How to Convert Cups to Grams (With a Free Calculator)

Why Cups Are an Imprecise Measurement

If you've ever made a recipe from an American cookbook and had it turn out wrong, cups are probably the culprit. Unlike grams, which measure weight, a cup measures volume — and volume varies wildly depending on the ingredient.

A cup of plain flour can weigh anywhere from 120 g to 165 g depending on whether you scoop it packed, spooned loosely, or sifted first. That's a 37% difference — enough to turn a tender cake into a dense brick.

Professional bakers and food scientists almost universally use weight (grams or ounces) rather than volume. When you see a recipe from a serious bakery, it will specify grams. It's more accurate, more consistent, and easier to scale.

Common Cups to Grams Conversions

The following weights are for standard US cups (240 ml) using the most common preparation method for each ingredient.

Ingredient	1 Cup	½ Cup	¼ Cup
Plain flour (all-purpose)	125 g	63 g	31 g
Caster sugar	200 g	100 g	50 g
Brown sugar (packed)	220 g	110 g	55 g
Icing sugar (powdered)	120 g	60 g	30 g
Rolled oats	90 g	45 g	23 g
Long-grain white rice	185 g	93 g	46 g
Butter (softened)	227 g	114 g	57 g
Cocoa powder	85 g	43 g	21 g
Honey	340 g	170 g	85 g
Milk	240 g	120 g	60 g

These are approximate. Ingredients like flour and cocoa powder are particularly variable because they compact easily. Always spoon them into the cup and level off with a knife for the most consistent result — or better yet, use a scale.

How to Convert Cups to Grams Manually

If your ingredient isn't in the table above, the formula is:

grams = cups × density (g per cup)

For example, to convert ¾ cup of almond flour:

1. Look up or estimate the density: almond flour ≈ 96 g per cup
2. Multiply: 0.75 × 96 = 72 g

The challenge is that every ingredient has a different density. That's why a general-purpose cup-to-grams calculator doesn't exist — you need ingredient-specific values.

The Easiest Way: Use a Calculator That Knows Every Ingredient

Rather than maintaining a mental library of densities or hunting through tables, use KitchenConvert to convert any recipe from cups to grams instantly. Paste or type your recipe, choose your target units, and every measurement is converted with ingredient-specific values — not a one-size-fits-all approximation.

KitchenConvert also handles temperatures (°F to °C), scaling (double or halve any recipe), and can scan a recipe photo directly if you're working from a physical cookbook.

Frequently Asked Questions

How many grams is 1 cup of flour? Standard plain flour (all-purpose) weighs approximately 125 g per cup when spooned into the cup and levelled. If you scoop directly from the bag, it can be as heavy as 165 g due to compaction.

Is 1 cup always 250 ml? In Australia, yes — the standard metric cup is 250 ml. In the United States, 1 cup is 240 ml. The difference is small (4%) but worth knowing when precision matters.

Why do my baked goods turn out different when I use a cup? The most common cause is inconsistent scooping. Scooping flour directly compacts it; spooning it in loosely results in less. The same recipe measured two different ways can produce very different results. Using grams eliminates this variability entirely.

Can I convert cups to grams for liquids? For water-based liquids (water, milk, most juices), 1 cup ≈ 240 g since their density is close to water. For heavier liquids like honey or maple syrup, the weight is significantly higher — check the table above or use a kitchen scale.