Methodology & sources

A converter is only as good as its numbers. This page states exactly where GramChef's values come from and which assumptions sit behind them, so any cook can check our work.

Primary source: King Arthur Baking

For baking ingredients, our primary reference is the King Arthur Baking Ingredient Weight Chart, published by King Arthur Baking Company — one of the most widely used and carefully tested cups-to-grams references in home baking. Where King Arthur publishes a weight for an ingredient, we use it. Examples: all-purpose flour 120 g per cup, bread flour 120 g, whole wheat flour 113 g, cake flour 113 g, granulated sugar 198 g, packed brown sugar 213 g, powdered sugar 113 g, butter 227 g, cocoa powder 84 g and rolled oats 99 g.

Secondary source: USDA FoodData Central

For ingredients the King Arthur chart does not cover — most fresh produce, sauces, spreads and general cooking items — we use typical values from USDA FoodData Central, the United States Department of Agriculture's public food-composition database. Examples include honey (340 g per cup), whole milk (245 g), water (236.6 g) and uncooked long-grain rice (185 g). Where the two sources overlap and differ slightly, King Arthur takes precedence for baking ingredients because its values are measured the way bakers actually measure.

The assumptions behind every number

• US cup = 236.588 ml. All volume values use the US customary cup. A metric cup (250 ml) is about 6 percent larger; multiply our gram results by 1.06 to approximate metric-cup recipes.
• Spoon-and-level for dry goods. Flour and similar dry ingredients are weighed as spooned into the cup and levelled with a straight edge — never scooped from the bag, which can add 20 percent or more.
• Brown sugar is packed. Our 213 g per cup assumes brown sugar pressed firmly into the cup, the standard convention in US recipes.
• Spoons derive from cups. One tablespoon is one sixteenth of a cup and one teaspoon one forty-eighth, so spoon weights are the cup weight divided by 16 and 48 respectively.
• Butter sticks. One US stick of butter is treated as half a cup, 113.5 g (the labelled weight of a standard stick).
• Eggs by count. Whole eggs are counted, not weighed, in the recipe converter. A large egg weighs roughly 50 g out of its shell if you need the weight for scaling.

Oven temperatures

Fahrenheit-to-Celsius conversions use the exact formula (°F − 32) × 5⁄9, then round to the nearest setting found on real ovens and in published charts. Gas Mark equivalents follow the standard British table (Gas Mark 4 = 180°C = 350°F). Fan-assisted temperatures follow the widely used rule of subtracting 20°C from the conventional Celsius figure.

Pan volumes

Pan capacities are total volumes to the brim, expressed in US cups of batter, consistent with the pan-volume references published by major baking references and manufacturers. Individual pans vary slightly by brand and depth; treat the figures as accurate to within a few percent, and never fill a cake pan more than about two-thirds full.

Honest limits

Ingredient weights vary in the real world: flour absorbs humidity, brands mill differently, and no two scoops are identical. Published reference values are the best possible starting point, not a laboratory guarantee. Every GramChef value is reviewed by our founder, a NAVTTC Certified Chef (Level 2), and we correct values when a better-published source appears. To suggest a correction, use our contact page and name the source you are citing.