diff --git a/apps/probability/calculation/finite_integral_calculation.cpp b/apps/probability/calculation/finite_integral_calculation.cpp
index faffc59a4..d843c88dd 100644
--- a/apps/probability/calculation/finite_integral_calculation.cpp
+++ b/apps/probability/calculation/finite_integral_calculation.cpp
@@ -1,4 +1,5 @@
 #include "finite_integral_calculation.h"
+#include "../law/normal_law.h"
 #include <assert.h>
 #include <ion.h>
 #include <math.h>
@@ -23,6 +24,9 @@ int FiniteIntegralCalculation::numberOfParameters() {
 }
 
 int FiniteIntegralCalculation::numberOfEditableParameters() {
+  if (m_law->type() == Law::Type::Normal) {
+    return 3;
+  }
   return 2;
 }
 
@@ -76,6 +80,13 @@ void FiniteIntegralCalculation::compute(int indexKnownElement) {
   if (m_law == nullptr) {
     return;
   }
+  if (indexKnownElement == 2) {
+    assert(m_law->type() == Law::Type::Normal);
+    float p = (1.0f+m_result)/2.0f;
+    float a = ((NormalLaw *)m_law)->cumulativeDistributiveInverseForProbability(&p);
+    m_lowerBound = roundf((2.0f*m_law->parameterValueAtIndex(0)-a)/k_precision)*k_precision;
+    m_upperBound = roundf(a/k_precision)*k_precision;
+  }
   m_result = m_law->finiteIntegralBetweenAbscissas(m_lowerBound, m_upperBound);
   /* Results in probability application are rounder to 3 decimals */
   m_result = roundf(m_result/k_precision)*k_precision;
diff --git a/apps/probability/calculation_controller.cpp b/apps/probability/calculation_controller.cpp
index ebdae47c1..580fee545 100644
--- a/apps/probability/calculation_controller.cpp
+++ b/apps/probability/calculation_controller.cpp
@@ -82,13 +82,13 @@ void CalculationController::ContentView::layoutSubviews() {
   KDCoordinate numberOfCharacters = strlen(I18n::translate(m_calculation->legendForParameterAtIndex(0)));
   m_text[0].setFrame(KDRect(xCoordinate, titleHeight+ImageTableView::k_totalMargin, numberOfCharacters*charSize.width(), ImageCell::k_height));
   xCoordinate += numberOfCharacters*charSize.width() + k_textWidthMargin;
-  m_calculationCell[0].setFrame(KDRect(xCoordinate, titleHeight+ImageTableView::k_totalMargin, k_textFieldWidth, ImageCell::k_height));
-  xCoordinate += k_textFieldWidth + k_textWidthMargin;
+  m_calculationCell[0].setFrame(KDRect(xCoordinate, titleHeight+ImageTableView::k_totalMargin, k_largeTextFieldWidth, ImageCell::k_height));
+  xCoordinate += k_largeTextFieldWidth + k_textWidthMargin;
   numberOfCharacters = strlen(I18n::translate(m_calculation->legendForParameterAtIndex(1)));
   m_text[1].setFrame(KDRect(xCoordinate, titleHeight+ImageTableView::k_totalMargin, numberOfCharacters*charSize.width(), ImageCell::k_height));
   xCoordinate += numberOfCharacters*charSize.width() + k_textWidthMargin;
-  m_calculationCell[1].setFrame(KDRect(xCoordinate, titleHeight+ImageTableView::k_totalMargin, k_textFieldWidth, ImageCell::k_height));
-  xCoordinate += k_textFieldWidth + k_textWidthMargin;
+  m_calculationCell[1].setFrame(KDRect(xCoordinate, titleHeight+ImageTableView::k_totalMargin, k_largeTextFieldWidth, ImageCell::k_height));
+  xCoordinate += k_largeTextFieldWidth + k_textWidthMargin;
   if (m_calculation->numberOfParameters() > 2) {
     numberOfCharacters = strlen(I18n::translate(m_calculation->legendForParameterAtIndex(2)));;
     m_text[2].setFrame(KDRect(xCoordinate, titleHeight+ImageTableView::k_totalMargin, numberOfCharacters*charSize.width(), ImageCell::k_height));
@@ -103,24 +103,23 @@ void CalculationController::ContentView::layoutSubviews() {
 void CalculationController::ContentView::drawRect(KDContext * ctx, KDRect rect) const {
   KDCoordinate titleHeight = KDText::stringSize("", KDText::FontSize::Small).height()+k_titleHeightMargin;
   ctx->fillRect(KDRect(0,titleHeight, bounds().width(), ImageTableView::k_oneCellWidth), KDColorWhite);
-  if (m_calculation->numberOfEditableParameters() == 0) {
-    return;
-  }
   KDSize charSize = KDText::stringSize(" ");
+  int numberOfCharacters;
   KDCoordinate xCoordinate = ImageTableView::k_oneCellWidth + k_textWidthMargin;
-  KDCoordinate numberOfCharacters = strlen(I18n::translate(m_calculation->legendForParameterAtIndex(0)));
-  xCoordinate += numberOfCharacters*charSize.width() + k_textWidthMargin;
+  KDCoordinate textFieldWidth = k_largeTextFieldWidth;
+  for (int i = 0; i < k_maxNumberOfEditableFields; i++) {
+    if (m_calculation->numberOfEditableParameters() == i) {
+      return;
+    }
+    if (i == 2) {
+      textFieldWidth = k_textFieldWidth;
+    }
+    numberOfCharacters = strlen(I18n::translate(m_calculation->legendForParameterAtIndex(i)));
+    xCoordinate += numberOfCharacters*charSize.width() + k_textWidthMargin;
 
-  ctx->drawRect(KDRect(xCoordinate-ImageTableView::k_outline, titleHeight+ImageTableView::k_margin, k_textFieldWidth+ImageTableView::k_outline, ImageCell::k_height+ImageTableView::k_outline), Palette::GreyMiddle);
-
-  if (m_calculation->numberOfEditableParameters() < 2) {
-    return;
+    ctx->drawRect(KDRect(xCoordinate-ImageTableView::k_outline, titleHeight+ImageTableView::k_margin, textFieldWidth+ImageTableView::k_outline, ImageCell::k_height+ImageTableView::k_outline), Palette::GreyMiddle);
+    xCoordinate += textFieldWidth + k_textWidthMargin;
   }
-  xCoordinate += k_textFieldWidth + k_textWidthMargin;
-  numberOfCharacters = strlen(I18n::translate(m_calculation->legendForParameterAtIndex(1)));
-  xCoordinate += numberOfCharacters*charSize.width() + k_textWidthMargin;
-
-  ctx->drawRect(KDRect(xCoordinate-ImageTableView::k_outline, titleHeight+ImageTableView::k_margin, k_textFieldWidth+ImageTableView::k_outline, ImageCell::k_height+ImageTableView::k_outline), Palette::GreyMiddle);
 }
 
 LawCurveView * CalculationController::ContentView::lawCurveView() {
@@ -261,7 +260,7 @@ void CalculationController::didBecomeFirstResponder() {
   App::Snapshot * snapshot = (App::Snapshot *)app()->snapshot();
   snapshot->setActivePage(App::Snapshot::Page::Calculations);
   updateTitle();
-  for (int subviewIndex = 0; subviewIndex < 2; subviewIndex++) {
+  for (int subviewIndex = 0; subviewIndex < ContentView::k_maxNumberOfEditableFields; subviewIndex++) {
     EditableTextCell * calculCell = m_contentView.calculationCellAtIndex(subviewIndex);
     calculCell->setHighlighted(false);
   }
diff --git a/apps/probability/calculation_controller.h b/apps/probability/calculation_controller.h
index 12a3c7d21..f2301ce55 100644
--- a/apps/probability/calculation_controller.h
+++ b/apps/probability/calculation_controller.h
@@ -38,8 +38,9 @@ private:
     ImageTableView * imageTableView();
     EditableTextCell * calculationCellAtIndex(int index);
     void willDisplayEditableCellAtIndex(int index);
-  private:
     constexpr static int k_maxNumberOfEditableFields = 3;
+  private:
+    constexpr static KDCoordinate k_largeTextFieldWidth = 60;
     constexpr static KDCoordinate k_textFieldWidth = 50;
     constexpr static KDCoordinate k_textWidthMargin = 5;
     constexpr static KDCoordinate k_titleHeightMargin = 5;