Why I built this
In January 2026 I was baking sourdough from a Korean recipe that used grams, but the instructional video I was following used US cups. Halfway through I realised the brioche-style recipe used 250 g of bread flour, but the video poured "two cups." Two cups of bread flour is 240 g — a 4% gap that, in bread, is the difference between a soft crumb and a brick.
The conversion sites I found used a generic "1 cup = 128 g" for all flour types, ignoring that bread flour is denser than cake flour. So I built this with USDA FoodData Central density values for 29 distinct ingredients. Bread flour is 130 g, cake flour is 114 g, all-purpose is 125 g — small differences, but they matter when your loaf is at stake.
Why one cup of flour does not equal one cup of sugar
A cup is a unit of volume — the space the ingredient occupies in your measuring cup. A gram is a unit of mass. Different ingredients have different densities, so they weigh different amounts even when they fill the exact same cup. A cup of all-purpose flour weighs about 125 g, but a cup of granulated sugar weighs 200 g, and a cup of honey weighs 340 g.
For baking, this matters a lot. Most professional bakers and recipe developers weigh ingredients on a kitchen scale instead of measuring by volume, because the same "cup of flour" can vary by 20% depending on whether the flour was scooped, sifted, or spooned.
How to convert step by step
- Pick the ingredient from the dropdown above. Each ingredient stores its grams-per-cup density.
- Type the number of cups you have (or want). Decimals like 1.5 work fine.
- The grams field updates instantly. You can also type grams to get cups back.
- The reference table shows common amounts (1/4 cup, 1/2 cup, 1 cup, etc.) at a glance.
Tips for accuracy
Use the spoon-and-level method when measuring flour by cup: spoon the flour loosely into the cup, then sweep a knife across the top. Never scoop directly with the measuring cup — that compacts the flour and you can end up 20% over.
Brown sugar is measured packed: press it firmly into the cup so it holds its shape when turned out. Powdered sugar is measured sifted, otherwise lumps make it weigh more than the table suggests.
FAQ
Is this a US cup or metric cup? US cup, 240 ml. A metric/Australian cup is 250 ml — about 4% larger. UK recipes sometimes use the imperial cup (284 ml) which is 18% larger; if your recipe specifies UK measurements, multiply our gram values by 1.18.
Why does my recipe call for "8 oz of flour"? Some recipes use ounces by weight (the standard in professional baking). 8 oz = 226.8 g ≈ 1.8 cups of all-purpose flour. Don't confuse this with fluid ounces (8 fl oz = 1 cup of liquid).
Sifted vs unsifted flour? The 125 g/cup figure for flour assumes the spoon-and-level method (loose, leveled with a knife). Sifted flour is closer to 100–110 g/cup. If your recipe says "1 cup sifted flour", sift first, then measure.
Why do different sources give different gram values for the same ingredient? Density varies based on humidity, age of the ingredient, brand, and how packed the cup is. Our values come from USDA FoodData Central and King Arthur Flour's baking standards — both well-tested averages. Variations of ±5g are normal.
How accurate is this conversion? Accurate to within ±5% for most ingredients. For precision baking (sourdough, pâtisserie), use a kitchen scale instead of volume measurements. The same "cup of flour" can vary by 20% depending on whether it was scooped, sifted, or spooned.
Why is honey 340 g per cup but flour only 125 g? Honey is a dense liquid (≈1.42 g/ml). Flour is a low-density powder with lots of air pockets (≈0.52 g/ml). The cup is the same volume, but it holds nearly 3× more honey by weight than flour.