Why use this calculator
A cup is a volume and a gram is a mass, so there is no single conversion between them. Flour is a compressible powder full of air, honey is dense and syrupy, and rolled oats are mostly gaps, which is why one cup of them weighs 125 g, 340 g and 90 g in that order.
Two further things move the number that most converters ignore. The first is the cup standard, because a metric cup holds 5.7 per cent more than the US customary cup a recipe probably means. The second is technique: scooping a cup straight into a flour bag compacts it and can add twenty per cent of extra flour without changing the reading.
This tool exposes both, gives the gram figure for your exact combination, and shows what the same recipe would weigh under the other cup standard so you can see the size of the error you were about to make.
How to use it
- Enter the number of cups the recipe calls for in the first box, using decimals for fractions.
- Choose the ingredient from the list, since the density of that specific ingredient drives the entire calculation.
- Set the cup standard to match where the recipe came from, which for most American recipe sites is the US customary cup and for Australian and New Zealand sources is the 250 mL metric cup.
- Finally choose how the cup is filled: spooned and levelled is the published standard behind almost every cup weight, scooped is what most people actually do, and sifted applies when the recipe says to sift before measuring.
- Read the highlighted weight, set your scale to grams, and measure that instead.
What each result means
- Weight
- The gram figure to dial into your scale. This is the number that makes the recipe repeatable.
- Weight in ounces
- The same mass in avoirdupois ounces, for scales and recipes that work in imperial weight.
- Volume measured
- The millilitres your cups add up to, before any ingredient density is applied.
- Grams per cup used
- The weight of a single cup at the standard and packing you chose. Handy for scaling a recipe in your head.
- Same recipe with a US customary cup
- What the ingredient weighs if the recipe meant the American 236.588 mL cup.
- Same recipe with a metric 250 mL cup
- What it weighs with an Australian or New Zealand cup, and the extra grams that adds.
- In metric tablespoons (15 mL)
- The same volume counted in 15 mL tablespoons, useful for quantities under half a cup.
The formula
The weight is built from density:
- Density_g_per_mL = publishedGramsPerUSCup / 236.588
- Then grams = cups x cupVolume_mL x density_g_per_mL x packingFactor
Here cups is the recipe quantity, cupVolume_mL is 236.588, 240, 250 or 284.131 depending on the standard chosen, and packingFactor is 1.00 for spooned and levelled, 1.18 for scooped from the bag and 0.88 for sifted. Packing is applied only to flours and powders. Ounces are grams divided by 28.3495.
How this number is used in practice
Ask ten people to measure a cup of flour and you will get answers between 110 g and 150 g. Sifting first traps air and drops the weight to around 110 g. Spooning flour into the cup and levelling it with a knife gives the 120 g to 125 g figure that published charts use.
Dipping the cup into the bag and pressing packs it to 145 g or more. That spread is up to a quarter of the flour in a cake, applied to the one ingredient that sets the structure, which is exactly why the same recipe can be light for one cook and dense for another with nobody making a mistake.
This is the reason professional kitchens and serious home bakers weigh. A digital scale costs less than a set of measuring cups, removes the packing question, removes the cup standard question, and lets you tare the bowl and add ingredients one after another without washing anything.
Bread and pastry recipes written in baker's percentages assume weight from the start. If a recipe you love gives only cups, weigh what you measured the first time it worked and write the grams in the margin, and it will work every time after that.
Worked examples
2 cups of plain flour, US customary cup, spooned and levelled
250.0 g, or 8.82 oz
The same 2 cups scooped straight from the bag
295.0 g, which is 45 g of extra flour
Half a cup of honey measured with an Australian metric cup
179.6 g, against 170.0 g from a US cup
When people use it
- Rewriting an American cup recipe as grams before baking it on a metric scale
- Working out why a cake came out dense when the recipe was followed exactly
- Batch baking, where small volume errors compound across a multiplied recipe
- Tracking nutrition accurately, which needs weight rather than volume
- Buying ingredients by weight when a recipe is written only in cups
Tips
- Spoon flour into the cup and level with the back of a knife. Never scoop and never tap the cup on the bench.
- Weigh flour, sugar, butter and cocoa. Cup measures are fine for liquids, where a millilitre is a millilitre.
- Tare the bowl on the scale between ingredients and you can build a whole recipe in one bowl with nothing to wash.
- Brown sugar is the one ingredient meant to be packed. Press it in until it holds its shape when tipped out.
- Butter sold in sticks is already weighed: one US stick is half a cup and 113 g, so a full cup is 227 g.
- If a recipe says sifted flour, sift before you measure. Sifting after measuring gives a different weight entirely.
What it assumes, and where it stops being accurate
- Gram weights per cup are published averages. Brand, humidity and how long a bag has been open all move them by a few per cent.
- The packing factors of 1.18 for scooped and 0.88 for sifted are typical rather than exact, and apply only to flours and powders.
- Butter follows the US stick convention of 227 g per cup, which assumes it is packed solid with no air gaps.
- Liquids are at ordinary room temperature. Density shifts slightly with temperature but not enough to matter in a kitchen.
- The list covers common baking staples. Anything not listed should be weighed directly rather than estimated.
Terms used on this page
- Density
- Mass per unit volume, in grams per millilitre. It is what converts a cup into a weight.
- Spoon and level
- Spooning an ingredient loosely into a cup and scraping the top flat. The standard behind published cup weights.
- Packed cup
- An ingredient pressed firmly into the cup, which is correct for brown sugar and wrong for flour.
- Tare
- Zeroing a scale with the bowl on it so only the ingredient is weighed.
- Baker's percentage
- Expressing every ingredient as a percentage of the flour weight, which only works with weights.
Questions people ask
- How many grams is a cup of flour?
- About 125 g for a US customary cup of plain flour spooned in and levelled off. The same cup scooped straight from the bag holds closer to 148 g, and sifted flour drops to around 110 g. An Australian 250 mL cup of spooned flour is about 132 g. Weighing removes the guesswork entirely.
- Why does the weight change so much between ingredients?
- Because density varies enormously. Rolled oats are full of air at roughly 0.38 g per millilitre, flour sits near 0.53, granulated sugar near 0.85, and honey is 1.44 because it is a dense syrup. A cup is the same volume for all of them, so the weight follows the ingredient, not the cup.
- Does it matter whether I scoop or spoon the flour?
- It matters more than the cup standard does. Dipping the cup into the bag compacts the flour and adds up to twenty per cent extra, which is the single most common cause of dry, heavy baking. Published cup weights assume flour spooned into the cup and levelled with a straight edge.
- Should I use these conversions for liquids as well?
- Water and milk are covered here and are reliable, since water is very close to one gram per millilitre and milk is about 1.03. For other liquids the density differs a little, but pouring into a millilitre jug is easier than converting anyway, and volume is the natural measure for a liquid.
- Are US and Australian cup weights different for the same ingredient?
- Yes, by about 5.7 per cent, because the metric cup holds 250 mL against the US customary 236.588 mL. One cup of plain flour is roughly 125 g American and 132 g metric. Across three cups of flour that gap is more than twenty grams, which is enough to stiffen a batter.
- Why do published charts disagree about grams per cup?
- Different sources assume different filling techniques and sometimes different cup standards, and flour brands genuinely differ in particle size and moisture. Most charts land between 120 g and 127 g for a US cup of plain flour. Pick one source and use it consistently, and your results will be consistent even if another chart says 121.
Use this with
Cups to Grams Converter answers one part of the question. These pick up where it stops: Cup Converter, Tablespoon and Teaspoon Converter, Bread Hydration Calculator and Recipe Scaler.
Where these figures come from
This calculation is jurisdiction-neutral arithmetic. No country-specific rules are applied.
- USDA FoodData Central. Gram weights for household measures of common ingredients
- NIST Office of Weights and Measures. US customary volume definitions and Handbook 44
- Food Standards Australia New Zealand. Australian and New Zealand metric measures and food safety guidance
Cups to Grams Converter produces an estimate for general information. It is not financial, tax, medical, legal or engineering advice. read the full disclaimer. Spotted a wrong number? Report it and it gets fixed. The form picks up this calculator and the inputs you used.