Cups ⇄ Grams Converter (flour, sugar, butter, rice)

Understanding the cups to grams converter — concept and principle

This converter turns US cup measurements into grams for common baking and cooking ingredients, and also shows the same volume in tablespoons and millilitres. It is useful when you follow an American recipe with a kitchen scale, or want to write a recipe that others can repeat exactly.

A cup measures volume, so its weight depends on how dense the ingredient is.

How it is calculated

Grams = cups × grams per cup of the chosen ingredient.
Tablespoons = cups × 16.
mL = cups × 240.

Grams per cup used here: all-purpose flour 125, granulated sugar 200, packed brown sugar 220, butter 227, powdered sugar 120, raw rice 185, rolled oats 90, water or milk 240, honey 340.

The principle

A cup measures volume, while a scale measures mass. The two are linked by density: mass = volume × density. Water has a density of about 1 g/mL, so 240 mL weighs about 240 g. Flour is light and full of air, so a cup weighs only about half as much; honey is denser than water, so the same cup weighs more. For powders, the grams per cup also depend on how the cup is filled, which is why recipes specify "spooned and levelled" or "packed". The US legal cup of 240 mL, used on nutrition labels, is slightly larger than the traditional US customary cup of about 236.6 mL; the difference is under 2% and rarely matters in cooking.

Worked example

Inputs: 1 cup, all-purpose flour (125 g per cup).
Grams = 1 × 125 = 125 g.
Tablespoons = 1 × 16 = 16 tbsp.
Millilitres = 1 × 240 = 240 mL.

Each point is the calculator re-run with only “Cups (US 240 mL)” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

Cups (US 240 mL)	Grams
0.25	31.25
0.5	62.5
0.75	93.75
1	125
1.25	156.25
1.5	187.5
2	250

How to read the result

The grams figure is a typical value, good enough for everyday cooking. For baking, where the flour-to-liquid ratio controls texture, weighing gives more repeatable results than any cup. If you scoop flour straight from the bag, a cup can weigh noticeably more than 125 g, which makes cakes dry and dense. Note that cups differ between countries: Australia and several other countries use a 250 mL metric cup, and Korean recipes often use a 200 mL cup.

Common mistakes

Using the flour figure for every powder; sugar is much heavier per cup.
Packing flour into the cup, or not packing brown sugar when the recipe expects it.
Measuring sticky ingredients like honey without greasing the cup, so some stays behind.
Mixing up fluid ounces (volume) with ounces (weight).

Keep in mind: Ingredient weights per cup vary with brand, grind, moisture and filling method. When a recipe gives grams, follow the grams rather than converting from cups.

Frequently asked questions

How many grams is one stick of butter?

A US stick is half a cup, about 113 g, so two sticks make the 227 g cup used here.

How many teaspoons are in a tablespoon?

Three. With a 240 mL cup, one tablespoon is 15 mL and one teaspoon is 5 mL.

Why does 1 cup of milk weigh about the same as water?

Milk is mostly water and its density is only slightly higher, so 240 mL weighs close to 240–250 g.

Sources: U.S. Food and Drug Administration, 21 CFR 101.9(b)(5)(viii), household measures for nutrition labeling (1 cup = 240 mL) · NIST Handbook 44, Appendix C, General Tables of Units of Measurement

Checked 8 Nov 2026. Typical coverage rates and standard formulas. Always check the product label and local building rules; buy 5–10% extra for waste.

Your numbers