.247
127	10.128.79.248/30	10.128.79.249 – 10.128.79.250	10.128.79.251
128	10.128.79.252/30	10.128.79.253 – 10.128.79.254	10.128.79.255

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 /23
/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	1
/24	255.255.255.0	256	254	2 split →
/25	255.255.255.128	128	126	4 split →
/26	255.255.255.192	64	62	8 split →
/27	255.255.255.224	32	30	16 split →
/28	255.255.255.240	16	14	32 split →
/29	255.255.255.248	8	6	64 split →
/30	255.255.255.252	4	2	128 split →
/31	255.255.255.254	2	2	256 split →
/32	255.255.255.255	1	1	512 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 →