How to scale a recipe up or down without doing the maths

Guide · Updated 2026-11-10

Paste a recipe, set the servings or a factor, and get every amount resized into cups, spoons or grams you can actually measure, with a note for part eggs.

Open the Recipe scaler Free, in your browser, nothing uploaded.

A recipe written for four is awkward when ten people are coming, and halving one in your head at the counter is how a cake ends up with twice the salt. The recipe scaler takes a pasted ingredient list, multiplies every amount by the same factor and gives the answer back in measures you can scoop: kitchen fractions for cups and spoons, rounded grams for weights. It is for home cooks, people batch-cooking for the week, and anyone cooking for a crowd. When the new amount also needs a different tin, the pan size converter gives the factor for the pan, cups to grams converts single ingredients in more detail, and a meal planner helps plan the week the bigger batch will feed.

What it is

Scaling a recipe means multiplying everything by one number, the scale factor:

• k = new servings ÷ old servings

If a recipe serves 4 and you want 10, k = 10 ÷ 4 = 2.5. Every amount is multiplied by 2.5, and the ratios between ingredients stay exactly the same, which is what keeps the taste and texture.

The hard part is not the multiplication but the result. 0.75 cups × 2.5 is 1.875 cups, and no one owns a 1.875 cup measure. So the tool rounds cups to the nearest eighth or third (1⅞ cups) and spoons to the halves, thirds, quarters and eighths that spoon sets come in. Grams and millilitres round to whole numbers, and to the nearest 5 once they pass 100.

It reads the amount at the start of each line in several forms: whole numbers, decimals, typed fractions like 1 1/2, symbols like ¾ and ranges like 2-3. A line with no amount at the front, such as “Pinch of salt”, is left as written.

How to use it

1. Paste or type the ingredients into the box, one per line, with the amount at the start of each line.
2. Choose Servings and fill in Recipe serves and I want to serve, or choose A factor and type a number in Multiply by (2 doubles, 0.5 halves).
3. Read the scaled list. The line at the top shows the factor in use, and lines the tool could not scale appear greyed out.
4. Tick Change cups, spoons, oz and lb to grams or ml if you prefer to weigh. The old amount appears in brackets beside each line.
5. Press Copy to put the list on your clipboard. Clear empties the box and Example brings back the sample recipe.

A worked example

Lee has an oat and blueberry bake that serves 4 and wants to make it for 10. The recipe is:

• 1 1/2 cups rolled oats
• 3/4 cup milk
• 1 egg
• 2 tbsp honey
• 1/2 tsp cinnamon
• 1 1/4 cups plain flour
• 2 tsp baking powder
• 125 g blueberries
• Pinch of salt

The factor is 10 ÷ 4 = 2.5. The tool returns:

• 1.5 cups × 2.5 = 3¾ cups rolled oats
• 0.75 cup × 2.5 = 1.875, shown as 1⅞ cups milk
• 1 egg × 2.5 = 2½ eggs, with a note to beat 3 eggs and use about 125 g (2.5 × 50 g)
• 2 tbsp × 2.5 = 5 tbsp honey
• 0.5 tsp × 2.5 = 1¼ tsp cinnamon
• 1.25 cups × 2.5 = 3.125, shown as 3⅛ cups plain flour
• 2 tsp × 2.5 = 5 tsp baking powder
• 125 g × 2.5 = 312.5 g, rounded to 315 g blueberries
• Pinch of salt, unchanged and greyed out

With the grams box ticked, the oats become about 305 g and the flour about 390 g, using the cup weights the cups-to-grams tool knows. Five tablespoons is a lot to count, so Lee might measure it as ⅓ cup minus a teaspoon, or simply weigh about 105 g of honey from the grams view.

Where it is used

• Family cooking, when guests change the head count.
• Batch cooking and meal prep, scaling a dinner for two into five lunches.
• Small bakers and market stalls, scaling a tested recipe up by 3 or 4 for a sale, then weighing in grams for consistency.
• School and club kitchens, where one recipe has to feed a whole class.
• Cutting down, such as halving a cake for a small tin or making a single portion to test a new dish.

Common mistakes

• Putting the amount after the ingredient. “Flour, 2 cups” is not read as an amount. Start each line with the number.
• Scaling time and temperature. The tool changes ingredients only. A larger dish usually needs a lower heat for longer, not twice the time; check it as it cooks.
• Trusting big jumps for baking. Raising agents, salt and spices do not always scale in a straight line. Beyond about double or half, test a small batch, and round these down rather than up.
• Mixing up US and other cups. The grams view assumes US cups. If your recipe uses metric cups (250 ml), weigh with care or adjust.
• Forgetting the pan. More batter in the same tin bakes differently. Work out the new tin with the pan size converter.

Questions people ask

Can I paste a recipe straight from a website? Yes, as long as each ingredient is on its own line with the amount first. Headings and notes without a number pass through unchanged.

What happens to a range like 2-3 tbsp? Both ends are scaled, so at 2.5 times it becomes 5–7½ tbsp, and you pick within the range as before.

Why does 312.5 g show as 315 g? From 100 g up, weights round to the nearest 5 g. That is close enough for cooking and easier to read on a kitchen scale.