How to convert cups to grams
A cup is a measure of volume — how much space something takes up — while a gram is a measure of weight. To convert between them you need one extra piece of information: the ingredient’s density, which is how many grams fit into one millilitre.
The math is simple once you have the density. First convert the volume to millilitres (one US cup is 236.6 ml), then multiply by the density:
- grams = millilitres × density
- millilitres = grams ÷ density
This is why you can’t use a single number to convert “a cup” into grams for every recipe. A cup of flour is light and airy, so it weighs far less than a cup of honey, which is dense and heavy. The converter above applies the correct density automatically when you choose an ingredient.
Common kitchen conversions
Keep this quick-reference table handy for the ingredients and measures that show up most often in recipes:
| Measure | Equivalent |
|---|---|
| 1 cup all-purpose flour | ≈ 125 g |
| 1 cup granulated sugar | ≈ 200 g |
| 1 cup butter | ≈ 227 g |
| 1 cup water | ≈ 237 g (237 ml) |
| 1 tablespoon | = 15 ml |
| 1 teaspoon | = 5 ml |
Why measuring by weight is more accurate
Professional bakers almost always weigh their ingredients, and for good reason. The way you scoop flour can change its weight by 20% or more — a packed cup versus a loosely spooned one are very different amounts. That variation is enough to leave a cake dry or a dough too wet.
Weighing removes the guesswork: 125 g of flour is always 125 g, no matter who measures it or how they scoop. A basic digital kitchen scale costs very little and makes your results repeatable every single time. When a recipe gives both cups and grams, reach for the grams.
Cook without the conversion headache
Once you know your measurements, the next step is the cooking itself. Swoodie stores every recipe you save and lets you scale, convert, and build a shopping list from it in a tap. Pair this tool with our recipe scaler to resize a dish for any number of servings, or the oven temperature converter when a recipe lists the wrong temperature scale for your oven.
Frequently asked questions
How do I convert cups to grams?
Multiply the volume in millilitres by the ingredient's density in grams per millilitre. One US cup is 236.6 ml, so a cup of all-purpose flour (density 0.53) is about 125 g, while a cup of granulated sugar (density 0.85) is about 200 g. This converter handles the density for you when you pick the ingredient.
Why does a cup of flour weigh less than a cup of sugar?
Because they have different densities. A cup is a fixed volume, but flour is light and full of air while sugar is denser and packs together. That is why converting between volume (cups, ml) and weight (grams, oz) always needs to know which ingredient you are measuring.
Are these US cups or metric cups?
This tool uses the US legal cup of 236.588 ml, which is the standard in most US recipes. A metric cup is 250 ml and an imperial (UK) cup is roughly 284 ml, so double-check your recipe's origin if precision matters for baking.
How many ml is a tablespoon?
One US tablespoon is 14.79 ml (often rounded to 15 ml) and one US teaspoon is 4.93 ml (often rounded to 5 ml). There are 3 teaspoons in a tablespoon and 16 tablespoons in a US cup.
Is it more accurate to measure by weight or volume?
Weight is far more accurate, especially for baking. Scooping flour can vary by 20% or more depending on how packed it is, but 125 g is always 125 g. A digital kitchen scale removes that guesswork entirely.
Density values are typical averages and can vary by brand, grind, and how packed an ingredient is. For precision baking, weigh your ingredients with a kitchen scale.