Baking Ingredient Weight

How Ingredient Weight Conversion Works

A cup of flour and a cup of sugar don’t weigh the same — converting a baking measurement from volume to weight requires knowing that specific ingredient’s own density. Select an ingredient, enter an amount in cups, tablespoons, teaspoons, or milliliters, and this calculator converts it to grams and ounces using published, ingredient-specific weight data.

The weights come from King Arthur Baking’s own Ingredient Weight Chart — a widely-cited reference in home baking, built from actually weighing each ingredient rather than assuming a single “1 cup = X grams” rule that would only be true for one specific ingredient. The USDA’s own household-measures reference below independently confirms the same underlying point: different foods pack a different weight into the same cup, so a genuinely accurate conversion has to be looked up per ingredient, not applied as one flat multiplier.

The Formula

$$\text{Weight (g)} = \vA{\text{Amount}} \times \vB{\text{Cups Per Unit}} \times \vC{\text{Grams Per Cup}}$$

“Grams per cup” is the ingredient-specific density figure from the chart; “cups per unit” converts whatever unit you entered (tablespoon, teaspoon) into cups first (16 tablespoons or 48 teaspoons per cup).

Worked Example

1 cup of all-purpose flour: $1 \times 1 \times 120 = 120$ g (about 4.23 oz).

2 cups of granulated sugar: $2 \times 1 \times 198 = 396$ g (about 13.97 oz) — noticeably more than the same volume of flour, since sugar is denser.

Key Factors to Consider

• Sifted vs. unsifted flour can change the effective weight per cup. A cup of sifted flour weighs noticeably less than a cup of unsifted flour of the same type, since sifting introduces more air — check whether your recipe specifies “1 cup flour, sifted” versus “1 cup sifted flour,” which are conventionally two different things (sift before vs. after measuring).
• Liquid and dry measuring cups are calibrated the same way but used differently in practice. A liquid measuring cup is typically read at eye level with the cup on a flat surface, while a dry measuring cup is meant to be filled and leveled off — using the wrong type of cup for an ingredient can introduce its own measurement inconsistency beyond what this converter accounts for.
• Brand and moisture content cause real ingredient-to-ingredient variation. Even within one ingredient category (all-purpose flour, for example), humidity, brand milling differences, and how long the ingredient has been stored can shift its actual density somewhat from the published reference chart’s value.
• A kitchen scale eliminates volume-measurement variability entirely. If a recipe provides both a weight and a volume measurement, using the weight (grams) directly on a scale is more precise and repeatable than any volume-to-weight conversion, since it sidesteps packing and scooping technique altogether.

Common Mistakes

• Assuming one “cup to grams” rule applies to every ingredient. It doesn’t — this is exactly why a dedicated ingredient-specific converter exists rather than a single flat multiplier.
• Scooping flour straight from the bag instead of spooning and leveling. This can pack in 20% more flour than the chart’s own reference measurement assumes, throwing off the conversion regardless of how precise the math is.
• Treating this as valid for a different ingredient with a similar name or texture. Whole wheat flour, bread flour, and cake flour all have different densities from all-purpose flour — always select the specific ingredient you’re actually using.

Useful to Know

The “cup” this calculator converts from is the US customary cup (236.588 mL), not the 250 mL “metric cup” used in Australia, the UK, and much of the rest of the metric world. The two are about 5-6% apart — close enough that it rarely matters for a forgiving recipe, but enough to throw off a precise one. If you’re following a recipe written in metric cups, enter the amount in milliliters instead of cups (250 mL per metric cup) rather than typing “1” into the cup field, which this calculator will always treat as the smaller US cup.

The “oz” this calculator shows is weight (avoirdupois) ounces, not fluid ounces — and the two only match for ingredients about as dense as water. A cup of milk is close to both 8 fluid ounces by volume and 8 ounces by weight, since milk is nearly as dense as water. A cup of honey, though, is still 8 fluid ounces by volume but weighs almost 12 ounces, since honey is considerably denser. If a recipe lists a liquid ingredient in fluid ounces, don’t assume this calculator’s weight-ounce result will match it directly — check which kind of ounce the recipe actually means.