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.
private IP (RFC 1918)10.4.160.0/21
network10.4.160.0/21
broadcast10.4.167.255
first host10.4.160.1
last host10.4.167.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.4.160.0/21
address00001010.00000100.10100000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000100.10100000.00000000
broadcast00001010.00000100.10100111.11111111
green = network part, grey = host part
hex0x0a04a000
decimal168075264
reverse dns0.160.4.10.in-addr.arpa
ipv4-mapped::ffff:a04:a000
/21 split into /28 · 128 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.4.160.0/28 | 10.4.160.1 – 10.4.160.14 | 10.4.160.15 |
| 2 | 10.4.160.16/28 | 10.4.160.17 – 10.4.160.30 | 10.4.160.31 |
| 3 | 10.4.160.32/28 | 10.4.160.33 – 10.4.160.46 | 10.4.160.47 |
| 4 | 10.4.160.48/28 | 10.4.160.49 – 10.4.160.62 | 10.4.160.63 |
| 5 | 10.4.160.64/28 | 10.4.160.65 – 10.4.160.78 | 10.4.160.79 |
| 6 | 10.4.160.80/28 | 10.4.160.81 – 10.4.160.94 | 10.4.160.95 |
| 7 | 10.4.160.96/28 | 10.4.160.97 – 10.4.160.110 | 10.4.160.111 |
| 8 | 10.4.160.112/28 | 10.4.160.113 – 10.4.160.126 | 10.4.160.127 |
| 9 | 10.4.160.128/28 | 10.4.160.129 – 10.4.160.142 | 10.4.160.143 |
| 10 | 10.4.160.144/28 | 10.4.160.145 – 10.4.160.158 | 10.4.160.159 |
| 11 | 10.4.160.160/28 | 10.4.160.161 – 10.4.160.174 | 10.4.160.175 |
| 12 | 10.4.160.176/28 | 10.4.160.177 – 10.4.160.190 | 10.4.160.191 |
| 13 | 10.4.160.192/28 | 10.4.160.193 – 10.4.160.206 | 10.4.160.207 |
| 14 | 10.4.160.208/28 | 10.4.160.209 – 10.4.160.222 | 10.4.160.223 |
| 15 | 10.4.160.224/28 | 10.4.160.225 – 10.4.160.238 | 10.4.160.239 |
| 16 | 10.4.160.240/28 | 10.4.160.241 – 10.4.160.254 | 10.4.160.255 |
| 17 | 10.4.161.0/28 | 10.4.161.1 – 10.4.161.14 | 10.4.161.15 |
| 18 | 10.4.161.16/28 | 10.4.161.17 – 10.4.161.30 | 10.4.161.31 |
| 19 | 10.4.161.32/28 | 10.4.161.33 – 10.4.161.46 | 10.4.161.47 |
| 20 | 10.4.161.48/28 | 10.4.161.49 – 10.4.161.62 | 10.4.161.63 |
| 21 | 10.4.161.64/28 | 10.4.161.65 – 10.4.161.78 | 10.4.161.79 |
| 22 | 10.4.161.80/28 | 10.4.161.81 – 10.4.161.94 | 10.4.161.95 |
| 23 | 10.4.161.96/28 | 10.4.161.97 – 10.4.161.110 | 10.4.161.111 |
| 24 | 10.4.161.112/28 | 10.4.161.113 – 10.4.161.126 | 10.4.161.127 |
| 25 | 10.4.161.128/28 | 10.4.161.129 – 10.4.161.142 | 10.4.161.143 |
| 26 | 10.4.161.144/28 | 10.4.161.145 – 10.4.161.158 | 10.4.161.159 |
| 27 | 10.4.161.160/28 | 10.4.161.161 – 10.4.161.174 | 10.4.161.175 |
| 28 | 10.4.161.176/28 | 10.4.161.177 – 10.4.161.190 | 10.4.161.191 |
| 29 | 10.4.161.192/28 | 10.4.161.193 – 10.4.161.206 | 10.4.161.207 |
| 30 | 10.4.161.208/28 | 10.4.161.209 – 10.4.161.222 | 10.4.161.223 |
| 31 | 10.4.161.224/28 | 10.4.161.225 – 10.4.161.238 | 10.4.161.239 |
| 32 | 10.4.161.240/28 | 10.4.161.241 – 10.4.161.254 | 10.4.161.255 |
| 33 | 10.4.162.0/28 | 10.4.162.1 – 10.4.162.14 | 10.4.162.15 |
| 34 | 10.4.162.16/28 | 10.4.162.17 – 10.4.162.30 | 10.4.162.31 |
| 35 | 10.4.162.32/28 | 10.4.162.33 – 10.4.162.46 | 10.4.162.47 |
| 36 | 10.4.162.48/28 | 10.4.162.49 – 10.4.162.62 | 10.4.162.63 |
| 37 | 10.4.162.64/28 | 10.4.162.65 – 10.4.162.78 | 10.4.162.79 |
| 38 | 10.4.162.80/28 | 10.4.162.81 – 10.4.162.94 | 10.4.162.95 |
| 39 | 10.4.162.96/28 | 10.4.162.97 – 10.4.162.110 | 10.4.162.111 |
| 40 | 10.4.162.112/28 | 10.4.162.113 – 10.4.162.126 | 10.4.162.127 |
| 41 | 10.4.162.128/28 | 10.4.162.129 – 10.4.162.142 | 10.4.162.143 |
| 42 | 10.4.162.144/28 | 10.4.162.145 – 10.4.162.158 | 10.4.162.159 |
| 43 | 10.4.162.160/28 | 10.4.162.161 – 10.4.162.174 | 10.4.162.175 |
| 44 | 10.4.162.176/28 | 10.4.162.177 – 10.4.162.190 | 10.4.162.191 |
| 45 | 10.4.162.192/28 | 10.4.162.193 – 10.4.162.206 | 10.4.162.207 |
| 46 | 10.4.162.208/28 | 10.4.162.209 – 10.4.162.222 | 10.4.162.223 |
| 47 | 10.4.162.224/28 | 10.4.162.225 – 10.4.162.238 | 10.4.162.239 |
| 48 | 10.4.162.240/28 | 10.4.162.241 – 10.4.162.254 | 10.4.162.255 |
| 49 | 10.4.163.0/28 | 10.4.163.1 – 10.4.163.14 | 10.4.163.15 |
| 50 | 10.4.163.16/28 | 10.4.163.17 – 10.4.163.30 | 10.4.163.31 |
| 51 | 10.4.163.32/28 | 10.4.163.33 – 10.4.163.46 | 10.4.163.47 |
| 52 | 10.4.163.48/28 | 10.4.163.49 – 10.4.163.62 | 10.4.163.63 |
| 53 | 10.4.163.64/28 | 10.4.163.65 – 10.4.163.78 | 10.4.163.79 |
| 54 | 10.4.163.80/28 | 10.4.163.81 – 10.4.163.94 | 10.4.163.95 |
| 55 | 10.4.163.96/28 | 10.4.163.97 – 10.4.163.110 | 10.4.163.111 |
| 56 | 10.4.163.112/28 | 10.4.163.113 – 10.4.163.126 | 10.4.163.127 |
| 57 | 10.4.163.128/28 | 10.4.163.129 – 10.4.163.142 | 10.4.163.143 |
| 58 | 10.4.163.144/28 | 10.4.163.145 – 10.4.163.158 | 10.4.163.159 |
| 59 | 10.4.163.160/28 | 10.4.163.161 – 10.4.163.174 | 10.4.163.175 |
| 60 | 10.4.163.176/28 | 10.4.163.177 – 10.4.163.190 | 10.4.163.191 |
| 61 | 10.4.163.192/28 | 10.4.163.193 – 10.4.163.206 | 10.4.163.207 |
| 62 | 10.4.163.208/28 | 10.4.163.209 – 10.4.163.222 | 10.4.163.223 |
| 63 | 10.4.163.224/28 | 10.4.163.225 – 10.4.163.238 | 10.4.163.239 |
| 64 | 10.4.163.240/28 | 10.4.163.241 – 10.4.163.254 | 10.4.163.255 |
| 65 | 10.4.164.0/28 | 10.4.164.1 – 10.4.164.14 | 10.4.164.15 |
| 66 | 10.4.164.16/28 | 10.4.164.17 – 10.4.164.30 | 10.4.164.31 |
| 67 | 10.4.164.32/28 | 10.4.164.33 – 10.4.164.46 | 10.4.164.47 |
| 68 | 10.4.164.48/28 | 10.4.164.49 – 10.4.164.62 | 10.4.164.63 |
| 69 | 10.4.164.64/28 | 10.4.164.65 – 10.4.164.78 | 10.4.164.79 |
| 70 | 10.4.164.80/28 | 10.4.164.81 – 10.4.164.94 | 10.4.164.95 |
| 71 | 10.4.164.96/28 | 10.4.164.97 – 10.4.164.110 | 10.4.164.111 |
| 72 | 10.4.164.112/28 | 10.4.164.113 – 10.4.164.126 | 10.4.164.127 |
| 73 | 10.4.164.128/28 | 10.4.164.129 – 10.4.164.142 | 10.4.164.143 |
| 74 | 10.4.164.144/28 | 10.4.164.145 – 10.4.164.158 | 10.4.164.159 |
| 75 | 10.4.164.160/28 | 10.4.164.161 – 10.4.164.174 | 10.4.164.175 |
| 76 | 10.4.164.176/28 | 10.4.164.177 – 10.4.164.190 | 10.4.164.191 |
| 77 | 10.4.164.192/28 | 10.4.164.193 – 10.4.164.206 | 10.4.164.207 |
| 78 | 10.4.164.208/28 | 10.4.164.209 – 10.4.164.222 | 10.4.164.223 |
| 79 | 10.4.164.224/28 | 10.4.164.225 – 10.4.164.238 | 10.4.164.239 |
| 80 | 10.4.164.240/28 | 10.4.164.241 – 10.4.164.254 | 10.4.164.255 |
| 81 | 10.4.165.0/28 | 10.4.165.1 – 10.4.165.14 | 10.4.165.15 |
| 82 | 10.4.165.16/28 | 10.4.165.17 – 10.4.165.30 | 10.4.165.31 |
| 83 | 10.4.165.32/28 | 10.4.165.33 – 10.4.165.46 | 10.4.165.47 |
| 84 | 10.4.165.48/28 | 10.4.165.49 – 10.4.165.62 | 10.4.165.63 |
| 85 | 10.4.165.64/28 | 10.4.165.65 – 10.4.165.78 | 10.4.165.79 |
| 86 | 10.4.165.80/28 | 10.4.165.81 – 10.4.165.94 | 10.4.165.95 |
| 87 | 10.4.165.96/28 | 10.4.165.97 – 10.4.165.110 | 10.4.165.111 |
| 88 | 10.4.165.112/28 | 10.4.165.113 – 10.4.165.126 | 10.4.165.127 |
| 89 | 10.4.165.128/28 | 10.4.165.129 – 10.4.165.142 | 10.4.165.143 |
| 90 | 10.4.165.144/28 | 10.4.165.145 – 10.4.165.158 | 10.4.165.159 |
| 91 | 10.4.165.160/28 | 10.4.165.161 – 10.4.165.174 | 10.4.165.175 |
| 92 | 10.4.165.176/28 | 10.4.165.177 – 10.4.165.190 | 10.4.165.191 |
| 93 | 10.4.165.192/28 | 10.4.165.193 – 10.4.165.206 | 10.4.165.207 |
| 94 | 10.4.165.208/28 | 10.4.165.209 – 10.4.165.222 | 10.4.165.223 |
| 95 | 10.4.165.224/28 | 10.4.165.225 – 10.4.165.238 | 10.4.165.239 |
| 96 | 10.4.165.240/28 | 10.4.165.241 – 10.4.165.254 | 10.4.165.255 |
| 97 | 10.4.166.0/28 | 10.4.166.1 – 10.4.166.14 | 10.4.166.15 |
| 98 | 10.4.166.16/28 | 10.4.166.17 – 10.4.166.30 | 10.4.166.31 |
| 99 | 10.4.166.32/28 | 10.4.166.33 – 10.4.166.46 | 10.4.166.47 |
| 100 | 10.4.166.48/28 | 10.4.166.49 – 10.4.166.62 | 10.4.166.63 |
| 101 | 10.4.166.64/28 | 10.4.166.65 – 10.4.166.78 | 10.4.166.79 |
| 102 | 10.4.166.80/28 | 10.4.166.81 – 10.4.166.94 | 10.4.166.95 |
| 103 | 10.4.166.96/28 | 10.4.166.97 – 10.4.166.110 | 10.4.166.111 |
| 104 | 10.4.166.112/28 | 10.4.166.113 – 10.4.166.126 | 10.4.166.127 |
| 105 | 10.4.166.128/28 | 10.4.166.129 – 10.4.166.142 | 10.4.166.143 |
| 106 | 10.4.166.144/28 | 10.4.166.145 – 10.4.166.158 | 10.4.166.159 |
| 107 | 10.4.166.160/28 | 10.4.166.161 – 10.4.166.174 | 10.4.166.175 |
| 108 | 10.4.166.176/28 | 10.4.166.177 – 10.4.166.190 | 10.4.166.191 |
| 109 | 10.4.166.192/28 | 10.4.166.193 – 10.4.166.206 | 10.4.166.207 |
| 110 | 10.4.166.208/28 | 10.4.166.209 – 10.4.166.222 | 10.4.166.223 |
| 111 | 10.4.166.224/28 | 10.4.166.225 – 10.4.166.238 | 10.4.166.239 |
| 112 | 10.4.166.240/28 | 10.4.166.241 – 10.4.166.254 | 10.4.166.255 |
| 113 | 10.4.167.0/28 | 10.4.167.1 – 10.4.167.14 | 10.4.167.15 |
| 114 | 10.4.167.16/28 | 10.4.167.17 – 10.4.167.30 | 10.4.167.31 |
| 115 | 10.4.167.32/28 | 10.4.167.33 – 10.4.167.46 | 10.4.167.47 |
| 116 | 10.4.167.48/28 | 10.4.167.49 – 10.4.167.62 | 10.4.167.63 |
| 117 | 10.4.167.64/28 | 10.4.167.65 – 10.4.167.78 | 10.4.167.79 |
| 118 | 10.4.167.80/28 | 10.4.167.81 – 10.4.167.94 | 10.4.167.95 |
| 119 | 10.4.167.96/28 | 10.4.167.97 – 10.4.167.110 | 10.4.167.111 |
| 120 | 10.4.167.112/28 | 10.4.167.113 – 10.4.167.126 | 10.4.167.127 |
| 121 | 10.4.167.128/28 | 10.4.167.129 – 10.4.167.142 | 10.4.167.143 |
| 122 | 10.4.167.144/28 | 10.4.167.145 – 10.4.167.158 | 10.4.167.159 |
| 123 | 10.4.167.160/28 | 10.4.167.161 – 10.4.167.174 | 10.4.167.175 |
| 124 | 10.4.167.176/28 | 10.4.167.177 – 10.4.167.190 | 10.4.167.191 |
| 125 | 10.4.167.192/28 | 10.4.167.193 – 10.4.167.206 | 10.4.167.207 |
| 126 | 10.4.167.208/28 | 10.4.167.209 – 10.4.167.222 | 10.4.167.223 |
| 127 | 10.4.167.224/28 | 10.4.167.225 – 10.4.167.238 | 10.4.167.239 |
| 128 | 10.4.167.240/28 | 10.4.167.241 – 10.4.167.254 | 10.4.167.255 |
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 /21 |
|---|---|---|---|---|
| /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 | 1 |
| /22 | 255.255.252.0 | 1,024 | 1,022 | 2 split → |
| /23 | 255.255.254.0 | 512 | 510 | 4 split → |
| /24 | 255.255.255.0 | 256 | 254 | 8 split → |
| /25 | 255.255.255.128 | 128 | 126 | 16 split → |
| /26 | 255.255.255.192 | 64 | 62 | 32 split → |
| /27 | 255.255.255.224 | 32 | 30 | 64 split → |
| /28 | 255.255.255.240 | 16 | 14 | 128 split → |
| /29 | 255.255.255.248 | 8 | 6 | 256 split → |
| /30 | 255.255.255.252 | 4 | 2 | 512 split → |
| /31 | 255.255.255.254 | 2 | 2 | 1,024 split → |
| /32 | 255.255.255.255 | 1 | 1 | 2,048 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.