diff --git a/include/ctranslate2/storage_view.h b/include/ctranslate2/storage_view.h
index d6f3e0941..c4ca311f1 100644
--- a/include/ctranslate2/storage_view.h
+++ b/include/ctranslate2/storage_view.h
@@ -133,6 +133,8 @@ namespace ctranslate2 {
       return _size;
     }
 
+    dim_t item_size() const;
+
     bool is_scalar() const {
       return _size == 1 && _shape.empty();
     }
diff --git a/src/storage_view.cc b/src/storage_view.cc
index 093c9f04e..1535e65d5 100644
--- a/src/storage_view.cc
+++ b/src/storage_view.cc
@@ -118,9 +118,7 @@ namespace ctranslate2 {
   }
 
   dim_t StorageView::reserved_memory() const {
-    dim_t buffer_size = 0;
-    TYPE_DISPATCH(_dtype, buffer_size = _allocated_size * sizeof (T));
-    return buffer_size;
+    return _allocated_size * item_size();
   }
 
   StorageView& StorageView::clear() {
@@ -143,10 +141,8 @@ namespace ctranslate2 {
     if (size <= _allocated_size)
       return *this;
     release();
-    dim_t required_bytes = 0;
-    TYPE_DISPATCH(_dtype, required_bytes = size * sizeof (T));
     _allocator = &get_allocator(_device);
-    _data = _allocator->allocate(required_bytes, _device_index);
+    _data = _allocator->allocate(size * item_size(), _device_index);
     if (_data == nullptr)
       THROW_RUNTIME_ERROR("failed to allocated memory");
     _allocated_size = size;
@@ -157,6 +153,12 @@ namespace ctranslate2 {
     return _allocator;
   }
 
+  dim_t StorageView::item_size() const {
+    dim_t size = 0;
+    TYPE_DISPATCH(_dtype, size = sizeof (T));
+    return size;
+  }
+
   StorageView& StorageView::reshape(Shape new_shape) {
     dim_t unknown_dim = -1;
     dim_t known_size = 1;