diff --git a/src/Service/Allocation/BucketRoomCalculator.php b/src/Service/Allocation/BucketRoomCalculator.php
new file mode 100644
index 0000000..fa76772
--- /dev/null
+++ b/src/Service/Allocation/BucketRoomCalculator.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace App\Service\Allocation;
+
+use App\Entity\Bucket;
+use App\Enum\BucketAllocationType;
+use App\Enum\FillStage;
+
+class BucketRoomCalculator
+{
+    public function roomFor(
+        Bucket $bucket,
+        FillStage $fillStage,
+        int $income,
+        int $alreadyAllocated,
+    ): int {
+        return match ($bucket->getAllocationType()) {
+            BucketAllocationType::PERCENTAGE => $this->handlePercentage($bucket, $fillStage, $income, $alreadyAllocated),
+            BucketAllocationType::FIXED_LIMIT => $this->handleFixedLimit($bucket, $fillStage, $alreadyAllocated),
+            BucketAllocationType::UNLIMITED => $this->handleUnlimited(),
+        };
+    }
+
+    private function handlePercentage(Bucket $bucket, FillStage $fillStage, int $income, int $alreadyAllocated): int
+    {
+        if (FillStage::Buffer === $fillStage) {
+            return 0;
+        }
+
+        $room = (($bucket->getAllocationValue() ?? 0) * $income / 10000);
+
+        return $this->clamp($room, $bucket->getStartingAmount(), $alreadyAllocated);
+    }
+
+    private function handleFixedLimit(Bucket $bucket, FillStage $fillStage, int $alreadyAllocated): int
+    {
+        $room = $bucket->getAllocationValue() ?? 0;
+
+        if (FillStage::Buffer === $fillStage) {
+            $room *= (1 + (float) $bucket->getBufferMultiplier());
+        }
+
+        return $this->clamp($room, $bucket->getStartingAmount(), $alreadyAllocated);
+    }
+
+    private function handleUnlimited(): int
+    {
+        return \PHP_INT_MAX;
+    }
+
+    private function clamp(int|float $cap, int $startingAmount, int $alreadyAllocated): int
+    {
+        return max(0, (int) floor($cap - $startingAmount - $alreadyAllocated));
+    }
+}
diff --git a/src/Service/BucketRoomCalculator.php b/src/Service/BucketRoomCalculator.php
deleted file mode 100644
index b48134e..0000000
--- a/src/Service/BucketRoomCalculator.php
+++ /dev/null
@@ -1,71 +0,0 @@
-<?php
-
-namespace App\Service;
-
-use App\Entity\Bucket;
-use App\Enum\BucketAllocationType;
-use App\Enum\FillStage;
-
-class BucketRoomCalculator
-{
-    public function roomFor(
-        Bucket $bucket,
-        FillStage $fillStage,
-        int $income,
-        int $alreadyAllocated,
-    ): int {
-        return match ($bucket->getAllocationType()) {
-            BucketAllocationType::PERCENTAGE => $this->handlePercentage($bucket, $fillStage, $income, $alreadyAllocated),
-            BucketAllocationType::FIXED_LIMIT => $this->handleFixedLimit($bucket, $fillStage, $income, $alreadyAllocated),
-            BucketAllocationType::UNLIMITED => $this->handleUnlimited(),
-        };
-    }
-
-    private function handlePercentage(Bucket $bucket, FillStage $fillStage, int $income, int $alreadyAllocated): int
-    {
-        if (BucketAllocationType::PERCENTAGE === $bucket->getAllocationType() && FillStage::Buffer === $fillStage) {
-            return 0;
-        }
-
-        if (BucketAllocationType::PERCENTAGE === $bucket->getAllocationType() && 0 === $income) {
-            return 0;
-        }
-
-        $room = (int) (($bucket->getAllocationValue() / 10000) * $income)
-            - $bucket->getStartingAmount()
-            - $alreadyAllocated;
-
-        return max(0, $room);
-    }
-
-    private function handleFixedLimit(Bucket $bucket, FillStage $fillStage, int $income, int $alreadyAllocated): int
-    {
-        if (FillStage::Base === $fillStage) {
-            $multiplierEnabled = false;
-        }
-
-        return $this->basicRoom($bucket, $income, $alreadyAllocated, $multiplierEnabled ?? true);
-    }
-
-    private function handleUnlimited(): int
-    {
-        return \PHP_INT_MAX;
-    }
-
-    private function basicRoom(Bucket $bucket, int $income, int $alreadyAllocated, bool $multiplierEnabled = true): int
-    {
-        $room = $bucket->getAllocationValue() - $bucket->getStartingAmount();
-
-        if ($room < $alreadyAllocated) {
-            return 0;
-        }
-
-        if ($multiplierEnabled && ((float) $bucket->getBufferMultiplier()) > 0) {
-            $room *= (1 + ((float) $bucket->getBufferMultiplier()));
-        }
-
-        $room -= $alreadyAllocated;
-
-        return floor($room);
-    }
-}
diff --git a/tests/Service/BucketRoomCalculatorTest.php b/tests/Service/Allocation/BucketRoomCalculatorTest.php
similarity index 86%
rename from tests/Service/BucketRoomCalculatorTest.php
rename to tests/Service/Allocation/BucketRoomCalculatorTest.php
index f207dcd..a5325cb 100644
--- a/tests/Service/BucketRoomCalculatorTest.php
+++ b/tests/Service/Allocation/BucketRoomCalculatorTest.php
@@ -1,13 +1,13 @@
 <?php
 
-namespace App\Tests\Service;
+namespace App\Tests\Service\Allocation;
 
 use App\Entity\Bucket;
 use App\Entity\Scenario;
 use App\Enum\BucketAllocationType;
 use App\Enum\BucketType;
 use App\Enum\FillStage;
-use App\Service\BucketRoomCalculator;
+use App\Service\Allocation\BucketRoomCalculator;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\TestCase;
 
@@ -185,7 +185,6 @@ final class BucketRoomCalculatorTest extends TestCase
         $room = (new BucketRoomCalculator())->roomFor($bucket, FillStage::Buffer, income: 10000, alreadyAllocated: 0);
 
         self::assertSame(13301, $room);
-        self::assertIsInt($room);
     }
 
     public function testFixedLimitBufferWithZeroMultiplierEqualsBaseCap(): void
@@ -226,7 +225,28 @@ final class BucketRoomCalculatorTest extends TestCase
         $room = (new BucketRoomCalculator())->roomFor($bucket, FillStage::Buffer, income: 10000, alreadyAllocated: 0);
 
         self::assertSame(7501, $room);
-        self::assertIsInt($room);
+    }
+
+    public function testFixedLimitBufferRoomWhenAlreadyAllocatedExceedsBaseCap(): void
+    {
+        $bucket = $this->makeFixedLimitBucket(
+            allocationValue: 1000,
+            startingAmount: 0,
+            bufferMultiplier: '0.50'
+        );
+
+        // buffered cap = (int) floor(1000 * 1.50) = 1500.
+        // alreadyAllocated (1200) exceeds the BASE cap (1000) but is below the BUFFERED
+        // cap (1500); buffer-stage room must be the gap to the buffered cap (300), not 0.
+        // Regression test for the early-return-before-buffer bug.
+        $room = (new BucketRoomCalculator())->roomFor(
+            $bucket,
+            FillStage::Buffer,
+            income: 10000,
+            alreadyAllocated: 1200
+        );
+
+        self::assertSame(300, $room);
     }
 
     public function testFixedLimitBufferOverSubscribedIsZero(): void
@@ -265,7 +285,6 @@ final class BucketRoomCalculatorTest extends TestCase
         $room = (new BucketRoomCalculator())->roomFor($bucket, FillStage::Base, income: 10001, alreadyAllocated: 0);
 
         self::assertSame(3333, $room);
-        self::assertIsInt($room);
     }
 
     public function testPercentageBaseFloorsFractionalCap(): void
@@ -285,7 +304,6 @@ final class BucketRoomCalculatorTest extends TestCase
         );
 
         self::assertSame(3750, $room);
-        self::assertIsInt($room);
     }
 
     public function testPercentageBaseStartingAmountReducesRoom(): void
@@ -381,6 +399,46 @@ final class BucketRoomCalculatorTest extends TestCase
         self::assertSame(0, $room);
     }
 
+    public function testPercentageBaseWithNullAllocationValueIsZero(): void
+    {
+        // Mirrors testFixedLimitBaseWithNullAllocationValueIsZero: roomFor must tolerate
+        // a null allocationValue on the PERCENTAGE path too (null basis points = 0% = no
+        // room), not throw when multiplying it against income.
+        $bucket = (new Bucket())
+            ->setScenario(new Scenario())
+            ->setType(BucketType::NEED)
+            ->setName('Bucket')
+            ->setPriority(1)
+            ->setAllocationType(BucketAllocationType::PERCENTAGE)
+            ->setAllocationValue(null)
+            ->setStartingAmount(0)
+            ->setBufferMultiplier('0.00');
+
+        $room = (new BucketRoomCalculator())->roomFor($bucket, FillStage::Base, income: 10000, alreadyAllocated: 0);
+
+        self::assertSame(0, $room);
+    }
+
+    public function testPercentageBufferWithNullAllocationValueIsZero(): void
+    {
+        // Same null-allocationValue bucket, but the Buffer stage -- percentage buffer
+        // room is always 0 regardless of allocationValue, so this confirms the null
+        // case doesn't throw in the buffer path either.
+        $bucket = (new Bucket())
+            ->setScenario(new Scenario())
+            ->setType(BucketType::NEED)
+            ->setName('Bucket')
+            ->setPriority(1)
+            ->setAllocationType(BucketAllocationType::PERCENTAGE)
+            ->setAllocationValue(null)
+            ->setStartingAmount(0)
+            ->setBufferMultiplier('0.00');
+
+        $room = (new BucketRoomCalculator())->roomFor($bucket, FillStage::Buffer, income: 10000, alreadyAllocated: 0);
+
+        self::assertSame(0, $room);
+    }
+
     // --- unlimited (overflow) -------------------------------------------------
 
     public function testUnlimitedBucketHasInfiniteBaseRoom(): void