diff --git a/src/components/shopping/shopping.js b/src/components/shopping/shopping.js
index 4488666..37a91b6 100644
--- a/src/components/shopping/shopping.js
+++ b/src/components/shopping/shopping.js
@@ -1,10 +1,19 @@
 import units from '@/units.js';
 
+function scaleFactor(meal, recipe) {
+    const numYield = recipe.serves;
+    const numConsumers = meal.consumers.length;
+
+    return numConsumers / numYield;
+}
+
 export function mealToShoppingListSources(meal) {
     const sources = [];
     for (const recipe of meal.recipes) {
+        const scale = scaleFactor(meal, recipe);
         for (const ingredient of recipe.ingredients) {
-            sources.push({ ingredient, meal, recipe, });
+            const quantity = ingredient.quantity * scale;
+            sources.push({ meal, recipe, ingredient: { ...ingredient, quantity, }, });
         }
     }