diff --git a/changelog/55_UNRELEASED_2019-xx-xx.md b/changelog/55_UNRELEASED_2019-xx-xx.md
index 7ba8f5c6..9027446c 100644
--- a/changelog/55_UNRELEASED_2019-xx-xx.md
+++ b/changelog/55_UNRELEASED_2019-xx-xx.md
@@ -6,6 +6,7 @@
 
 ### Stock fixes
 - Fixed that entering partial amounts was not possible on the inventory page (only applies if the product option "Allow partial units in stock" is enabled)
+- Fixed that on purchase a wrong minimum amount was enforced for products with enabled tare weight handling in combination with different purchase/stock quantity units
 
 ### Shopping list fixes
 - Fixed that when `FEATURE_FLAG_SHOPPINGLIST_MULTIPLE_LISTS` was set to `false`, the shopping list appeared empty after some actions
diff --git a/public/viewjs/purchase.js b/public/viewjs/purchase.js
index 26073c20..368264cc 100644
--- a/public/viewjs/purchase.js
+++ b/public/viewjs/purchase.js
@@ -160,8 +160,9 @@ if (Grocy.Components.ProductPicker !== undefined)
 
 					if (productDetails.product.enable_tare_weight_handling == 1)
 					{
-						var minAmount = parseFloat(productDetails.product.tare_weight) + parseFloat(productDetails.stock_amount) + 1;
+						var minAmount = parseFloat(productDetails.product.tare_weight) / productDetails.product.qu_factor_purchase_to_stock + parseFloat(productDetails.stock_amount);
 						$("#amount").attr("min", minAmount);
+						$("#amount").attr("step", "0.0001");
 						$("#amount").parent().find(".invalid-feedback").text(__t('The amount cannot be lower than %s', minAmount.toLocaleString()));
 						$("#tare-weight-handling-info").removeClass("d-none");
 					}