Reference
Kitchen measurement reference
Check US kitchen volume and weight relationships, convert recipe fractions, and choose the matching calculator without assuming a volume-to-weight conversion.
Overview
Use this reference to keep recipe and purchase quantities on a compatible measurement basis. US customary volume measures, weight measures, metric prefixes, and recipe fractions can be converted within their own dimensions. A cup is volume; an ounce can mean weight or fluid volume. No table of kitchen units can tell you how much a particular food weighs in a cup without a measured, ingredient-specific relationship.
How to choose and use a kitchen measure
- Copy the unit from the package or recipe. Record whether a quantity is weight, fluid volume, or count. Preserve US customary wording when the recipe uses cups, tablespoons, or US fluid ounces.
- Convert within the same dimension. Use the volume table for volume-to-volume changes and the weight table for weight-to-weight changes. Keep the quantity unit visible in the costing record.
- Convert a fraction carefully. Use the decimal table when a numeric field cannot accept a fraction. The repeating decimals are rounded references, so retain more precision if your measurement supports it.
- Stop before changing volume to weight. A volume-to-weight calculation needs a measured density for the named ingredient and state. Use a scale or a relevant density record; do not use water as a general food conversion.
- Cost only after the units match. Use the ingredient-line calculator for matching units, a same-dimension conversion for a verified factor, or the density calculator for a measured weight-per-volume relationship.
A conversion path that preserves the measurement dimension
- Identify Read the unit
Weight, volume, or count from the actual record.
- Convert Stay in dimension
Use lb ↔ oz or cup ↔ tbsp relationships.
- Measure Weigh the ingredient
For volume ↔ weight, measure a named product and state.
- Cost Match calculator inputs
Use the same dimension or verified conversion basis.
Choose the correct conversion basis
These relationships are not interchangeable. Match the conversion to the units your calculator and records actually use.
| From and to | Example | What makes it valid |
|---|---|---|
| Weight to weight | 2 lb = 32 oz by weight | Both quantities measure mass/weight. |
| Volume to volume | 1 US cup = 16 tbsp | Both quantities are US customary volume. |
| Metric to metric within one dimension | 1 L = 1,000 mL | Both quantities are volume; prefix scaling does not change the dimension. |
| Volume to weight | 1 cup of a named flour to grams | Requires an ingredient-, state-, and method-specific measured relationship. |
US kitchen volume
These are US customary volume relationships. An Imperial measure or a recipe calling for a metric cup may differ; use the unit system actually specified.
| Measure | Equivalent |
|---|---|
| 1 tablespoon (tbsp) | 3 teaspoons (tsp) |
| 1 US fluid ounce (fl oz) | 2 tbsp |
| 1 US cup | 8 US fl oz · 16 tbsp |
| 1 US liquid pint (pt) | 2 cups · 16 US fl oz |
| 1 US liquid quart (qt) | 4 cups · 32 US fl oz |
| 1 US liquid gallon (gal) | 4 qt · 16 cups · 128 US fl oz |
| 1 liter (L) | 1,000 milliliters (mL) |
Weight and purchase units
Weight is measured on a scale. An ounce by weight and a US fluid ounce describe different dimensions even though both use the word ounce.
| Measure | Equivalent |
|---|---|
| 1 pound (lb) | 16 ounces (oz) by weight |
| 1 kilogram (kg) | 1,000 grams (g) |
Common recipe fractions
Use these decimal equivalents only as far as their shown precision supports. The repeating fractions are rounded to four decimal places.
| Fraction | Decimal |
|---|---|
| 1/8 | 0.125 |
| 1/4 | 0.25 |
| 1/3 | 0.3333 (rounded) |
| 1/2 | 0.5 |
| 2/3 | 0.6667 (rounded) |
| 3/4 | 0.75 |
Before using a conversion
A cup does not have one universal weight across foods. Packing, moisture, particle size, and preparation affect the measured relationship.
- For lb to oz, both quantities describe weight. For cups to fl oz, both describe volume.
- Keep liquid and dry bulk measures distinct. Do not interpret a dry quart or bushel as a liquid measure.
- When a recipe uses a metric cup or a rounded food-label measure, keep that declared convention rather than silently switching it to a US customary cup.
Worked example: cost a matching weight quantity
A package contains 2 lb of an ingredient and a recipe uses 8 oz by weight. The invoice price is $6.00 for the package.
Inputs
- Package quantity
- 2 lb = 32 oz by weight
- Recipe quantity
- 8 oz by weight
- Package price
- $6.00
- Convert the package quantity: 2 lb × 16 oz/lb = 32 oz by weight.
- Unit cost = $6.00 ÷ 32 oz = $0.1875 per oz.
- Used cost = $0.1875 per oz × 8 oz = $1.50. An 8 fl oz recipe volume would require a measured food density instead.
- Unit check: 2 lb × 16 oz/lb = 32 oz by weight
- Volume boundary: 8 fl oz = volume; not 8 oz by weight
Result: $1.50 for 8 oz by weight
The weight conversion is exact within the stated US customary units. Keep the unit cost unrounded until the final amount is displayed to cents.
Keep the unit attached to every amount
Convert weight to weight and volume to volume using the matching table. When a recipe and purchase cross dimensions, use a verified measurement for that ingredient and state before costing. The table does not supply universal food densities or override a package label.