diff --git a/controllers/StockApiController.php b/controllers/StockApiController.php
index 5db2038b..0ebe85f6 100644
--- a/controllers/StockApiController.php
+++ b/controllers/StockApiController.php
@@ -88,13 +88,19 @@ class StockApiController extends BaseApiController
 				$shoppingLocationId = $requestBody['shopping_location_id'];
 			}
 
+			$quFactorPurchaseToStock = null;
+			if (array_key_exists('qu_factor_purchase_to_stock', $requestBody) && is_numeric($requestBody['qu_factor_purchase_to_stock']))
+			{
+				$quFactorPurchaseToStock = $requestBody['qu_factor_purchase_to_stock'];
+			}
+
 			$transactionType = StockService::TRANSACTION_TYPE_PURCHASE;
 			if (array_key_exists('transaction_type', $requestBody)  && !empty($requestBody['transactiontype']))
 			{
 				$transactionType = $requestBody['transactiontype'];
 			}
 
-			$bookingId = $this->getStockService()->AddProduct($args['productId'], $requestBody['amount'], $bestBeforeDate, $transactionType, date('Y-m-d'), $price, $locationId, $shoppingLocationId);
+			$bookingId = $this->getStockService()->AddProduct($args['productId'], $requestBody['amount'], $bestBeforeDate, $transactionType, date('Y-m-d'), $price, $quFactorPurchaseToStock, $locationId, $shoppingLocationId);
 			return $this->ApiResponse($response, $this->getDatabase()->stock_log($bookingId));
 		}
 		catch (\Exception $ex)
diff --git a/public/viewjs/purchase.js b/public/viewjs/purchase.js
index 2f5ebad7..d82dbb6c 100644
--- a/public/viewjs/purchase.js
+++ b/public/viewjs/purchase.js
@@ -8,7 +8,7 @@
 	Grocy.Api.Get('stock/products/' + jsonForm.product_id,
 		function(productDetails)
 		{
-			var amount = jsonForm.amount * productDetails.product.qu_factor_purchase_to_stock;
+			var amount = jsonForm.amount * jsonForm.qu_factor_purchase_to_stock;
 
 			var price = "";
 			if (!jsonForm.price.toString().isEmpty())
@@ -37,6 +37,7 @@
 			{
 				jsonData.location_id = Grocy.Components.LocationPicker.GetValue();
 			}
+			jsonData.qu_factor_purchase_to_stock = jsonForm.qu_factor_purchase_to_stock;
 
 			Grocy.Api.Post('stock/products/' + jsonForm.product_id + '/add', jsonData,
 				function(result)
@@ -162,14 +163,20 @@ if (Grocy.Components.ProductPicker !== undefined)
 					}
 
 					$('#amount_qu_unit').attr("qu-factor-purchase-to-stock", productDetails.product.qu_factor_purchase_to_stock);
+					$('#amount_qu_unit').attr("quantity-unit-purchase-name", productDetails.quantity_unit_purchase.name);
 					$('#amount_qu_unit').attr("quantity-unit-stock-name", productDetails.quantity_unit_stock.name);
+					$('#amount_qu_unit').attr("quantity-unit-stock-name-plural", productDetails.quantity_unit_stock.name_plural);
+					$('#qu_factor_purchase_to_stock').val(productDetails.product.qu_factor_purchase_to_stock);
+
 					if (productDetails.product.qu_id_purchase === productDetails.product.qu_id_stock)
 					{
 						$('#amount_qu_unit').text(productDetails.quantity_unit_purchase.name);
+						$('#group-qu_factor_purchase_to_stock').addClass('d-none');
 					}
 					else
 					{
 						$('#amount_qu_unit').text(productDetails.quantity_unit_purchase.name + " (" + __t("will be multiplied by a factor of %1$s to get %2$s", parseFloat(productDetails.product.qu_factor_purchase_to_stock).toLocaleString({ minimumFractionDigits: 0, maximumFractionDigits: 2 }), __n(2, productDetails.quantity_unit_stock.name, productDetails.quantity_unit_stock.name_plural)) + ")");
+						$('#group-qu_factor_purchase_to_stock').removeClass('d-none');
 					}
 
 					var priceTypeUnitPrice = $("#price-type-unit-price");
@@ -339,6 +346,15 @@ $('#amount').on('change', function(e)
 	Grocy.FrontendHelpers.ValidateForm('purchase-form');
 });
 
+$('#qu_factor_purchase_to_stock').on('change', function(e)
+{
+	var value = $(e.target).val();
+	$('#amount_qu_unit').attr("qu-factor-purchase-to-stock", value);
+	$('#amount_qu_unit').text(document.getElementById("amount_qu_unit").getAttribute("quantity-unit-purchase-name")  + " (" + __t("will be multiplied by a factor of %1$s to get %2$s", parseFloat(value).toLocaleString({ minimumFractionDigits: 0, maximumFractionDigits: 2 }), __n(2, document.getElementById("amount_qu_unit").getAttribute("quantity-unit-stock-name"), document.getElementById("amount_qu_unit").getAttribute("quantity-unit-stock-name-plural")) + ")"));
+	refreshPriceHint();
+	Grocy.FrontendHelpers.ValidateForm('purchase-form');
+});
+
 if (GetUriParam("flow") === "shoppinglistitemtostock")
 {
 	$('#amount').val(parseFloat(GetUriParam("amount")).toLocaleString({ minimumFractionDigits: 0, maximumFractionDigits: 4 }));
diff --git a/services/StockService.php b/services/StockService.php
index 273b790c..81df22e7 100644
--- a/services/StockService.php
+++ b/services/StockService.php
@@ -217,7 +217,7 @@ class StockService extends BaseService
 		return FindAllObjectsInArrayByPropertyValue($stockEntries, 'location_id', $locationId);
 	}
 
-	public function AddProduct(int $productId, float $amount, $bestBeforeDate, $transactionType, $purchasedDate, $price, $locationId = null, $shoppingLocationId = null, &$transactionId = null)
+	public function AddProduct(int $productId, float $amount, $bestBeforeDate, $transactionType, $purchasedDate, $price, $quFactorPurchaseToStock, $locationId = null, $shoppingLocationId = null, &$transactionId = null)
 	{
 		if (!$this->ProductExists($productId))
 		{
@@ -275,6 +275,7 @@ class StockService extends BaseService
 				'location_id' => $locationId,
 				'transaction_id' => $transactionId,
 				'shopping_location_id' => $shoppingLocationId,
+				'qu_factor_purchase_to_stock' => $quFactorPurchaseToStock,
 			));
 			$logRow->save();
 
@@ -289,6 +290,7 @@ class StockService extends BaseService
 				'price' => $price,
 				'location_id' => $locationId,
 				'shopping_location_id' => $shoppingLocationId,
+				'qu_factor_purchase_to_stock' => $quFactorPurchaseToStock,
 			));
 			$stockRow->save();
 
diff --git a/views/components/numberpicker.blade.php b/views/components/numberpicker.blade.php
index 623e0103..3ffa3cb6 100644
--- a/views/components/numberpicker.blade.php
+++ b/views/components/numberpicker.blade.php
@@ -16,7 +16,7 @@
 @php if(!isset($isRequired)) { $isRequired = true; } @endphp
 @php if(!isset($noNameAttribute)) { $noNameAttribute = false; } @endphp
 
-<div class="form-group {{ $additionalGroupCssClasses }}">
+<div id="group-{{ $id }}" class="form-group {{ $additionalGroupCssClasses }}">
 	<label for="{{ $id }}">
 		{{ $__t($label) }}&nbsp;
 		<i class="fas fa-question-circle" id="{{ $hintId }}" data-toggle="tooltip" title="{{ $hint }}"></i>{!! $additionalHtmlContextHelp !!}</label>
diff --git a/views/purchase.blade.php b/views/purchase.blade.php
index d9068c07..1e398ead 100644
--- a/views/purchase.blade.php
+++ b/views/purchase.blade.php
@@ -96,6 +96,16 @@
 			<input type="hidden" name="price" id="price" value="0">
 			@endif
 
+			@include('components.numberpicker', array(
+				'id' => 'qu_factor_purchase_to_stock',
+				'label' => 'Factor purchase to stock quantity unit',
+				'min' => 1,
+				'additionalGroupCssClasses' => 'd-none',
+				'invalidFeedback' => $__t('The amount cannot be lower than %s', '1'),
+				'additionalCssClasses' => 'input-group-qu',
+				'additionalHtmlElements' => '<p id="qu-conversion-info" class="form-text text-muted small d-none"></p>'
+			))
+
 			@if(GROCY_FEATURE_FLAG_STOCK_LOCATION_TRACKING)
 			@include('components.locationpicker', array(
 				'locations' => $locations,