Cooking for a different crowd? Enter a recipe's ingredients and its original serving count, then set your target servings to rescale every quantity at once.
For strong seasonings like salt or spices, scale a little less than the ratio suggests and adjust to taste. Baking is more sensitive to exact ratios, so stick closely to the scaled amounts there.
Flour, sugar, water, milk, meat and vegetables scale linearly. Doubling the recipe doubles these.
Salt and spices scale less than linearly. Doubling salt exactly usually tastes too salty. Start at 1.5–1.75× and adjust by tasting.
Baking powder, bicarbonate of soda and yeast need a separate calculation. More batter needs more lift, but scaling them proportionally tends to leave a bitter taste or a cake that rises then collapses.
Oil for greasing a pan barely scales at all, since it depends on pan area rather than batch size.
This is the most common mistake. Doubling a recipe does not double the cooking time.
Heat travels inward from the surface. Doubling the quantity cubes the volume but only squares the surface area, so time increases with thickness, not with batch size.
Oven dishes spread across a larger pan keep the same depth, and the time barely changes. Double the depth in the same pan and it can take 1.5× longer or more.
When simmering, reaching the boil takes longer; the simmering time afterwards is similar.
When frying, overloading the pan drops the temperature and turns a sauté into a steam. Cook in batches.
A cup of flour can be 100g or 140g depending on whether you scoop or spoon it, and whether you pack it down — up to a 40% difference.
Baking is especially sensitive: a small change in the flour ratio transforms the dough.
Use a scale. An inexpensive kitchen scale is far more accurate than any set of measuring cups.
Reference weights: flour ≈ 120g per cup, sugar ≈ 200g, butter ≈ 227g, water ≈ 240g.
US 240ml · Japan and Korea 200ml · Australia 250ml · Imperial (old UK) 284ml.
A 20% difference changes results, particularly in baking.
Tablespoons differ too — 15ml in most places but 20ml in Australia.
Check which country a recipe comes from, or look for weights in grams, which are unambiguous.
For cakes and traybakes, scale by area.
Round pans scale with the square of the radius: 20cm and 23cm diameters differ by about 1.3× in area. Three centimetres is not a small change.
Rectangular pans are simply width × length. Moving from 20×20cm (400cm²) to 23×33cm (759cm²) is about 1.9×, so the recipe needs roughly doubling to keep the same depth.
Changing depth means adjusting time and temperature too — shallower bakes faster, deeper wants 10–15°C lower for longer.
Rescaling produces quantities like "1.5 × ⅓ cup". This tool resolves them into fractions you can actually measure.
When the fraction gets unwieldy, convert to tablespoons: 1 cup = 16 tablespoons, so ⅓ cup is 5⅓ tablespoons.
Everything is computed in the browser and nothing is transmitted.
Enter the original number of servings and your target number, and each ingredient amount is multiplied by that ratio automatically.
Yes. Amounts in grams, millilitres, cups or spoons are all scaled by the same ratio, so proportions stay correct.
No — cooking time doesn't scale proportionally with ingredient quantity. Judge doneness by appearance and texture rather than multiplying the time.
What this tool bases its numbers on, and how far those numbers go.
Every parsed quantity is multiplied by target servings divided by original servings. Units are preserved as written, so the output is the same recipe expressed at a different size — no unit conversion and no density assumption is applied.Going from 3 servings to 5 is a factor of 5 ÷ 3 ≈ 1.667, so 200 g of flour becomes 200 × 1.667 ≈ 333 g.