Kitchen Weight to Volume Converter

Turning a bag weight into cups

Flour, rice, oats, and sugar are sold by the pound. Recipes ask for cups. One bidirectional page covers that gap. Cups = (pounds × 453.592) ÷ grams per cup. The 453.592 factor is the avoirdupois pound in grams used in US weights and measures.

All-purpose flour at 120 g per cup makes 1 pound equal 453.592 ÷ 120 = 3.78 cups, about 3.8 cups in the kitchen. A 5 lb bag is about 18.9 cups if you spoon and level the same way that 120 g cup was defined. Scooping from the bag without fluffing the flour shrinks the cup count because each cup then holds more grams.

Butter at 227 g per cup makes 1 lb about 2.00 cups, which is four US sticks. That check is why many parents remember "a pound of butter is four sticks" without doing the gram math.

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How to use weight to volume

Enter pounds. Use decimals for a half pound (0.5) or a quarter pound (0.25). Select the food. Read cups. The grams line is the same mass in metric, useful when a scale is in the drawer after all.

The pounds-per-cup line is the inverse density. Flour shows about 0.265 lb per cup. Sugar shows about 0.441 lb per cup. That inverse is how you go the other way: pounds = cups × pounds per cup.

If a neighbor leaves a note that says "take 3 cups of sugar," and you are staring at a 4 lb bag, 3 cups of granulated sugar is 3 × 200 = 600 g, or 1.32 lb. Leave a little more than a quarter of a 4 lb bag. That is neighbor math, not a diet plan. Put the bag back tied, not scooped into a leaking baggie.

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Formula and the 1 lb flour example

Mass in grams = pounds × 453.592. Cups = that mass ÷ grams per cup for the selected food.

Flour: 1 × 453.592 = 453.592 g. Cups = 453.592 ÷ 120 = 3.78. Brown sugar: 453.592 ÷ 220 = 2.06 cups, packed. Granulated sugar: 453.592 ÷ 200 = 2.27 cups.

USDA ARS conversion tables often round the pound to 453.6 g. The 0.008 g difference does not change a home cup reading.

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Reading the bag and the scale

Use net weight, not the shipping weight. A 5 lb flour bag is 5 lb of flour. A turkey is a different tool. If your scale shows ounces, divide ounces by 16 to get pounds before you enter the field.

Institutional kitchens using the USDA Food Buying Guide work in pounds and cooked yield, not in home cups. This page is the home-cup cousin of that planning habit. School-meal rice yields still belong on the rice tools when you care about cooked volume.

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Using the cup result without over-baking

If the cup result is 3.8, measure 3 cups plus a bit more than 3/4 cup, or weigh 454 g and skip cups. Weighing wins for cakes. Cups win for overnight oats when the scale battery is dead.

Oats at 5.6 cups per pound look generous. That is dry rolled oats. Cooked oatmeal is a different volume. Do not pack a lunch thermos from the dry cup figure.

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Bulk bags, pancakes, and class snacks

A 10 lb bag of flour at 3.78 cups per pound is about 38 cups. A class pancake breakfast that needs 12 cups of flour uses about 3.2 lb. Buy a 5 lb bag and you still have flour for weekday muffins.

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Sugar bags are not a weekly plan

A 4 lb bag of granulated sugar is about 9.1 cups. That is a lot of added sugar relative to the AHA child ceiling of 25 g (about 6 teaspoons) per day after age 2. The conversion tells you how many cups are in the bag. It does not tell you how much belongs in a lunch.

Dietary Guidelines for Americans tell households to avoid added sugars before age 2 and to keep them under 10 percent of calories after age 2. Use the label teaspoon tool when the question is a snack, not a sack.

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Shopping a warehouse bag without a scale at the store

Warehouse rice sacks are often 20 lb or 25 lb. At 185 g per cup, 20 lb is 20 × 453.592 ÷ 185 = 49.0 cups of dry white rice. That is about 16 cooked family pots if each pot starts with 3 dry cups. The number matters when you share a sack with a neighbor and need a fair split. Ten pounds is 24.5 dry cups, not "half the bag looks even."

Rolled oats in a 3 lb canister are about 16.8 cups. A weekday microwave bowl that uses 1/2 cup dry oats will last about a month for one child if nobody else raids the canister. That planning is why pounds-to-cups exists. It is not nutrition advice. It is cupboard math.

A 25 lb bag of flour will go stale at the edges if you live in a humid apartment and take six months to finish it. Convert what you will use in eight weeks, then freeze the rest in 2 lb zipper bags. Two pounds is 7.6 cups. Label the bag with that cup estimate so a babysitter does not open every bag looking for "about 2 cups."

Cocoa at 86 g per cup makes 1 lb equal 5.27 cups. Baking cocoa sold in 8 oz tins is 0.5 lb, about 2.6 cups. That tin will not survive a double batch of brownies and a hot-chocolate week. Buy two tins or weigh what remains after the brownies.

Salt at 1.55 cups per pound is a reminder that bulk salt is cheap and heavy. Do not store a 4 lb box over a child's high chair. The conversion is not the hazard. The falling box is.

Brown sugar sold in 2 lb boxes is 2 × 453.592 ÷ 220 = 4.12 packed cups. That box will do one ambitious cookie week. It will not do a holiday tray plus school treats plus a coffee-cake Sunday unless you bake small. Buy the second box before you start the tray, or you will stretch the last cup by unpacking it, and the cookies will spread.

Butter sold as a 1 lb box is the cleanest check on this page: 2.00 cups. If your "pound" of imported butter is a 250 g block, that is 0.55 lb, about 1.10 cups, not a US pound. Read the gram line on the wrapper before you enter 1 in the pounds field.

Uncooked rice at 2.45 cups per pound means a 2 lb bag is about 4.9 dry cups, which becomes about 15 cups cooked white rice at the 3× yield on the rice page. Plan freezer bags before you boil the whole bag on a hot night.

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Limits of a pounds-to-cups estimate

Powdered sugar, sifted cake flour, and whole-wheat flour do not all sit at 120 g per cup. This flour row is all-purpose, spooned. Kosher salt is not the table-salt row. Shortening is not butter.

A liter of oil is a volume sold as a volume. Do not enter 1 in the pounds field for a 1 L bottle. Convert liters to milliliters on the cooking-measurement page, then use milliliters to grams.

NIST and ARS factors assume ordinary gravity and ordinary kitchen temperatures. They do not correct for a wet brown-sugar brick that has dried into a lump.

A postal scale that reads ounces is fine. Divide by 16. A bathroom scale is not fine. You will invent pounds and then bake a dry cake.

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How it works

Mass in grams divided by the household cup weight. One bidirectional page covers pounds to cups and the inverse density.

Frequently asked questions

• Butter pounds to cups?

  Butter is about 227 g per cup, so 1 lb is about 2 cups.

Related calculators

References

1. USDA Agricultural Research Service. FoodData Central
2. USDA ARS. Measurement conversion tables
3. NIST. NIST Handbook 44 (2024) Appendix C, general tables of units of measurement
4. USDA Food and Nutrition Service. Food Buying Guide for Child Nutrition Programs
5. NIST. SI Units - Volume
6. Vos et al., American Heart Association. Added Sugars and Cardiovascular Disease Risk in Children
7. USDA and HHS. Dietary Guidelines for Americans, 2020-2025
8. NIST Office of Weights and Measures. Metric Household