diff --git a/src/main/java/poomasi/domain/admin/statistics/service/StatisticsService.java b/src/main/java/poomasi/domain/admin/statistics/service/StatisticsService.java
index dfb5d9f8..063dd430 100644
--- a/src/main/java/poomasi/domain/admin/statistics/service/StatisticsService.java
+++ b/src/main/java/poomasi/domain/admin/statistics/service/StatisticsService.java
@@ -8,6 +8,7 @@
 import org.springframework.transaction.annotation.Transactional;
 import poomasi.domain.admin.statistics.dto.response.StoreMonthlySalesResponse;
 import poomasi.domain.order.entity.Order;
+import poomasi.domain.order.entity.OrderedProduct;
 import poomasi.domain.order.entity.OrderedProductStatus;
 import poomasi.domain.order.service.OrderService;
 import poomasi.domain.admin.statistics.dto.response.CategoryMonthlySalesResponse;
@@ -15,7 +16,6 @@
 import poomasi.domain.product._category.service.CategoryService;
 import poomasi.domain.product.entity.Product;
 
-
 import java.math.BigDecimal;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
@@ -32,61 +32,73 @@ public class StatisticsService {
     private final OrderService orderService;
     private final CategoryService categoryService;
 
+    private List<OrderedProduct> getDeliveredProducts(List<Order> orders) {
+        return orders.stream()
+                .flatMap(order -> order.getOrderedProducts().stream())
+                .filter(orderedProduct -> orderedProduct.getOrderedProductStatus() == OrderedProductStatus.DELIVERED)
+                .collect(Collectors.toList());
+    }
+
+    private LocalDateTime[] calculateDateRange(LocalDate startDate, int months) {
+        LocalDate endDate = startDate.plusMonths(months);
+        return new LocalDateTime[]{
+                startDate.atStartOfDay(),
+                endDate.atTime(23, 59, 59)
+        };
+    }
+
+    private StoreMonthlySalesResponse createStoreSalesResponse(OrderedProduct orderedProduct) {
+        BigDecimal totalSales = orderedProduct.getPrice().multiply(BigDecimal.valueOf(orderedProduct.getCount()));
+        return new StoreMonthlySalesResponse(orderedProduct.getStore(), totalSales);
+    }
+
+    private void updateCategorySales(Map<Category, CategoryMonthlySalesResponse> salesMap, OrderedProduct orderedProduct) {
+        Product product = orderedProduct.getProduct();
+        Category category = categoryService.getCategory(product.getCategoryId());
+
+        CategoryMonthlySalesResponse salesResponse = salesMap.computeIfAbsent(category, k ->
+                new CategoryMonthlySalesResponse(category.getName(), 0, BigDecimal.ZERO)
+        );
+
+        salesResponse.setCount(salesResponse.getCount() + 1);
+        BigDecimal productTotal = product.getPrice().multiply(BigDecimal.valueOf(orderedProduct.getCount()));
+        salesResponse.setTotalSales(salesResponse.getTotalSales().add(productTotal));
+    }
+
     public Page<StoreMonthlySalesResponse> getMonthlyStoreSales(Long storeId, String startMonth, String endMonth, Pageable pageable) {
         LocalDate start = LocalDate.parse(startMonth + "-01");
-        LocalDate end = LocalDate.parse(endMonth + "-01");
-        end = end.withDayOfMonth(end.lengthOfMonth());
+        LocalDate end = LocalDate.parse(endMonth + "-01").withDayOfMonth(LocalDate.parse(endMonth + "-01").lengthOfMonth());
 
         LocalDateTime startDate = start.atStartOfDay();
         LocalDateTime endDate = end.atTime(23, 59, 59);
 
         List<Order> orders = orderService.getOrdersByUpdateAtBetween(startDate, endDate);
 
-        List<StoreMonthlySalesResponse> salesResponses = orders.stream()
-                .flatMap(order -> order.getOrderedProducts().stream())
-                .filter(orderedProduct -> orderedProduct.getStoreId()
-                        .equals(storeId) && orderedProduct.getOrderedProductStatus() == OrderedProductStatus.DELIVERED)
-                .map(orderedProduct -> {
-                    BigDecimal totalSales = orderedProduct.getPrice().multiply(BigDecimal.valueOf(orderedProduct.getCount()));
-                    return new StoreMonthlySalesResponse(orderedProduct.getStore(), totalSales);
-                })
+        List<OrderedProduct> deliveredProducts = getDeliveredProducts(orders);
+
+        List<StoreMonthlySalesResponse> salesResponses = deliveredProducts.stream()
+                .filter(orderedProduct -> orderedProduct.getStoreId().equals(storeId))
+                .map(this::createStoreSalesResponse)
                 .collect(Collectors.toList());
 
         return new PageImpl<>(salesResponses, pageable, salesResponses.size());
     }
 
     public Page<CategoryMonthlySalesResponse> getCategoryMonthlySales(LocalDate startDate, Pageable pageable) {
+        LocalDateTime[] dateRange = calculateDateRange(startDate, 5);
+        List<Order> orders = orderService.getOrdersByUpdateAtBetween(dateRange[0], dateRange[1]);
 
-        LocalDate endDate = startDate.plusMonths(5);
-
-        List<Order> orders = orderService.getOrdersByUpdateAtBetween(startDate.atStartOfDay(), endDate.atTime(23, 59, 59));
+        List<OrderedProduct> deliveredProducts = getDeliveredProducts(orders);
 
         Map<Category, CategoryMonthlySalesResponse> salesMap = new HashMap<>();
 
-        orders.stream()
-                .flatMap(order -> order.getOrderedProducts().stream())
-                .filter(orderedProduct -> orderedProduct.getOrderedProductStatus() == OrderedProductStatus.DELIVERED)
-                .forEach(orderedProduct -> {
-                    Product product = orderedProduct.getProduct();
-                    Long categoryId = product.getCategoryId();
-                    Category category = categoryService.getCategory(categoryId);
-
-                    CategoryMonthlySalesResponse salesResponse = salesMap.computeIfAbsent(category, k ->
-                            new CategoryMonthlySalesResponse(category.getName(), 0, BigDecimal.ZERO)
-                    );
-
-                    salesResponse.setCount(salesResponse.getCount() + 1);
-                    BigDecimal productTotal = product.getPrice().multiply(BigDecimal.valueOf(orderedProduct.getCount()));
-                    salesResponse.setTotalSales(salesResponse.getTotalSales().add(productTotal));
-                });
+        deliveredProducts.forEach(orderedProduct -> updateCategorySales(salesMap, orderedProduct));
 
         List<CategoryMonthlySalesResponse> responseList = new ArrayList<>(salesMap.values());
 
         int start = (int) pageable.getOffset();
-        int end = Math.min((start + pageable.getPageSize()), responseList.size());
-        Page<CategoryMonthlySalesResponse> page = new PageImpl<>(responseList.subList(start, end), pageable, responseList.size());
-
-        return page;
+        int end = Math.min(start + pageable.getPageSize(), responseList.size());
+        return new PageImpl<>(responseList.subList(start, end), pageable, responseList.size());
     }
 }