Create a Personal Budget Tracker in C# Using JSON and Console UI

Introduction

Managing personal expenses is essential, and building a budget tracker is a great beginner project to practice file handling, serialization, and console UI in C#. This guide walks through creating a simple budget tracker that uses JSON to store data and supports adding, viewing, deleting expenses, and showing total spending.

Prerequisites

• .NET SDK installed  
• Basic C# knowledge  
• Visual Studio or any C# editor

1. Project Setup

dotnet new console -n BudgetTrackerApp
cd BudgetTrackerApp

2. Create the Expense Model (Expense.cs)

public class Expense
{
    public int Id { get; set; }
    public string Description { get; set; }
    public decimal Amount { get; set; }
    public DateTime Date { get; set; }
}

3. Add JSON Storage Helpers (Program.cs)

using System.Text.Json;

public static class BudgetHelper
{
    private const string FilePath = "expenses.json";

    public static List<Expense> LoadExpenses()
    {
        if (!File.Exists(FilePath)) 
            return new List<Expense>();

        var json = File.ReadAllText(FilePath);
        return JsonSerializer.Deserialize<List<Expense>>(json) ?? new List<Expense>();
    }

    public static void SaveExpenses(List<Expense> expenses)
    {
        var json = JsonSerializer.Serialize(expenses, new JsonSerializerOptions 
        { 
            WriteIndented = true 
        });
        
        File.WriteAllText(FilePath, json);
    }
}

4. Console Application Logic (Program.cs)

class Program
{
    static List<Expense> expenses = BudgetHelper.LoadExpenses();
    static int idCounter = expenses.Count > 0 ? expenses.Max(e => e.Id) + 1 : 1;

    static void Main()
    {
        while (true)
        {
            Console.Clear();
            Console.WriteLine("=== Personal Budget Tracker ===");
            Console.WriteLine("1. Add Expense");
            Console.WriteLine("2. View Expenses");
            Console.WriteLine("3. Delete Expense");
            Console.WriteLine("4. Total Spent");
            Console.WriteLine("5. Exit");
            Console.Write("Select an option: ");

            var input = Console.ReadLine();

            switch (input)
            {
                case "1": AddExpense(); break;
                case "2": ViewExpenses(); break;
                case "3": DeleteExpense(); break;
                case "4": ShowTotal(); break;
                case "5": return;
                default: Console.WriteLine("Invalid option"); break;
            }

            Console.WriteLine("Press any key to continue...");
            Console.ReadKey();
        }
    }

    static void AddExpense()
    {
        Console.Write("Description: ");
        var desc = Console.ReadLine();

        Console.Write("Amount: ");
        decimal amt = decimal.TryParse(Console.ReadLine(), out amt) ? amt : 0;

        expenses.Add(new Expense
        {
            Id = idCounter++,
            Description = desc,
            Amount = amt,
            Date = DateTime.Now
        });

        BudgetHelper.SaveExpenses(expenses);
        Console.WriteLine("Expense added!");
    }

    static void ViewExpenses()
    {
        Console.WriteLine("\n--- Expenses ---");
        foreach (var e in expenses)
        {
            Console.WriteLine($"{e.Id}. {e.Description} - ₹{e.Amount} on {e.Date:dd/MM/yyyy}");
        }
    }

    static void DeleteExpense()
    {
        ViewExpenses();
        Console.Write("Enter ID to delete: ");
        if (int.TryParse(Console.ReadLine(), out int id))
        {
            var item = expenses.FirstOrDefault(e => e.Id == id);
            if (item != null)
            {
                expenses.Remove(item);
                BudgetHelper.SaveExpenses(expenses);
                Console.WriteLine("Deleted!");
            }
            else
            {
                Console.WriteLine("ID not found.");
            }
        }
    }

    static void ShowTotal()
    {
        var total = expenses.Sum(e => e.Amount);
        Console.WriteLine($"\nTotal Spent: ₹{total}");
    }
}

Output Example

Extensions (Optional)

• Add monthly limits
• Use categories (e.g., food, rent)
• Export to CSV
• Convert to GUI using WPF or MAUI

Conclusion

This simple budget tracker project demonstrates how to use C# and JSON to manage personal finance data. It's beginner-friendly and provides a strong foundation for learning file I/O, serialization, and structured application logic.