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)10.167.176.0/21
network10.167.176.0/21
broadcast10.167.183.255
first host10.167.176.1
last host10.167.183.254
subnet mask255.255.248.0
wildcard0.0.7.255
addresses2,048
usable hosts2,046
classA
ipcalc 10.167.176.0/21
address00001010.10100111.10110000.00000000
subnet mask11111111.11111111.11111000.00000000
network00001010.10100111.10110000.00000000
broadcast00001010.10100111.10110111.11111111
green = network part, grey = host part
hex0x0aa7b000
decimal178761728
reverse dns0.176.167.10.in-addr.arpa
ipv4-mapped::ffff:aa7:b000
/21 split into /28 · 128 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.167.176.0/28 | 10.167.176.1 – 10.167.176.14 | 10.167.176.15 |
| 2 | 10.167.176.16/28 | 10.167.176.17 – 10.167.176.30 | 10.167.176.31 |
| 3 | 10.167.176.32/28 | 10.167.176.33 – 10.167.176.46 | 10.167.176.47 |
| 4 | 10.167.176.48/28 | 10.167.176.49 – 10.167.176.62 | 10.167.176.63 |
| 5 | 10.167.176.64/28 | 10.167.176.65 – 10.167.176.78 | 10.167.176.79 |
| 6 | 10.167.176.80/28 | 10.167.176.81 – 10.167.176.94 | 10.167.176.95 |
| 7 | 10.167.176.96/28 | 10.167.176.97 – 10.167.176.110 | 10.167.176.111 |
| 8 | 10.167.176.112/28 | 10.167.176.113 – 10.167.176.126 | 10.167.176.127 |
| 9 | 10.167.176.128/28 | 10.167.176.129 – 10.167.176.142 | 10.167.176.143 |
| 10 | 10.167.176.144/28 | 10.167.176.145 – 10.167.176.158 | 10.167.176.159 |
| 11 | 10.167.176.160/28 | 10.167.176.161 – 10.167.176.174 | 10.167.176.175 |
| 12 | 10.167.176.176/28 | 10.167.176.177 – 10.167.176.190 | 10.167.176.191 |
| 13 | 10.167.176.192/28 | 10.167.176.193 – 10.167.176.206 | 10.167.176.207 |
| 14 | 10.167.176.208/28 | 10.167.176.209 – 10.167.176.222 | 10.167.176.223 |
| 15 | 10.167.176.224/28 | 10.167.176.225 – 10.167.176.238 | 10.167.176.239 |
| 16 | 10.167.176.240/28 | 10.167.176.241 – 10.167.176.254 | 10.167.176.255 |
| 17 | 10.167.177.0/28 | 10.167.177.1 – 10.167.177.14 | 10.167.177.15 |
| 18 | 10.167.177.16/28 | 10.167.177.17 – 10.167.177.30 | 10.167.177.31 |
| 19 | 10.167.177.32/28 | 10.167.177.33 – 10.167.177.46 | 10.167.177.47 |
| 20 | 10.167.177.48/28 | 10.167.177.49 – 10.167.177.62 | 10.167.177.63 |
| 21 | 10.167.177.64/28 | 10.167.177.65 – 10.167.177.78 | 10.167.177.79 |
| 22 | 10.167.177.80/28 | 10.167.177.81 – 10.167.177.94 | 10.167.177.95 |
| 23 | 10.167.177.96/28 | 10.167.177.97 – 10.167.177.110 | 10.167.177.111 |
| 24 | 10.167.177.112/28 | 10.167.177.113 – 10.167.177.126 | 10.167.177.127 |
| 25 | 10.167.177.128/28 | 10.167.177.129 – 10.167.177.142 | 10.167.177.143 |
| 26 | 10.167.177.144/28 | 10.167.177.145 – 10.167.177.158 | 10.167.177.159 |
| 27 | 10.167.177.160/28 | 10.167.177.161 – 10.167.177.174 | 10.167.177.175 |
| 28 | 10.167.177.176/28 | 10.167.177.177 – 10.167.177.190 | 10.167.177.191 |
| 29 | 10.167.177.192/28 | 10.167.177.193 – 10.167.177.206 | 10.167.177.207 |
| 30 | 10.167.177.208/28 | 10.167.177.209 – 10.167.177.222 | 10.167.177.223 |
| 31 | 10.167.177.224/28 | 10.167.177.225 – 10.167.177.238 | 10.167.177.239 |
| 32 | 10.167.177.240/28 | 10.167.177.241 – 10.167.177.254 | 10.167.177.255 |
| 33 | 10.167.178.0/28 | 10.167.178.1 – 10.167.178.14 | 10.167.178.15 |
| 34 | 10.167.178.16/28 | 10.167.178.17 – 10.167.178.30 | 10.167.178.31 |
| 35 | 10.167.178.32/28 | 10.167.178.33 – 10.167.178.46 | 10.167.178.47 |
| 36 | 10.167.178.48/28 | 10.167.178.49 – 10.167.178.62 | 10.167.178.63 |
| 37 | 10.167.178.64/28 | 10.167.178.65 – 10.167.178.78 | 10.167.178.79 |
| 38 | 10.167.178.80/28 | 10.167.178.81 – 10.167.178.94 | 10.167.178.95 |
| 39 | 10.167.178.96/28 | 10.167.178.97 – 10.167.178.110 | 10.167.178.111 |
| 40 | 10.167.178.112/28 | 10.167.178.113 – 10.167.178.126 | 10.167.178.127 |
| 41 | 10.167.178.128/28 | 10.167.178.129 – 10.167.178.142 | 10.167.178.143 |
| 42 | 10.167.178.144/28 | 10.167.178.145 – 10.167.178.158 | 10.167.178.159 |
| 43 | 10.167.178.160/28 | 10.167.178.161 – 10.167.178.174 | 10.167.178.175 |
| 44 | 10.167.178.176/28 | 10.167.178.177 – 10.167.178.190 | 10.167.178.191 |
| 45 | 10.167.178.192/28 | 10.167.178.193 – 10.167.178.206 | 10.167.178.207 |
| 46 | 10.167.178.208/28 | 10.167.178.209 – 10.167.178.222 | 10.167.178.223 |
| 47 | 10.167.178.224/28 | 10.167.178.225 – 10.167.178.238 | 10.167.178.239 |
| 48 | 10.167.178.240/28 | 10.167.178.241 – 10.167.178.254 | 10.167.178.255 |
| 49 | 10.167.179.0/28 | 10.167.179.1 – 10.167.179.14 | 10.167.179.15 |
| 50 | 10.167.179.16/28 | 10.167.179.17 – 10.167.179.30 | 10.167.179.31 |
| 51 | 10.167.179.32/28 | 10.167.179.33 – 10.167.179.46 | 10.167.179.47 |
| 52 | 10.167.179.48/28 | 10.167.179.49 – 10.167.179.62 | 10.167.179.63 |
| 53 | 10.167.179.64/28 | 10.167.179.65 – 10.167.179.78 | 10.167.179.79 |
| 54 | 10.167.179.80/28 | 10.167.179.81 – 10.167.179.94 | 10.167.179.95 |
| 55 | 10.167.179.96/28 | 10.167.179.97 – 10.167.179.110 | 10.167.179.111 |
| 56 | 10.167.179.112/28 | 10.167.179.113 – 10.167.179.126 | 10.167.179.127 |
| 57 | 10.167.179.128/28 | 10.167.179.129 – 10.167.179.142 | 10.167.179.143 |
| 58 | 10.167.179.144/28 | 10.167.179.145 – 10.167.179.158 | 10.167.179.159 |
| 59 | 10.167.179.160/28 | 10.167.179.161 – 10.167.179.174 | 10.167.179.175 |
| 60 | 10.167.179.176/28 | 10.167.179.177 – 10.167.179.190 | 10.167.179.191 |
| 61 | 10.167.179.192/28 | 10.167.179.193 – 10.167.179.206 | 10.167.179.207 |
| 62 | 10.167.179.208/28 | 10.167.179.209 – 10.167.179.222 | 10.167.179.223 |
| 63 | 10.167.179.224/28 | 10.167.179.225 – 10.167.179.238 | 10.167.179.239 |
| 64 | 10.167.179.240/28 | 10.167.179.241 – 10.167.179.254 | 10.167.179.255 |
| 65 | 10.167.180.0/28 | 10.167.180.1 – 10.167.180.14 | 10.167.180.15 |
| 66 | 10.167.180.16/28 | 10.167.180.17 – 10.167.180.30 | 10.167.180.31 |
| 67 | 10.167.180.32/28 | 10.167.180.33 – 10.167.180.46 | 10.167.180.47 |
| 68 | 10.167.180.48/28 | 10.167.180.49 – 10.167.180.62 | 10.167.180.63 |
| 69 | 10.167.180.64/28 | 10.167.180.65 – 10.167.180.78 | 10.167.180.79 |
| 70 | 10.167.180.80/28 | 10.167.180.81 – 10.167.180.94 | 10.167.180.95 |
| 71 | 10.167.180.96/28 | 10.167.180.97 – 10.167.180.110 | 10.167.180.111 |
| 72 | 10.167.180.112/28 | 10.167.180.113 – 10.167.180.126 | 10.167.180.127 |
| 73 | 10.167.180.128/28 | 10.167.180.129 – 10.167.180.142 | 10.167.180.143 |
| 74 | 10.167.180.144/28 | 10.167.180.145 – 10.167.180.158 | 10.167.180.159 |
| 75 | 10.167.180.160/28 | 10.167.180.161 – 10.167.180.174 | 10.167.180.175 |
| 76 | 10.167.180.176/28 | 10.167.180.177 – 10.167.180.190 | 10.167.180.191 |
| 77 | 10.167.180.192/28 | 10.167.180.193 – 10.167.180.206 | 10.167.180.207 |
| 78 | 10.167.180.208/28 | 10.167.180.209 – 10.167.180.222 | 10.167.180.223 |
| 79 | 10.167.180.224/28 | 10.167.180.225 – 10.167.180.238 | 10.167.180.239 |
| 80 | 10.167.180.240/28 | 10.167.180.241 – 10.167.180.254 | 10.167.180.255 |
| 81 | 10.167.181.0/28 | 10.167.181.1 – 10.167.181.14 | 10.167.181.15 |
| 82 | 10.167.181.16/28 | 10.167.181.17 – 10.167.181.30 | 10.167.181.31 |
| 83 | 10.167.181.32/28 | 10.167.181.33 – 10.167.181.46 | 10.167.181.47 |
| 84 | 10.167.181.48/28 | 10.167.181.49 – 10.167.181.62 | 10.167.181.63 |
| 85 | 10.167.181.64/28 | 10.167.181.65 – 10.167.181.78 | 10.167.181.79 |
| 86 | 10.167.181.80/28 | 10.167.181.81 – 10.167.181.94 | 10.167.181.95 |
| 87 | 10.167.181.96/28 | 10.167.181.97 – 10.167.181.110 | 10.167.181.111 |
| 88 | 10.167.181.112/28 | 10.167.181.113 – 10.167.181.126 | 10.167.181.127 |
| 89 | 10.167.181.128/28 | 10.167.181.129 – 10.167.181.142 | 10.167.181.143 |
| 90 | 10.167.181.144/28 | 10.167.181.145 – 10.167.181.158 | 10.167.181.159 |
| 91 | 10.167.181.160/28 | 10.167.181.161 – 10.167.181.174 | 10.167.181.175 |
| 92 | 10.167.181.176/28 | 10.167.181.177 – 10.167.181.190 | 10.167.181.191 |
| 93 | 10.167.181.192/28 | 10.167.181.193 – 10.167.181.206 | 10.167.181.207 |
| 94 | 10.167.181.208/28 | 10.167.181.209 – 10.167.181.222 | 10.167.181.223 |
| 95 | 10.167.181.224/28 | 10.167.181.225 – 10.167.181.238 | 10.167.181.239 |
| 96 | 10.167.181.240/28 | 10.167.181.241 – 10.167.181.254 | 10.167.181.255 |
| 97 | 10.167.182.0/28 | 10.167.182.1 – 10.167.182.14 | 10.167.182.15 |
| 98 | 10.167.182.16/28 | 10.167.182.17 – 10.167.182.30 | 10.167.182.31 |
| 99 | 10.167.182.32/28 | 10.167.182.33 – 10.167.182.46 | 10.167.182.47 |
| 100 | 10.167.182.48/28 | 10.167.182.49 – 10.167.182.62 | 10.167.182.63 |
| 101 | 10.167.182.64/28 | 10.167.182.65 – 10.167.182.78 | 10.167.182.79 |
| 102 | 10.167.182.80/28 | 10.167.182.81 – 10.167.182.94 | 10.167.182.95 |
| 103 | 10.167.182.96/28 | 10.167.182.97 – 10.167.182.110 | 10.167.182.111 |
| 104 | 10.167.182.112/28 | 10.167.182.113 – 10.167.182.126 | 10.167.182.127 |
| 105 | 10.167.182.128/28 | 10.167.182.129 – 10.167.182.142 | 10.167.182.143 |
| 106 | 10.167.182.144/28 | 10.167.182.145 – 10.167.182.158 | 10.167.182.159 |
| 107 | 10.167.182.160/28 | 10.167.182.161 – 10.167.182.174 | 10.167.182.175 |
| 108 | 10.167.182.176/28 | 10.167.182.177 – 10.167.182.190 | 10.167.182.191 |
| 109 | 10.167.182.192/28 | 10.167.182.193 – 10.167.182.206 | 10.167.182.207 |
| 110 | 10.167.182.208/28 | 10.167.182.209 – 10.167.182.222 | 10.167.182.223 |
| 111 | 10.167.182.224/28 | 10.167.182.225 – 10.167.182.238 | 10.167.182.239 |
| 112 | 10.167.182.240/28 | 10.167.182.241 – 10.167.182.254 | 10.167.182.255 |
| 113 | 10.167.183.0/28 | 10.167.183.1 – 10.167.183.14 | 10.167.183.15 |
| 114 | 10.167.183.16/28 | 10.167.183.17 – 10.167.183.30 | 10.167.183.31 |
| 115 | 10.167.183.32/28 | 10.167.183.33 – 10.167.183.46 | 10.167.183.47 |
| 116 | 10.167.183.48/28 | 10.167.183.49 – 10.167.183.62 | 10.167.183.63 |
| 117 | 10.167.183.64/28 | 10.167.183.65 – 10.167.183.78 | 10.167.183.79 |
| 118 | 10.167.183.80/28 | 10.167.183.81 – 10.167.183.94 | 10.167.183.95 |
| 119 | 10.167.183.96/28 | 10.167.183.97 – 10.167.183.110 | 10.167.183.111 |
| 120 | 10.167.183.112/28 | 10.167.183.113 – 10.167.183.126 | 10.167.183.127 |
| 121 | 10.167.183.128/28 | 10.167.183.129 – 10.167.183.142 | 10.167.183.143 |
| 122 | 10.167.183.144/28 | 10.167.183.145 – 10.167.183.158 | 10.167.183.159 |
| 123 | 10.167.183.160/28 | 10.167.183.161 – 10.167.183.174 | 10.167.183.175 |
| 124 | 10.167.183.176/28 | 10.167.183.177 – 10.167.183.190 | 10.167.183.191 |
| 125 | 10.167.183.192/28 | 10.167.183.193 – 10.167.183.206 | 10.167.183.207 |
| 126 | 10.167.183.208/28 | 10.167.183.209 – 10.167.183.222 | 10.167.183.223 |
| 127 | 10.167.183.224/28 | 10.167.183.225 – 10.167.183.238 | 10.167.183.239 |
| 128 | 10.167.183.240/28 | 10.167.183.241 – 10.167.183.254 | 10.167.183.255 |
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.