diff --git a/core/evaluator.cpp b/core/evaluator.cpp
index 333d8885..cb70b205 100644
--- a/core/evaluator.cpp
+++ b/core/evaluator.cpp
@@ -1314,10 +1314,9 @@ void Evaluator::compile(const Tokens& tokens)
                        m_codes.append(Opcode(Opcode::Fact));
                        break;
                    case Token::Percent:
-                       syntaxStack.pop();
-                       m_constants.append(HNumber("0.01"));
-                       m_codes.append(Opcode(Opcode::Load, m_constants.count() - 1));
-                       m_codes.append(Opcode(Opcode::Mul));
+                       ruleFound = true;
+                       syntaxStack.reduce(2);
+                       m_codes.append(Opcode(Opcode::Pct));
                        break;
                    default:;
                    }
@@ -1924,6 +1923,27 @@ Quantity Evaluator::exec(const QVector<Opcode>& opcodes,
                 stack.push(val2);
                 break;
 
+            case Opcode::Pct:
+                if (stack.count() < 1) {
+                    m_error = tr("invalid expression");
+                    return CMath::nan();
+                }
+                val1 = stack.pop();
+
+                switch ((pc + 1) < opcodes.count() ?
+                        opcodes.at(pc + 1).type : Opcode::Nop) {
+                case Opcode::Add:
+                case Opcode::Sub:
+                    val2 = stack.pop();
+                    stack.push(val2);
+                    break;
+                default:
+                    val2 = 1;
+                }
+                val1 = checkOperatorResult(val2 * (val1 * HNumber("0.01")));
+                stack.push(val1);
+                break;
+
             case Opcode::Conv:
                 if (stack.count() < 2) {
                     m_error = tr("invalid expression");
@@ -2470,6 +2490,9 @@ QString Evaluator::dump()
             case Opcode::BOr:
                 code = "BOr";
                 break;
+            case Opcode::Pct:
+                code = "Pct";
+                break;
             default:
                 code = "Unknown";
                 break;
diff --git a/core/opcode.h b/core/opcode.h
index 1a47eca0..40a73f18 100644
--- a/core/opcode.h
+++ b/core/opcode.h
@@ -28,7 +28,7 @@ class Opcode
 {
 public:
     enum  Type { Nop, Load, Ref, Function, Add, Sub, Neg, Mul, Div, Pow,
-           Fact, Modulo, IntDiv, LSh, RSh, BAnd, BOr, Conv };
+           Fact, Modulo, IntDiv, LSh, RSh, BAnd, BOr, Conv, Pct };
 
     Type type;
     unsigned index;