Use GetByteCount to return the number of bytes required to encode an array of Unicode characters, using UTF8Encoding. : Unicode « I18N Internationalization « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. I18N Internationalization
3. Unicode

using System;
using System.Text;

class MainClass{
    public static void Main() {
        // Unicode characters.
        Char[] chars = new Char[] {
            '\u0023', // #
            '\u0025', // %
            '\u03a0', // Pi
            '\u03a3'  // Sigma
        };

        UTF8Encoding utf8 = new UTF8Encoding();
        int byteCount = utf8.GetByteCount(chars, 1, 2);
        Console.WriteLine("{0} bytes needed to encode characters.", byteCount);
    }
}