How To Convert Cooking Weights

Dry ingredients can be measured by weight or by volume. Weight is more accurate because it does not depend on how the ingredient is packed, but many recipes still use cups.

The US customary system uses ounces and pounds, with sixteen ounces in a pound. Most of the world and every kitchen scale uses grams and kilograms.

The exact link is that one ounce is 28.349523125 grams, so one pound is sixteen times that, or 453.59237 grams. A kilogram is a thousand grams.

Converting a weight to a volume is possible for a specific ingredient because density links the two. The converter includes two common shortcuts, a cup of all-purpose flour and a cup of granulated sugar.

A US cup of all-purpose flour weighs about 120 grams when spooned lightly into the cup. Scooping directly from the bag packs the flour and can push the weight to 140 grams or more.

A US cup of granulated sugar weighs about 200 grams, because sugar is denser than flour. This is why the same cup of different ingredients has very different weights.

The converter expresses every unit as a size in grams and converts by multiplying the value by the source factor and dividing by the target factor. That keeps every pair consistent.

The most common baking conversion is grams to ounces: divide the grams by 28.349523125. A 500 gram bag of flour is about 17.637 ounces.

Going the other way, multiply the ounces by 28.349523125 to get grams. A 10 ounce bag is about 283.5 grams.

Because flour and sugar have different densities, a cup of each weighs differently. Substituting one for the other by volume, rather than by weight, is a frequent source of failed bakes.

A frequent mistake is to assume one cup of any dry ingredient weighs the same. Flour at 120 grams and sugar at 200 grams differ by about 67 percent.

A second trap is to confuse fluid ounces with weight ounces. A fluid ounce measures volume and an ounce measures weight, and they only coincide for water.

A kitchen scale removes the guesswork from baking. Weighing flour at 120 grams per cup is repeatable, while scooping the same flour can vary by twenty percent from one baker to the next.

European recipes are usually in grams, so a scale set to ounces needs converting. Dividing the grams by 28.349523125 gives ounces, and most scales switch between the two at the touch of a button.

Chocolate, butter and nuts all have different densities, so their cup weights differ from flour and sugar. The converter's gram base lets you enter any weight and read it in the unit you have.

Portion control uses the same conversions. A 150 gram serving is about 5.29 ounces, a figure that appears on nutrition labels written in both systems.

When a recipe gives a range, such as 120 to 130 grams of flour, aim for the middle and adjust with liquid. The small variation is normal and rarely changes the outcome.

Bread baking is the most sensitive to weight, because the ratio of flour to water sets the structure. A ten percent error in the flour weight changes the dough enough to notice in the crumb.

Some scales read in pounds and ounces together, showing a decimal point rather than a fraction. A reading of 1.5 pounds is one pound eight ounces, which is 680.388555 grams.

Freezing and thawing do not change weight, so a frozen portion converts exactly as a fresh one. Only water loss during cooking reduces the weight, and that is a change in the ingredient rather than in the unit.

The calculator models the fixed relationships between the units and nothing more. It does not know your measuring technique or the ingredient, so treat the output as exact arithmetic on the number you entered.