Cups measure volume; grams measure weight. Converting between them isn't a single fixed number — it depends on what you're measuring. This guide explains why, and how to get an accurate answer for any ingredient.
A cup is a unit of volume — how much space an ingredient takes up in a measuring cup. A gram is a unit of weight — how heavy that ingredient is on a scale. The two only match up when you know how much a specific ingredient weighs for a given volume, which is its density.
1 US cup of all-purpose flour weighs about 125g. 1 US cup of honey weighs about 340g — more than double, in the exact same cup. Honey is a dense, heavy liquid with almost no trapped air; flour is a light, airy powder. Same volume, very different weight.
That's why a reliable cups-to-grams conversion has to be ingredient-specific. A generic "1 cup = 240 grams" rule is only close for ingredients with a density near water — it's wrong for most of your pantry.
The most reliable way is using the GramToCup calculator: choose your ingredient, switch to Cups → Grams mode, and enter your amount. It applies that ingredient's real density automatically, so you don't need to know or remember the number.
If you're checking multiple ingredients or amounts at once, the Cups to Grams Conversion Chart has the most common cup measurements — 1/4 cup through 2 cups — already converted for every ingredient on the site.
For example, 1/4 cup of all-purpose flour weighs about 31g — the same density figure as above, just at a smaller quantity.
GramToCup uses the US customary cup everywhere on this site — the calculator, every ingredient page, and both charts. If a recipe was written using a metric cup, the two won't match exactly; see the US vs Metric Cups guide for how much that matters.
Even with the right density figure, how you fill the cup changes the result. Spooning flour into a cup and leveling it gives a lighter cup than scooping directly from the bag; brown sugar is meant to be packed firmly, not spooned loose. See Why Different Sites Show Different Values for the full breakdown, or any ingredient's own page for its specific technique.
If a recipe already lists an amount in grams, weigh it directly rather than converting to cups and measuring by volume — that reintroduces the exact packing and density variation a gram measurement is meant to avoid. A scale is also the most accurate choice for recipes with multiple dry ingredients, where each small volume error adds together.
Use the calculator for any ingredient and amount, or check the full chart for a quick reference across all ingredients.
Use the Gram to Cup Calculator →About 125g. That figure comes from flour's density (125g per US cup) — every ingredient has its own value, which is why there's no single "1 cup = X grams" answer that works for all of them.
1 cup of honey weighs about 340g, versus about 125g for flour. Honey is a dense liquid with very little trapped air, while flour is a light, airy powder — the same volume holds far more weight in honey.
It's a practical approximation, not a lab measurement. Brand, humidity, and how an ingredient is packed into the cup can all shift the real weight slightly — see each ingredient's own page for its specific measuring technique.