diff --git a/app/templates/index.html b/app/templates/index.html
index 1eb4a73..09bc243 100644
--- a/app/templates/index.html
+++ b/app/templates/index.html
@@ -176,8 +176,21 @@
           columns: cols,
         };
 
+        // add sum_amount to the footer using column calculations
+        // If you want to sum the "amount" column, add a bottomCalc to the column definition
+        cols.forEach(col => {
+          if (col.field === 'amount') {
+            col.bottomCalc = 'sum';
+            col.bottomCalcFormatter = cell => cell.getValue().toFixed(2);
+          }
+        });
+        // Recreate table with updated columns
         if (table) table.destroy();
-        table = new Tabulator('#table', opts);
+        table = new Tabulator('#table', {
+          ...opts,
+          columns: cols,
+        });
+
       } catch (err) {
         console.error(err); alert('Failed to load table data');
       } finally { hideLoading(); }