diff --git a/src/Spout/Writer/Common/Helper/CellHelper.php b/src/Spout/Writer/Common/Helper/CellHelper.php
index 50ead93..0bee960 100644
--- a/src/Spout/Writer/Common/Helper/CellHelper.php
+++ b/src/Spout/Writer/Common/Helper/CellHelper.php
@@ -64,6 +64,17 @@ class CellHelper
         return (gettype($value) === 'string' && $value !== '');
     }
 
+    /**
+     * Returns whether the given value looks like a formula
+     *
+     * @param $value
+     * @return bool whether the given value looks like a formula
+     */
+    public static function isFormulaString($value)
+    {
+        return (strpos($value,'=') === 0);
+    }
+
     /**
      * Returns whether the given value is numeric.
      * A numeric value is from type "integer" or "double" ("float" is not returned by gettype).