diff --git a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
index 994a7b1419..2d8011d1c6 100644
--- a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.cpp
@@ -27,19 +27,19 @@ template<typename T>
     return ::max(min, ::min(value, max));
 }
 
-static float get_pixel_width(LayoutState const& state, Box const& box, Optional<CSS::LengthPercentage> const& length_percentage)
+float FlexFormattingContext::get_pixel_width(Box const& box, Optional<CSS::LengthPercentage> const& length_percentage) const
 {
     if (!length_percentage.has_value())
         return 0;
-    auto inner_width = CSS::Length::make_px(state.get(*box.containing_block()).content_width());
+    auto inner_width = CSS::Length::make_px(containing_block_width_for(box));
     return length_percentage->resolved(box, inner_width).to_px(box);
 }
 
-static float get_pixel_height(LayoutState const& state, Box const& box, Optional<CSS::LengthPercentage> const& length_percentage)
+float FlexFormattingContext::get_pixel_height(Box const& box, Optional<CSS::LengthPercentage> const& length_percentage) const
 {
     if (!length_percentage.has_value())
         return 0;
-    auto inner_height = CSS::Length::make_px(state.get(*box.containing_block()).content_height());
+    auto inner_height = CSS::Length::make_px(containing_block_height_for(box));
     return length_percentage->resolved(box, inner_height).to_px(box);
 }
 
@@ -339,7 +339,8 @@ float FlexFormattingContext::resolved_definite_cross_size(Box const& box) const
         return specified_cross_size(flex_container());
     if (cross_value.is_length())
         return specified_cross_size(box);
-    return cross_value.resolved(box, CSS::Length::make_px(specified_cross_size(flex_container()))).to_px(box);
+    auto containing_block_size = !is_row_layout() ? containing_block_width_for(box) : containing_block_height_for(box);
+    return cross_value.resolved(box, CSS::Length::make_px(containing_block_size)).to_px(box);
 }
 
 float FlexFormattingContext::resolved_definite_main_size(Box const& box) const
@@ -349,7 +350,8 @@ float FlexFormattingContext::resolved_definite_main_size(Box const& box) const
         return specified_main_size(flex_container());
     if (main_value.is_length())
         return specified_main_size(box);
-    return main_value.resolved(box, CSS::Length::make_px(specified_main_size(flex_container()))).to_px(box);
+    auto containing_block_size = is_row_layout() ? containing_block_width_for(box) : containing_block_height_for(box);
+    return main_value.resolved(box, CSS::Length::make_px(containing_block_size)).to_px(box);
 }
 
 bool FlexFormattingContext::has_main_min_size(Box const& box) const
@@ -380,15 +382,15 @@ float FlexFormattingContext::specified_main_size_of_child_box(Box const& child_b
 float FlexFormattingContext::specified_main_min_size(Box const& box) const
 {
     return is_row_layout()
-        ? get_pixel_width(m_state, box, box.computed_values().min_width())
-        : get_pixel_height(m_state, box, box.computed_values().min_height());
+        ? get_pixel_width(box, box.computed_values().min_width())
+        : get_pixel_height(box, box.computed_values().min_height());
 }
 
 float FlexFormattingContext::specified_cross_min_size(Box const& box) const
 {
     return is_row_layout()
-        ? get_pixel_height(m_state, box, box.computed_values().min_height())
-        : get_pixel_width(m_state, box, box.computed_values().min_width());
+        ? get_pixel_height(box, box.computed_values().min_height())
+        : get_pixel_width(box, box.computed_values().min_width());
 }
 
 bool FlexFormattingContext::has_main_max_size(Box const& box) const
@@ -406,15 +408,15 @@ bool FlexFormattingContext::has_cross_max_size(Box const& box) const
 float FlexFormattingContext::specified_main_max_size(Box const& box) const
 {
     return is_row_layout()
-        ? get_pixel_width(m_state, box, box.computed_values().max_width())
-        : get_pixel_height(m_state, box, box.computed_values().max_height());
+        ? get_pixel_width(box, box.computed_values().max_width())
+        : get_pixel_height(box, box.computed_values().max_height());
 }
 
 float FlexFormattingContext::specified_cross_max_size(Box const& box) const
 {
     return is_row_layout()
-        ? get_pixel_height(m_state, box, box.computed_values().max_height())
-        : get_pixel_width(m_state, box, box.computed_values().max_width());
+        ? get_pixel_height(box, box.computed_values().max_height())
+        : get_pixel_width(box, box.computed_values().max_width());
 }
 
 float FlexFormattingContext::calculated_main_size(Box const& box) const
@@ -659,8 +661,8 @@ void FlexFormattingContext::determine_flex_base_size_and_hypothetical_main_size(
         // A. If the item has a definite used flex basis, that’s the flex base size.
         if (flex_item.used_flex_basis_is_definite) {
             if (is_row_layout())
-                return get_pixel_width(m_state, child_box, flex_item.used_flex_basis.length_percentage.value());
-            return get_pixel_height(m_state, child_box, flex_item.used_flex_basis.length_percentage.value());
+                return get_pixel_width(child_box, flex_item.used_flex_basis.length_percentage.value());
+            return get_pixel_height(child_box, flex_item.used_flex_basis.length_percentage.value());
         }
 
         // B. If the flex item has ...
diff --git a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h
index d40645a56c..247fce83a5 100644
--- a/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h
+++ b/Userland/Libraries/LibWeb/Layout/FlexFormattingContext.h
@@ -106,6 +106,9 @@ private:
     Optional<float> transferred_size_suggestion(FlexItem const&) const;
     float content_size_suggestion(FlexItem const&) const;
 
+    float get_pixel_width(Box const& box, Optional<CSS::LengthPercentage> const& length_percentage) const;
+    float get_pixel_height(Box const& box, Optional<CSS::LengthPercentage> const& length_percentage) const;
+
     bool flex_item_is_stretched(FlexItem const&) const;
 
     void set_main_size(Box const&, float size);