diff --git a/poincare/include/poincare/trigonometry.h b/poincare/include/poincare/trigonometry.h
index 86e49da2a..8c038e24e 100644
--- a/poincare/include/poincare/trigonometry.h
+++ b/poincare/include/poincare/trigonometry.h
@@ -16,6 +16,7 @@ public:
   static bool isDirectTrigonometryFunction(const Expression & e);
   static bool isInverseTrigonometryFunction(const Expression & e);
   static bool AreInverseFunctions(const Expression & directFunction, const Expression & inverseFunction);
+  static Expression UnitConversionFactor(Preferences::AngleUnit fromUnit, Preferences::AngleUnit toUnit);
   static bool ExpressionIsEquivalentToTangent(const Expression & e);
   static Expression shallowReduceDirectFunction(Expression & e, ExpressionNode::ReductionContext reductionContext);
   static Expression shallowReduceInverseFunction(Expression & e,  ExpressionNode::ReductionContext reductionContext);
diff --git a/poincare/src/trigonometry.cpp b/poincare/src/trigonometry.cpp
index 51ccdce30..a9c849c33 100644
--- a/poincare/src/trigonometry.cpp
+++ b/poincare/src/trigonometry.cpp
@@ -3,6 +3,7 @@
 #include <poincare/constant.h>
 #include <poincare/decimal.h>
 #include <poincare/derivative.h>
+#include <poincare/division.h>
 #include <poincare/float.h>
 #include <poincare/multiplication.h>
 #include <poincare/power.h>
@@ -87,6 +88,13 @@ bool Trigonometry::AreInverseFunctions(const Expression & directFunction, const
   return inverseFunction.type() == correspondingType;
 }
 
+Expression Trigonometry::UnitConversionFactor(Preferences::AngleUnit fromUnit, Preferences::AngleUnit toUnit) {
+  if (fromUnit == toUnit) {
+    return Rational::Builder(1);
+  }
+  return Division::Builder(piExpression(toUnit), piExpression(fromUnit));
+}
+
 bool Trigonometry::ExpressionIsEquivalentToTangent(const Expression & e) {
   // We look for (cos^-1 * sin)
   assert(ExpressionNode::Type::Power < ExpressionNode::Type::Sine);