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)10.6.192.0/21
network10.6.192.0/21
broadcast10.6.199.255
first host10.6.192.1
last host10.6.199.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.6.192.0/21
address00001010.00000110.11000000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.00000110.11000000.00000000
broadcast00001010.00000110.11000111.11111111
green = network part, grey = host part
hex0x0a06c000
decimal168214528
reverse dns0.192.6.10.in-addr.arpa
ipv4-mapped::ffff:a06:c000
/21 split into /28 · 128 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.6.192.0/28 | 10.6.192.1 – 10.6.192.14 | 10.6.192.15 |
| 2 | 10.6.192.16/28 | 10.6.192.17 – 10.6.192.30 | 10.6.192.31 |
| 3 | 10.6.192.32/28 | 10.6.192.33 – 10.6.192.46 | 10.6.192.47 |
| 4 | 10.6.192.48/28 | 10.6.192.49 – 10.6.192.62 | 10.6.192.63 |
| 5 | 10.6.192.64/28 | 10.6.192.65 – 10.6.192.78 | 10.6.192.79 |
| 6 | 10.6.192.80/28 | 10.6.192.81 – 10.6.192.94 | 10.6.192.95 |
| 7 | 10.6.192.96/28 | 10.6.192.97 – 10.6.192.110 | 10.6.192.111 |
| 8 | 10.6.192.112/28 | 10.6.192.113 – 10.6.192.126 | 10.6.192.127 |
| 9 | 10.6.192.128/28 | 10.6.192.129 – 10.6.192.142 | 10.6.192.143 |
| 10 | 10.6.192.144/28 | 10.6.192.145 – 10.6.192.158 | 10.6.192.159 |
| 11 | 10.6.192.160/28 | 10.6.192.161 – 10.6.192.174 | 10.6.192.175 |
| 12 | 10.6.192.176/28 | 10.6.192.177 – 10.6.192.190 | 10.6.192.191 |
| 13 | 10.6.192.192/28 | 10.6.192.193 – 10.6.192.206 | 10.6.192.207 |
| 14 | 10.6.192.208/28 | 10.6.192.209 – 10.6.192.222 | 10.6.192.223 |
| 15 | 10.6.192.224/28 | 10.6.192.225 – 10.6.192.238 | 10.6.192.239 |
| 16 | 10.6.192.240/28 | 10.6.192.241 – 10.6.192.254 | 10.6.192.255 |
| 17 | 10.6.193.0/28 | 10.6.193.1 – 10.6.193.14 | 10.6.193.15 |
| 18 | 10.6.193.16/28 | 10.6.193.17 – 10.6.193.30 | 10.6.193.31 |
| 19 | 10.6.193.32/28 | 10.6.193.33 – 10.6.193.46 | 10.6.193.47 |
| 20 | 10.6.193.48/28 | 10.6.193.49 – 10.6.193.62 | 10.6.193.63 |
| 21 | 10.6.193.64/28 | 10.6.193.65 – 10.6.193.78 | 10.6.193.79 |
| 22 | 10.6.193.80/28 | 10.6.193.81 – 10.6.193.94 | 10.6.193.95 |
| 23 | 10.6.193.96/28 | 10.6.193.97 – 10.6.193.110 | 10.6.193.111 |
| 24 | 10.6.193.112/28 | 10.6.193.113 – 10.6.193.126 | 10.6.193.127 |
| 25 | 10.6.193.128/28 | 10.6.193.129 – 10.6.193.142 | 10.6.193.143 |
| 26 | 10.6.193.144/28 | 10.6.193.145 – 10.6.193.158 | 10.6.193.159 |
| 27 | 10.6.193.160/28 | 10.6.193.161 – 10.6.193.174 | 10.6.193.175 |
| 28 | 10.6.193.176/28 | 10.6.193.177 – 10.6.193.190 | 10.6.193.191 |
| 29 | 10.6.193.192/28 | 10.6.193.193 – 10.6.193.206 | 10.6.193.207 |
| 30 | 10.6.193.208/28 | 10.6.193.209 – 10.6.193.222 | 10.6.193.223 |
| 31 | 10.6.193.224/28 | 10.6.193.225 – 10.6.193.238 | 10.6.193.239 |
| 32 | 10.6.193.240/28 | 10.6.193.241 – 10.6.193.254 | 10.6.193.255 |
| 33 | 10.6.194.0/28 | 10.6.194.1 – 10.6.194.14 | 10.6.194.15 |
| 34 | 10.6.194.16/28 | 10.6.194.17 – 10.6.194.30 | 10.6.194.31 |
| 35 | 10.6.194.32/28 | 10.6.194.33 – 10.6.194.46 | 10.6.194.47 |
| 36 | 10.6.194.48/28 | 10.6.194.49 – 10.6.194.62 | 10.6.194.63 |
| 37 | 10.6.194.64/28 | 10.6.194.65 – 10.6.194.78 | 10.6.194.79 |
| 38 | 10.6.194.80/28 | 10.6.194.81 – 10.6.194.94 | 10.6.194.95 |
| 39 | 10.6.194.96/28 | 10.6.194.97 – 10.6.194.110 | 10.6.194.111 |
| 40 | 10.6.194.112/28 | 10.6.194.113 – 10.6.194.126 | 10.6.194.127 |
| 41 | 10.6.194.128/28 | 10.6.194.129 – 10.6.194.142 | 10.6.194.143 |
| 42 | 10.6.194.144/28 | 10.6.194.145 – 10.6.194.158 | 10.6.194.159 |
| 43 | 10.6.194.160/28 | 10.6.194.161 – 10.6.194.174 | 10.6.194.175 |
| 44 | 10.6.194.176/28 | 10.6.194.177 – 10.6.194.190 | 10.6.194.191 |
| 45 | 10.6.194.192/28 | 10.6.194.193 – 10.6.194.206 | 10.6.194.207 |
| 46 | 10.6.194.208/28 | 10.6.194.209 – 10.6.194.222 | 10.6.194.223 |
| 47 | 10.6.194.224/28 | 10.6.194.225 – 10.6.194.238 | 10.6.194.239 |
| 48 | 10.6.194.240/28 | 10.6.194.241 – 10.6.194.254 | 10.6.194.255 |
| 49 | 10.6.195.0/28 | 10.6.195.1 – 10.6.195.14 | 10.6.195.15 |
| 50 | 10.6.195.16/28 | 10.6.195.17 – 10.6.195.30 | 10.6.195.31 |
| 51 | 10.6.195.32/28 | 10.6.195.33 – 10.6.195.46 | 10.6.195.47 |
| 52 | 10.6.195.48/28 | 10.6.195.49 – 10.6.195.62 | 10.6.195.63 |
| 53 | 10.6.195.64/28 | 10.6.195.65 – 10.6.195.78 | 10.6.195.79 |
| 54 | 10.6.195.80/28 | 10.6.195.81 – 10.6.195.94 | 10.6.195.95 |
| 55 | 10.6.195.96/28 | 10.6.195.97 – 10.6.195.110 | 10.6.195.111 |
| 56 | 10.6.195.112/28 | 10.6.195.113 – 10.6.195.126 | 10.6.195.127 |
| 57 | 10.6.195.128/28 | 10.6.195.129 – 10.6.195.142 | 10.6.195.143 |
| 58 | 10.6.195.144/28 | 10.6.195.145 – 10.6.195.158 | 10.6.195.159 |
| 59 | 10.6.195.160/28 | 10.6.195.161 – 10.6.195.174 | 10.6.195.175 |
| 60 | 10.6.195.176/28 | 10.6.195.177 – 10.6.195.190 | 10.6.195.191 |
| 61 | 10.6.195.192/28 | 10.6.195.193 – 10.6.195.206 | 10.6.195.207 |
| 62 | 10.6.195.208/28 | 10.6.195.209 – 10.6.195.222 | 10.6.195.223 |
| 63 | 10.6.195.224/28 | 10.6.195.225 – 10.6.195.238 | 10.6.195.239 |
| 64 | 10.6.195.240/28 | 10.6.195.241 – 10.6.195.254 | 10.6.195.255 |
| 65 | 10.6.196.0/28 | 10.6.196.1 – 10.6.196.14 | 10.6.196.15 |
| 66 | 10.6.196.16/28 | 10.6.196.17 – 10.6.196.30 | 10.6.196.31 |
| 67 | 10.6.196.32/28 | 10.6.196.33 – 10.6.196.46 | 10.6.196.47 |
| 68 | 10.6.196.48/28 | 10.6.196.49 – 10.6.196.62 | 10.6.196.63 |
| 69 | 10.6.196.64/28 | 10.6.196.65 – 10.6.196.78 | 10.6.196.79 |
| 70 | 10.6.196.80/28 | 10.6.196.81 – 10.6.196.94 | 10.6.196.95 |
| 71 | 10.6.196.96/28 | 10.6.196.97 – 10.6.196.110 | 10.6.196.111 |
| 72 | 10.6.196.112/28 | 10.6.196.113 – 10.6.196.126 | 10.6.196.127 |
| 73 | 10.6.196.128/28 | 10.6.196.129 – 10.6.196.142 | 10.6.196.143 |
| 74 | 10.6.196.144/28 | 10.6.196.145 – 10.6.196.158 | 10.6.196.159 |
| 75 | 10.6.196.160/28 | 10.6.196.161 – 10.6.196.174 | 10.6.196.175 |
| 76 | 10.6.196.176/28 | 10.6.196.177 – 10.6.196.190 | 10.6.196.191 |
| 77 | 10.6.196.192/28 | 10.6.196.193 – 10.6.196.206 | 10.6.196.207 |
| 78 | 10.6.196.208/28 | 10.6.196.209 – 10.6.196.222 | 10.6.196.223 |
| 79 | 10.6.196.224/28 | 10.6.196.225 – 10.6.196.238 | 10.6.196.239 |
| 80 | 10.6.196.240/28 | 10.6.196.241 – 10.6.196.254 | 10.6.196.255 |
| 81 | 10.6.197.0/28 | 10.6.197.1 – 10.6.197.14 | 10.6.197.15 |
| 82 | 10.6.197.16/28 | 10.6.197.17 – 10.6.197.30 | 10.6.197.31 |
| 83 | 10.6.197.32/28 | 10.6.197.33 – 10.6.197.46 | 10.6.197.47 |
| 84 | 10.6.197.48/28 | 10.6.197.49 – 10.6.197.62 | 10.6.197.63 |
| 85 | 10.6.197.64/28 | 10.6.197.65 – 10.6.197.78 | 10.6.197.79 |
| 86 | 10.6.197.80/28 | 10.6.197.81 – 10.6.197.94 | 10.6.197.95 |
| 87 | 10.6.197.96/28 | 10.6.197.97 – 10.6.197.110 | 10.6.197.111 |
| 88 | 10.6.197.112/28 | 10.6.197.113 – 10.6.197.126 | 10.6.197.127 |
| 89 | 10.6.197.128/28 | 10.6.197.129 – 10.6.197.142 | 10.6.197.143 |
| 90 | 10.6.197.144/28 | 10.6.197.145 – 10.6.197.158 | 10.6.197.159 |
| 91 | 10.6.197.160/28 | 10.6.197.161 – 10.6.197.174 | 10.6.197.175 |
| 92 | 10.6.197.176/28 | 10.6.197.177 – 10.6.197.190 | 10.6.197.191 |
| 93 | 10.6.197.192/28 | 10.6.197.193 – 10.6.197.206 | 10.6.197.207 |
| 94 | 10.6.197.208/28 | 10.6.197.209 – 10.6.197.222 | 10.6.197.223 |
| 95 | 10.6.197.224/28 | 10.6.197.225 – 10.6.197.238 | 10.6.197.239 |
| 96 | 10.6.197.240/28 | 10.6.197.241 – 10.6.197.254 | 10.6.197.255 |
| 97 | 10.6.198.0/28 | 10.6.198.1 – 10.6.198.14 | 10.6.198.15 |
| 98 | 10.6.198.16/28 | 10.6.198.17 – 10.6.198.30 | 10.6.198.31 |
| 99 | 10.6.198.32/28 | 10.6.198.33 – 10.6.198.46 | 10.6.198.47 |
| 100 | 10.6.198.48/28 | 10.6.198.49 – 10.6.198.62 | 10.6.198.63 |
| 101 | 10.6.198.64/28 | 10.6.198.65 – 10.6.198.78 | 10.6.198.79 |
| 102 | 10.6.198.80/28 | 10.6.198.81 – 10.6.198.94 | 10.6.198.95 |
| 103 | 10.6.198.96/28 | 10.6.198.97 – 10.6.198.110 | 10.6.198.111 |
| 104 | 10.6.198.112/28 | 10.6.198.113 – 10.6.198.126 | 10.6.198.127 |
| 105 | 10.6.198.128/28 | 10.6.198.129 – 10.6.198.142 | 10.6.198.143 |
| 106 | 10.6.198.144/28 | 10.6.198.145 – 10.6.198.158 | 10.6.198.159 |
| 107 | 10.6.198.160/28 | 10.6.198.161 – 10.6.198.174 | 10.6.198.175 |
| 108 | 10.6.198.176/28 | 10.6.198.177 – 10.6.198.190 | 10.6.198.191 |
| 109 | 10.6.198.192/28 | 10.6.198.193 – 10.6.198.206 | 10.6.198.207 |
| 110 | 10.6.198.208/28 | 10.6.198.209 – 10.6.198.222 | 10.6.198.223 |
| 111 | 10.6.198.224/28 | 10.6.198.225 – 10.6.198.238 | 10.6.198.239 |
| 112 | 10.6.198.240/28 | 10.6.198.241 – 10.6.198.254 | 10.6.198.255 |
| 113 | 10.6.199.0/28 | 10.6.199.1 – 10.6.199.14 | 10.6.199.15 |
| 114 | 10.6.199.16/28 | 10.6.199.17 – 10.6.199.30 | 10.6.199.31 |
| 115 | 10.6.199.32/28 | 10.6.199.33 – 10.6.199.46 | 10.6.199.47 |
| 116 | 10.6.199.48/28 | 10.6.199.49 – 10.6.199.62 | 10.6.199.63 |
| 117 | 10.6.199.64/28 | 10.6.199.65 – 10.6.199.78 | 10.6.199.79 |
| 118 | 10.6.199.80/28 | 10.6.199.81 – 10.6.199.94 | 10.6.199.95 |
| 119 | 10.6.199.96/28 | 10.6.199.97 – 10.6.199.110 | 10.6.199.111 |
| 120 | 10.6.199.112/28 | 10.6.199.113 – 10.6.199.126 | 10.6.199.127 |
| 121 | 10.6.199.128/28 | 10.6.199.129 – 10.6.199.142 | 10.6.199.143 |
| 122 | 10.6.199.144/28 | 10.6.199.145 – 10.6.199.158 | 10.6.199.159 |
| 123 | 10.6.199.160/28 | 10.6.199.161 – 10.6.199.174 | 10.6.199.175 |
| 124 | 10.6.199.176/28 | 10.6.199.177 – 10.6.199.190 | 10.6.199.191 |
| 125 | 10.6.199.192/28 | 10.6.199.193 – 10.6.199.206 | 10.6.199.207 |
| 126 | 10.6.199.208/28 | 10.6.199.209 – 10.6.199.222 | 10.6.199.223 |
| 127 | 10.6.199.224/28 | 10.6.199.225 – 10.6.199.238 | 10.6.199.239 |
| 128 | 10.6.199.240/28 | 10.6.199.241 – 10.6.199.254 | 10.6.199.255 |
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.