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)172.16.5.4/20
network172.16.0.0/20
broadcast172.16.15.255
first host172.16.0.1
last host172.16.15.254
subnet mask255.255.240.0
wildcard0.0.15.255
addresses4,096
usable hosts4,094
classB
ipcalc 172.16.5.4/20
address10101100.00010000.00000101.00000100
subnet mask11111111.11111111.11110000.00000000
network10101100.00010000.00000000.00000000
broadcast10101100.00010000.00001111.11111111
green = network part, grey = host part
hex0xac100504
decimal2886731012
reverse dns4.5.16.172.in-addr.arpa
ipv4-mapped::ffff:ac10:504
/20 split into /27 · 128 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 172.16.0.0/27 | 172.16.0.1 – 172.16.0.30 | 172.16.0.31 |
| 2 | 172.16.0.32/27 | 172.16.0.33 – 172.16.0.62 | 172.16.0.63 |
| 3 | 172.16.0.64/27 | 172.16.0.65 – 172.16.0.94 | 172.16.0.95 |
| 4 | 172.16.0.96/27 | 172.16.0.97 – 172.16.0.126 | 172.16.0.127 |
| 5 | 172.16.0.128/27 | 172.16.0.129 – 172.16.0.158 | 172.16.0.159 |
| 6 | 172.16.0.160/27 | 172.16.0.161 – 172.16.0.190 | 172.16.0.191 |
| 7 | 172.16.0.192/27 | 172.16.0.193 – 172.16.0.222 | 172.16.0.223 |
| 8 | 172.16.0.224/27 | 172.16.0.225 – 172.16.0.254 | 172.16.0.255 |
| 9 | 172.16.1.0/27 | 172.16.1.1 – 172.16.1.30 | 172.16.1.31 |
| 10 | 172.16.1.32/27 | 172.16.1.33 – 172.16.1.62 | 172.16.1.63 |
| 11 | 172.16.1.64/27 | 172.16.1.65 – 172.16.1.94 | 172.16.1.95 |
| 12 | 172.16.1.96/27 | 172.16.1.97 – 172.16.1.126 | 172.16.1.127 |
| 13 | 172.16.1.128/27 | 172.16.1.129 – 172.16.1.158 | 172.16.1.159 |
| 14 | 172.16.1.160/27 | 172.16.1.161 – 172.16.1.190 | 172.16.1.191 |
| 15 | 172.16.1.192/27 | 172.16.1.193 – 172.16.1.222 | 172.16.1.223 |
| 16 | 172.16.1.224/27 | 172.16.1.225 – 172.16.1.254 | 172.16.1.255 |
| 17 | 172.16.2.0/27 | 172.16.2.1 – 172.16.2.30 | 172.16.2.31 |
| 18 | 172.16.2.32/27 | 172.16.2.33 – 172.16.2.62 | 172.16.2.63 |
| 19 | 172.16.2.64/27 | 172.16.2.65 – 172.16.2.94 | 172.16.2.95 |
| 20 | 172.16.2.96/27 | 172.16.2.97 – 172.16.2.126 | 172.16.2.127 |
| 21 | 172.16.2.128/27 | 172.16.2.129 – 172.16.2.158 | 172.16.2.159 |
| 22 | 172.16.2.160/27 | 172.16.2.161 – 172.16.2.190 | 172.16.2.191 |
| 23 | 172.16.2.192/27 | 172.16.2.193 – 172.16.2.222 | 172.16.2.223 |
| 24 | 172.16.2.224/27 | 172.16.2.225 – 172.16.2.254 | 172.16.2.255 |
| 25 | 172.16.3.0/27 | 172.16.3.1 – 172.16.3.30 | 172.16.3.31 |
| 26 | 172.16.3.32/27 | 172.16.3.33 – 172.16.3.62 | 172.16.3.63 |
| 27 | 172.16.3.64/27 | 172.16.3.65 – 172.16.3.94 | 172.16.3.95 |
| 28 | 172.16.3.96/27 | 172.16.3.97 – 172.16.3.126 | 172.16.3.127 |
| 29 | 172.16.3.128/27 | 172.16.3.129 – 172.16.3.158 | 172.16.3.159 |
| 30 | 172.16.3.160/27 | 172.16.3.161 – 172.16.3.190 | 172.16.3.191 |
| 31 | 172.16.3.192/27 | 172.16.3.193 – 172.16.3.222 | 172.16.3.223 |
| 32 | 172.16.3.224/27 | 172.16.3.225 – 172.16.3.254 | 172.16.3.255 |
| 33 | 172.16.4.0/27 | 172.16.4.1 – 172.16.4.30 | 172.16.4.31 |
| 34 | 172.16.4.32/27 | 172.16.4.33 – 172.16.4.62 | 172.16.4.63 |
| 35 | 172.16.4.64/27 | 172.16.4.65 – 172.16.4.94 | 172.16.4.95 |
| 36 | 172.16.4.96/27 | 172.16.4.97 – 172.16.4.126 | 172.16.4.127 |
| 37 | 172.16.4.128/27 | 172.16.4.129 – 172.16.4.158 | 172.16.4.159 |
| 38 | 172.16.4.160/27 | 172.16.4.161 – 172.16.4.190 | 172.16.4.191 |
| 39 | 172.16.4.192/27 | 172.16.4.193 – 172.16.4.222 | 172.16.4.223 |
| 40 | 172.16.4.224/27 | 172.16.4.225 – 172.16.4.254 | 172.16.4.255 |
| 41 | 172.16.5.0/27 | 172.16.5.1 – 172.16.5.30 | 172.16.5.31 |
| 42 | 172.16.5.32/27 | 172.16.5.33 – 172.16.5.62 | 172.16.5.63 |
| 43 | 172.16.5.64/27 | 172.16.5.65 – 172.16.5.94 | 172.16.5.95 |
| 44 | 172.16.5.96/27 | 172.16.5.97 – 172.16.5.126 | 172.16.5.127 |
| 45 | 172.16.5.128/27 | 172.16.5.129 – 172.16.5.158 | 172.16.5.159 |
| 46 | 172.16.5.160/27 | 172.16.5.161 – 172.16.5.190 | 172.16.5.191 |
| 47 | 172.16.5.192/27 | 172.16.5.193 – 172.16.5.222 | 172.16.5.223 |
| 48 | 172.16.5.224/27 | 172.16.5.225 – 172.16.5.254 | 172.16.5.255 |
| 49 | 172.16.6.0/27 | 172.16.6.1 – 172.16.6.30 | 172.16.6.31 |
| 50 | 172.16.6.32/27 | 172.16.6.33 – 172.16.6.62 | 172.16.6.63 |
| 51 | 172.16.6.64/27 | 172.16.6.65 – 172.16.6.94 | 172.16.6.95 |
| 52 | 172.16.6.96/27 | 172.16.6.97 – 172.16.6.126 | 172.16.6.127 |
| 53 | 172.16.6.128/27 | 172.16.6.129 – 172.16.6.158 | 172.16.6.159 |
| 54 | 172.16.6.160/27 | 172.16.6.161 – 172.16.6.190 | 172.16.6.191 |
| 55 | 172.16.6.192/27 | 172.16.6.193 – 172.16.6.222 | 172.16.6.223 |
| 56 | 172.16.6.224/27 | 172.16.6.225 – 172.16.6.254 | 172.16.6.255 |
| 57 | 172.16.7.0/27 | 172.16.7.1 – 172.16.7.30 | 172.16.7.31 |
| 58 | 172.16.7.32/27 | 172.16.7.33 – 172.16.7.62 | 172.16.7.63 |
| 59 | 172.16.7.64/27 | 172.16.7.65 – 172.16.7.94 | 172.16.7.95 |
| 60 | 172.16.7.96/27 | 172.16.7.97 – 172.16.7.126 | 172.16.7.127 |
| 61 | 172.16.7.128/27 | 172.16.7.129 – 172.16.7.158 | 172.16.7.159 |
| 62 | 172.16.7.160/27 | 172.16.7.161 – 172.16.7.190 | 172.16.7.191 |
| 63 | 172.16.7.192/27 | 172.16.7.193 – 172.16.7.222 | 172.16.7.223 |
| 64 | 172.16.7.224/27 | 172.16.7.225 – 172.16.7.254 | 172.16.7.255 |
| 65 | 172.16.8.0/27 | 172.16.8.1 – 172.16.8.30 | 172.16.8.31 |
| 66 | 172.16.8.32/27 | 172.16.8.33 – 172.16.8.62 | 172.16.8.63 |
| 67 | 172.16.8.64/27 | 172.16.8.65 – 172.16.8.94 | 172.16.8.95 |
| 68 | 172.16.8.96/27 | 172.16.8.97 – 172.16.8.126 | 172.16.8.127 |
| 69 | 172.16.8.128/27 | 172.16.8.129 – 172.16.8.158 | 172.16.8.159 |
| 70 | 172.16.8.160/27 | 172.16.8.161 – 172.16.8.190 | 172.16.8.191 |
| 71 | 172.16.8.192/27 | 172.16.8.193 – 172.16.8.222 | 172.16.8.223 |
| 72 | 172.16.8.224/27 | 172.16.8.225 – 172.16.8.254 | 172.16.8.255 |
| 73 | 172.16.9.0/27 | 172.16.9.1 – 172.16.9.30 | 172.16.9.31 |
| 74 | 172.16.9.32/27 | 172.16.9.33 – 172.16.9.62 | 172.16.9.63 |
| 75 | 172.16.9.64/27 | 172.16.9.65 – 172.16.9.94 | 172.16.9.95 |
| 76 | 172.16.9.96/27 | 172.16.9.97 – 172.16.9.126 | 172.16.9.127 |
| 77 | 172.16.9.128/27 | 172.16.9.129 – 172.16.9.158 | 172.16.9.159 |
| 78 | 172.16.9.160/27 | 172.16.9.161 – 172.16.9.190 | 172.16.9.191 |
| 79 | 172.16.9.192/27 | 172.16.9.193 – 172.16.9.222 | 172.16.9.223 |
| 80 | 172.16.9.224/27 | 172.16.9.225 – 172.16.9.254 | 172.16.9.255 |
| 81 | 172.16.10.0/27 | 172.16.10.1 – 172.16.10.30 | 172.16.10.31 |
| 82 | 172.16.10.32/27 | 172.16.10.33 – 172.16.10.62 | 172.16.10.63 |
| 83 | 172.16.10.64/27 | 172.16.10.65 – 172.16.10.94 | 172.16.10.95 |
| 84 | 172.16.10.96/27 | 172.16.10.97 – 172.16.10.126 | 172.16.10.127 |
| 85 | 172.16.10.128/27 | 172.16.10.129 – 172.16.10.158 | 172.16.10.159 |
| 86 | 172.16.10.160/27 | 172.16.10.161 – 172.16.10.190 | 172.16.10.191 |
| 87 | 172.16.10.192/27 | 172.16.10.193 – 172.16.10.222 | 172.16.10.223 |
| 88 | 172.16.10.224/27 | 172.16.10.225 – 172.16.10.254 | 172.16.10.255 |
| 89 | 172.16.11.0/27 | 172.16.11.1 – 172.16.11.30 | 172.16.11.31 |
| 90 | 172.16.11.32/27 | 172.16.11.33 – 172.16.11.62 | 172.16.11.63 |
| 91 | 172.16.11.64/27 | 172.16.11.65 – 172.16.11.94 | 172.16.11.95 |
| 92 | 172.16.11.96/27 | 172.16.11.97 – 172.16.11.126 | 172.16.11.127 |
| 93 | 172.16.11.128/27 | 172.16.11.129 – 172.16.11.158 | 172.16.11.159 |
| 94 | 172.16.11.160/27 | 172.16.11.161 – 172.16.11.190 | 172.16.11.191 |
| 95 | 172.16.11.192/27 | 172.16.11.193 – 172.16.11.222 | 172.16.11.223 |
| 96 | 172.16.11.224/27 | 172.16.11.225 – 172.16.11.254 | 172.16.11.255 |
| 97 | 172.16.12.0/27 | 172.16.12.1 – 172.16.12.30 | 172.16.12.31 |
| 98 | 172.16.12.32/27 | 172.16.12.33 – 172.16.12.62 | 172.16.12.63 |
| 99 | 172.16.12.64/27 | 172.16.12.65 – 172.16.12.94 | 172.16.12.95 |
| 100 | 172.16.12.96/27 | 172.16.12.97 – 172.16.12.126 | 172.16.12.127 |
| 101 | 172.16.12.128/27 | 172.16.12.129 – 172.16.12.158 | 172.16.12.159 |
| 102 | 172.16.12.160/27 | 172.16.12.161 – 172.16.12.190 | 172.16.12.191 |
| 103 | 172.16.12.192/27 | 172.16.12.193 – 172.16.12.222 | 172.16.12.223 |
| 104 | 172.16.12.224/27 | 172.16.12.225 – 172.16.12.254 | 172.16.12.255 |
| 105 | 172.16.13.0/27 | 172.16.13.1 – 172.16.13.30 | 172.16.13.31 |
| 106 | 172.16.13.32/27 | 172.16.13.33 – 172.16.13.62 | 172.16.13.63 |
| 107 | 172.16.13.64/27 | 172.16.13.65 – 172.16.13.94 | 172.16.13.95 |
| 108 | 172.16.13.96/27 | 172.16.13.97 – 172.16.13.126 | 172.16.13.127 |
| 109 | 172.16.13.128/27 | 172.16.13.129 – 172.16.13.158 | 172.16.13.159 |
| 110 | 172.16.13.160/27 | 172.16.13.161 – 172.16.13.190 | 172.16.13.191 |
| 111 | 172.16.13.192/27 | 172.16.13.193 – 172.16.13.222 | 172.16.13.223 |
| 112 | 172.16.13.224/27 | 172.16.13.225 – 172.16.13.254 | 172.16.13.255 |
| 113 | 172.16.14.0/27 | 172.16.14.1 – 172.16.14.30 | 172.16.14.31 |
| 114 | 172.16.14.32/27 | 172.16.14.33 – 172.16.14.62 | 172.16.14.63 |
| 115 | 172.16.14.64/27 | 172.16.14.65 – 172.16.14.94 | 172.16.14.95 |
| 116 | 172.16.14.96/27 | 172.16.14.97 – 172.16.14.126 | 172.16.14.127 |
| 117 | 172.16.14.128/27 | 172.16.14.129 – 172.16.14.158 | 172.16.14.159 |
| 118 | 172.16.14.160/27 | 172.16.14.161 – 172.16.14.190 | 172.16.14.191 |
| 119 | 172.16.14.192/27 | 172.16.14.193 – 172.16.14.222 | 172.16.14.223 |
| 120 | 172.16.14.224/27 | 172.16.14.225 – 172.16.14.254 | 172.16.14.255 |
| 121 | 172.16.15.0/27 | 172.16.15.1 – 172.16.15.30 | 172.16.15.31 |
| 122 | 172.16.15.32/27 | 172.16.15.33 – 172.16.15.62 | 172.16.15.63 |
| 123 | 172.16.15.64/27 | 172.16.15.65 – 172.16.15.94 | 172.16.15.95 |
| 124 | 172.16.15.96/27 | 172.16.15.97 – 172.16.15.126 | 172.16.15.127 |
| 125 | 172.16.15.128/27 | 172.16.15.129 – 172.16.15.158 | 172.16.15.159 |
| 126 | 172.16.15.160/27 | 172.16.15.161 – 172.16.15.190 | 172.16.15.191 |
| 127 | 172.16.15.192/27 | 172.16.15.193 – 172.16.15.222 | 172.16.15.223 |
| 128 | 172.16.15.224/27 | 172.16.15.225 – 172.16.15.254 | 172.16.15.255 |
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 /20 |
|---|---|---|---|---|
| /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 | 1 |
| /21 | 255.255.248.0 | 2,048 | 2,046 | 2 split → |
| /22 | 255.255.252.0 | 1,024 | 1,022 | 4 split → |
| /23 | 255.255.254.0 | 512 | 510 | 8 split → |
| /24 | 255.255.255.0 | 256 | 254 | 16 split → |
| /25 | 255.255.255.128 | 128 | 126 | 32 split → |
| /26 | 255.255.255.192 | 64 | 62 | 64 split → |
| /27 | 255.255.255.224 | 32 | 30 | 128 split → |
| /28 | 255.255.255.240 | 16 | 14 | 256 split → |
| /29 | 255.255.255.248 | 8 | 6 | 512 split → |
| /30 | 255.255.255.252 | 4 | 2 | 1,024 split → |
| /31 | 255.255.255.254 | 2 | 2 | 2,048 split → |
| /32 | 255.255.255.255 | 1 | 1 | 4,096 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.