Output

A structured result with these fields:

CIDR Notation (normalized)
Network Address
Broadcast Address
Subnet Mask
Wildcard Mask
First Usable Host
Last Usable Host
Total Hosts (2^(32-N))
Usable Hosts
IP Class (A / B / C / D Multicast / E Reserved)
Network Type (Private / Public)
Binary Representation of the IP

Instructions

Validate the input. It must match \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\/\d{1,2}. Each octet must be 0–255. Prefix must be 0–32.
Compute values using standard subnet math:
- maskNum = (0xFFFFFFFF << (32 - prefix)) >>> 0
- wildcardNum = ~maskNum >>> 0
- networkNum = (ipNum & maskNum) >>> 0
- broadcastNum = (networkNum | wildcardNum) >>> 0
- totalHosts = 2^(32 - prefix)
- usableHosts: if prefix == 32 → 1; if prefix == 31 → 2; else totalHosts - 2
Determine IP class from first octet:
- 1–126 → A; 128–191 → B; 192–223 → C; 224–239 → D (Multicast); 240–255 → E (Reserved); 127 → Loopback
Determine private vs public:
- Private: 10.x.x.x, 172.16–31.x.x, 192.168.x.x, 127.x.x.x (loopback)
Compute binary as four 8-bit groups joined by dots.
Present results in a clear labeled format.

Quick CIDR reference

CIDR	Subnet Mask	Total Hosts
/8	255.0.0.0	16,777,216
/16	255.255.0.0	65,536
/20	255.255.240.0	4,096
/22	255.255.252.0	1,024
/24	255.255.255.0	256
/28	255.255.255.240	16
/30	255.255.255.252	4
/32	255.255.255.255	1

Options

Input is always a single CIDR string; no additional options.

Examples

Input: 192.168.1.0/24

Output:

CIDR Notation:   192.168.1.0/24
Network Address: 192.168.1.0
Broadcast:       192.168.1.255
Subnet Mask:     255.255.255.0
Wildcard Mask:   0.0.0.255
First Host:      192.168.1.1
Last Host:       192.168.1.254
Total Hosts:     256
Usable Hosts:    254
IP Class:        C
Network Type:    Private
Binary:          11000000.10101000.00000001.00000000

Input: 10.0.0.0/8

Output:

CIDR Notation:   10.0.0.0/8
Network Address: 10.0.0.0
Broadcast:       10.255.255.255
Subnet Mask:     255.0.0.0
Wildcard Mask:   0.255.255.255
First Host:      10.0.0.1
Last Host:       10.255.255.254
Total Hosts:     16,777,216
Usable Hosts:    16,777,214
IP Class:        A
Network Type:    Private
Binary:          00001010.00000000.00000000.00000000

Error Handling

If the input is not valid CIDR notation, say so and provide the expected format (A.B.C.D/N).
If an octet exceeds 255 or the prefix exceeds 32, explain the validation error.
If the user provides an IP without a prefix (e.g. 192.168.1.1), ask for the prefix length or assume /32.

cidr-calc

CIDR Calculator

Input