A bag of flour is sold in pounds. Your recipe uses cups. A supermarket sells butter by the pound and the recipe wants half a cup. You need to know how much one turns into the other, and the answer is never the same twice.
A cup is a unit of volume and a pound is a unit of weight, so you cannot convert one into the other without knowing what is in the cup. This cups to pounds converter has the weight of a cup for sixteen common ingredients, and does the sum for you.
How to use the Cups to Pounds Converter#
- Enter the cups. Type the number of cups. Use decimals for fractions.
- Pick the ingredient. This sets the weight of one cup.
- Choose your cup. Use the US cup unless your recipe is metric.
- Read the weight. You get pounds, pounds and ounces, ounces, grams and kilograms.
The formula#
To change cups to pounds, multiply the number of cups by the weight of one cup of the ingredient, then divide by 453.592, the number of grams in a pound. For example, 2 cups of all-purpose flour at 125 grams a cup is 250 grams, and 250 divided by 453.592 is 0.55 pounds, or about 8.8 ounces. A pound is exactly 0.45359237 kilograms by international agreement, and a pound contains 16 ounces.
Weight of one cup and cups per pound#
| Ingredient | Grams per cup | Pounds per cup | Cups per pound |
|---|---|---|---|
| All-purpose flour | 125 | 0.28 | 3.63 |
| Granulated sugar | 200 | 0.44 | 2.27 |
| Brown sugar (packed) | 213 | 0.47 | 2.13 |
| Butter | 227 | 0.50 | 2.00 |
| Honey | 340 | 0.75 | 1.33 |
| White rice (uncooked) | 185 | 0.41 | 2.45 |
| Rolled oats | 90 | 0.20 | 5.04 |
| Cocoa powder | 85 | 0.19 | 5.34 |
Values are for a US cup of 236.6 millilitres, using standard baking chart weights such as the King Arthur ingredient chart and the USDA household measure data. Individual products vary a little.
Why a cup of flour is not a cup of honey#
Density is the weight packed into a given space. Honey is dense, around 1.4 grams per millilitre, so a cup is about 340 grams, or three quarters of a pound. Flour is full of air, at about 0.53 grams per millilitre, so a cup is only 125 grams. Butter sits between the two at 227 grams, exactly half a pound, which is why a pound of butter is two cups or four sticks.
The same ingredient can also change. Sifted flour is lighter than flour scooped straight from the bag. Brown sugar is heavier when packed. The calculator uses the usual textbook values, and for the best accuracy in baking you should weigh.
Working backwards#
If you know the pounds and want cups, divide by the pounds per cup. A 5 pound bag of flour holds about 18 cups, a 2 pound bag of sugar holds about 4.5 cups and a pound of butter is exactly 2 cups. Our pounds to cups converter does this sum for you.
Choosing the right cup#
A US cup holds about 237 millilitres, and a metric cup holds 250, which is 5.7 percent more. For a heavy ingredient this adds up, since a metric cup of sugar is about 211 grams instead of 200. If you are not sure which your recipe uses, look at where it was published. American recipes use the US cup, and recipes from Australia, New Zealand and Canada often use the metric cup.
Common package sizes#
Packages are sold in pounds and recipes use cups, so it helps to know how far a bag goes. Here is what common bag sizes hold, using the weights above.
| Package | Weight | Approximate cups |
|---|---|---|
| Bag of flour | 5 lb | 18.1 |
| Bag of granulated sugar | 4 lb | 9.1 |
| Bag of brown sugar | 2 lb | 4.3 |
| Box of butter | 1 lb | 2.0 |
| Bag of rice | 2 lb | 4.9 |
| Container of rolled oats | 1 lb | 5.0 |
Treat these as estimates. Brands and pack sizes vary, and you will get different results depending on how you fill the cup.
Frequently asked questions#
About 0.28 pounds, which is around 4.4 ounces or 125 grams for all-purpose flour.
About 3.6 cups of all-purpose flour.
About 2.3 cups of granulated sugar.
Two cups, which is four sticks.
No. A US cup of water weighs about 0.52 pounds, so a pint weighs roughly a pound, as in the old saying.
It uses standard ingredient weights. Real products vary by a few percent, so a scale is more accurate for baking.
Sources and further reading#
- King Arthur Baking: Ingredient Weight Chart. Weights per cup for flour, sugar, butter, honey and more.
- USDA FoodData Central. Food composition and household measure weights.
- NIST Special Publication 811: Guide for the Use of the International System of Units. Exact definitions of the inch, pound, ounce and the units derived from them.
- Wikipedia: Pound (mass). The international avoirdupois pound.