This page contains common units that my be useful when using the nutrient database.

When measuring food, it is important to distinguish between weight(mass) and volume. Both are acceptable conventions of measuring food. A conversion between weight and volume is not possible without knowing the density of food first. For example, a cup of meringue and a cup corn meal can easily be measured, but the cups of those items won't weigh the same because their density is different. A meringue is much lighter than corn meal. If measurements are not in volumes but in weights, then equal weights of something won't have the same volume unless they have the same density. For example, a pound of meringue and a pound of corn meal both weigh the same, they're both a pound, but the volume, meaning the number of cups of each of those, will be different. It takes far fewer cups of corn meal to reach a pound than it would of meringue.

Abbreviations

oz ounce
lb pound
mcg, µg microgram
mg milligram
g, gm gram
kg kilogram
tsp teaspoon
Tbl, tbsp, T Tablespoon
c, cp cup
fl oz fluid ounce
pt pint
qt quart
gal gallon
mL milliliter or millilitre
L liter or litre

Mass

16 ounces = 1 pound

1000 grams = 1 kilogram
1000 milligrams = 1 gram
1,000,000 micrograms = 1 gram
1000 micrograms = 1 milligram

Volume

3 teaspoons = 1 tablespoon
16 tablespoons = 1 cup
8 fluid ounce = 1 cup
2 cups = 1 pint
2 pints = 1 quart
4 quarts = 1 gallon

1000 milliliters = 1 liter

Conversion

1 L = 1.056688 quart
1 quart = 0.946352946 L

1/4 teaspoon = 1.2322304 mL
1 teaspoon = 4.92892161 mL
1 tablespoon = 14.7867648 mL

1 gram = 0.0352739619 ounces
1 ounce = 28.3495231 grams
1 pound = 0.45359237 kilograms
1 kilogram = 2.20462262 pounds