A cup of flour and a cup of sugar do not weigh the same, and that single fact explains why so many recipes go wrong when cooks convert between cups and grams. Cups measure volume, grams measure weight, so the conversion depends entirely on the ingredient: a cup of flour is around 125 grams, while a cup of sugar is closer to 200. There is no universal “cup to gram” number, only an ingredient-by-ingredient one. This guide gives you a conversion chart for the most common baking ingredients, explains why weighing produces better results than measuring by volume, and flags the cup-size differences that trip people up. To scale a whole recipe up or down, the CalcRange Recipe Scaler adjusts every quantity at once.
Why There Is No Single Conversion
The reason you cannot memorise one number is that a cup is a measure of space, and different ingredients pack different amounts of weight into that space.
A cup is a fixed volume, roughly 240 millilitres in the common US definition. How much that volume weighs depends on the ingredient’s density and how it settles. Flour is light and full of air, so a cup holds around 125 grams. Sugar is denser and packs tighter, so the same cup holds about 200 grams. Honey is denser still, at around 340 grams a cup. This is why a recipe written in cups can be converted to grams only ingredient by ingredient, using a value specific to each one. Once you have those values, the conversion is simple multiplication; the trap is assuming one figure fits everything.
Cups to Grams Chart
These are approximate weights for one standard cup of each common baking ingredient. Treat them as reliable working figures rather than exact constants, since brand, humidity, and packing all vary.
| Ingredient | Approx. grams per cup |
|---|---|
| Plain / all-purpose flour | ~125 g |
| Granulated white sugar | ~200 g |
| Brown sugar (packed) | ~220 g |
| Icing / powdered sugar | ~120 g |
| Butter | ~227 g |
| Water or milk | ~240 g |
| Vegetable oil | ~220 g |
| Honey | ~340 g |
| Rolled oats | ~90 g |
| Uncooked rice | ~195 g |
| Cocoa powder | ~90 g |
| Chocolate chips | ~170 g |
Notice the spread: from 90 grams of oats to 340 grams of honey in the identical cup. Water is the tidy exception, since one millilitre of water weighs almost exactly one gram, so a 240 ml cup of water is about 240 grams.
Why Weighing Beats Measuring by Cup
For baking in particular, a kitchen scale gives more consistent results than cups, and flour is the clearest example of why.
How you fill a cup of flour changes how much you get. Scooping the cup straight into the bag compresses the flour and can pack in a fair bit more than gently spooning it in and levelling the top, and that difference can be a meaningful fraction of the intended amount. In baking, where the ratio of flour to liquid to fat decides whether something is dense or light, that variation shows up in the result. Weighing removes it entirely: 125 grams is 125 grams however you get it into the bowl. This is why professional and serious home bakers work in grams, and why many recipe writers now give both. If you bake often, a cheap digital scale is the upgrade that most improves consistency.
Not All Cups Are the Same Size
To add one more wrinkle, the “cup” itself is not a single standard worldwide, which is another reason volume measures drift.
The common US cup used in most American recipes is about 240 millilitres, and the US customary cup is very slightly smaller at around 237. A metric cup, used in Australia and some other countries, is 250 millilitres, noticeably larger. Older British recipes sometimes used an imperial cup larger still. So a recipe’s cup and your measuring cup may not match, especially across countries, which quietly shifts every quantity. The gram values in the chart above assume a roughly 240 ml cup. If your recipe or measuring cup uses the 250 ml metric size, the weights run a little higher. This is yet another argument for weighing: a gram is the same everywhere, while a cup is not.
Scale a Whole Recipe
Once your ingredients are in consistent units, changing the yield is easy. The CalcRange Recipe Scaler multiplies every quantity for a new number of servings, and our guide on how to scale a recipe up or down covers what does not scale in a straight line, like leavening and baking time. For other unit swaps, the unit converter handles millilitres, ounces, and more.
Getting the Measurement Right
- For flour with a cup, spoon it in and level the top with a knife rather than scooping, which packs it and adds weight.
- For brown sugar, pack it firmly into the cup unless the recipe says otherwise, since that is how the standard weight is defined.
- Weigh sticky ingredients like honey and syrup rather than fighting to fill and empty a cup cleanly.
- Zero (tare) the scale between ingredients to weigh several into one bowl without arithmetic.
- When a recipe gives both cups and grams, follow the grams for baking; they are the more precise figure.
Frequently Asked Questions
How many grams are in a cup?
It depends entirely on the ingredient, because a cup measures volume and different ingredients have different densities. A cup of flour is about 125 grams, a cup of granulated sugar about 200 grams, and a cup of honey about 340 grams. There is no single cups-to-grams number; you convert each ingredient using its own value from a chart.
Why do flour and sugar weigh different amounts per cup?
Because they have different densities and pack differently into the same volume. Flour is light and airy, so a cup holds around 125 grams, while sugar is denser and settles tighter, giving about 200 grams a cup. The cup is a fixed space; how much weight fills it varies with the ingredient, which is why conversions must be ingredient-specific.
Is it better to weigh ingredients or use cups?
Weighing is more accurate and consistent, especially for baking. Filling a cup of flour by scooping compresses it and adds more than spooning and levelling, and that variation affects the result. A scale removes the inconsistency, since a gram is a gram however you measure it. Many bakers and recipe writers now prefer grams for this reason.
How many grams is a cup of flour?
About 125 grams for plain or all-purpose flour, assuming a roughly 240 ml cup and flour that is spooned in and levelled rather than scooped. Scooping can pack in noticeably more. Because flour is so sensitive to how it is measured, it is the ingredient that benefits most from being weighed rather than measured by volume.
Are US and metric cups the same size?
No. The common US cup is about 240 millilitres and the US customary cup around 237, while the metric cup used in Australia and elsewhere is 250 millilitres, which is larger. Older imperial cups were larger again. The difference shifts every quantity in a recipe, so check which cup a recipe assumes, or weigh in grams to avoid the issue.
How do I convert a cup of butter to grams?
One cup of butter is about 227 grams, which is why butter is often sold in sticks marked with gram and tablespoon equivalents. As with other ingredients, weighing is the most reliable method, particularly for firm butter that is awkward to press into a cup without gaps. Check the wrapper, which usually prints the gram markings directly.
Do these conversions change with humidity or brand?
Slightly, yes. Flour can absorb moisture in humid conditions, and different brands and grinds settle a little differently, so chart values are approximate working figures rather than exact constants. For most home baking the small variation does not matter, but for precise or professional results, weighing your specific ingredient is the way to remove the uncertainty.
The Bottom Line
There is no single cups-to-grams conversion, because a cup of each ingredient weighs a different amount: roughly 125 grams for flour, 200 for sugar, 340 for honey. Use an ingredient-specific chart, and for baking, prefer a scale, since weighing removes the packing and cup-size differences that make volume measures drift. When you need to change the yield, keep the units consistent and let the recipe scaler adjust everything at once.
Last reviewed: August 2026. Recommended editorial review: every 24 months. Gram-per-cup values are approximate and vary with brand, humidity, and how the ingredient is packed; weigh for precise baking.