diff --git a/backend/src/main/java/com/example/todoapp/controller/ToBuysController.java b/backend/src/main/java/com/example/todoapp/controller/ToBuysController.java
index 048c69f..d5753e9 100644
--- a/backend/src/main/java/com/example/todoapp/controller/ToBuysController.java
+++ b/backend/src/main/java/com/example/todoapp/controller/ToBuysController.java
@@ -92,7 +92,6 @@ public class ToBuysController {
     }
 
 
-
     /**
      * 指定されたユーザーIDに基づいてすべての「買うもの」リストを取得する
      *
@@ -186,7 +185,8 @@ public class ToBuysController {
             Authentication authentication) {
 
         Long recipeId = payload.get("recipeId");
-        List<ToBuyResponseDTO> responseList = toBuysService.addByRecipeId(recipeId, authentication);
+        Long servings = payload.get("servings");
+        List<ToBuyResponseDTO> responseList = toBuysService.addByRecipeId(recipeId, servings,authentication);
 
         //shopのフィールドを削除
         List<Map<String, Object>> filteredList = responseList.stream()
diff --git a/backend/src/main/java/com/example/todoapp/service/ToBuysService.java b/backend/src/main/java/com/example/todoapp/service/ToBuysService.java
index 4de730a..fe3bfe7 100644
--- a/backend/src/main/java/com/example/todoapp/service/ToBuysService.java
+++ b/backend/src/main/java/com/example/todoapp/service/ToBuysService.java
@@ -220,7 +220,7 @@ public class ToBuysService {
      * @param authentication 認証情報
      * @return 追加された「買うもの」のリスト
      */
-    public List<ToBuyResponseDTO> addByRecipeId(Long recipeId, Authentication authentication) {
+    public List<ToBuyResponseDTO> addByRecipeId(Long recipeId, Long servings,Authentication authentication) {
         // ユーザー情報を取得
         String username = authentication.getName();
         User user = userRepository.findByUsername(username)
@@ -233,7 +233,9 @@ public class ToBuysService {
 
         for (RecipeStuffs rs : recipeStuffsList) {
             Stuffs stuff = rs.getStuff();
-            int requiredAmount = rs.getAmount();
+            
+            // 材料の数量をサービング数に基づいて計算
+            int requiredAmount = rs.getAmount() * (servings != null ? servings.intValue() : 1);
 
             Optional<ToBuys> existingToBuyOpt = toBuysRepository.findByUserAndStuff(user, stuff);