#ip-calculator-pro h2 { color: #2c3e50; text-align: center; margin-bottom: 25px; font-size: 28px; }
.ip-input-group { display: flex; align-items: center; justify-content: center; margin-bottom: 20px; gap: 10px; flex-wrap: wrap; }
.octet-wrapper { display: flex; align-items: center; }
.ip-dot { margin: 0 5px; font-weight: bold; color: #7f8c8d; }
.ip-calculator-pro input[type="number"] { width: 70px; padding: 12px; border: 2px solid #ddd; border-radius: 6px; text-align: center; font-size: 16px; transition: border-color 0.3s; }
.ip-calculator-pro input[type="number"]:focus { border-color: #3498db; outline: none; }
.cidr-input { width: 80px !important; background-color: #f8f9fa; border: 2px solid #3498db !important; font-weight: bold; }
.ip-calc-btn { width: 100%; padding: 15px; background-color: #3498db; color: white; border: none; border-radius: 6px; font-size: 18px; font-weight: 600; cursor: pointer; transition: background-color 0.3s; margin-top: 10px; }
.ip-calc-btn:hover { background-color: #2980b9; }
#ip-results-area { margin-top: 30px; display: none; }
.ip-result-table { width: 100%; border-collapse: collapse; margin-top: 15px; }
.ip-result-table td { padding: 12px; border-bottom: 1px solid #eee; font-size: 15px; }
.ip-result-table td:first-child { font-weight: bold; color: #34495e; width: 40%; }
.ip-result-table td:last-child { font-family: 'Courier New', Courier, monospace; color: #27ae60; font-weight: bold; }
.ip-label { display: block; text-align: center; margin-bottom: 8px; font-weight: 600; color: #555; }
.error-msg { color: #e74c3c; text-align: center; margin-top: 10px; font-size: 14px; display: none; }
@media (max-width: 600px) { .ip-input-group { gap: 5px; } .ip-calculator-pro input[type="number"] { width: 60px; padding: 8px; } }
function calculateSubnet() {
var o1 = parseInt(document.getElementById('oct1').value);
var o2 = parseInt(document.getElementById('oct2').value);
var o3 = parseInt(document.getElementById('oct3').value);
var o4 = parseInt(document.getElementById('oct4').value);
var cidr = parseInt(document.getElementById('cidr').value);
var errorDiv = document.getElementById('ip-error');
var resultsDiv = document.getElementById('ip-results-area');
if (isNaN(o1) || isNaN(o2) || isNaN(o3) || isNaN(o4) || isNaN(cidr) ||
o1 255 || o2 255 || o3 255 || o4 255 ||
cidr 32) {
errorDiv.style.display = 'block';
resultsDiv.style.display = 'none';
return;
}
errorDiv.style.display = 'none';
var ipInt = ((o1 <>> 0) + (o2 << 16) + (o3 < 0) {
maskInt = (0xFFFFFFFF <>> 0;
}
var netInt = (ipInt & maskInt) >>> 0;
var broadInt = (netInt | (~maskInt)) >>> 0;
var wildInt = (~maskInt) >>> 0;
function intToIp(i) {
return ((i >>> 24) & 0xFF) + "." + ((i >>> 16) & 0xFF) + "." + ((i >>> 8) & 0xFF) + "." + (i & 0xFF);
}
var usableHosts = 0;
var hostRange = "N/A";
if (cidr <= 30) {
usableHosts = Math.pow(2, 32 – cidr) – 2;
hostRange = intToIp(netInt + 1) + " – " + intToIp(broadInt – 1);
} else if (cidr === 31) {
usableHosts = 2;
hostRange = intToIp(netInt) + " – " + intToIp(broadInt);
} else if (cidr === 32) {
usableHosts = 1;
hostRange = intToIp(netInt);
}
document.getElementById('resNet').innerText = intToIp(netInt);
document.getElementById('resMask').innerText = intToIp(maskInt);
document.getElementById('resBroad').innerText = intToIp(broadInt);
document.getElementById('resWild').innerText = intToIp(wildInt);
document.getElementById('resRange').innerText = hostRange;
document.getElementById('resHosts').innerText = usableHosts.toLocaleString();
document.getElementById('resCidrFull').innerText = intToIp(o1 << 24 | o2 << 16 | o3 << 8 | o4) + " /" + cidr;
resultsDiv.style.display = 'block';
}
IPv4 Subnet Calculator
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Please enter valid IP octets (0-255) and CIDR (0-32).
| Network Address: | |
| Subnet Mask: | |
| Broadcast Address: | |
| Usable Host Range: | |
| Total Usable Hosts: | |
| Wildcard Mask: | |
| CIDR Notation: |
Understanding IPv4 Subnetting
In the world of computer networking, an IP address is a unique identifier for a device on a network. However, large networks are often difficult to manage as a single entity. This is where Subnetting comes in. Subnetting is the process of dividing a single large network into smaller, manageable sub-networks (subnets).
Key Components of an IP Configuration
- IP Address: The specific numerical label assigned to your device (e.g., 192.168.1.1).
- Subnet Mask: A 32-bit number that masks an IP address and divides the IP address into the network address and host address.
- CIDR (Classless Inter-Domain Routing): A modern way of representing the subnet mask using a slash followed by the number of bits used for the network (e.g., /24).
- Network Address: The first address in a subnet, used to identify the network itself. It cannot be assigned to a device.
- Broadcast Address: The last address in a subnet, used to send data to all devices on that network.
Why Use a Subnet Calculator?
Calculating subnets manually involves converting decimal numbers into binary, performing bitwise AND operations, and converting back to decimal. This is time-consuming and prone to human error. Our IP Calculator automates this process, providing instant results for network engineers, students, and IT professionals.
Real-World Example
If you have an IP address of 10.0.0.1 with a /24 CIDR:
- Subnet Mask: 255.255.255.0
- Network ID: 10.0.0.0
- Usable Hosts: 10.0.0.1 through 10.0.0.254
- Broadcast Address: 10.0.0.255
- Total Usable Hosts: 254
How to Use This Tool
To use the calculator, simply enter the four octets of your IPv4 address into the input boxes. Then, specify the CIDR prefix (ranging from 0 to 32) and click "Calculate". The tool will instantly generate the network address, the subnet mask in decimal format, the broadcast address, and the range of IP addresses you can actually assign to your computers or servers.