Method and sources

This page explains where the numbers on Grams to Cups come from and what their limits are.

Where the weights come from

Ingredient weights come from the King Arthur Baking ingredient weight chart, last checked on 31 October 2026. For example, the chart lists all-purpose flour at 120 g per cup and granulated sugar at 198 g per cup.

How we scale smaller measures to a cup

Some ingredients are listed per tablespoon, quarter cup or half cup. We multiply those to a full cup. Cornstarch is listed at 28 g per 1/4 cup, so we use 112 g per cup. Honey is listed at 21 g per tablespoon, so we use 336 g per cup (16 tablespoons).

Water and unit definitions

One US customary cup is 236.588 ml and equals 16 tablespoons. Water is about 1 g per ml, so we use 237 g per cup. One ounce is 28.3495 g.

How the kitchen measure is rounded

The converter shows the exact number of cups and a practical kitchen measure. It picks the nearest simple fraction (eighths and thirds) when that is within 3 percent of the exact amount. Otherwise it shows cups plus tablespoons, rounded to the nearest half tablespoon. Under 4 tablespoons it uses tablespoons or teaspoons.

Limits

These are average weights. A cup of the same ingredient changes with brand, humidity and how the cup is filled, and different charts use different measuring methods. Some charts use about 125 g per cup for all-purpose flour, for example. For baking, weighing your ingredients on a scale is more reliable than any conversion.

Update log

• 31 October 2026: first release with 51 ingredients.