C# Program to get free space in a drive

To get the free space in a drive, use the AvailableFreeSpace and TotalFreeSpace properties of the DriveInfo class in C#. This is useful for monitoring disk space and making decisions based on available storage.

Syntax

Following is the syntax for creating a DriveInfo object and accessing free space properties −

DriveInfo driveInfo = new DriveInfo("DriveLetter");
long availableSpace = driveInfo.AvailableFreeSpace;
long totalFreeSpace = driveInfo.TotalFreeSpace;

Properties

Using DriveInfo to Check Available Space

The following example demonstrates how to get free space information for a specific drive −

using System;
using System.IO;

public class Demo {
    public static void Main() {
        DriveInfo dInfo = new DriveInfo("C");
        
        // Get available free space
        Console.WriteLine("Available Free Space: " + dInfo.AvailableFreeSpace + " bytes");
        
        // Get total free space
        Console.WriteLine("Total Free Space: " + dInfo.TotalFreeSpace + " bytes");
        
        // Get total size of the drive
        Console.WriteLine("Total Size: " + dInfo.TotalSize + " bytes");
        
        // Calculate used space
        long usedSpace = dInfo.TotalSize - dInfo.TotalFreeSpace;
        Console.WriteLine("Used Space: " + usedSpace + " bytes");
    }
}

The output of the above code is −

Available Free Space: 245760000000 bytes
Total Free Space: 245760000000 bytes
Total Size: 500000000000 bytes
Used Space: 254240000000 bytes

Converting Bytes to Human-Readable Format

Since the values are returned in bytes, you might want to convert them to more readable units like GB or MB −

using System;
using System.IO;

public class DriveSpaceDemo {
    public static void Main() {
        DriveInfo dInfo = new DriveInfo("C");
        
        // Convert bytes to GB
        double availableGB = (double)dInfo.AvailableFreeSpace / (1024 * 1024 * 1024);
        double totalGB = (double)dInfo.TotalSize / (1024 * 1024 * 1024);
        double usedGB = totalGB - availableGB;
        
        Console.WriteLine("Drive: " + dInfo.Name);
        Console.WriteLine("Total Size: " + totalGB.ToString("F2") + " GB");
        Console.WriteLine("Available Space: " + availableGB.ToString("F2") + " GB");
        Console.WriteLine("Used Space: " + usedGB.ToString("F2") + " GB");
        
        // Calculate percentage
        double usedPercentage = (usedGB / totalGB) * 100;
        Console.WriteLine("Used Percentage: " + usedPercentage.ToString("F1") + "%");
    }
}

The output of the above code is −

Drive: C:\
Total Size: 465.66 GB
Available Space: 228.91 GB
Used Space: 236.75 GB
Used Percentage: 50.8%

Checking All Available Drives

You can also get information for all drives on the system −

using System;
using System.IO;

public class AllDrivesDemo {
    public static void Main() {
        DriveInfo[] drives = DriveInfo.GetDrives();
        
        foreach (DriveInfo drive in drives) {
            if (drive.IsReady) {
                double freeSpaceGB = (double)drive.AvailableFreeSpace / (1024 * 1024 * 1024);
                double totalSpaceGB = (double)drive.TotalSize / (1024 * 1024 * 1024);
                
                Console.WriteLine("Drive: " + drive.Name);
                Console.WriteLine("Type: " + drive.DriveType);
                Console.WriteLine("Free Space: " + freeSpaceGB.ToString("F2") + " GB");
                Console.WriteLine("Total Space: " + totalSpaceGB.ToString("F2") + " GB");
                Console.WriteLine("----------");
            }
        }
    }
}

The output of the above code is −

Drive: C:\
Type: Fixed
Free Space: 228.91 GB
Total Space: 465.66 GB
----------
Drive: D:\
Type: Fixed
Free Space: 150.25 GB
Total Space: 200.00 GB
----------

Conclusion

The DriveInfo class provides easy access to drive space information through AvailableFreeSpace and TotalFreeSpace properties. This is essential for applications that need to monitor disk usage or ensure sufficient space before performing file operations.