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 | 10.167.112.0/28 | 10.167.112.1 – 10.167.112.14 | 10.167.112.15 |
| 2 | 10.167.112.16/28 | 10.167.112.17 – 10.167.112.30 | 10.167.112.31 |
| 3 | 10.167.112.32/28 | 10.167.112.33 – 10.167.112.46 | 10.167.112.47 |
| 4 | 10.167.112.48/28 | 10.167.112.49 – 10.167.112.62 | 10.167.112.63 |
| 5 | 10.167.112.64/28 | 10.167.112.65 – 10.167.112.78 | 10.167.112.79 |
| 6 | 10.167.112.80/28 | 10.167.112.81 – 10.167.112.94 | 10.167.112.95 |
| 7 | 10.167.112.96/28 | 10.167.112.97 – 10.167.112.110 | 10.167.112.111 |
| 8 | 10.167.112.112/28 | 10.167.112.113 – 10.167.112.126 | 10.167.112.127 |
| 9 | 10.167.112.128/28 | 10.167.112.129 – 10.167.112.142 | 10.167.112.143 |
| 10 | 10.167.112.144/28 | 10.167.112.145 – 10.167.112.158 | 10.167.112.159 |
| 11 | 10.167.112.160/28 | 10.167.112.161 – 10.167.112.174 | 10.167.112.175 |
| 12 | 10.167.112.176/28 | 10.167.112.177 – 10.167.112.190 | 10.167.112.191 |
| 13 | 10.167.112.192/28 | 10.167.112.193 – 10.167.112.206 | 10.167.112.207 |
| 14 | 10.167.112.208/28 | 10.167.112.209 – 10.167.112.222 | 10.167.112.223 |
| 15 | 10.167.112.224/28 | 10.167.112.225 – 10.167.112.238 | 10.167.112.239 |
| 16 | 10.167.112.240/28 | 10.167.112.241 – 10.167.112.254 | 10.167.112.255 |
| 17 | 10.167.113.0/28 | 10.167.113.1 – 10.167.113.14 | 10.167.113.15 |
| 18 | 10.167.113.16/28 | 10.167.113.17 – 10.167.113.30 | 10.167.113.31 |
| 19 | 10.167.113.32/28 | 10.167.113.33 – 10.167.113.46 | 10.167.113.47 |
| 20 | 10.167.113.48/28 | 10.167.113.49 – 10.167.113.62 | 10.167.113.63 |
| 21 | 10.167.113.64/28 | 10.167.113.65 – 10.167.113.78 | 10.167.113.79 |
| 22 | 10.167.113.80/28 | 10.167.113.81 – 10.167.113.94 | 10.167.113.95 |
| 23 | 10.167.113.96/28 | 10.167.113.97 – 10.167.113.110 | 10.167.113.111 |
| 24 | 10.167.113.112/28 | 10.167.113.113 – 10.167.113.126 | 10.167.113.127 |
| 25 | 10.167.113.128/28 | 10.167.113.129 – 10.167.113.142 | 10.167.113.143 |
| 26 | 10.167.113.144/28 | 10.167.113.145 – 10.167.113.158 | 10.167.113.159 |
| 27 | 10.167.113.160/28 | 10.167.113.161 – 10.167.113.174 | 10.167.113.175 |
| 28 | 10.167.113.176/28 | 10.167.113.177 – 10.167.113.190 | 10.167.113.191 |
| 29 | 10.167.113.192/28 | 10.167.113.193 – 10.167.113.206 | 10.167.113.207 |
| 30 | 10.167.113.208/28 | 10.167.113.209 – 10.167.113.222 | 10.167.113.223 |
| 31 | 10.167.113.224/28 | 10.167.113.225 – 10.167.113.238 | 10.167.113.239 |
| 32 | 10.167.113.240/28 | 10.167.113.241 – 10.167.113.254 | 10.167.113.255 |
| 33 | 10.167.114.0/28 | 10.167.114.1 – 10.167.114.14 | 10.167.114.15 |
| 34 | 10.167.114.16/28 | 10.167.114.17 – 10.167.114.30 | 10.167.114.31 |
| 35 | 10.167.114.32/28 | 10.167.114.33 – 10.167.114.46 | 10.167.114.47 |
| 36 | 10.167.114.48/28 | 10.167.114.49 – 10.167.114.62 | 10.167.114.63 |
| 37 | 10.167.114.64/28 | 10.167.114.65 – 10.167.114.78 | 10.167.114.79 |
| 38 | 10.167.114.80/28 | 10.167.114.81 – 10.167.114.94 | 10.167.114.95 |
| 39 | 10.167.114.96/28 | 10.167.114.97 – 10.167.114.110 | 10.167.114.111 |
| 40 | 10.167.114.112/28 | 10.167.114.113 – 10.167.114.126 | 10.167.114.127 |
| 41 | 10.167.114.128/28 | 10.167.114.129 – 10.167.114.142 | 10.167.114.143 |
| 42 | 10.167.114.144/28 | 10.167.114.145 – 10.167.114.158 | 10.167.114.159 |
| 43 | 10.167.114.160/28 | 10.167.114.161 – 10.167.114.174 | 10.167.114.175 |
| 44 | 10.167.114.176/28 | 10.167.114.177 – 10.167.114.190 | 10.167.114.191 |
| 45 | 10.167.114.192/28 | 10.167.114.193 – 10.167.114.206 | 10.167.114.207 |
| 46 | 10.167.114.208/28 | 10.167.114.209 – 10.167.114.222 | 10.167.114.223 |
| 47 | 10.167.114.224/28 | 10.167.114.225 – 10.167.114.238 | 10.167.114.239 |
| 48 | 10.167.114.240/28 | 10.167.114.241 – 10.167.114.254 | 10.167.114.255 |
| 49 | 10.167.115.0/28 | 10.167.115.1 – 10.167.115.14 | 10.167.115.15 |
| 50 | 10.167.115.16/28 | 10.167.115.17 – 10.167.115.30 | 10.167.115.31 |
| 51 | 10.167.115.32/28 | 10.167.115.33 – 10.167.115.46 | 10.167.115.47 |
| 52 | 10.167.115.48/28 | 10.167.115.49 – 10.167.115.62 | 10.167.115.63 |
| 53 | 10.167.115.64/28 | 10.167.115.65 – 10.167.115.78 | 10.167.115.79 |
| 54 | 10.167.115.80/28 | 10.167.115.81 – 10.167.115.94 | 10.167.115.95 |
| 55 | 10.167.115.96/28 | 10.167.115.97 – 10.167.115.110 | 10.167.115.111 |
| 56 | 10.167.115.112/28 | 10.167.115.113 – 10.167.115.126 | 10.167.115.127 |
| 57 | 10.167.115.128/28 | 10.167.115.129 – 10.167.115.142 | 10.167.115.143 |
| 58 | 10.167.115.144/28 | 10.167.115.145 – 10.167.115.158 | 10.167.115.159 |
| 59 | 10.167.115.160/28 | 10.167.115.161 – 10.167.115.174 | 10.167.115.175 |
| 60 | 10.167.115.176/28 | 10.167.115.177 – 10.167.115.190 | 10.167.115.191 |
| 61 | 10.167.115.192/28 | 10.167.115.193 – 10.167.115.206 | 10.167.115.207 |
| 62 | 10.167.115.208/28 | 10.167.115.209 – 10.167.115.222 | 10.167.115.223 |
| 63 | 10.167.115.224/28 | 10.167.115.225 – 10.167.115.238 | 10.167.115.239 |
| 64 | 10.167.115.240/28 | 10.167.115.241 – 10.167.115.254 | 10.167.115.255 |
| 65 | 10.167.116.0/28 | 10.167.116.1 – 10.167.116.14 | 10.167.116.15 |
| 66 | 10.167.116.16/28 | 10.167.116.17 – 10.167.116.30 | 10.167.116.31 |
| 67 | 10.167.116.32/28 | 10.167.116.33 – 10.167.116.46 | 10.167.116.47 |
| 68 | 10.167.116.48/28 | 10.167.116.49 – 10.167.116.62 | 10.167.116.63 |
| 69 | 10.167.116.64/28 | 10.167.116.65 – 10.167.116.78 | 10.167.116.79 |
| 70 | 10.167.116.80/28 | 10.167.116.81 – 10.167.116.94 | 10.167.116.95 |
| 71 | 10.167.116.96/28 | 10.167.116.97 – 10.167.116.110 | 10.167.116.111 |
| 72 | 10.167.116.112/28 | 10.167.116.113 – 10.167.116.126 | 10.167.116.127 |
| 73 | 10.167.116.128/28 | 10.167.116.129 – 10.167.116.142 | 10.167.116.143 |
| 74 | 10.167.116.144/28 | 10.167.116.145 – 10.167.116.158 | 10.167.116.159 |
| 75 | 10.167.116.160/28 | 10.167.116.161 – 10.167.116.174 | 10.167.116.175 |
| 76 | 10.167.116.176/28 | 10.167.116.177 – 10.167.116.190 | 10.167.116.191 |
| 77 | 10.167.116.192/28 | 10.167.116.193 – 10.167.116.206 | 10.167.116.207 |
| 78 | 10.167.116.208/28 | 10.167.116.209 – 10.167.116.222 | 10.167.116.223 |
| 79 | 10.167.116.224/28 | 10.167.116.225 – 10.167.116.238 | 10.167.116.239 |
| 80 | 10.167.116.240/28 | 10.167.116.241 – 10.167.116.254 | 10.167.116.255 |
| 81 | 10.167.117.0/28 | 10.167.117.1 – 10.167.117.14 | 10.167.117.15 |
| 82 | 10.167.117.16/28 | 10.167.117.17 – 10.167.117.30 | 10.167.117.31 |
| 83 | 10.167.117.32/28 | 10.167.117.33 – 10.167.117.46 | 10.167.117.47 |
| 84 | 10.167.117.48/28 | 10.167.117.49 – 10.167.117.62 | 10.167.117.63 |
| 85 | 10.167.117.64/28 | 10.167.117.65 – 10.167.117.78 | 10.167.117.79 |
| 86 | 10.167.117.80/28 | 10.167.117.81 – 10.167.117.94 | 10.167.117.95 |
| 87 | 10.167.117.96/28 | 10.167.117.97 – 10.167.117.110 | 10.167.117.111 |
| 88 | 10.167.117.112/28 | 10.167.117.113 – 10.167.117.126 | 10.167.117.127 |
| 89 | 10.167.117.128/28 | 10.167.117.129 – 10.167.117.142 | 10.167.117.143 |
| 90 | 10.167.117.144/28 | 10.167.117.145 – 10.167.117.158 | 10.167.117.159 |
| 91 | 10.167.117.160/28 | 10.167.117.161 – 10.167.117.174 | 10.167.117.175 |
| 92 | 10.167.117.176/28 | 10.167.117.177 – 10.167.117.190 | 10.167.117.191 |
| 93 | 10.167.117.192/28 | 10.167.117.193 – 10.167.117.206 | 10.167.117.207 |
| 94 | 10.167.117.208/28 | 10.167.117.209 – 10.167.117.222 | 10.167.117.223 |
| 95 | 10.167.117.224/28 | 10.167.117.225 – 10.167.117.238 | 10.167.117.239 |
| 96 | 10.167.117.240/28 | 10.167.117.241 – 10.167.117.254 | 10.167.117.255 |
| 97 | 10.167.118.0/28 | 10.167.118.1 – 10.167.118.14 | 10.167.118.15 |
| 98 | 10.167.118.16/28 | 10.167.118.17 – 10.167.118.30 | 10.167.118.31 |
| 99 | 10.167.118.32/28 | 10.167.118.33 – 10.167.118.46 | 10.167.118.47 |
| 100 | 10.167.118.48/28 | 10.167.118.49 – 10.167.118.62 | 10.167.118.63 |
| 101 | 10.167.118.64/28 | 10.167.118.65 – 10.167.118.78 | 10.167.118.79 |
| 102 | 10.167.118.80/28 | 10.167.118.81 – 10.167.118.94 | 10.167.118.95 |
| 103 | 10.167.118.96/28 | 10.167.118.97 – 10.167.118.110 | 10.167.118.111 |
| 104 | 10.167.118.112/28 | 10.167.118.113 – 10.167.118.126 | 10.167.118.127 |
| 105 | 10.167.118.128/28 | 10.167.118.129 – 10.167.118.142 | 10.167.118.143 |
| 106 | 10.167.118.144/28 | 10.167.118.145 – 10.167.118.158 | 10.167.118.159 |
| 107 | 10.167.118.160/28 | 10.167.118.161 – 10.167.118.174 | 10.167.118.175 |
| 108 | 10.167.118.176/28 | 10.167.118.177 – 10.167.118.190 | 10.167.118.191 |
| 109 | 10.167.118.192/28 | 10.167.118.193 – 10.167.118.206 | 10.167.118.207 |
| 110 | 10.167.118.208/28 | 10.167.118.209 – 10.167.118.222 | 10.167.118.223 |
| 111 | 10.167.118.224/28 | 10.167.118.225 – 10.167.118.238 | 10.167.118.239 |
| 112 | 10.167.118.240/28 | 10.167.118.241 – 10.167.118.254 | 10.167.118.255 |
| 113 | 10.167.119.0/28 | 10.167.119.1 – 10.167.119.14 | 10.167.119.15 |
| 114 | 10.167.119.16/28 | 10.167.119.17 – 10.167.119.30 | 10.167.119.31 |
| 115 | 10.167.119.32/28 | 10.167.119.33 – 10.167.119.46 | 10.167.119.47 |
| 116 | 10.167.119.48/28 | 10.167.119.49 – 10.167.119.62 | 10.167.119.63 |
| 117 | 10.167.119.64/28 | 10.167.119.65 – 10.167.119.78 | 10.167.119.79 |
| 118 | 10.167.119.80/28 | 10.167.119.81 – 10.167.119.94 | 10.167.119.95 |
| 119 | 10.167.119.96/28 | 10.167.119.97 – 10.167.119.110 | 10.167.119.111 |
| 120 | 10.167.119.112/28 | 10.167.119.113 – 10.167.119.126 | 10.167.119.127 |
| 121 | 10.167.119.128/28 | 10.167.119.129 – 10.167.119.142 | 10.167.119.143 |
| 122 | 10.167.119.144/28 | 10.167.119.145 – 10.167.119.158 | 10.167.119.159 |
| 123 | 10.167.119.160/28 | 10.167.119.161 – 10.167.119.174 | 10.167.119.175 |
| 124 | 10.167.119.176/28 | 10.167.119.177 – 10.167.119.190 | 10.167.119.191 |
| 125 | 10.167.119.192/28 | 10.167.119.193 – 10.167.119.206 | 10.167.119.207 |
| 126 | 10.167.119.208/28 | 10.167.119.209 – 10.167.119.222 | 10.167.119.223 |
| 127 | 10.167.119.224/28 | 10.167.119.225 – 10.167.119.238 | 10.167.119.239 |
| 128 | 10.167.119.240/28 | 10.167.119.241 – 10.167.119.254 | 10.167.119.255 |
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.