diff --git a/app/Services/Quote/FormulaEvaluatorService.php b/app/Services/Quote/FormulaEvaluatorService.php
index 5ded0b6..c34373e 100644
--- a/app/Services/Quote/FormulaEvaluatorService.php
+++ b/app/Services/Quote/FormulaEvaluatorService.php
@@ -1675,7 +1675,13 @@ private function calculateKyungdongBom(
         // 핸들러가 필요한 키 보장 (inputVariables에서 전달되지 않으면 기본값)
         $productModel = $inputVariables['product_model'] ?? 'KSS01';
         $finishingType = $inputVariables['finishing_type'] ?? 'SUS';
-        $installationType = $inputVariables['installation_type'] ?? '벽면형';
+
+        // 가이드레일 설치타입: 프론트 GT(wall/floor/mixed) → installation_type(벽면형/측면형/혼합형) 매핑
+        $installationType = $inputVariables['installation_type'] ?? match ($inputVariables['GT'] ?? 'wall') {
+            'floor' => '측면형',
+            'mixed' => '혼합형',
+            default => '벽면형',
+        };
 
         // 모터 전압: 프론트 MP(single/three) → motor_voltage(220V/380V) 매핑
         $motorVoltage = $inputVariables['motor_voltage'] ?? match ($inputVariables['MP'] ?? 'single') {