Cups vs Grams: Why Weighing Ingredients Works Better
A practical look at why grams give more repeatable results than cups, and how to start weighing at home.
- A cup of flour varies with technique, and one experiment found weights differing by about 30 grams [1][2].
- Flour volume also shifts with humidity, so a cup can be more or less full [3].
- Weighing matters most for cakes, pastries, and breads; cookies are more forgiving [1].
- Zero the scale before the first ingredient and again before each new one [4][5].
- Weighing can give more consistent results and fewer dirty dishes [4].
Why a cup of flour is not one fixed amount
A gram measures mass or weight, while a teaspoon measures volume [5]. That difference is the heart of the cups versus grams question. Weighing is more accurate because 125 grams of flour is always 125 grams of flour [1].
Cups are less reliable because people fill them differently. Some dip and sweep, some spoon and level, some pack the flour in, and some are very light with it [1]. Each of those techniques gives a different amount of flour [1]. Others scoop and level, pack and shake the cup to level it, or end up with a cup that is not full or is overflowing [2].
The cups themselves vary too. The actual volume of a set of measuring cups can differ significantly from brand to brand [2]. Spooning flour instead of scooping it can create a variance of 30 to 50 grams [4].
There is a careful way to measure flour in cups: spoon it into the cup without compressing it. That method is time-consuming and will never give as accurate a result as a scale and grams [5].
What the flour experiment showed
One published experiment had eight different people weigh 1 cup of all-purpose flour using two different measuring cups. Their scooping methods ranged from packing to lightly spooning and leveling [2].
Same ingredient and nominal cup measure, yet the flour weights varied by about 30 grams [2]. Against a standard weight of 120 grams per cup of all-purpose flour, that gap is almost a quarter cup [2].
Ingredients that drift most, and ones that do not
Not every ingredient benefits equally. Sugar is almost always accurate when measured in cups, while flour and brown sugar are especially susceptible to inaccurate measuring [2]. Brown sugar is full of air pockets and clumps, so one cook's idea of "packed" may differ from another's [2].
Flour also changes with the weather. Its volume fluctuates with the humidity in the air, and drier conditions make flour lighter [3]. One instructor described living in Chicago, where summer humidity was 100% and winter humidity was 15% [3]. Because flour changes a lot with humidity, a cup of it may be more or less full [3].
Eggs are another case. Bakers weigh eggs rather than counting them as small, medium, or large [3]. They crack a batch of eggs, whisk them, and weigh the result [3]. If a recipe asks for 50 grams of eggs, you weigh out 50 grams [3]. This removes the worry about whether an egg is too big or too small [3].
Weighing is not only for baking. One writer also weighs cheese, meat, greens, herbs, and pasta, generally in ounces [2].
Where weighing matters most
Cakes are especially important to weigh because they can be finicky and the mass being created is large [1]. Pastries and breads also need weighing because they rely on a delicate balance between ingredients [1]. Cookies are more forgiving of measurement variations [1].
Too much flour can lead to a hard, dry, or crumbly texture, and it can alter the ratios in a recipe [2]. Cakes, cookies, and pie dough are especially susceptible to textural changes from too much flour [2]. Extra flour also makes gluten free and einkorn bread, muffins, cakes, and cookies come out less than perfect, especially bread [5]. Variance in flour can mean the difference between light and tender versus dense and tough baked goods [4].
One instructor reports that guests said their bread was not coming out like hers, and once they got used to the scale they confirmed they had been adding too much flour [5]. When people contact her team about recipe problems, recommending a scale almost always clears up the issues [5].
Weighing helps with portioning as well. Unevenly sized cookies bake unevenly, with small ones crisping while large ones stay doughy [4]. Professional bakers weigh each dough ball before it goes on the baking sheet [4]. That way the dough balls are the same size and bake at the same rate [4].
How to weigh ingredients, step by step
Choose a digital scale rather than a mechanical one [5]. Scales with a built-in, dishwasher-safe bowl are also available [4]. One ounce equals about 28 grams [5].
A simple routine keeps the bowl's own weight out of your measurements:
- Set your mixing bowl on the scale and press tare to zero out its weight before adding anything [4][5].
- Weigh the first ingredient into the bowl [5].
- Press tare again to zero out the weight, then weigh the next ingredient [5].
- Zero out the scale each time for accuracy [4].
- For eggs, crack them, whisk them, and weigh the amount the recipe lists [3].
- For cookies and similar portions, weigh each dough ball before baking [4].
Fewer dishes and easier recipe use
Using a scale means you avoid dirtying a bunch of different measuring cups and spoons [4]. Baking with a scale usually involves only a spoon and a mixing bowl [2]. Preparing recipes by weight can give more consistent results along with fewer dirty dishes [4].
Weight is not yet the habit for most home cooks. Cooking by weight is the norm in restaurants, but using a scale at home is still mostly uncharted territory [4]. One instructor asks her students whether they bake with a scale, and only a few raise their hands [5]. Professional bakers rarely use volume measurements when baking [2].
Recipes are catching up. More cookbooks now include weights alongside cups and tablespoons [4]. Some recipe sources list ingredients in both grams and cups so they do not exclude cooks who bake without a scale [5]. In European baking, liquids are often listed in ml and measured by volume, while flour and sugar are listed by weight in grams [5].
If you need to convert, one baking book offers an exhaustive list of weight conversions, with volume to grams conversion for nearly every baking ingredient [1].
| Measuring cup | Lowest weight | Highest weight |
|---|---|---|
| First cup | 117 grams | 145 grams |
| Second cup | 110 grams | 141 grams |
Frequently asked questions
Do I have to weigh every ingredient?
No. Sugar is almost always accurate when measured in cups, while flour and brown sugar are especially susceptible to inaccurate measuring [2]. Cookies are also more forgiving of measurement variations than cakes, pastries, and breads [1].
What if I only have measuring cups?
Spoon the flour into the cup without compressing it. That method is time-consuming and will never be as accurate as a scale and grams [5].
Which kind of scale should I buy?
One source recommends a digital scale over a mechanical one [5]. Scales with a built-in, dishwasher-safe bowl are available [4].
Why do bakers weigh eggs?
Weighing eggs removes the worry about whether an egg is too big or too small [3]. Bakers crack and whisk the eggs, then weigh the amount the recipe asks for [3].
How many grams are in an ounce?
One ounce equals about 28 grams [5].
Sources
- Jessica Reed on Baking by Weight - Bake from Scratch - Page 2 (bakefromscratch.com)
- Step Up Your Baking Game by Weighing Your Ingredients (cuisineathome.com)
- Why would you scale (weigh) for a recipe instead of using cups or teaspoons? | Rouxbe Online Culinary School (rouxbe.com)
- Why You Should Be Weighing Your Ingredients (giadzy.com)
- Baking With A Kitchen Scale In Grams (jovialfoods.com)