Java: Get file size in bytes, kb, mb

Last update on May 19 2025 13:13:38 (UTC/GMT +8 hours)

9. Get File Size

Write a Java program to get the file size in bytes, KB, MB.

Sample Solution:

Java Code:

import java.io.File;
 
public class Exercise9 {
 
      public static void main(String[] args) 
      {
        File file = new File("/home/students/test.txt");
        if(file.exists())
        {
        System.out.println(filesize_in_Bytes(file));
        System.out.println(filesize_in_kiloBytes(file));
        System.out.println(filesize_in_megaBytes(file));
        }
        else 
        System.out.println("File doesn't exist");
         
    }
 
    private static String filesize_in_megaBytes(File file) {
        return (double) file.length()/(1024*1024)+" mb";
    }
 
    private static String filesize_in_kiloBytes(File file) {
        return (double) file.length()/1024+"  kb";
    }
 
    private static String filesize_in_Bytes(File file) {
        return file.length()+" bytes";
    }
 }

Sample Output:

151 bytes                                                                                                 
0.1474609375  kb                                                                                              
1.4400482177734375E-4 mb

Flowchart:

Flowchart: Get file size in bytes, kb, mb

For more Practice: Solve these Related Problems:

Write a Java program to compute the size of a file in bytes and convert it to KB and MB with appropriate rounding.
Write a Java program to display the sizes of all files in a directory in a human-readable format.
Write a Java program to compare the sizes of two files and output the difference in megabytes.
Write a Java program to recursively calculate the total size of all files in a directory tree.

Go to:

PREV : Read Console Input.
NEXT : Read File into Byte Array.

Java Code Editor:

Contribute your code and comments through Disqus.