You typed the grams into a converter and the cup amount isn’t what you expected. It doesn’t match the original recipe, or another site gave you a different number. Before deciding the math is off, check what the number was worked out from. The result shows all of it.
Our guide on how to use the converter covers setting it up and reading the result. When you’re tracking down a mistake, the line to read is the one that starts with “Based on”, for example “Based on 1 US cup of All-purpose flour = 120g”. It names the ingredient, the cup and the weight per cup the answer came from, all in one place.
The calculator is still on the last ingredient
The calculator converts whatever is selected in the Ingredient list, not what you’re holding. On the home page the converter opens on all-purpose flour, and on an ingredient’s own page it only converts that ingredient. Change the grams without touching the ingredient and you get an answer for flour, or for whatever you picked last.
The difference is not small. Say you need 200 grams of granulated sugar and the list is still on flour: you’ll read 1.67 cups instead of 1.01. Measure that out in sugar and you’ve put in far more than the recipe calls for.
Read the first line of the result before you measure, because it names the ingredient: “200 grams of All-purpose flour =”. If that isn’t the ingredient you’re measuring, change it in the Ingredient list. On another ingredient’s page the ingredient can’t be changed, so use the grams to cups converter on the home page, where you can choose any of them.
Similar sugars are different ingredients
Picking the wrong sugar is the same mistake as picking the wrong ingredient. At 100 grams, powdered sugar comes to 0.83 cups and granulated sugar to 0.51. If the recipe calls for granulated and you select powdered, you’ll measure out too much. Why two sugars with such similar names weigh so differently is explained in why grams to cups depends on the ingredient.
The “Based on” line catches this one too, since it names the sugar you selected along with its weight per cup. One US cup (240 ml) of powdered sugar weighs 120 grams; one of granulated sugar weighs 198 grams. When the line reads Powdered sugar and your recipe says granulated, switch it before you measure.
Measuring with a 250 ml cup, converting with 240 ml
Unless you change the Cup type setting, the calculator uses its default, the 240 ml US cup. If your measuring cups are 250 ml metric cups, each one holds a little more than the calculation assumes.
For 200 grams of flour, the US cup gives 1.67 cups and the metric cup gives 1.60. Measure out 1.67 metric cups and you’ve used a bit more flour than the recipe wants. Over a single cup the gap is small, but it builds up in a recipe that uses several.
Two places show which cup the calculator used: the unit next to the number (“US cups” or “metric cups”) and the “Based on” line. If that isn’t the cup in your drawer, select yours, for example “Metric cup / 250 ml”, before you measure. Don’t switch cup types just to get a tidier number; the result has to match the cup you’ll actually fill. The cup sizes guide explains how to tell which cup a recipe was written for.
Rounding the result a second time
Cup results are rounded to two decimal places, as set out in our methodology. The whole number is full cups and the decimal is the part of the next cup you still have to fill: 100 grams of all-purpose flour is 0.83 cups, short of a full cup, and 200 grams is 1.67, one full cup and part of another. You don’t have to work out that part yourself. The “Approximately” line under the number turns it into measuring cups, plus a tablespoon where needed, and choosing Kitchen fraction under Precision makes that the main result.
A round number looks more trustworthy, but the decimal and the kitchen measure are both rounded already. Rounding again to the nearest measuring cup takes you further from the calculation, not closer.
Take flour: one cup, spooned in and leveled, weighs about 120 grams. Round 0.83 cups up to one cup and you put in those 120 grams instead of the 100 the recipe asked for. When an amount falls awkwardly between cups, weigh it instead. Our comparison of grams vs. cups for baking goes through the recipes where weighing pays off.
Filling the cup a different way
Every grams-per-cup value assumes a particular way of filling the cup: flour and powdered sugar unsifted, spooned in and leveled; brown sugar packed firmly into the cup. Fill it some other way and the cup holds a different weight from the one the conversion used. The measuring method for every ingredient is listed in our ingredient weight data, and the steps for flour are in how to measure flour.
Check your conversion
Go back to the converter and confirm the ingredient and the cup on the "Based on" line before you measure.
Frequently asked questions
Why does another calculator give me a different number of cups?
Usually because it works from different data. It may use another weight per cup for the same ingredient or another cup size, and it may round differently. Compare the cup type and the weight of one cup of that ingredient on both calculators first. The values and rounding we use are on our methodology page.
Does the result work with a teacup or a coffee mug?
No. The result is calculated for measuring cups of a known size: 240 ml, 236.6 ml or 250 ml, depending on the cup type you choose. A cup you drink from can be bigger or smaller than that, and you can't tell by how much. If you don't have measuring cups, weigh the ingredient on a kitchen scale.