How to convert grams to cups
Grams are weight and cups are volume, so the conversion needs the ingredient's density: cups = grams ÷ (density × 236.6), since a US cup is 236.6 mL. For water (density 1), 120 g is about 0.51 cups; flour is lighter (0.53), so 120 g is about 0.96 cups.
Worked example: 200 g of granulated sugar at 0.85 g/mL is 200 ÷ (0.85 × 236.6) = 0.99 cups, so almost exactly one cup. The same 200 g of honey at 1.42 g/mL fills only 0.60 cups, because honey is far denser. The weight is identical; the volume it occupies is not.
The density figure used in cooking is really a packed bulk density rather than the density of the material itself. Flour at 0.53 g/mL reflects the air trapped between particles, which is exactly why sifting, scooping and settling change the answer.
If you are checking your work, the grams to tablespoons calculator gives you a second reference point.
How to use this calculator
Enter the grams and the ingredient density in g/mL. Density in g/mL: water 1, flour ~0.53, granulated sugar ~0.85, milk ~1.03, honey ~1.42, butter ~0.96. For baking precision, a kitchen scale beats cup measures. To go the other way, use the cups to grams calculator.
This tool uses the US customary cup of 236.6 mL. If your recipe is Australian or assumes a 250 mL metric cup, a converted figure will read about 5.7% low in cup count, and against a 240 mL US legal cup about 1.4%. Check which cup the recipe means before trusting the number.
Quick reference for one US cup: water about 237 g, milk 244 g, granulated sugar 201 g, all-purpose flour 125 g, butter 227 g and honey 336 g.
The mL to grams calculator is the natural next step once you have this figure.
Frequently asked questions
- How many cups is 120 grams?
- It depends on the ingredient. For water it's about 0.51 cups; for flour about 0.96 cups, because flour is less dense.
- Why do I need density?
- Grams measure weight and cups measure volume. Density links the two and differs by ingredient.
- What density should I use for flour?
- About 0.53 g/mL for all-purpose flour.
- Is a US cup the same as a metric cup?
- No. A US cup is 236.6 mL; a metric cup is 250 mL.
- Should I scoop or spoon flour into the cup?
- Spoon it in and level the top — scooping straight from the bag compacts the flour and can add 20% more weight to the same cup. That is why one cup of all-purpose flour is quoted anywhere between 120 g and 145 g, and why weighing is more reliable for baking.