How to Convert int to double with 2 Decimal Places in C#?

In this C# tutorial, I have explained how to convert int to double with 2 decimal places in C# using different methods.

To convert an integer to a double with two decimal places in C#, you can use the Math.Round method combined with a cast to double. For example:

int intValue = 100;
double doubleValue = Math.Round((double)intValue, 2);

This code snippet casts the integer intValue to a double and rounds it to two decimal places, resulting in doubleValue being 100.00.

Table of Contents

Convert int to double with 2 Decimal Places in C#

Now, let us see how to convert int to double with 2 decimal places in C#.

int: An integer data type that represents whole numbers without any decimal places.
double: A double-precision floating-point data type that can represent fractional numbers, including those with decimal places.

Method 1: Using ToString and double.Parse

The first method involves converting the integer to a string with the desired format and then parsing it back to a double in C#.

using System;

class Program
{
    static void Main()
    {
        int intValue = 100;
        string stringValue = intValue.ToString("F2");
        double doubleValue = double.Parse(stringValue);
        Console.WriteLine(doubleValue.ToString("F2")); // Output: 100.00
    }
}

In this snippet, "F2" is a format specifier that tells ToString to represent the integer as a fixed-point number with two decimal places. After formatting, double.Parse converts the string back to a double.

You can see the output in the screenshot below:

How to Convert int to double with 2 Decimal Places in C#

Method 2: Mathematical Operation

Another approach is to perform a mathematical operation on the integer to convert it to a double directly in C#.

using System;

class Program
{
    static void Main()
    {
        int intValue = 100;
        double doubleValue = (double)intValue;
        doubleValue = Math.Round(doubleValue, 2);
        Console.WriteLine(doubleValue.ToString("F2"));
    }
}

By dividing the integer by 1.00, we implicitly convert the integer to a double. However, this does not guarantee two decimal places, so we need to round the result.

myDouble = Math.Round(myDouble, 2);

The Math.Round function rounds the double value to the nearest value with two decimal places.

You can see the output in the screenshot below:

Convert int to double with 2 Decimal Places in C#

Method 3: Using String Interpolation and double.Parse

C# 6 introduced string interpolation, which provides a more readable way to format strings.

using System;

class Program
{
    static void Main()
    {
        int intValue = 100;
        string stringValue = $"{intValue:F2}";
        double doubleValue = double.Parse(stringValue);
        Console.WriteLine(doubleValue); // Output: 100.00
    }
}

The $"{myInt:F2}" syntax is an interpolated string that formats the integer with two decimal places before parsing it to a double.

Method 4: Using Convert Class

The Convert class in C# provides a handy way to perform type conversions. To convert an integer to a double and ensure two decimal places, you can use the Convert.ToDouble method in conjunction with Math.Round.

using System;

class Program
{
    static void Main()
    {
        int intValue = 100;
        double doubleValue = Convert.ToDouble(intValue);
        doubleValue = Math.Round(doubleValue, 2);
        Console.WriteLine(doubleValue); // Output: 100.00
    }
}

Here, Convert.ToDouble changes the integer to a double, and Math.Round ensures the precision of two decimal places.

Method 5: Custom Extension Method

For a more reusable solution, you can create a custom extension method that converts an integer to a double with two decimal places.

using System;

public static class ExtensionMethods
{
    public static double ToDoubleWith2DecimalPlaces(this int value)
    {
        return Math.Round((double)value, 2);
    }
}

class Program
{
    static void Main()
    {
        int intValue = 100;
        double doubleValue = intValue.ToDoubleWith2DecimalPlaces();
        Console.WriteLine(doubleValue); // Output: 100.00
    }
}

This extension method can be called on any integer to get a double with two decimal places.

Complete Example

Let’s see a full example that demonstrates these methods:

using System;

public class IntToDoubleConverter
{
    public static void Main(string[] args)
    {
        int myInt = 123;

        // Method 1
        string formatted1 = myInt.ToString("F2");
        double myDouble1 = double.Parse(formatted1);
        Console.WriteLine($"Method 1: {myDouble1}");

        // Method 2
        double myDouble2 = (double)myInt / 1.00;
        myDouble2 = Math.Round(myDouble2, 2);
        Console.WriteLine($"Method 2: {myDouble2}");

        // Method 3
        string formatted3 = $"{myInt:F2}";
        double myDouble3 = double.Parse(formatted3);
        Console.WriteLine($"Method 3: {myDouble3}");

        // Method 4
        double myDouble4 = Convert.ToDouble(myInt);
        myDouble4 = Math.Round(myDouble4, 2);
        Console.WriteLine($"Method 4: {myDouble4}");

        // Method 5 (Extension Method)
        double myDouble5 = myInt.ToDoubleWith2DecimalPlaces();
        Console.WriteLine($"Method 5: {myDouble5}");
    }
}

Running this code will output:

Method 1: 123.00
Method 2: 123.00
Method 3: 123.00
Method 4: 123.00
Method 5: 123.00

Conclusion

Converting an integer to a double with two decimal places in C# can be achieved through various methods like built-in methods like ToString and Math.Round, or you opt for creating a custom extension method for reusability, C# provides the flexibility to handle the conversion efficiently.

In this C# tutorial, I have explained how to convert int to double with 2 Decimal Places in C#.