Subnet Calculator
0
32
64
96
128
160
192
224
Network
Host
Broadcast
CIDR /23 visualization inactive (only available for /24 to /32)
Public IP Information
IP Address Information
103.181.30.0
01100111101101010001111000000000
255.255.254.0
11111111111111111111111000000000
103.181.30.0
01100111101101010001111000000000
103.181.31.255
01100111101101010001111111111111
0.0.1.255
00000000000000000000000111111111
/23
Network Bits: 23 |Host Bits: 9
103.181.30.1
01100111101101010001111000000001
103.181.31.254
01100111101101010001111111111110
Network Information
512
510
103.181.30.1 – 103.181.31.254
Subnet Cheat Sheet
| CIDR | Subnet Mask | Wildcard Mask | Total IPs | Usable Hosts | Network Bits | Host Bits |
|---|---|---|---|---|---|---|
| /32 | 255.255.255.255 | 0.0.0.0 | 1 | 1 | 32 | 0 |
| /31 | 255.255.255.254 | 0.0.0.1 | 2 | 2 | 31 | 1 |
| /30 | 255.255.255.252 | 0.0.0.3 | 4 | 2 | 30 | 2 |
| /29 | 255.255.255.248 | 0.0.0.7 | 8 | 6 | 29 | 3 |
| /28 | 255.255.255.240 | 0.0.0.15 | 16 | 14 | 28 | 4 |
| /27 | 255.255.255.224 | 0.0.0.31 | 32 | 30 | 27 | 5 |
| /26 | 255.255.255.192 | 0.0.0.63 | 64 | 62 | 26 | 6 |
| /25 | 255.255.255.128 | 0.0.0.127 | 128 | 126 | 25 | 7 |
| /24 | 255.255.255.0 | 0.0.0.255 | 256 | 254 | 24 | 8 |
| /23 | 255.255.254.0 | 0.0.1.255 | 512 | 510 | 23 | 9 |
| /22 | 255.255.252.0 | 0.0.3.255 | 1,024 | 1,022 | 22 | 10 |
| /21 | 255.255.248.0 | 0.0.7.255 | 2,048 | 2,046 | 21 | 11 |
| /20 | 255.255.240.0 | 0.0.15.255 | 4,096 | 4,094 | 20 | 12 |
| /19 | 255.255.224.0 | 0.0.31.255 | 8,192 | 8,190 | 19 | 13 |
| /18 | 255.255.192.0 | 0.0.63.255 | 16,384 | 16,382 | 18 | 14 |
| /17 | 255.255.128.0 | 0.0.127.255 | 32,768 | 32,766 | 17 | 15 |
| /16 | 255.255.0.0 | 0.0.255.255 | 65,536 | 65,534 | 16 | 16 |
| /15 | 255.254.0.0 | 0.1.255.255 | 131,072 | 131,070 | 15 | 17 |
| /14 | 255.252.0.0 | 0.3.255.255 | 262,144 | 262,142 | 14 | 18 |
| /13 | 255.248.0.0 | 0.7.255.255 | 524,288 | 524,286 | 13 | 19 |
| /12 | 255.240.0.0 | 0.15.255.255 | 1,048,576 | 1,048,574 | 12 | 20 |
| /11 | 255.224.0.0 | 0.31.255.255 | 2,097,152 | 2,097,150 | 11 | 21 |
| /10 | 255.192.0.0 | 0.63.255.255 | 4,194,304 | 4,194,302 | 10 | 22 |
| /9 | 255.128.0.0 | 0.127.255.255 | 8,388,608 | 8,388,606 | 9 | 23 |
| /8 | 255.0.0.0 | 0.255.255.255 | 16,777,216 | 16,777,214 | 8 | 24 |
| /7 | 254.0.0.0 | 1.255.255.255 | 33,554,432 | 33,554,430 | 7 | 25 |
| /6 | 252.0.0.0 | 3.255.255.255 | 67,108,864 | 67,108,862 | 6 | 26 |
| /5 | 248.0.0.0 | 7.255.255.255 | 134,217,728 | 134,217,726 | 5 | 27 |
| /4 | 240.0.0.0 | 15.255.255.255 | 268,435,456 | 268,435,454 | 4 | 28 |
| /3 | 224.0.0.0 | 31.255.255.255 | 536,870,912 | 536,870,910 | 3 | 29 |
| /2 | 192.0.0.0 | 63.255.255.255 | 1,073,741,824 | 1,073,741,822 | 2 | 30 |
| /1 | 128.0.0.0 | 127.255.255.255 | 2,147,483,648 | 2,147,483,646 | 1 | 31 |
| /0 | 0.0.0.0 | 255.255.255.255 | 4,294,967,296 | 4,294,967,294 | 0 | 32 |
Quick Reference
Frequently Asked Questions
How to Use
Enter an IP address and CIDR prefix above to calculate subnet details including network address, broadcast address, subnet mask, and usable host range.
CIDR Notation
CIDR (Classless Inter-Domain Routing) replaced traditional classful networking. The prefix length (e.g., /24) specifies how many bits identify the network, with the remaining bits identifying hosts.
Common Subnet Sizes
/24 (254 hosts) is the most common LAN size. /16 (65,534 hosts) suits large campuses. /30 (2 hosts) is used for point-to-point links. /32 represents a single host.