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.
/21 split into /28 · 128 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.6.232.0/28 | 10.6.232.1 – 10.6.232.14 | 10.6.232.15 |
| 2 | 10.6.232.16/28 | 10.6.232.17 – 10.6.232.30 | 10.6.232.31 |
| 3 | 10.6.232.32/28 | 10.6.232.33 – 10.6.232.46 | 10.6.232.47 |
| 4 | 10.6.232.48/28 | 10.6.232.49 – 10.6.232.62 | 10.6.232.63 |
| 5 | 10.6.232.64/28 | 10.6.232.65 – 10.6.232.78 | 10.6.232.79 |
| 6 | 10.6.232.80/28 | 10.6.232.81 – 10.6.232.94 | 10.6.232.95 |
| 7 | 10.6.232.96/28 | 10.6.232.97 – 10.6.232.110 | 10.6.232.111 |
| 8 | 10.6.232.112/28 | 10.6.232.113 – 10.6.232.126 | 10.6.232.127 |
| 9 | 10.6.232.128/28 | 10.6.232.129 – 10.6.232.142 | 10.6.232.143 |
| 10 | 10.6.232.144/28 | 10.6.232.145 – 10.6.232.158 | 10.6.232.159 |
| 11 | 10.6.232.160/28 | 10.6.232.161 – 10.6.232.174 | 10.6.232.175 |
| 12 | 10.6.232.176/28 | 10.6.232.177 – 10.6.232.190 | 10.6.232.191 |
| 13 | 10.6.232.192/28 | 10.6.232.193 – 10.6.232.206 | 10.6.232.207 |
| 14 | 10.6.232.208/28 | 10.6.232.209 – 10.6.232.222 | 10.6.232.223 |
| 15 | 10.6.232.224/28 | 10.6.232.225 – 10.6.232.238 | 10.6.232.239 |
| 16 | 10.6.232.240/28 | 10.6.232.241 – 10.6.232.254 | 10.6.232.255 |
| 17 | 10.6.233.0/28 | 10.6.233.1 – 10.6.233.14 | 10.6.233.15 |
| 18 | 10.6.233.16/28 | 10.6.233.17 – 10.6.233.30 | 10.6.233.31 |
| 19 | 10.6.233.32/28 | 10.6.233.33 – 10.6.233.46 | 10.6.233.47 |
| 20 | 10.6.233.48/28 | 10.6.233.49 – 10.6.233.62 | 10.6.233.63 |
| 21 | 10.6.233.64/28 | 10.6.233.65 – 10.6.233.78 | 10.6.233.79 |
| 22 | 10.6.233.80/28 | 10.6.233.81 – 10.6.233.94 | 10.6.233.95 |
| 23 | 10.6.233.96/28 | 10.6.233.97 – 10.6.233.110 | 10.6.233.111 |
| 24 | 10.6.233.112/28 | 10.6.233.113 – 10.6.233.126 | 10.6.233.127 |
| 25 | 10.6.233.128/28 | 10.6.233.129 – 10.6.233.142 | 10.6.233.143 |
| 26 | 10.6.233.144/28 | 10.6.233.145 – 10.6.233.158 | 10.6.233.159 |
| 27 | 10.6.233.160/28 | 10.6.233.161 – 10.6.233.174 | 10.6.233.175 |
| 28 | 10.6.233.176/28 | 10.6.233.177 – 10.6.233.190 | 10.6.233.191 |
| 29 | 10.6.233.192/28 | 10.6.233.193 – 10.6.233.206 | 10.6.233.207 |
| 30 | 10.6.233.208/28 | 10.6.233.209 – 10.6.233.222 | 10.6.233.223 |
| 31 | 10.6.233.224/28 | 10.6.233.225 – 10.6.233.238 | 10.6.233.239 |
| 32 | 10.6.233.240/28 | 10.6.233.241 – 10.6.233.254 | 10.6.233.255 |
| 33 | 10.6.234.0/28 | 10.6.234.1 – 10.6.234.14 | 10.6.234.15 |
| 34 | 10.6.234.16/28 | 10.6.234.17 – 10.6.234.30 | 10.6.234.31 |
| 35 | 10.6.234.32/28 | 10.6.234.33 – 10.6.234.46 | 10.6.234.47 |
| 36 | 10.6.234.48/28 | 10.6.234.49 – 10.6.234.62 | 10.6.234.63 |
| 37 | 10.6.234.64/28 | 10.6.234.65 – 10.6.234.78 | 10.6.234.79 |
| 38 | 10.6.234.80/28 | 10.6.234.81 – 10.6.234.94 | 10.6.234.95 |
| 39 | 10.6.234.96/28 | 10.6.234.97 – 10.6.234.110 | 10.6.234.111 |
| 40 | 10.6.234.112/28 | 10.6.234.113 – 10.6.234.126 | 10.6.234.127 |
| 41 | 10.6.234.128/28 | 10.6.234.129 – 10.6.234.142 | 10.6.234.143 |
| 42 | 10.6.234.144/28 | 10.6.234.145 – 10.6.234.158 | 10.6.234.159 |
| 43 | 10.6.234.160/28 | 10.6.234.161 – 10.6.234.174 | 10.6.234.175 |
| 44 | 10.6.234.176/28 | 10.6.234.177 – 10.6.234.190 | 10.6.234.191 |
| 45 | 10.6.234.192/28 | 10.6.234.193 – 10.6.234.206 | 10.6.234.207 |
| 46 | 10.6.234.208/28 | 10.6.234.209 – 10.6.234.222 | 10.6.234.223 |
| 47 | 10.6.234.224/28 | 10.6.234.225 – 10.6.234.238 | 10.6.234.239 |
| 48 | 10.6.234.240/28 | 10.6.234.241 – 10.6.234.254 | 10.6.234.255 |
| 49 | 10.6.235.0/28 | 10.6.235.1 – 10.6.235.14 | 10.6.235.15 |
| 50 | 10.6.235.16/28 | 10.6.235.17 – 10.6.235.30 | 10.6.235.31 |
| 51 | 10.6.235.32/28 | 10.6.235.33 – 10.6.235.46 | 10.6.235.47 |
| 52 | 10.6.235.48/28 | 10.6.235.49 – 10.6.235.62 | 10.6.235.63 |
| 53 | 10.6.235.64/28 | 10.6.235.65 – 10.6.235.78 | 10.6.235.79 |
| 54 | 10.6.235.80/28 | 10.6.235.81 – 10.6.235.94 | 10.6.235.95 |
| 55 | 10.6.235.96/28 | 10.6.235.97 – 10.6.235.110 | 10.6.235.111 |
| 56 | 10.6.235.112/28 | 10.6.235.113 – 10.6.235.126 | 10.6.235.127 |
| 57 | 10.6.235.128/28 | 10.6.235.129 – 10.6.235.142 | 10.6.235.143 |
| 58 | 10.6.235.144/28 | 10.6.235.145 – 10.6.235.158 | 10.6.235.159 |
| 59 | 10.6.235.160/28 | 10.6.235.161 – 10.6.235.174 | 10.6.235.175 |
| 60 | 10.6.235.176/28 | 10.6.235.177 – 10.6.235.190 | 10.6.235.191 |
| 61 | 10.6.235.192/28 | 10.6.235.193 – 10.6.235.206 | 10.6.235.207 |
| 62 | 10.6.235.208/28 | 10.6.235.209 – 10.6.235.222 | 10.6.235.223 |
| 63 | 10.6.235.224/28 | 10.6.235.225 – 10.6.235.238 | 10.6.235.239 |
| 64 | 10.6.235.240/28 | 10.6.235.241 – 10.6.235.254 | 10.6.235.255 |
| 65 | 10.6.236.0/28 | 10.6.236.1 – 10.6.236.14 | 10.6.236.15 |
| 66 | 10.6.236.16/28 | 10.6.236.17 – 10.6.236.30 | 10.6.236.31 |
| 67 | 10.6.236.32/28 | 10.6.236.33 – 10.6.236.46 | 10.6.236.47 |
| 68 | 10.6.236.48/28 | 10.6.236.49 – 10.6.236.62 | 10.6.236.63 |
| 69 | 10.6.236.64/28 | 10.6.236.65 – 10.6.236.78 | 10.6.236.79 |
| 70 | 10.6.236.80/28 | 10.6.236.81 – 10.6.236.94 | 10.6.236.95 |
| 71 | 10.6.236.96/28 | 10.6.236.97 – 10.6.236.110 | 10.6.236.111 |
| 72 | 10.6.236.112/28 | 10.6.236.113 – 10.6.236.126 | 10.6.236.127 |
| 73 | 10.6.236.128/28 | 10.6.236.129 – 10.6.236.142 | 10.6.236.143 |
| 74 | 10.6.236.144/28 | 10.6.236.145 – 10.6.236.158 | 10.6.236.159 |
| 75 | 10.6.236.160/28 | 10.6.236.161 – 10.6.236.174 | 10.6.236.175 |
| 76 | 10.6.236.176/28 | 10.6.236.177 – 10.6.236.190 | 10.6.236.191 |
| 77 | 10.6.236.192/28 | 10.6.236.193 – 10.6.236.206 | 10.6.236.207 |
| 78 | 10.6.236.208/28 | 10.6.236.209 – 10.6.236.222 | 10.6.236.223 |
| 79 | 10.6.236.224/28 | 10.6.236.225 – 10.6.236.238 | 10.6.236.239 |
| 80 | 10.6.236.240/28 | 10.6.236.241 – 10.6.236.254 | 10.6.236.255 |
| 81 | 10.6.237.0/28 | 10.6.237.1 – 10.6.237.14 | 10.6.237.15 |
| 82 | 10.6.237.16/28 | 10.6.237.17 – 10.6.237.30 | 10.6.237.31 |
| 83 | 10.6.237.32/28 | 10.6.237.33 – 10.6.237.46 | 10.6.237.47 |
| 84 | 10.6.237.48/28 | 10.6.237.49 – 10.6.237.62 | 10.6.237.63 |
| 85 | 10.6.237.64/28 | 10.6.237.65 – 10.6.237.78 | 10.6.237.79 |
| 86 | 10.6.237.80/28 | 10.6.237.81 – 10.6.237.94 | 10.6.237.95 |
| 87 | 10.6.237.96/28 | 10.6.237.97 – 10.6.237.110 | 10.6.237.111 |
| 88 | 10.6.237.112/28 | 10.6.237.113 – 10.6.237.126 | 10.6.237.127 |
| 89 | 10.6.237.128/28 | 10.6.237.129 – 10.6.237.142 | 10.6.237.143 |
| 90 | 10.6.237.144/28 | 10.6.237.145 – 10.6.237.158 | 10.6.237.159 |
| 91 | 10.6.237.160/28 | 10.6.237.161 – 10.6.237.174 | 10.6.237.175 |
| 92 | 10.6.237.176/28 | 10.6.237.177 – 10.6.237.190 | 10.6.237.191 |
| 93 | 10.6.237.192/28 | 10.6.237.193 – 10.6.237.206 | 10.6.237.207 |
| 94 | 10.6.237.208/28 | 10.6.237.209 – 10.6.237.222 | 10.6.237.223 |
| 95 | 10.6.237.224/28 | 10.6.237.225 – 10.6.237.238 | 10.6.237.239 |
| 96 | 10.6.237.240/28 | 10.6.237.241 – 10.6.237.254 | 10.6.237.255 |
| 97 | 10.6.238.0/28 | 10.6.238.1 – 10.6.238.14 | 10.6.238.15 |
| 98 | 10.6.238.16/28 | 10.6.238.17 – 10.6.238.30 | 10.6.238.31 |
| 99 | 10.6.238.32/28 | 10.6.238.33 – 10.6.238.46 | 10.6.238.47 |
| 100 | 10.6.238.48/28 | 10.6.238.49 – 10.6.238.62 | 10.6.238.63 |
| 101 | 10.6.238.64/28 | 10.6.238.65 – 10.6.238.78 | 10.6.238.79 |
| 102 | 10.6.238.80/28 | 10.6.238.81 – 10.6.238.94 | 10.6.238.95 |
| 103 | 10.6.238.96/28 | 10.6.238.97 – 10.6.238.110 | 10.6.238.111 |
| 104 | 10.6.238.112/28 | 10.6.238.113 – 10.6.238.126 | 10.6.238.127 |
| 105 | 10.6.238.128/28 | 10.6.238.129 – 10.6.238.142 | 10.6.238.143 |
| 106 | 10.6.238.144/28 | 10.6.238.145 – 10.6.238.158 | 10.6.238.159 |
| 107 | 10.6.238.160/28 | 10.6.238.161 – 10.6.238.174 | 10.6.238.175 |
| 108 | 10.6.238.176/28 | 10.6.238.177 – 10.6.238.190 | 10.6.238.191 |
| 109 | 10.6.238.192/28 | 10.6.238.193 – 10.6.238.206 | 10.6.238.207 |
| 110 | 10.6.238.208/28 | 10.6.238.209 – 10.6.238.222 | 10.6.238.223 |
| 111 | 10.6.238.224/28 | 10.6.238.225 – 10.6.238.238 | 10.6.238.239 |
| 112 | 10.6.238.240/28 | 10.6.238.241 – 10.6.238.254 | 10.6.238.255 |
| 113 | 10.6.239.0/28 | 10.6.239.1 – 10.6.239.14 | 10.6.239.15 |
| 114 | 10.6.239.16/28 | 10.6.239.17 – 10.6.239.30 | 10.6.239.31 |
| 115 | 10.6.239.32/28 | 10.6.239.33 – 10.6.239.46 | 10.6.239.47 |
| 116 | 10.6.239.48/28 | 10.6.239.49 – 10.6.239.62 | 10.6.239.63 |
| 117 | 10.6.239.64/28 | 10.6.239.65 – 10.6.239.78 | 10.6.239.79 |
| 118 | 10.6.239.80/28 | 10.6.239.81 – 10.6.239.94 | 10.6.239.95 |
| 119 | 10.6.239.96/28 | 10.6.239.97 – 10.6.239.110 | 10.6.239.111 |
| 120 | 10.6.239.112/28 | 10.6.239.113 – 10.6.239.126 | 10.6.239.127 |
| 121 | 10.6.239.128/28 | 10.6.239.129 – 10.6.239.142 | 10.6.239.143 |
| 122 | 10.6.239.144/28 | 10.6.239.145 – 10.6.239.158 | 10.6.239.159 |
| 123 | 10.6.239.160/28 | 10.6.239.161 – 10.6.239.174 | 10.6.239.175 |
| 124 | 10.6.239.176/28 | 10.6.239.177 – 10.6.239.190 | 10.6.239.191 |
| 125 | 10.6.239.192/28 | 10.6.239.193 – 10.6.239.206 | 10.6.239.207 |
| 126 | 10.6.239.208/28 | 10.6.239.209 – 10.6.239.222 | 10.6.239.223 |
| 127 | 10.6.239.224/28 | 10.6.239.225 – 10.6.239.238 | 10.6.239.239 |
| 128 | 10.6.239.240/28 | 10.6.239.241 – 10.6.239.254 | 10.6.239.255 |
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 → |
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.