diff --git a/Assets/Scripts/Mechanics/EnemyController.cs b/Assets/Scripts/Mechanics/EnemyController.cs
index bb6d6a0..7baec92 100644
--- a/Assets/Scripts/Mechanics/EnemyController.cs
+++ b/Assets/Scripts/Mechanics/EnemyController.cs
@@ -133,14 +133,16 @@ namespace Platformer.Mechanics
             _lastX = transform.position.x;
         }
 
+        // BT103 — 정확 측정 (PD 명시 2026-05-08): Start 시점 1회 측정·간격 0.1m·Capsule 발 영역 정확
         float MeasureSafeWalkDistance(float dir)
         {
-            float groundY = transform.position.y - 0.34f;  // 발 영역 위 0.05m (Capsule offset 영역 기반 추정)
-            for (float d = 0.5f; d <= patrolMaxRange; d += 0.5f)
+            if (_collider == null) return patrolMaxRange;
+            float groundY = _collider.bounds.min.y + 0.05f;  // Capsule 발 영역 위 0.05m
+            for (float d = 0.1f; d <= patrolMaxRange; d += 0.1f)
             {
                 Vector2 origin = new Vector2(_startX + dir * d, groundY);
                 RaycastHit2D hit = Physics2D.Raycast(origin, Vector2.down, cliffCheckDepth, groundLayerMask);
-                if (hit.collider == null) return Mathf.Max(0f, d - 1.5f);
+                if (hit.collider == null) return Mathf.Max(0f, d - 0.5f);  // 안전 margin 0.5m
             }
             return patrolMaxRange;
         }