About

Volume-to-weight conversion is the single largest source of error in home baking. A cup of sifted flour weighs roughly 0.28 lb, while a cup of packed brown sugar reaches 0.51 lb. Using a generic "1 cup = 0.5 lb" rule introduces up to 80% error depending on ingredient density ρ. This tool applies USDA-sourced density coefficients for over 60 common ingredients, converting through the chain: cups → milliliters → grams → pounds. One US customary cup equals exactly 236.588 mL, and one avoirdupois pound equals 453.592 g.

The tool assumes standard US measuring cups, not imperial cups (284.131 mL) or metric cups (250 mL). Density values represent loosely packed or spooned measurements unless noted otherwise. Scooping directly from a bag compresses flour and can add 15 - 20% extra mass. For critical recipes, weigh ingredients on a kitchen scale calibrated against a known 100 g reference mass.

Formulas

The conversion from cups to pounds passes through two unit bridges. One US customary cup equals 236.588 mL. One avoirdupois pound equals 453.592 g. The ingredient density ρ connects volume to mass.

lb = cups × 236.588 × ρ453.592

The inverse for pounds-to-cups conversion:

cups = lb × 453.592236.588 × ρ

Where lb = weight in pounds, cups = volume in US cups, and ρ = ingredient density in g/mL. For water (ρ = 1.000), one cup equals approximately 0.522 lb. The constant 236.588453.592 ≈ 0.52158 serves as the base conversion factor before density scaling.

Reference Data

Ingredient	Density (g/mL)	1 Cup (g)	1 Cup (lb)
Water	1.000	236.6	0.522
All-Purpose Flour (spooned)	0.529	125.2	0.276
Bread Flour	0.550	130.1	0.287
Cake Flour	0.488	115.5	0.255
Whole Wheat Flour	0.512	121.1	0.267
Granulated Sugar	0.845	199.9	0.441
Powdered Sugar (unsifted)	0.512	121.1	0.267
Brown Sugar (packed)	0.930	220.0	0.485
Butter	0.959	226.8	0.500
Vegetable Oil	0.920	217.7	0.480
Olive Oil	0.913	216.0	0.476
Coconut Oil (melted)	0.925	218.8	0.482
Whole Milk	1.030	243.7	0.537
Heavy Cream	0.994	235.2	0.519
Sour Cream	0.970	229.5	0.506
Honey	1.420	335.9	0.741
Maple Syrup	1.320	312.3	0.688
Molasses	1.410	333.6	0.735
Corn Syrup	1.380	326.5	0.720
Cocoa Powder	0.448	106.0	0.234
Cornstarch	0.541	128.0	0.282
Baking Powder	0.900	212.9	0.469
Baking Soda	0.920	217.7	0.480
Table Salt	1.217	287.9	0.635
Kosher Salt (Morton)	1.015	240.1	0.529
White Rice (uncooked)	0.810	191.6	0.422
Brown Rice (uncooked)	0.800	189.3	0.417
Rolled Oats	0.340	80.4	0.177
Peanut Butter	1.090	257.9	0.569
Cream Cheese	1.010	238.9	0.527
Ricotta Cheese	1.050	248.4	0.548
Shredded Cheddar	0.476	112.6	0.248
Grated Parmesan	0.424	100.3	0.221
Yogurt (plain)	1.030	243.7	0.537
Egg (beaten)	1.030	243.7	0.537
Chocolate Chips	0.718	169.9	0.375
Almonds (sliced)	0.381	90.1	0.199
Walnuts (chopped)	0.487	115.2	0.254
Pecans (chopped)	0.461	109.1	0.240
Coconut (shredded)	0.339	80.2	0.177
Raisins	0.695	164.4	0.362
Dried Cranberries	0.550	130.1	0.287
Lentils (dry)	0.810	191.6	0.422
Chickpeas (dry)	0.800	189.3	0.417
Black Beans (dry)	0.780	184.5	0.407
Breadcrumbs (dry)	0.475	112.4	0.248
Cornmeal	0.660	156.1	0.344
Semolina	0.710	168.0	0.370
Almond Flour	0.406	96.1	0.212
Coconut Flour	0.541	128.0	0.282
Tapioca Starch	0.541	128.0	0.282
Flaxseed (ground)	0.560	132.5	0.292
Chia Seeds	0.680	160.9	0.355
Poppy Seeds	0.604	142.9	0.315
Sesame Seeds	0.595	140.8	0.310
Sunflower Seeds	0.593	140.3	0.309
Cinnamon (ground)	0.560	132.5	0.292
Paprika	0.490	115.9	0.256
Black Pepper (ground)	0.520	123.0	0.271
Gelatin (powder)	0.635	150.2	0.331
Active Dry Yeast	0.620	146.7	0.323

Frequently Asked Questions

Density determines the mass-per-volume ratio. All-purpose flour has a density of approximately 0.529 g/mL, while granulated sugar measures about 0.845 g/mL. Sugar granules pack more tightly with less air space. One cup of flour weighs roughly 0.276 lb (125 g), whereas one cup of sugar weighs 0.441 lb (200 g). This 60% difference is why professional bakers always measure by weight.

Significantly. The density values in this tool assume the spoon-and-level method: spooning the ingredient into the cup and leveling with a straight edge. Scooping directly from a container compresses flour by 15 - 20%, increasing a cup from roughly 125 g to 145 - 150 g. If your recipe was developed with the scoop method, expect the actual weight to exceed the value shown here.

The converter uses USDA average density values and the exact US cup volume of 236.588 mL. Real-world accuracy depends on ingredient temperature, humidity, grain size, and packing. Expect ±5 - 10% variance from scale readings. A digital kitchen scale accurate to 1 g remains the gold standard for precision baking.

No. This tool uses the US customary cup (236.588 mL). The imperial cup used in the UK equals 284.131 mL (about 20% larger), and the metric cup used in Australia equals 250 mL. To convert from an imperial cup, multiply your cup quantity by 1.201 before entering it into this tool. For metric cups, multiply by 1.057.

Honey has a density of approximately 1.42 g/mL due to its high sugar concentration (roughly 80% sugars) and low water content (17 - 20%). Dissolved sugars increase molecular packing density beyond that of pure water. One cup of honey weighs about 0.741 lb (336 g), making it 42% heavier than the same volume of water.

Liquid fats expand when heated. Vegetable oil at 20°C has a density near 0.920 g/mL, but at 100°C it drops to approximately 0.895 g/mL. Melted butter differs from cold cubed butter in packing density. All values in this tool assume room temperature (20 - 25°C). For hot liquids, expect 2 - 3% less mass per cup.