Kitchen Measurements: Cups, Spoons, Volume and Weight

Cups, spoons, fluid ounces, pints and gallons all measure volume, but their size depends on which system the recipe uses. The US customary values below are derived from the US gallon of exactly 3.785411784 L (NIST Handbook 44, Appendix C); the Imperial values from the Imperial gallon of exactly 4.54609 L (UK Weights and Measures Act 1985, Schedule 1). The 240 mL US cup is the rounded value used for US nutrition labelling (21 CFR 101.9). The 250 mL metric cup and 20 mL Australian tablespoon are metric definitions used in Australian recipes.

• Fluid ounces go one way, pints the other. The Imperial fluid ounce (28.41 mL) is slightly *smaller* than the US fluid ounce (29.57 mL), but the Imperial pint holds 20 fluid ounces against the US pint's 16, so the Imperial pint is about 20% *larger*.
• Tablespoons. An Australian tablespoon is 20 mL; a US tablespoon is about 14.8 mL. Three Australian tablespoons is a third more than three US ones.
• Cups. A US customary cup (236.6 mL), a US labelling cup (240 mL) and a metric cup (250 mL) differ by up to about 6%.
• Fluid ounce vs ounce. A fluid ounce is volume; an ounce (avoirdupois, 28.349523125 g) is mass. A recipe line "8 oz" usually means weight; "8 fl oz" means volume.

When a recipe does not say which system it uses, its origin is the best clue. Use the cups to millilitres and fluid ounces to millilitres converters for US units.

Millilitres, cups and spoons measure how much space an ingredient takes up. Grams and ounces measure how much it weighs. Turning one into the other needs the ingredient's density:

mass (g) = volume (mL) × density (g/mL)

There is no single "cups to grams" factor. A cup of flour and a cup of sugar occupy the same volume but do not weigh the same, and even one ingredient varies with how it is filled — flour that is sifted, spooned or scooped packs to different densities. Water is the convenient exception: at room temperature 1 mL of water weighs very close to 1 g, so for water (and close to it for many water-based liquids) mL and g are almost interchangeable.

For dry ingredients, use the gram weight the recipe author gives, or a weight printed for that specific ingredient by a reliable source. This site does not publish a universal cup-to-gram table because any such table depends on the ingredient and the filling method.

• Multiply every quantity by the same factor (2 to double, 0.5 to halve), in the units the recipe uses, before converting anything.
• Convert once, at the end. Converting, rounding, then scaling compounds rounding errors.
• Scaling by weight is simpler. 500 g × 1.5 is exactly 750 g; 1⅓ cups × 1.5 has to be turned back into cups and spoons.
• Small quantities matter most. A rounding error that is negligible on 500 g of flour can be a large share of a teaspoon of salt or raising agent, which is why baking is less forgiving than most cooking.

Pan size, cooking time and temperature do not scale in the same simple way; they are outside the scope of a measurement conversion.

• Measuring jug — marked in mL (and often US or Imperial units); read at eye level for liquids.
• Dry measuring cups and spoons — filled and levelled; check which system the set follows.
• Kitchen scale — measures mass directly, so it avoids the density problem altogether. Use the tare button to zero the bowl.

A scale reports to its display resolution; check the manufacturer's stated accuracy if a recipe uses very small quantities.

• Cups to millilitres and fluid ounces to millilitres for US volumes.
• Teaspoons to tablespoons for spoon conversions.
• Ounces to grams and the ounces to grams guide for weight.
• The Metric vs Imperial guide for how the measurement systems differ beyond the kitchen.

Sources and definitions are listed on the methodology page.