C# / .NET - calculate average of List

In this article, we would like to show you how to calculate average of List in C#.

Quick solution:

List<int> list = new List<int> { 1, 2, 4, 8 };

double average = list.Average();

Console.WriteLine(average); // Output: 3.75

or:

List<int> list = new List<int> { 1, 2, 3, 4 };

int sum = 0;

if (list.Any())
    foreach (int number in list)
        sum += number;

double average = (double)sum / list.Count;

Console.WriteLine(average); // Output: 2.5

1. Practical example using Linq

In this example, we use Average() method from System.Linq to caluclate average of the List.

using System;
using System.Linq;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        List<int> list = new List<int> { 1, 2, 4, 8 };

        double average = list.Average();

        Console.WriteLine(average);
    }
}

Output:

3.75

2. Using foreach

In this example, we use foreach to sum all numbers in the List, then we divide the sum by the number of elements.

using System;
using System.Linq;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        List<int> myList = new List<int> { 1, 2, 3, 4 };

        Console.WriteLine(average(myList));
    }

    private static double average(List<int> list)
    {
        int sum = 0;
        if (list.Any())
            foreach (int number in list)
                sum += number;

        return (double)sum / list.Count;
    }
}

Output:

2.5

References

1. Enumerable.Average Method (System.Linq) | Microsoft Docs
2. Enumerable.Any Method (System.Linq) | Microsoft Docs
3. List<T>.Count Property (System.Collections.Generic) | Microsoft Docs