Subnet Calculator
0
32
64
96
128
160
192
224
Network
Host
Broadcast
CIDR /1 visualization inactive (only available for /24 to /32)
Public IP Information
IP Address Information
128.0.0.0
10000000000000000000000000000000
128.0.0.0
10000000000000000000000000000000
128.0.0.0
10000000000000000000000000000000
255.255.255.255
11111111111111111111111111111111
127.255.255.255
01111111111111111111111111111111
/1
Network Bits: 1 |Host Bits: 31
128.0.0.1
10000000000000000000000000000001
255.255.255.254
11111111111111111111111111111110
Network Information
2,147,483,648
2,147,483,646
128.0.0.1 – 255.255.255.254
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.