diff --git a/apps/calculation/calculation.cpp b/apps/calculation/calculation.cpp
index 5839a50b0..f51dd5eae 100644
--- a/apps/calculation/calculation.cpp
+++ b/apps/calculation/calculation.cpp
@@ -11,20 +11,14 @@ Calculation::Calculation() :
   m_exactOutputText(),
   m_approximateOutputText(),
   m_input(nullptr),
-  m_inputLayout(nullptr),
   m_exactOutput(nullptr),
-  m_exactOutputLayout(nullptr),
   m_approximateOutput(nullptr),
-  m_approximateOutputLayout(nullptr),
+  m_height(-1),
   m_equalSign(EqualSign::Unknown)
 {
 }
 
 Calculation::~Calculation() {
-  if (m_inputLayout != nullptr) {
-    delete m_inputLayout;
-    m_inputLayout = nullptr;
-  }
   if (m_input != nullptr) {
     delete m_input;
     m_input = nullptr;
@@ -33,18 +27,10 @@ Calculation::~Calculation() {
     delete m_exactOutput;
     m_exactOutput = nullptr;
   }
-  if (m_exactOutputLayout != nullptr) {
-    delete m_exactOutputLayout;
-    m_exactOutputLayout = nullptr;
-  }
   if (m_approximateOutput != nullptr) {
     delete m_approximateOutput;
     m_approximateOutput = nullptr;
   }
-  if (m_approximateOutputLayout != nullptr) {
-    delete m_approximateOutputLayout;
-    m_approximateOutputLayout = nullptr;
-  }
 }
 
 Calculation& Calculation::operator=(const Calculation& other) {
@@ -78,6 +64,27 @@ void Calculation::setContent(const char * c, Context * context, Expression * ans
   m_approximateOutput->writeTextInBuffer(m_approximateOutputText, sizeof(m_approximateOutputText));
 }
 
+KDCoordinate Calculation::height(Context * context) {
+  if (m_height < 0) {
+    ExpressionLayout * inputLayout = createInputLayout();
+    KDCoordinate inputHeight = inputLayout->size().height();
+    delete inputLayout;
+    Poincare::ExpressionLayout * approximateLayout = createApproximateOutputLayout(context);
+    KDCoordinate approximateOutputHeight = approximateLayout->size().height();
+    if (shouldOnlyDisplayApproximateOutput(context)) {
+      m_height = inputHeight+approximateOutputHeight;
+    } else {
+      Poincare::ExpressionLayout * exactLayout = createExactOutputLayout(context);
+      KDCoordinate exactOutputHeight = exactLayout->size().height();
+      KDCoordinate outputHeight = max(exactLayout->baseline(), approximateLayout->baseline()) + max(exactOutputHeight-exactLayout->baseline(), approximateOutputHeight-approximateLayout->baseline());
+      delete exactLayout;
+      m_height = inputHeight + outputHeight;
+    }
+    delete approximateLayout;
+  }
+  return m_height;
+}
+
 const char * Calculation::inputText() {
   return m_inputText;
 }
@@ -97,11 +104,11 @@ Expression * Calculation::input() {
   return m_input;
 }
 
-ExpressionLayout * Calculation::inputLayout() {
-  if (m_inputLayout == nullptr && input() != nullptr) {
-    m_inputLayout = input()->createLayout(PrintFloat::Mode::Decimal, Expression::ComplexFormat::Cartesian);
+ExpressionLayout * Calculation::createInputLayout() {
+  if (input() != nullptr) {
+    return input()->createLayout(PrintFloat::Mode::Decimal, Expression::ComplexFormat::Cartesian);
   }
-  return m_inputLayout;
+  return nullptr;
 }
 
 bool Calculation::isEmpty() {
@@ -123,26 +130,15 @@ void Calculation::tidy() {
     delete m_input;
   }
   m_input = nullptr;
-  if (m_inputLayout != nullptr) {
-    delete m_inputLayout;
-  }
-  m_inputLayout = nullptr;
   if (m_exactOutput != nullptr) {
     delete m_exactOutput;
   }
   m_exactOutput = nullptr;
-  if (m_exactOutputLayout != nullptr) {
-    delete m_exactOutputLayout;
-  }
-  m_exactOutputLayout = nullptr;
   if (m_approximateOutput != nullptr) {
     delete m_approximateOutput;
   }
   m_approximateOutput = nullptr;
-  if (m_approximateOutputLayout != nullptr) {
-    delete m_approximateOutputLayout;
-  }
-  m_approximateOutputLayout = nullptr;
+  m_height = -1;
   m_equalSign = EqualSign::Unknown;
 }
 
@@ -155,11 +151,11 @@ Expression * Calculation::exactOutput(Context * context) {
   return m_exactOutput;
 }
 
-ExpressionLayout * Calculation::exactOutputLayout(Context * context) {
-  if (m_exactOutputLayout == nullptr && exactOutput(context) != nullptr) {
-    m_exactOutputLayout = exactOutput(context)->createLayout();
+ExpressionLayout * Calculation::createExactOutputLayout(Context * context) {
+  if (exactOutput(context) != nullptr) {
+    return exactOutput(context)->createLayout();
   }
-  return m_exactOutputLayout;
+  return nullptr;
 }
 
 Expression * Calculation::approximateOutput(Context * context) {
@@ -177,11 +173,11 @@ Expression * Calculation::approximateOutput(Context * context) {
   return m_approximateOutput;
 }
 
-ExpressionLayout * Calculation::approximateOutputLayout(Context * context) {
-  if (m_approximateOutputLayout == nullptr && approximateOutput(context) != nullptr) {
-    m_approximateOutputLayout = approximateOutput(context)->createLayout();
+ExpressionLayout * Calculation::createApproximateOutputLayout(Context * context) {
+  if (approximateOutput(context) != nullptr) {
+    return approximateOutput(context)->createLayout();
   }
-  return m_approximateOutputLayout;
+  return nullptr;
 }
 
 bool Calculation::shouldOnlyDisplayApproximateOutput(Context * context) {
diff --git a/apps/calculation/calculation.h b/apps/calculation/calculation.h
index 8a224cd69..68f692876 100644
--- a/apps/calculation/calculation.h
+++ b/apps/calculation/calculation.h
@@ -24,15 +24,16 @@ public:
   /* c.reset() is the equivalent of c = Calculation() without copy assingment. */
   void reset();
   void setContent(const char * c, Poincare::Context * context, Poincare::Expression * ansExpression);
+  KDCoordinate height(Poincare::Context * context);
   const char * inputText();
   const char * exactOutputText();
   const char * approximateOutputText();
   Poincare::Expression * input();
-  Poincare::ExpressionLayout * inputLayout();
+  Poincare::ExpressionLayout * createInputLayout();
   Poincare::Expression * approximateOutput(Poincare::Context * context);
   Poincare::Expression * exactOutput(Poincare::Context * context);
-  Poincare::ExpressionLayout * exactOutputLayout(Poincare::Context * context);
-  Poincare::ExpressionLayout * approximateOutputLayout(Poincare::Context * context);
+  Poincare::ExpressionLayout * createExactOutputLayout(Poincare::Context * context);
+  Poincare::ExpressionLayout * createApproximateOutputLayout(Poincare::Context * context);
   bool isEmpty();
   void tidy();
   bool shouldOnlyDisplayApproximateOutput(Poincare::Context * context);
@@ -46,11 +47,9 @@ private:
   char m_exactOutputText[k_printedExpressionSize];
   char m_approximateOutputText[k_printedExpressionSize];
   Poincare::Expression * m_input;
-  Poincare::ExpressionLayout * m_inputLayout;
   Poincare::Expression * m_exactOutput;
-  Poincare::ExpressionLayout * m_exactOutputLayout;
   Poincare::Expression * m_approximateOutput;
-  Poincare::ExpressionLayout * m_approximateOutputLayout;
+  KDCoordinate m_height;
   EqualSign m_equalSign;
 };
 
diff --git a/apps/calculation/history_controller.cpp b/apps/calculation/history_controller.cpp
index 90bffc092..a30e82b8c 100644
--- a/apps/calculation/history_controller.cpp
+++ b/apps/calculation/history_controller.cpp
@@ -158,17 +158,8 @@ KDCoordinate HistoryController::rowHeight(int j) {
     return 0;
   }
   Calculation * calculation = m_calculationStore->calculationAtIndex(j);
-  KDCoordinate inputHeight = calculation->inputLayout()->size().height();
   App * calculationApp = (App *)app();
-  Poincare::ExpressionLayout * approximateLayout = calculation->approximateOutputLayout(calculationApp->localContext());
-  KDCoordinate approximateOutputHeight = approximateLayout->size().height();
-  if (calculation->shouldOnlyDisplayApproximateOutput(calculationApp->localContext())) {
-    return inputHeight + approximateOutputHeight + 3*HistoryViewCell::k_digitVerticalMargin;
-  }
-  Poincare::ExpressionLayout * exactLayout = calculation->exactOutputLayout(calculationApp->localContext());
-  KDCoordinate exactOutputHeight = exactLayout->size().height();
-  KDCoordinate outputHeight = max(exactLayout->baseline(), approximateLayout->baseline()) + max(exactOutputHeight-exactLayout->baseline(), approximateOutputHeight-approximateLayout->baseline());
-  return inputHeight + outputHeight + 3*HistoryViewCell::k_digitVerticalMargin;
+  return calculation->height(calculationApp->localContext()) + 3*HistoryViewCell::k_digitVerticalMargin;
 }
 
 KDCoordinate HistoryController::cumulatedHeightFromIndex(int j) {
diff --git a/apps/calculation/history_view_cell.cpp b/apps/calculation/history_view_cell.cpp
index 3b901f486..7e38a02f8 100644
--- a/apps/calculation/history_view_cell.cpp
+++ b/apps/calculation/history_view_cell.cpp
@@ -9,12 +9,30 @@ namespace Calculation {
 
 HistoryViewCell::HistoryViewCell(Responder * parentResponder) :
   Responder(parentResponder),
+  m_inputLayout(nullptr),
+  m_exactOutputLayout(nullptr),
+  m_approximateOutputLayout(nullptr),
   m_inputView(this),
   m_scrollableOutputView(this),
   m_selectedSubviewType(HistoryViewCell::SubviewType::Output)
 {
 }
 
+HistoryViewCell::~HistoryViewCell() {
+  if (m_inputLayout != nullptr) {
+    delete m_inputLayout;
+    m_inputLayout = nullptr;
+  }
+  if (m_exactOutputLayout != nullptr) {
+    delete m_exactOutputLayout;
+    m_exactOutputLayout = nullptr;
+  }
+  if (m_approximateOutputLayout != nullptr) {
+    delete m_approximateOutputLayout;
+    m_approximateOutputLayout = nullptr;
+  }
+}
+
 OutputExpressionsView * HistoryViewCell::outputView() {
   return m_scrollableOutputView.outputView();
 
@@ -83,12 +101,27 @@ void HistoryViewCell::layoutSubviews() {
 }
 
 void HistoryViewCell::setCalculation(Calculation * calculation) {
-  m_inputView.setExpressionLayout(calculation->inputLayout());
+  if (m_inputLayout) {
+    delete m_inputLayout;
+  }
+  m_inputLayout = calculation->createInputLayout();
+  m_inputView.setExpressionLayout(m_inputLayout);
   App * calculationApp = (App *)app();
   /* Both output expressions have to be updated at the same time. The
    * outputView points to deleted layouts and a call to
    * outputView()->layoutSubviews() is going to fail. */
-  Poincare::ExpressionLayout * outputExpressions[2] = {calculation->approximateOutputLayout(calculationApp->localContext()), calculation->shouldOnlyDisplayApproximateOutput(calculationApp->localContext()) ? nullptr : calculation->exactOutputLayout(calculationApp->localContext())};
+  if (m_exactOutputLayout) {
+    delete m_exactOutputLayout;
+    m_exactOutputLayout = nullptr;
+  }
+  if (!calculation->shouldOnlyDisplayApproximateOutput(calculationApp->localContext())) {
+    m_exactOutputLayout = calculation->createExactOutputLayout(calculationApp->localContext());
+  }
+  if (m_approximateOutputLayout) {
+    delete m_approximateOutputLayout;
+  }
+  m_approximateOutputLayout = calculation->createApproximateOutputLayout(calculationApp->localContext());
+  Poincare::ExpressionLayout * outputExpressions[2] = {m_approximateOutputLayout, m_exactOutputLayout};
   m_scrollableOutputView.outputView()->setExpressions(outputExpressions);
   I18n::Message equalMessage = calculation->exactAndApproximateDisplayedOutputsAreEqual(calculationApp->localContext()) == Calculation::EqualSign::Equal ? I18n::Message::Equal : I18n::Message::AlmostEqual;
   m_scrollableOutputView.outputView()->setEqualMessage(equalMessage);
diff --git a/apps/calculation/history_view_cell.h b/apps/calculation/history_view_cell.h
index d6ca3c1d5..d99063038 100644
--- a/apps/calculation/history_view_cell.h
+++ b/apps/calculation/history_view_cell.h
@@ -15,6 +15,7 @@ public:
     Output
   };
   HistoryViewCell(Responder * parentResponder);
+  ~HistoryViewCell();
   void reloadCell() override;
   void reloadScroll();
   void setEven(bool even) override;
@@ -35,6 +36,9 @@ public:
   OutputExpressionsView * outputView();
 private:
   constexpr static KDCoordinate k_resultWidth = 80;
+  Poincare::ExpressionLayout * m_inputLayout;
+  Poincare::ExpressionLayout * m_exactOutputLayout;
+  Poincare::ExpressionLayout * m_approximateOutputLayout;
   ScrollableExpressionView m_inputView;
   ScrollableOutputExpressionsView m_scrollableOutputView;
   SubviewType m_selectedSubviewType;