Converting String to Double in C#

Converting a string to double might be a very challenging task in programming environments when you consider different culture settings. Most of the time you deal with "." (dot) or "," (comma) as a decimal seperator.

Here are the simplest solutions for you to convert string values to double in c# programming language.

Converting known string values to double in c#

First example tries to read as an invariant culture element:

double.Parse("3.5", CultureInfo.InvariantCulture);

However, we recommend you to use TryParse method for better programming experiences.

double temp = 0;
double.TryParse("3.5", NumberStyles.Number, CultureInfo.CreateSpecificCulture("en-US"), out temp);

A generalized string to double converter in c#

However, your double may use another number decimal seperator. In this case, writing a Double Parser may solve your issue:

public static double GetDouble(string value, double defaultValue)
{
    double result;

    //Try parsing in the current culture
    if (!double.TryParse(value, System.Globalization.NumberStyles.Any, CultureInfo.CurrentCulture, out result) &&

        //Then try in US english
        !double.TryParse(value, System.Globalization.NumberStyles.Any, CultureInfo.GetCultureInfo("en-US"), out result) &&

        //Then in neutral language
        !double.TryParse(value, System.Globalization.NumberStyles.Any, CultureInfo.InvariantCulture, out result))
    {
        result = defaultValue;
    }

    return result;
}

Culture Issue

Different regions use different decimal separators:

"123.45" → common in US
"123,45" → common in Europe (including Turkiye)

using System.Globalization;

string value = "123,45";
double number = double.Parse(value, CultureInfo.GetCultureInfo("tr-TR"));

Or culture-independent:

double number = double.Parse(value, CultureInfo.InvariantCulture);

Common Mistakes

• Not handling invalid input
• Ignoring culture differences
• Using Parse on user input without validation

Quick Recommendation

• Use TryParse → safest and most practical
• Use Parse → when input is guaranteed valid
• Use Convert.ToDouble → when working with general objects