TL;DR: Discover how to build an interactive loan calculator dashboard using WPF Charts and DataGrid. This dashboard calculates and visualizes loan breakdowns, EMIs, and amortization schedules using real-time user inputs; the result: actionable financial insights wrapped in a modern, responsive desktop UI.
Welcome to the Chart of the Week blog series!
Challenges in building financial dashboards with WPF
Building a loan calculator dashboard in desktop applications requires more than just basic math; developers need to present loan calculation data such as EMI, interest, and tenure and loan repayment data such as amortization schedules and monthly breakdowns in a clear, interactive format.
In this blog post, you’ll learn how to create a dynamic loan calculator dashboard using WPF Charts and DataGrid. This dashboard allows users to visualize financial insights in real time with C# and MVVM.
Benefits of implementing a loan calculator with WPF Charts and DataGrid
- Preview repayment schedules and overall costs before you take a loan, giving you confidence in your choices.
- Try out different loan amounts, interest rates, and tenures to instantly see how each factor affects your monthly payments and total outlay.
- Understand the long-term impact of your borrowing, see how changing the repayment period or amount can make a big difference in your financial journey.
Step 1: Configure the Syncfusion® Chart and DataGrid controls
Begin by installing the following NuGet packages:
These controls provide broad data visualization and manipulation capabilities, crucial for building real-time, interactive dashboards. For a detailed implementation guide, refer to the documentation.
Step 2: Define the model
We must set up data models to represent all pertinent aspects of the loan calculation, including annual summaries, monthly breakdowns, and EMI structure.
- Model: Represents the yearly loan summary.
- MonthlyDetails: Represents monthly payment breakdowns per period.
- EMIModel: This is used to summarize the chart’s EMI/principal/interest info.
These models allow the dashboard to handle complex data aggregation for display in charts and tables, while keeping UI logic cleanly separated from data/business logic.
C#
public class Model
{
. . .
}
public class MonthlyDetails
{
. . .
}
public class EMIModel
{
. . .
}
Step 3: Define the ViewModel
The ViewModel class implements INotifyPropertyChanged to support dynamic UI updates in a WPF application. It manages observable collections for:
- The annual amortization chart and table (LoanStatusData)
- The doughnut chart (EmiData)
- Visual styles for light/dark themes
With real-time data binding, any change in loan parameters like amount, rate, or tenure, triggers a complete refresh of all visualizations. This supports a seamless user experience where calculations and analytics remain in perfect sync.
Step 4: Define header
The header is the top section of the dashboard that helps users quickly identify the tool. It includes a calculator icon and the title “loan calculator,” making the purpose of the application clear while also supporting branding and user customization.
Personalization with theme switching
To enhance user comfort and accessibility, a theme selector is integrated into the header. Positioned prominently, the ComboBox allows users to switch between light and dark themes, catering to individual preferences and visual needs. This improves usability and reinforces a sense of control and personalization from the first interaction.
XAML
<Border Grid.Row="0" Grid.ColumnSpan="2" Background="#E44646" Height="95">
<Grid>
<Path ... /> <!-- Calculator Icon Path -->
<Label Content="Loan Calculator" ... />
<ComboBox ...> <!-- Theme Selection -->
<ComboBoxItem Content="Light"/>
<ComboBoxItem Content="Dark"/>
</ComboBox>
</Grid>
</Border>
Step 5: Configure interactive input controls
This section of the dashboard lets you adjust key loan parameters using simple, interactive controls designed for clarity and ease of use:
- Loan amount: Set the total amount you wish to borrow using a slider or number box.
- Interest rate: Adjust the interest percentage with precision using dedicated input controls.
- Tenure: Choose your preferred loan duration in years or months.
- Tenure type: Use the dropdown to switch between “year” and “month” formats.
Dynamic value handling and real-time updates
You can connect each input control through two-way data binding and event-driven logic, enabling the dashboard to respond immediately as values are adjusted. Whether modifying the loan amount, interest rate, or tenure, the system recalculates and updates the loan metrics in real time.
XAML
<Border ...>
<Grid ...>
<TextBlock Text="Loan Amount ($)" ... />
<extk:DoubleUpDown ... />
<syncfusion:SfRangeSlider ... />
<TextBlock Text="Rate of Interest (%)" ... />
<extk:DoubleUpDown ... />
<syncfusion:SfRangeSlider ... />
<TextBlock Text="Loan Tenure" ... />
<Grid ...>
<syncfusion:IntegerTextBox ... />
<ComboBox ...>
<ComboBoxItem Content="Year"/>
<ComboBoxItem Content="Month"/>
</ComboBox>
</Grid>
<syncfusion:SfRangeSlider ... />
</Grid>
</Border>
Step 6: Visualize payment breakdown with a Doughnut Chart
We can use a Doughnut Chart from Syncfusion® WPF SfCharts for the payment breakdown UI, giving you a clear, visual representation of your loan’s overall cost. The chart displays the split between the total amount you repay and the amount of principal versus interest.
XAML
<syncfusion:SfChart ...>
<syncfusion:DoughnutSeries ItemsSource="{Binding EmiData}"
XBindingPath="XValue"
YBindingPath="YValue">
<syncfusion:DoughnutSeries.CenterView>
<ContentControl ...>
<StackPanel>
<Label Content="Total Payable Amount" .../>
<Label x:Name="viewLabel" .../>
</StackPanel>
</ContentControl>
</syncfusion:DoughnutSeries.CenterView>
</syncfusion:DoughnutSeries>
</syncfusion:SfChart>
At the center of the chart, a custom view is added using the CenterView property of the DoughnutSeries. It displays the total payable amount, combining principal and interest, and keeps this key figure clearly visible while making efficient use of the available space.
Advantages
- Immediate visual clarity: This feature highlights how much of the total payment goes to principal vs. interest, often revealing the actual cost of borrowing.
- Quick comparison: This tool lets you see at a glance how changing the loan parameters like reducing tenure or increasing EMI, reduces the interest burden.
Step 7: Highlight EMI
One of the most valuable insights you’ll get from the dashboard is your equated monthly installment. The dashboard immediately displays your updated monthly payment whenever you change your loan details.
Advantage
Financial planning: It allows us to know the precise EMI, which helps you assess affordability before committing to a loan.
Step 8: Analyze repayment progress
To analyze repayment progress, we will use Stacked Column and Line Charts.
Stacked Column Chart
The WPF Stacked Column Chart displays the yearly amounts paid toward principal and interest, stacked for each year.
XAML
<syncfusion:StackingColumnSeries ItemsSource="{Binding LoanStatusData}"
XBindingPath="Years"
YBindingPath="PrincipalPaid"
ShowTooltip="True"
TooltipTemplate="{StaticResource tooltiptemplate}"
LegendIcon="SeriesType"
Interior="#AA65D3"
Label="Principal Paid">
</syncfusion:StackingColumnSeries>
<syncfusion:StackingColumnSeries ItemsSource="{Binding LoanStatusData}"
XBindingPath="Years"
YBindingPath="InterestPaid"
ShowTooltip="True"
TooltipTemplate="{StaticResource tooltiptemplate}"
LegendIcon="SeriesType"
Interior="#F67373"
Label="Interest Paid" />
Advantages
- Compositional insight: It shows how principal and interest payment balance evolves annually.
- Actionable data: Encourages strategies to prepay loans or negotiate shorter tenures to reduce interest.
Line Chart
The LineSeries in the chart represents the gradual decrease of the remaining loan balance throughout the repayment schedule.
XAML
<syncfusion:LineSeries ItemsSource="{Binding LoanStatusData}"
XBindingPath="Years"
YBindingPath="BalanceAmount"
ShowTooltip="True"
TooltipTemplate="{StaticResource tooltiptemplate}"
Label="Balance" />
Advantages
- Progress visualization: At exactly what point does the balance drop below key thresholds or become fully paid?
- Forecasting: Illustrates how early repayments or rate adjustments affect total outstanding amounts.
Tooltip template
To improve data clarity and user interaction, define a custom tooltip using a ** DataTemplate** within the chart’s resources. This template presents detailed information for each data point, including the year, principal paid, interest paid, and remaining balance. It ensures consistent and informative tooltips across the stacked column and line charts.
Step 9: Organize repayment details in DataGrid
The dashboard’s detailed table, built with Syncfusion’s WPF SfDataGrid, organizes your repayment information in a way that’s easy to understand and review.
- Years
- Total payment made
- Principal paid
- Interest paid
- Remaining balance
XAML
<syncfusion:SfDataGrid ... ItemsSource="{Binding LoanStatusData}">
<syncfusion:GridTextColumn MappingName="Years" ... />
<syncfusion:GridTextColumn MappingName="Payments" ... />
<syncfusion:GridTextColumn MappingName="PrincipalPaid" ... />
<syncfusion:GridTextColumn MappingName="InterestPaid" ... />
<syncfusion:GridTextColumn MappingName="BalanceAmount" ... />
</syncfusion:SfDataGrid>
Advantages
- Detailed auditing: Users, analysts, or consultants can trace every data point in the loan journey, for validation, record-keeping, or compliance.
- Exportability: Syncfusion® grids are readily exportable so that data can be shared or saved in multiple formats for later use.
Use case
Professional reporting: The table view complements the visuals by giving transparent, exact data to support the dashboard’s charts.
Step 10: Implement the loan calculation workflow
The loan computations are implemented using the CalculateLoan method of the MainWindow class. This method performs the EMI calculation, per-month principal and interest allocation, groups results by year, and refreshes the collections bound to charts and grids.
C#
public partial class MainWindow : Window
{
. . .
private void CalculateLoan()
{
double principal = principleAmount;
double annualInterestRate = interestAmount;
int tenureYears = (int)loanPeriod;
int totalMonths = periodType == "Year" ? tenureYears * 12 : tenureYears;
double monthlyRate = annualInterestRate / (12 * 100);
double emi = principal * monthlyRate * Math.Pow(1 + monthlyRate, totalMonths) /
(Math.Pow(1 + monthlyRate, totalMonths) - 1);
if (!double.IsNaN(emi))
{
double balanceAmount = principal;
DateTime startDate = selectedDate;
viewModel.LoanStatusData.Clear();
months.Clear();
for (int i = 1; i <= totalMonths; i++)
{
double interest = balanceAmount * monthlyRate;
double principalPaid = emi - interest;
balanceAmount = Math.Max(0, balanceAmount - principalPaid);
months.Add(new MonthlyDetails()
{
Month = new DateTime(startDate.Year, startDate.Month, startDate.Day),
Payments = emi,
PrincipalPaid = principalPaid,
InterestPaid = interest,
BalanceAmount = balanceAmount
});
startDate = startDate.AddMonths(1);
}
var groupedByYear = months.GroupBy(m => m.Month.Year);
foreach (var yearGroup in groupedByYear)
{
viewModel.LoanStatusData.Add(new Model(
new DateTime(yearGroup.Key, 1, 1),
yearGroup.Sum(m => m.Payments),
Math.Round(yearGroup.Sum(m => m.InterestPaid), 2),
Math.Round(yearGroup.Sum(m => m.PrincipalPaid), 2),
Math.Round(yearGroup.Last().BalanceAmount, 2),
viewModel.MonntlyLoanStatusData = GetMonntlyLoanStatusData(yearGroup.Key)
));
}
double totalInterest = (emi * totalMonths) - principal;
double totalAmount = principal + totalInterest;
label.Content = "$" + emi.ToString("F2");
viewLabel.Content = "$" + totalAmount.ToString("F2");
viewModel.EmiData.Clear();
viewModel.EmiData.Add(new EMIModel("Principal Amount", principal));
viewModel.EmiData.Add(new EMIModel("Total Interest", Math.Round(totalInterest, 2)));
}
}
. . .
}
When you launch your loan calculator sample, all your charts and tables will update in real time, giving you a clear, professional, and actionable view of your loan scenario.
GitHub Reference
You can find the complete source code of this sample on GitHub.
Conclusion
Thanks for reading! Integrating Syncfusion® WPF Charts with DataGrid is central to constructing a responsive, data-driven loan calculator dashboard. This combination allows developers to compute and visualize both loan calculation data (EMI, interest, tenure) and loan repayment data (monthly breakdowns, amortization schedules) within a unified interface.
The dashboard delivers real-time updates and interactive insights using MVVM for data binding and UI synchronization. It suits financial applications that demand precision and clarity in desktop environments.
For existing Syncfusion® customers, the latest version of Essential Studio® is available from the license and downloads page. If you are not a customer, try our 30-day free trial to check out these new features.
If you require assistance, please don’t hesitate to contact us via our support forums, support portal, or feedback portal. We are always eager to help you! Stay tuned for next week’s featured Chart of the Week.
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This article was originally published at Syncfusion.com.
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