Kitchen Measurement Converter

How it works

Every unit is stored as its size in one base unit (cubic metres for volume, kilograms for weight). The amount is multiplied by the size of the from unit and divided by the size of the to unit, and the factor shown is what one from unit equals in the to unit.

US customary measures are fixed by law: the US gallon is 231 cubic inches and the inch is exactly 25.4 mm, so a US cup (1/16 gallon) is 236.5882365 mL, a tablespoon 1/16 cup and a teaspoon 1/3 tablespoon. Nutrition labels use rounded sizes instead: 240 mL for a cup, 30 mL for a fluid ounce, 15 mL for a tablespoon and 5 mL for a teaspoon. The metric cup, as used in Health Canada's reference amounts and in many recipes from metric countries, is 250 mL.

Imperial measures come from the UK imperial gallon of exactly 4.54609 L: a pint is 1/8 gallon (568.26 mL), a fluid ounce 1/20 pint (28.41 mL) and the traditional imperial cup half a pint (284.13 mL). An imperial pint therefore holds 20 imperial fluid ounces, while a US pint holds 16 US fluid ounces of a slightly larger size. The Australian tablespoon is usually 20 mL, four 5 mL teaspoons rather than three; its size is an input here.

Weights use the avoirdupois pound of exactly 0.45359237 kg and the ounce of 1/16 pound (28.349523125 g). A weight cannot be turned into a volume without the ingredient's density.

Formula

result = amount × (size of from unit) ÷ (size of to unit)
US: 1 gal = 231 cu in = 3,785.411784 mL; 1 cup = 1/16 gal = 236.5882365 mL
    1 cup = 8 fl oz = 16 tbsp = 48 tsp
Nutrition label: cup 240 mL, fl oz 30 mL, tbsp 15 mL, tsp 5 mL
Metric cup 250 mL; Australian tbsp = size entered (typically 20 mL)
Imperial: gal 4,546.09 mL; pt = gal ÷ 8; fl oz = pt ÷ 20; cup = pt ÷ 2
Weight: 1 lb = 453.59237 g; 1 oz = lb ÷ 16 = 28.349523125 g

Example

The default, 1 US cup to millilitres: 3,785.411784 mL ÷ 16 = 236.5882 mL. The same amount is 0.9858 nutrition-label cups, 0.9464 metric cups and 0.8327 imperial cups, which is why recipes from different countries do not measure out identically.

1 imperial pint is 568.26 mL, or 1.2009 US pints. 3 US teaspoons are exactly 1 US tablespoon (14.7868 mL), and one 20 mL Australian tablespoon is 1.3526 US tablespoons. By weight, 8 oz is 226.7962 g and 1 kg is 2.2046 lb.

Assumptions and limitations

• US customary sizes follow the legal definitions (1 US gallon = 231 cubic inches, 1 inch = 25.4 mm), as tabulated in NIST Special Publication 811, Appendix B.9 (page updated 2025-08-18): 1 cup = 236.5882 mL, 1 tbsp = 14.78676 mL, 1 tsp = 4.928922 mL, 1 fl oz = 29.57353 mL.
• Nutrition-label sizes are those fixed for US labelling by 21 CFR 101.9(b)(5)(viii): teaspoon 5 mL, tablespoon 15 mL, cup 240 mL, fluid ounce 30 mL. The 250 mL metric cup and the 15 mL and 5 mL metric spoons are those used in Health Canada's Table of Reference Amounts for Food (2024-10-18).
• Imperial units follow the UK Weights and Measures Act 1985, Schedule 1: the pint of 0.56826125 L (⅛ gallon) in Part IV, and the gallon of 4.54609 L, the quart of ¼ gallon and the fluid ounce of 1/20 pint in Part VI. The imperial cup of half a pint is a traditional kitchen measure, not a statutory unit.
• The Australian tablespoon is the size entered, 20 mL by default. Food Standards Australia New Zealand's AUSNUT 2023 food measures (September 2025) record every tablespoon measure as 20 mL, every cup as 250 mL and every teaspoon as 5 mL, so Australian cups and teaspoons are the metric cup and teaspoon listed here. Older recipes and other countries use other spoon sizes.
• Conversions are exact arithmetic on these definitions; real measuring cups and spoons have manufacturing tolerances and are filled imperfectly. Results are rounded to four decimal places for display.
• Weight units are avoirdupois. A fluid ounce is a volume and an ounce is a weight; the two match only for liquids about as dense as water.

Frequently asked questions