diff --git a/src/main/java/dev/sillyangel/calc/BaseConverter.java b/src/main/java/dev/sillyangel/calc/BaseConverter.java
new file mode 100644
index 0000000..8c19789
--- /dev/null
+++ b/src/main/java/dev/sillyangel/calc/BaseConverter.java
@@ -0,0 +1,110 @@
+package dev.sillyangel.calc;
+
+import java.awt.BorderLayout;
+import java.awt.FlowLayout;
+import java.awt.GridLayout;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import javax.swing.JButton;
+import javax.swing.JComboBox;
+import javax.swing.JDialog;
+import javax.swing.JLabel;
+import javax.swing.JOptionPane;
+import javax.swing.JPanel;
+import javax.swing.JTextField;
+import javax.swing.border.EmptyBorder;
+
+public class BaseConverter {
+    private Calculator ci;
+    private JDialog BaseConverterDialog;
+    private JTextField inputField;
+    private JComboBox<String> fromBaseComboBox;
+    private JComboBox<String> toBaseComboBox;
+    private JLabel resultLabel;
+
+    public BaseConverter(Calculator ci) {
+        System.out.println("Initialized BaseConverter");
+        this.ci = ci;
+    }
+
+    public void BaseConverterGUI() {
+        BaseConverterDialog = new JDialog(this.ci, "Base System Converter");
+        BaseConverterDialog.setSize(400, 250);
+        BaseConverterDialog.setLocationRelativeTo(this.ci);
+        BaseConverterDialog.setLayout(new BorderLayout(10, 10));
+
+
+        JPanel inputPanel = new JPanel();
+        inputPanel.setBorder(new EmptyBorder(10, 10, 10, 10));
+        inputPanel.setLayout(new GridLayout(0, 2, 10, 10));
+
+        inputPanel.add(new JLabel("Input Number:"));
+        inputField = new JTextField(20);
+        inputPanel.add(inputField);
+
+        String[] bases = {"Binary (2)", "Octal (8)", "Decimal (10)", "Hexadecimal (16)"};
+        inputPanel.add(new JLabel("From Base:"));
+        fromBaseComboBox = new JComboBox<>(bases);
+        inputPanel.add(fromBaseComboBox);
+
+        inputPanel.add(new JLabel("To Base:"));
+        toBaseComboBox = new JComboBox<>(bases);
+        toBaseComboBox.setSelectedIndex(2); 
+        inputPanel.add(toBaseComboBox);
+
+        BaseConverterDialog.add(inputPanel, BorderLayout.CENTER);
+
+
+        JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
+        JButton convertButton = new JButton("Convert");
+        convertButton.addActionListener(new ActionListener() {
+            @Override
+            public void actionPerformed(ActionEvent e) {
+                convert();
+            }
+        });
+        buttonPanel.add(convertButton);
+        BaseConverterDialog.add(buttonPanel, BorderLayout.SOUTH);
+
+        // --- Result Panel ---
+        JPanel resultPanel = new JPanel();
+        resultPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
+        resultPanel.add(new JLabel("Result:"));
+        resultLabel = new JLabel("0");
+        resultPanel.add(resultLabel);
+        BaseConverterDialog.add(resultPanel, BorderLayout.NORTH); 
+        BaseConverterDialog.setVisible(true);
+    }
+
+    private void convert() {
+        String input = inputField.getText().trim();
+        if (input.isEmpty()) {
+            JOptionPane.showMessageDialog(BaseConverterDialog, "Please enter a number.", "Error", JOptionPane.ERROR_MESSAGE);
+            return;
+        }
+
+        int fromBase = getBaseFromComboBox(fromBaseComboBox);
+        int toBase = getBaseFromComboBox(toBaseComboBox);
+
+        try {
+            // 1. Convert from source base string to a standard long
+            long decimalValue = Long.parseLong(input, fromBase);
+
+            // 2. Convert from the standard long to the target base string
+            String result = Long.toString(decimalValue, toBase).toUpperCase();
+
+            resultLabel.setText(result);
+
+        } catch (NumberFormatException e) {
+            JOptionPane.showMessageDialog(BaseConverterDialog, "Invalid input for the selected 'From Base'. Please check your number.", "Error", JOptionPane.ERROR_MESSAGE);
+        } catch (Exception e) {
+            JOptionPane.showMessageDialog(BaseConverterDialog, "An unexpected error occurred: " + e.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
+        }
+    }
+
+    private int getBaseFromComboBox(JComboBox<String> comboBox) {
+        String selected = (String) comboBox.getSelectedItem();
+        // Extract the number from the string e.g., "Binary (2)" -> 2
+        return Integer.parseInt(selected.replaceAll("[^0-9]", ""));
+    }
+}
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