diff --git a/samples/XlsReaderBenchmark.php b/samples/XlsReaderBenchmark.php
new file mode 100644
index 000000000..a387e6107
--- /dev/null
+++ b/samples/XlsReaderBenchmark.php
@@ -0,0 +1,152 @@
+<?php
+
+/**
+ * Benchmark: XLS (BIFF8) Reader Performance.
+ *
+ * Generates .xls files of varying sizes with mixed numeric/string/formula
+ * content, then times repeated Xls reader loads, reporting median load
+ * times and peak memory usage.
+ *
+ * Usage:
+ *   php samples/XlsReaderBenchmark.php [iterations] [cellCounts]
+ *
+ * Examples:
+ *   php samples/XlsReaderBenchmark.php                # 5 iterations, 10000/50000/100000 cells
+ *   php samples/XlsReaderBenchmark.php 3 20000,80000  # 3 iterations, 20000 and 80000 cells
+ */
+
+use PhpOffice\PhpSpreadsheet\Reader\Xls as XlsReader;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Writer\Xls as XlsWriter;
+
+require __DIR__ . '/../vendor/autoload.php';
+
+$iterations = max(1, (int) ($argv[1] ?? 5));
+$cellCounts = array_map(intval(...), explode(',', $argv[2] ?? '10000,50000,100000'));
+$columnCount = 10;
+
+echo "=== XLS (BIFF8) Reader Benchmark ===\n";
+echo 'PHP version: ' . PHP_VERSION . "\n";
+echo "Iterations per size: {$iterations}\n";
+echo 'Cell counts: ' . implode(', ', $cellCounts) . "\n\n";
+
+/**
+ * Build an .xls file with mixed numeric, string and formula cells,
+ * plus enough styling to exercise the XF index mapping paths.
+ */
+function createXlsFile(int $cellCount, int $columnCount): string
+{
+    $rowCount = max(1, intdiv($cellCount, $columnCount));
+
+    $spreadsheet = new Spreadsheet();
+    $sheet = $spreadsheet->getActiveSheet();
+    $sheet->setTitle('Benchmark');
+
+    // Header row with styling
+    for ($col = 1; $col <= $columnCount; ++$col) {
+        $sheet->setCellValue([$col, 1], "Column{$col}");
+        $sheet->getStyle([$col, 1])->getFont()->setBold(true);
+    }
+
+    // Repeating strings exercise the shared string table (SST)
+    $labels = ['Alpha', 'Bravo', 'Charlie', 'Delta', 'Echo', 'Foxtrot'];
+    $labelCount = count($labels);
+
+    for ($row = 2; $row <= $rowCount + 1; ++$row) {
+        // Columns 1-4: numeric (RK / NUMBER records)
+        $sheet->setCellValue([1, $row], $row);
+        $sheet->setCellValue([2, $row], $row * 3.14159);
+        $sheet->setCellValue([3, $row], $row % 100);
+        $sheet->setCellValue([4, $row], round($row * 1.37, 2));
+
+        // Columns 5-8: strings (LABELSST records)
+        $sheet->setCellValue([5, $row], $labels[$row % $labelCount]);
+        $sheet->setCellValue([6, $row], "Item {$row}");
+        $sheet->setCellValue([7, $row], $labels[($row + 3) % $labelCount] . ' ' . ($row % 50));
+        $sheet->setCellValue([8, $row], 'Ref-' . str_pad((string) $row, 8, '0', STR_PAD_LEFT));
+
+        // Columns 9-10: formulas (FORMULA records)
+        $sheet->setCellValue([9, $row], "=B{$row}*D{$row}");
+        $sheet->setCellValue([10, $row], "=A{$row}+C{$row}");
+    }
+
+    // Number formats so cells carry non-default XF indexes
+    $sheet->getStyle("B2:B{$rowCount}")->getNumberFormat()->setFormatCode('#,##0.00');
+    $sheet->getStyle("D2:D{$rowCount}")->getNumberFormat()->setFormatCode('0.00');
+
+    $tempFile = tempnam(sys_get_temp_dir(), 'xls_bench_');
+    if ($tempFile === false) {
+        throw new RuntimeException('Unable to create temporary file');
+    }
+
+    $writer = new XlsWriter($spreadsheet);
+    $writer->save($tempFile);
+    $spreadsheet->disconnectWorksheets();
+
+    return $tempFile;
+}
+
+/** @param float[] $values */
+function median(array $values): float
+{
+    sort($values);
+    $count = count($values);
+    $middle = intdiv($count, 2);
+
+    if ($count % 2 === 0) {
+        return ($values[$middle - 1] + $values[$middle]) / 2;
+    }
+
+    return $values[$middle];
+}
+
+$results = [];
+
+foreach ($cellCounts as $cellCount) {
+    echo "--- {$cellCount} cells ---\n";
+
+    echo "Generating test file...\n";
+    $tempFile = createXlsFile($cellCount, $columnCount);
+    $fileSize = filesize($tempFile);
+    echo sprintf("File size: %.1fKB\n", ($fileSize ?: 0) / 1024);
+
+    $reader = new XlsReader();
+
+    // Warm up (autoloading, opcache)
+    $warmup = $reader->load($tempFile);
+    $warmup->disconnectWorksheets();
+    unset($warmup);
+    gc_collect_cycles();
+
+    $times = [];
+    for ($i = 0; $i < $iterations; ++$i) {
+        $start = hrtime(true);
+        $spreadsheet = $reader->load($tempFile);
+        $elapsedMs = (hrtime(true) - $start) / 1e6;
+
+        $times[] = $elapsedMs;
+        echo sprintf("Iteration %d: %.1fms\n", $i + 1, $elapsedMs);
+
+        $spreadsheet->disconnectWorksheets();
+        unset($spreadsheet);
+        gc_collect_cycles();
+    }
+
+    $medianMs = median($times);
+    $peakMb = memory_get_peak_usage(true) / 1048576;
+    echo sprintf("Median: %.1fms, Peak memory: %.1fMB\n\n", $medianMs, $peakMb);
+
+    $results[] = [
+        'cells' => $cellCount,
+        'median' => $medianMs,
+        'peak' => $peakMb,
+    ];
+
+    unlink($tempFile);
+}
+
+echo "--- Results ---\n";
+echo sprintf("%10s | %12s | %12s\n", 'Cells', 'Median (ms)', 'Peak (MB)');
+foreach ($results as $result) {
+    echo sprintf("%10d | %12.1f | %12.1f\n", $result['cells'], $result['median'], $result['peak']);
+}