diff --git a/src/PhpSpreadsheet/Style/Alignment.php b/src/PhpSpreadsheet/Style/Alignment.php
index a50229930d..605bcb91b3 100644
--- a/src/PhpSpreadsheet/Style/Alignment.php
+++ b/src/PhpSpreadsheet/Style/Alignment.php
@@ -223,6 +223,7 @@ public function applyFromArray(array $styleArray): static
                 $this->setReadOrder($styleArray['readOrder']);
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -259,6 +260,7 @@ public function setHorizontal(string $horizontalAlignment): static
         } else {
             $this->horizontal = $horizontalAlignment;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -288,6 +290,7 @@ public function setJustifyLastLine(bool $justifyLastLine): static
         } else {
             $this->justifyLastLine = $justifyLastLine;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -321,6 +324,7 @@ public function setVertical(string $verticalAlignment): static
         } else {
             $this->vertical = $verticalAlignment;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -360,6 +364,7 @@ public function setTextRotation(int $angleInDegrees): static
         } else {
             throw new PhpSpreadsheetException('Text rotation should be a value between -90 and 90.');
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -392,6 +397,7 @@ public function setWrapText(bool $wrapped): static
         } else {
             $this->wrapText = $wrapped;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -424,6 +430,7 @@ public function setShrinkToFit(bool $shrink): static
         } else {
             $this->shrinkToFit = $shrink;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -463,6 +470,7 @@ public function setIndent(int $indent): static
         } else {
             $this->indent = $indent;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -495,22 +503,17 @@ public function setReadOrder(int $readOrder): static
         } else {
             $this->readOrder = $readOrder;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
 
     /**
-     * Get hash code.
-     *
-     * @return string Hash code
+     * Update Hash when something changes.
      */
-    public function getHashCode(): string
+    protected function updateHash(): void
     {
-        if ($this->isSupervisor) {
-            return $this->getSharedComponent()->getHashCode();
-        }
-
-        return md5(
+        $this->md5Sum = md5(
             $this->horizontal
             . (($this->justifyLastLine === null) ? 'null' : ($this->justifyLastLine ? 't' : 'f'))
             . $this->vertical
@@ -521,6 +524,25 @@ public function getHashCode(): string
             . $this->readOrder
             . __CLASS__
         );
+        $this->updateMd5Sum = false;
+    }
+
+    /**
+     * Get hash code.
+     *
+     * @return string Hash code
+     */
+    public function getHashCode(): string
+    {
+        if ($this->isSupervisor) {
+            return $this->getSharedComponent()->getHashCode();
+        }
+
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
     }
 
     protected function exportArray1(): array
diff --git a/src/PhpSpreadsheet/Style/Border.php b/src/PhpSpreadsheet/Style/Border.php
index 07162566db..9c7fba043e 100644
--- a/src/PhpSpreadsheet/Style/Border.php
+++ b/src/PhpSpreadsheet/Style/Border.php
@@ -122,6 +122,7 @@ public function applyFromArray(array $styleArray): static
                 $this->getColor()->applyFromArray($styleArray['color']);
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -160,6 +161,7 @@ public function setBorderStyle(bool|string $style): static
         } else {
             $this->borderStyle = $style;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -188,10 +190,24 @@ public function setColor(Color $color): static
         } else {
             $this->color = $color;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
 
+    /**
+     * Update Hash when something changes.
+     */
+    protected function updateHash(): void
+    {
+        $this->md5Sum = md5(
+            $this->borderStyle
+            . $this->color->getHashCode()
+            . __CLASS__
+        );
+        $this->updateMd5Sum = false;
+    }
+
     /**
      * Get hash code.
      *
@@ -203,11 +219,11 @@ public function getHashCode(): string
             return $this->getSharedComponent()->getHashCode();
         }
 
-        return md5(
-            $this->borderStyle
-            . $this->color->getHashCode()
-            . __CLASS__
-        );
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
     }
 
     protected function exportArray1(): array
diff --git a/src/PhpSpreadsheet/Style/Borders.php b/src/PhpSpreadsheet/Style/Borders.php
index 1d23af3b4c..e8b29eca5a 100644
--- a/src/PhpSpreadsheet/Style/Borders.php
+++ b/src/PhpSpreadsheet/Style/Borders.php
@@ -199,6 +199,7 @@ public function applyFromArray(array $styleArray): static
                 $this->getBottom()->applyFromArray($styleArray['allBorders']);
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -330,22 +331,17 @@ public function setDiagonalDirection(int $direction): static
         } else {
             $this->diagonalDirection = $direction;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
 
     /**
-     * Get hash code.
-     *
-     * @return string Hash code
+     * Update Hash when something changes.
      */
-    public function getHashCode(): string
+    protected function updateHash(): void
     {
-        if ($this->isSupervisor) {
-            return $this->getSharedComponent()->getHashcode();
-        }
-
-        return md5(
+        $this->md5Sum = md5(
             $this->getLeft()->getHashCode()
             . $this->getRight()->getHashCode()
             . $this->getTop()->getHashCode()
@@ -356,6 +352,24 @@ public function getHashCode(): string
         );
     }
 
+    /**
+     * Get hash code.
+     *
+     * @return string Hash code
+     */
+    public function getHashCode(): string
+    {
+        if ($this->isSupervisor) {
+            return $this->getSharedComponent()->getHashcode();
+        }
+
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
+    }
+
     protected function exportArray1(): array
     {
         $exportedArray = [];
diff --git a/src/PhpSpreadsheet/Style/Color.php b/src/PhpSpreadsheet/Style/Color.php
index 8aa4734fc9..3c80cd8674 100644
--- a/src/PhpSpreadsheet/Style/Color.php
+++ b/src/PhpSpreadsheet/Style/Color.php
@@ -246,6 +246,7 @@ public function setARGB(?string $colorValue = self::COLOR_BLACK, bool $nullStrin
         } else {
             $this->argb = $colorValue;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -384,6 +385,18 @@ public static function indexedColor(int $colorIndex, bool $background = false, ?
         return ($background) ? new self(self::COLOR_WHITE) : new self(self::COLOR_BLACK);
     }
 
+    /**
+     * Update Hash when something changes.
+     */
+    protected function updateHash(): void
+    {
+        $this->md5Sum = md5(
+            $this->argb
+            . __CLASS__
+        );
+        $this->updateMd5Sum = false;
+    }
+
     /**
      * Get hash code.
      *
@@ -395,10 +408,11 @@ public function getHashCode(): string
             return $this->getSharedComponent()->getHashCode();
         }
 
-        return md5(
-            $this->argb
-            . __CLASS__
-        );
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
     }
 
     protected function exportArray1(): array
diff --git a/src/PhpSpreadsheet/Style/Fill.php b/src/PhpSpreadsheet/Style/Fill.php
index 9ec5d7336e..d0de784744 100644
--- a/src/PhpSpreadsheet/Style/Fill.php
+++ b/src/PhpSpreadsheet/Style/Fill.php
@@ -177,6 +177,7 @@ public function setFillType(string $fillType): static
         } else {
             $this->fillType = $fillType;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -206,6 +207,7 @@ public function setRotation(float $angleInDegrees): static
         } else {
             $this->rotation = $angleInDegrees;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -235,6 +237,7 @@ public function setStartColor(Color $color): static
         } else {
             $this->startColor = $color;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -264,6 +267,7 @@ public function setEndColor(Color $color): static
         } else {
             $this->endColor = $color;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -279,6 +283,18 @@ public function getColorsChanged(): bool
         return $changed || $this->startColor->getHasChanged() || $this->endColor->getHasChanged();
     }
 
+    protected function updateHash(): void
+    {
+        $this->md5Sum = md5(
+            $this->getFillType()
+            . $this->getRotation()
+            . ($this->getFillType() !== self::FILL_NONE ? $this->getStartColor()->getHashCode() : '')
+            . ($this->getFillType() !== self::FILL_NONE ? $this->getEndColor()->getHashCode() : '')
+            . ((string) $this->getColorsChanged())
+            . __CLASS__
+        );
+    }
+
     /**
      * Get hash code.
      *
@@ -290,16 +306,11 @@ public function getHashCode(): string
             return $this->getSharedComponent()->getHashCode();
         }
 
-        // Note that we don't care about colours for fill type NONE, but could have duplicate NONEs with
-        //  different hashes if we don't explicitly prevent this
-        return md5(
-            $this->getFillType()
-            . $this->getRotation()
-            . ($this->getFillType() !== self::FILL_NONE ? $this->getStartColor()->getHashCode() : '')
-            . ($this->getFillType() !== self::FILL_NONE ? $this->getEndColor()->getHashCode() : '')
-            . ((string) $this->getColorsChanged())
-            . __CLASS__
-        );
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
     }
 
     protected function exportArray1(): array
diff --git a/src/PhpSpreadsheet/Style/Font.php b/src/PhpSpreadsheet/Style/Font.php
index 7d70dc4f7a..5fd1997b0f 100644
--- a/src/PhpSpreadsheet/Style/Font.php
+++ b/src/PhpSpreadsheet/Style/Font.php
@@ -217,6 +217,7 @@ public function applyFromArray(array $styleArray): static
                 $this->setCap($styleArray['cap']);
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -274,6 +275,7 @@ public function setName(string $fontname): self
         } else {
             $this->name = $fontname;
         }
+        $this->updateHashBeforeUse();
 
         return $this->setScheme('');
     }
@@ -292,6 +294,7 @@ public function setLatin(string $fontname): self
             $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
             // @codeCoverageIgnoreEnd
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -310,6 +313,7 @@ public function setEastAsian(string $fontname): self
             $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
             // @codeCoverageIgnoreEnd
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -328,6 +332,7 @@ public function setComplexScript(string $fontname): self
             $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
             // @codeCoverageIgnoreEnd
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -371,6 +376,7 @@ public function setSize(mixed $sizeInPoints, bool $nullOk = false): static
         } else {
             $this->size = $sizeInPoints;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -403,6 +409,7 @@ public function setBold(bool $bold): static
         } else {
             $this->bold = $bold;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -435,6 +442,7 @@ public function setItalic(bool $italic): static
         } else {
             $this->italic = $italic;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -467,6 +475,7 @@ public function setSuperscript(bool $superscript): static
                 $this->subscript = false;
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -499,6 +508,7 @@ public function setSubscript(bool $subscript): static
                 $this->superscript = false;
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -523,6 +533,7 @@ public function setBaseLine(int $baseLine): self
             $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
             // @codeCoverageIgnoreEnd
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -547,6 +558,7 @@ public function setStrikeType(string $strikeType): self
             $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
             // @codeCoverageIgnoreEnd
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -571,6 +583,7 @@ public function setUnderlineColor(array $colorArray): self
             $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
             // @codeCoverageIgnoreEnd
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -595,6 +608,7 @@ public function setChartColor(array $colorArray): self
             $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
             // @codeCoverageIgnoreEnd
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -602,6 +616,7 @@ public function setChartColor(array $colorArray): self
     public function setChartColorFromObject(?ChartColor $chartColor): self
     {
         $this->chartColor = $chartColor;
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -640,6 +655,7 @@ public function setUnderline($underlineStyle): static
         } else {
             $this->underline = $underlineStyle;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -673,6 +689,7 @@ public function setStrikethrough(bool $strikethru): static
         } else {
             $this->strikethrough = $strikethru;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -701,6 +718,7 @@ public function setColor(Color $color): static
         } else {
             $this->color = $color;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -718,17 +736,11 @@ private function hashChartColor(?ChartColor $underlineColor): string
     }
 
     /**
-     * Get hash code.
-     *
-     * @return string Hash code
+     * Update Hash when something changes.
      */
-    public function getHashCode(): string
+    protected function updateHash(): void
     {
-        if ($this->isSupervisor) {
-            return $this->getSharedComponent()->getHashCode();
-        }
-
-        return md5(
+        $this->md5Sum = md5(
             $this->name
             . $this->size
             . ($this->bold ? 't' : 'f')
@@ -754,6 +766,25 @@ public function getHashCode(): string
             )
             . __CLASS__
         );
+        $this->updateMd5Sum = false;
+    }
+
+    /**
+     * Get hash code.
+     *
+     * @return string Hash code
+     */
+    public function getHashCode(): string
+    {
+        if ($this->isSupervisor) {
+            return $this->getSharedComponent()->getHashCode();
+        }
+
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
     }
 
     protected function exportArray1(): array
@@ -800,6 +831,7 @@ public function setScheme(string $scheme): self
                 $this->scheme = $scheme;
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -814,6 +846,7 @@ public function setScheme(string $scheme): self
     public function setCap(string $cap): self
     {
         $this->cap = in_array($cap, self::VALID_CAPS, true) ? $cap : null;
+        $this->updateHashBeforeUse();
 
         return $this;
     }
diff --git a/src/PhpSpreadsheet/Style/NumberFormat.php b/src/PhpSpreadsheet/Style/NumberFormat.php
index 9c9a54560e..1c1a8163de 100644
--- a/src/PhpSpreadsheet/Style/NumberFormat.php
+++ b/src/PhpSpreadsheet/Style/NumberFormat.php
@@ -256,6 +256,7 @@ public function setFormatCode(string $formatCode): static
             $this->formatCode = $formatCode;
             $this->builtInFormatCode = self::builtInFormatCodeIndex($formatCode);
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -290,6 +291,7 @@ public function setBuiltInFormatCode(int $formatCodeIndex): static
             $this->builtInFormatCode = $formatCodeIndex;
             $this->formatCode = self::builtInFormatCode($formatCodeIndex);
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -434,6 +436,19 @@ public static function builtInFormatCodeIndex(string $formatCodeIndex)
         return false;
     }
 
+    /**
+     * Update Hash when something changes.
+     */
+    protected function updateHash(): void
+    {
+        $this->md5Sum = md5(
+            $this->formatCode
+            . $this->builtInFormatCode
+            . __CLASS__
+        );
+        $this->updateMd5Sum = false;
+    }
+
     /**
      * Get hash code.
      *
@@ -445,11 +460,11 @@ public function getHashCode(): string
             return $this->getSharedComponent()->getHashCode();
         }
 
-        return md5(
-            $this->formatCode
-            . $this->builtInFormatCode
-            . __CLASS__
-        );
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Style/Protection.php b/src/PhpSpreadsheet/Style/Protection.php
index 55a6526c88..3bc970b6da 100644
--- a/src/PhpSpreadsheet/Style/Protection.php
+++ b/src/PhpSpreadsheet/Style/Protection.php
@@ -89,6 +89,7 @@ public function applyFromArray(array $styleArray): static
                 $this->setHidden($styleArray['hidden']);
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -120,6 +121,7 @@ public function setLocked(string $lockType): static
         } else {
             $this->locked = $lockType;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -151,10 +153,24 @@ public function setHidden(string $hiddenType): static
         } else {
             $this->hidden = $hiddenType;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
 
+    /**
+     * Update Hash when something changes.
+     */
+    protected function updateHash(): void
+    {
+        $this->md5Sum = md5(
+            $this->locked
+            . $this->hidden
+            . __CLASS__
+        );
+        $this->updateMd5Sum = false;
+    }
+
     /**
      * Get hash code.
      *
@@ -166,11 +182,11 @@ public function getHashCode(): string
             return $this->getSharedComponent()->getHashCode();
         }
 
-        return md5(
-            $this->locked
-            . $this->hidden
-            . __CLASS__
-        );
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
     }
 
     protected function exportArray1(): array
diff --git a/src/PhpSpreadsheet/Style/Style.php b/src/PhpSpreadsheet/Style/Style.php
index 7d36489af6..0f403e5ceb 100644
--- a/src/PhpSpreadsheet/Style/Style.php
+++ b/src/PhpSpreadsheet/Style/Style.php
@@ -340,6 +340,7 @@ public function applyFromArray(array $styleArray, bool $advancedBorders = true):
 
                 // restore initial cell selection range
                 $this->getActiveSheet()->getStyle($pRange);
+                $this->updateHashBeforeUse();
 
                 return $this;
             }
@@ -485,6 +486,7 @@ public function applyFromArray(array $styleArray, bool $advancedBorders = true):
                 $this->quotePrefix = $styleArray['quotePrefix'];
             }
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -562,6 +564,7 @@ public function getFont(): Font
     public function setFont(Font $font): static
     {
         $this->font = $font;
+        $this->updateHashBeforeUse();
 
         return $this;
     }
@@ -650,18 +653,17 @@ public function setQuotePrefix(bool $quotePrefix): static
         } else {
             $this->quotePrefix = (bool) $quotePrefix;
         }
+        $this->updateHashBeforeUse();
 
         return $this;
     }
 
     /**
-     * Get hash code.
-     *
-     * @return string Hash code
+     * Update Hash when something changes.
      */
-    public function getHashCode(): string
+    protected function updateHash(): void
     {
-        return md5(
+        $this->md5Sum = md5(
             $this->fill->getHashCode()
             . $this->font->getHashCode()
             . $this->borders->getHashCode()
@@ -671,6 +673,21 @@ public function getHashCode(): string
             . ($this->quotePrefix ? 't' : 'f')
             . __CLASS__
         );
+        $this->updateMd5Sum = false;
+    }
+
+    /**
+     * Get hash code.
+     *
+     * @return string Hash code
+     */
+    public function getHashCode(): string
+    {
+        if ($this->updateMd5Sum) {
+            $this->updateHash();
+        }
+
+        return $this->md5Sum;
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Style/Supervisor.php b/src/PhpSpreadsheet/Style/Supervisor.php
index 8388ef6cd7..4487dc47fa 100644
--- a/src/PhpSpreadsheet/Style/Supervisor.php
+++ b/src/PhpSpreadsheet/Style/Supervisor.php
@@ -20,6 +20,16 @@ abstract class Supervisor implements IComparable
      */
     protected $parent;
 
+    /**
+     * md5sum.
+     */
+    protected string $md5Sum = '';
+
+    /**
+     * do we need to recalculate the md5sum when next asked.
+     */
+    protected bool $updateMd5Sum = true;
+
     /**
      * Parent property name.
      */
@@ -51,6 +61,14 @@ public function bindParent(Spreadsheet|self $parent, ?string $parentPropertyName
         return $this;
     }
 
+    /**
+     * update the md5sum before next use.
+     */
+    public function updateHashBeforeUse(): void
+    {
+        $this->updateMd5Sum = true;
+    }
+
     /**
      * Is this a supervisor or a cell style component?
      */
@@ -89,6 +107,11 @@ public function getActiveCell(): string
         return $this->getActiveSheet()->getActiveCell();
     }
 
+    /**
+     * Update Hash when something changes.
+     */
+    abstract protected function updateHash(): void;
+
     /**
      * Implement PHP __clone to create a deep clone, not just a shallow copy.
      */