diff --git a/app/Services/Quote/Handlers/KyungdongFormulaHandler.php b/app/Services/Quote/Handlers/KyungdongFormulaHandler.php
index 0cf544a..1d6fe4d 100644
--- a/app/Services/Quote/Handlers/KyungdongFormulaHandler.php
+++ b/app/Services/Quote/Handlers/KyungdongFormulaHandler.php
@@ -348,7 +348,22 @@ public function calculateSteelItems(array $params): array
         $lbarLength = (float) ($params['lbar_length'] ?? ($width + 220)) / 1000;  // m 단위 (레거시: W0+220)
         $flatBarLength = (float) ($params['flatbar_length'] ?? ($width + 220)) / 1000;  // m 단위 (레거시: W0+220)
         $weightPlateQty = (int) ($params['weight_plate_qty'] ?? 0);  // 무게평철 수량
-        $roundBarQty = (int) ($params['round_bar_qty'] ?? 0);  // 환봉 수량
+        // 환봉 수량: 5130 자동계산 (col10=폭 기준)
+        // ≤3000→1, ≤6000→2, ≤9000→3, ≤12000→4 (× 수량)
+        $roundBarQty = (int) ($params['round_bar_qty'] ?? -1);
+        if ($roundBarQty < 0) {
+            if ($width <= 3000) {
+                $roundBarQty = 1 * $quantity;
+            } elseif ($width <= 6000) {
+                $roundBarQty = 2 * $quantity;
+            } elseif ($width <= 9000) {
+                $roundBarQty = 3 * $quantity;
+            } elseif ($width <= 12000) {
+                $roundBarQty = 4 * $quantity;
+            } else {
+                $roundBarQty = 0;
+            }
+        }
 
         // 1. 케이스 (단가/1000 × 길이mm × 수량)
         $casePrice = $this->priceService->getCasePrice($caseSpec);
@@ -618,17 +633,39 @@ public function calculatePartItems(array $params): array
             ];
         }
 
-        // 2. 각파이프 (5130: col68=3000mm 수량, col69=6000mm 수량)
+        // 2. 각파이프 (5130: col67 = col37 + 3000 × col66, col68/col69 자동계산)
         $pipeThickness = '1.4';
+        $caseLength = (float) ($params['case_length'] ?? ($width + 220));  // col37 (mm)
+        $connectionCount = (int) ($params['connection_count'] ?? 0);       // col66 (연결 수)
+        $pipeBaseLength = $caseLength + 3000 * $connectionCount;           // col67
+
+        // 5130 자동계산 공식: col67 기준
         $pipe3000Qty = (int) ($params['pipe_3000_qty'] ?? 0);
         $pipe6000Qty = (int) ($params['pipe_6000_qty'] ?? 0);
 
-        // 기본값: 둘 다 0이면 레거시 로직 (W0 기준 자동 결정)
         if ($pipe3000Qty === 0 && $pipe6000Qty === 0) {
-            if ($width > 3000) {
-                $pipe6000Qty = 1;
-            } else {
-                $pipe3000Qty = 1;
+            // col68: 3000mm 파이프 수량
+            if ($pipeBaseLength <= 9000) {
+                $pipe3000Qty = 3 * $quantity;
+            } elseif ($pipeBaseLength <= 12000) {
+                $pipe3000Qty = 4 * $quantity;
+            } elseif ($pipeBaseLength <= 15000) {
+                $pipe3000Qty = 5 * $quantity;
+            } elseif ($pipeBaseLength <= 18000) {
+                $pipe3000Qty = 6 * $quantity;
+            }
+
+            // col69: 6000mm 파이프 수량 (18000 초과 시)
+            if ($pipeBaseLength > 18000 && $pipeBaseLength <= 24000) {
+                $pipe6000Qty = 4 * $quantity;
+            } elseif ($pipeBaseLength > 24000 && $pipeBaseLength <= 30000) {
+                $pipe6000Qty = 5 * $quantity;
+            } elseif ($pipeBaseLength > 30000 && $pipeBaseLength <= 36000) {
+                $pipe6000Qty = 6 * $quantity;
+            } elseif ($pipeBaseLength > 36000 && $pipeBaseLength <= 42000) {
+                $pipe6000Qty = 7 * $quantity;
+            } elseif ($pipeBaseLength > 42000 && $pipeBaseLength <= 48000) {
+                $pipe6000Qty = 8 * $quantity;
             }
         }