Cooking Weight-Volume Calculator
Measuring dry ingredients by the cup is convenient but unreliable, because how loosely or tightly you scoop changes the amount in the cup. Weighing in grams fixes that, which is why careful baking recipes list weights rather than volumes. This calculator bridges the two by converting cups of a chosen ingredient into grams using that ingredient's density, the weight packed into a given volume. The ingredient choice is essential: a US cup of all-purpose flour is roughly 120 grams, while the same cup of granulated sugar is about 200 grams and a cup of water is about 237 grams, so the same volume gives very different weights. Pick your ingredient, enter the number of cups, and the calculator multiplies by the per-cup weight to give the total in grams. The per-cup weight is left editable because real values shift with humidity, milling and packing, so you can enter your own calibrated figure for better accuracy. The tool assumes the US customary cup of about 237 milliliters. Every figure is computed deterministically from the formula shown below, with a worked example that reconciles exactly to the calculator defaults so you can trust the weight before you bake.
Convert volume to weight with density: grams = cups x grams per cup. 2 cups of all-purpose flour at 120 g per cup weighs 240 grams.
Weight-volume formula
Weight (g) = Cups x Grams per cup
Grams per cup = the ingredient's density per US cup
(1 US cup is about 237 milliliters)
Multiply the volume in cups by the ingredient's weight per cup. Because every ingredient packs a different weight into a cup, the per-cup figure must match the ingredient.
Worked example
Convert 2 cups of all-purpose flour to grams.
- Flour weighs about 120 grams per US cup
- Weight = 2 cups x 120 g/cup
- Weight = 240 grams
2 cups of flour weighs 240 grams. These are the calculator's default inputs, so the result above matches the widget exactly.
Typical weight per US cup
Reference densities for common ingredients.
| Ingredient | Grams per cup | 2 cups |
|---|---|---|
| All-purpose flour | 120 g | 240 g |
| Granulated sugar | 200 g | 400 g |
| Butter | 227 g | 454 g |
| Water | 237 g | 474 g |
Food measures and labeling guidance: US Food and Drug Administration (FDA).
Cooking weight-volume calculator: frequently asked questions
Why convert cups to grams?
Volume measures like cups are imprecise for dry ingredients because how tightly you pack them changes the amount. Weighing in grams removes that variation and makes recipes repeatable, which is why most professional and baking recipes give weights. Converting requires the ingredient's density, since a cup of flour weighs far less than a cup of sugar.
Why does the ingredient matter?
Each ingredient has a different density, the weight packed into a given volume. A US cup of all-purpose flour is about 120 grams, but a cup of granulated sugar is about 200 grams and a cup of water is about 237 grams. Because the conversion multiplies volume by density, you must pick the right ingredient to get the right weight.
Are these densities exact?
They are typical reference values. Real weights vary with humidity, how finely an ingredient is milled and how it is packed or sifted. For the best accuracy, weigh your own ingredient once with a kitchen scale to calibrate, then reuse that figure. This tool leaves the per-cup weight editable so you can enter a value you have measured.
What cup size does this use?
It uses the US customary cup of about 237 milliliters. Other countries use different cup sizes, such as the 250 milliliter metric cup, so a recipe written abroad may assume a slightly different volume. If you know your cup size differs, adjust the per-cup weight accordingly.
What is the weight-volume formula?
Weight in grams equals the number of cups multiplied by the ingredient's weight per cup in grams. Choosing a different ingredient changes the per-cup weight and therefore the total.
Official sources
- Food measures, serving sizes and labeling guidance: US Food and Drug Administration (FDA). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.