diff --git a/financial-analysis/scripts/recalc.py b/financial-analysis/scripts/recalc.py
new file mode 100644
index 0000000..b7c4d17
--- /dev/null
+++ b/financial-analysis/scripts/recalc.py
@@ -0,0 +1,140 @@
+#!/usr/bin/env python3
+"""
+recalc.py — Excel formula recalculation and error detection.
+
+Opens an openpyxl-generated .xlsx file, scans all cells for formula error
+values (#REF!, #DIV/0!, #VALUE!, #NAME?, #NULL!, #N/A, #NUM!), and reports
+results as JSON.
+
+Usage:
+    python recalc.py <excel_file> [timeout_seconds]
+
+Output (JSON):
+    {
+      "status": "success" | "errors_found",
+      "total_errors": int,
+      "total_formulas": int,
+      "error_summary": {
+          "#REF!": {"count": N, "locations": ["Sheet!A1", ...]},
+          ...
+      }
+    }
+"""
+
+import json
+import signal
+import sys
+from pathlib import Path
+
+EXCEL_ERRORS = {
+    "#REF!", "#DIV/0!", "#VALUE!", "#NAME?", "#NULL!", "#N/A", "#NUM!"
+}
+
+
+def recalc(excel_path: str) -> dict:
+    """Scan an Excel file for formula errors and return a structured report."""
+    try:
+        import openpyxl
+    except ImportError:
+        return {
+            "status": "errors_found",
+            "total_errors": 1,
+            "total_formulas": 0,
+            "error_summary": {
+                "ImportError": {
+                    "count": 1,
+                    "locations": ["openpyxl not installed. Run: pip install openpyxl"],
+                }
+            },
+        }
+
+    path = Path(excel_path)
+    if not path.exists():
+        print(f"Error: File not found: {excel_path}", file=sys.stderr)
+        sys.exit(1)
+
+    # Load with data_only=False to see formulas, and data_only=True to see
+    # cached values (which is where Excel stores error results).
+    wb_formulas = openpyxl.load_workbook(str(path), data_only=False)
+    wb_values = openpyxl.load_workbook(str(path), data_only=True)
+
+    total_formulas = 0
+    error_summary: dict[str, dict] = {}
+
+    for sheet_name in wb_formulas.sheetnames:
+        ws_formulas = wb_formulas[sheet_name]
+        ws_values = wb_values[sheet_name]
+
+        for row in ws_formulas.iter_rows():
+            for cell in row:
+                # Check if cell contains a formula
+                if isinstance(cell.value, str) and cell.value.startswith("="):
+                    total_formulas += 1
+
+                    # Get the cached value from the data_only workbook
+                    val_cell = ws_values[cell.coordinate]
+                    cached = val_cell.value
+
+                    # Check for error values in cached result
+                    if isinstance(cached, str) and cached in EXCEL_ERRORS:
+                        loc = f"{sheet_name}!{cell.coordinate}"
+                        if cached not in error_summary:
+                            error_summary[cached] = {"count": 0, "locations": []}
+                        error_summary[cached]["count"] += 1
+                        error_summary[cached]["locations"].append(loc)
+
+    total_errors = sum(e["count"] for e in error_summary.values())
+
+    result = {
+        "status": "success" if total_errors == 0 else "errors_found",
+        "total_errors": total_errors,
+        "total_formulas": total_formulas,
+    }
+    if total_errors > 0:
+        result["error_summary"] = error_summary
+
+    return result
+
+
+def main():
+    if len(sys.argv) < 2:
+        print("Usage: python recalc.py <excel_file> [timeout_seconds]", file=sys.stderr)
+        sys.exit(1)
+
+    excel_path = sys.argv[1]
+    timeout = int(sys.argv[2]) if len(sys.argv) > 2 else 30
+
+    # Set timeout (Unix only; silently skip on Windows)
+    if hasattr(signal, "SIGALRM"):
+        def _timeout_handler(signum, frame):
+            print(
+                json.dumps(
+                    {
+                        "status": "errors_found",
+                        "total_errors": 1,
+                        "total_formulas": 0,
+                        "error_summary": {
+                            "Timeout": {
+                                "count": 1,
+                                "locations": [f"Exceeded {timeout}s limit"],
+                            }
+                        },
+                    }
+                )
+            )
+            sys.exit(1)
+
+        signal.signal(signal.SIGALRM, _timeout_handler)
+        signal.alarm(timeout)
+
+    result = recalc(excel_path)
+    print(json.dumps(result, indent=2))
+
+    if hasattr(signal, "SIGALRM"):
+        signal.alarm(0)
+
+    sys.exit(0 if result["status"] == "success" else 1)
+
+
+if __name__ == "__main__":
+    main()