How to Convert Cups to Grams

There is no conversion. There's an ingredient

One cup of…	Grams
Cocoa powder	84
Rolled oats	89
Flour	120
Granulated sugar	198
Brown sugar, packed	213
Butter	226
Milk	227
Water	236
Honey	336

Cocoa and honey are the same volume and four times apart in weight.

A cup measures volume. A gram measures mass. The only thing bridging them is density — which belongs to the ingredient, not to the cup. Any chart offering one number for everything is quietly assuming water.

Flour is the one that ruins recipes

And not because 120 g is uncertain. Because scooping is.

Dip a measuring cup straight into the bag and the flour compacts:

Method	Grams
Spooned in and levelled	120
Scooped from the bag	up to 140

Up to 17% extra — of the ingredient that provides the structure.

That's the most common reason home baking comes out dry and heavy, and it happens to people who measured carefully by their own lights.

The intended method is to spoon flour into the cup and level it off with a straight edge. Or weigh it.

The real argument for a scale

It isn't that grams are more precise in principle.

It's that a cup of flour is genuinely a different quantity of flour depending on who filled it — and 120 g is 120 g regardless.

That's not precision for its own sake. It's the removal of a large, real, invisible source of variation. It also means fewer things to wash, since most of a recipe can go into one bowl sitting on a scale.

Bread flour is the same weight as all-purpose

Both 120 g per cup.

People go looking for a separate conversion and there isn't one. The two differ in protein content — which changes how the dough behaves, not how much a cup holds.

"Packed" is part of the specification

For brown sugar, packed means pressed firmly into the cup so it holds the cup's shape when turned out.

Loose brown sugar occupies far more volume for the same weight. This is one of the few ingredients where the packing is specified rather than incidental — and if a recipe says a cup of brown sugar without qualifying it, packed is the convention.

Not all cups are the same cup

	Millilitres
US cup	236.6
Metric cup	250
Imperial cup (old)	284

That's a 20% spread between the extremes, which matters enormously in baking.

If you can't tell where a recipe is from, the ingredient weight is a more reliable guide than the volume. Which is one more argument for grams, where the question simply doesn't arise.

Ounces are two different units, and it matters

The calculator gives you ounces and pounds alongside the grams, and both are units of weight.

A fluid ounce is a unit of volume, and there are 8 in a US cup. An ounce of weight is 28.35 g. They share a name and measure different things — so "8 oz of flour" is genuinely ambiguous, and 8 fl oz of flour (one cup, 120 g) is nothing like 8 oz by weight (227 g).

American recipes usually mean fluid ounces for liquids and weight ounces for solids, but not always, and the difference is nearly two to one. The pounds output is there for when a recipe scales up far enough that grams stop being readable.

The volume conversions, which are easy

These are the same for every ingredient, because they're all volume:

• 1 cup = 16 tablespoons = 48 teaspoons
• 1 tablespoon = 3 teaspoons

Two ingredients that are easier than this makes them sound

Butter. A US stick is 113 g — half a cup — and the wrapper is printed with tablespoon markings you can cut straight through. You rarely need to measure it by volume at all, and pressing butter into a measuring cup is one of the more unpleasant jobs in a kitchen.

Liquids. Water, milk and stock are close enough to their volume that a jug is fine. Cups behave well here; it's the dry ingredients where they mislead.

Print the conversion chart — the ingredient weights are the half you can't work out from first principles, and it's designed to live inside a cupboard door.

Sources: King Arthur Baking — Ingredient Weight Chart