RSS Feed
Download our iPhone app
Browse DevX
Sign up for e-mail newsletters from DevX

Tip of the Day
Home » Tip Bank » .NET » C#
Language: .NET
Expertise: Intermediate
Nov 15, 2016

Calculate File Size in C#

In order to calculate a file's size in C#, you can use the FileInfo object and create some logic to calculate the physical KB, MB or GB of a file. You can use the following code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace GetFilesize
    public partial class Form1 : Form
        public Form1()

        public static string GetFileSizeInBytes(long TotalBytes)
            if (TotalBytes = 1073741824) //Giga Bytes
                Decimal FileSize = Decimal.Divide(TotalBytes, 1073741824);
                return String.Format("{0:##.##} GB", FileSize);
            else if (TotalBytes = 1048576) //Mega Bytes
                Decimal FileSize = Decimal.Divide(TotalBytes, 1048576);
                return String.Format("{0:##.##} MB", FileSize);
            else if (TotalBytes = 1024) //Kilo Bytes
                Decimal FileSize = Decimal.Divide(TotalBytes, 1024);
                return String.Format("{0:##.##} KB", FileSize);
            else if (TotalBytes  0 & TotalBytes              {
                Decimal FileSize = TotalBytes;
                return String.Format("{0:##.##} Bytes", FileSize);
                return "0 Bytes";


        private void button1_Click(object sender, EventArgs e)
            // The name of the file
            const string FileName = "C:\\INSTALL.LOG";

            // Create new FileInfo object and get the Length.
            FileInfo fInfo = new FileInfo(FileName);
            long Result = fInfo.Length;

            //Display In Label
            label1.Text = GetFileSizeInBytes(Result);
Hannes du Preez
Close Icon
Thanks for your registration, follow us on our social networks to keep up-to-date