The Complete Guide to Cooking Measurements: Cups, Tablespoons, and Metric

The Three Measurement Systems in Cooking

Recipes around the world use three different systems, and each defines "cup" and "tablespoon" differently. Confusing a US cup with an Australian (metric) cup can throw off a recipe by ~6%, which matters in baking.

• US Customary — Used in American cookbooks. 1 cup = 236.588 mL, 1 tablespoon = 14.787 mL
• Metric — Used in Australia, New Zealand, and many Asian countries. 1 cup = 250 mL, 1 tablespoon = 20 mL (Australia) or 15 mL (most other metric countries)
• Imperial (UK) — Used in older British cookbooks. 1 cup = 284.131 mL, 1 tablespoon = 17.758 mL

Cups: Not All Created Equal

The "cup" is the most commonly confused cooking unit. Here's exactly how they differ:

Yes, there's even a difference between the "US Legal Cup" (used on nutrition labels, exactly 240 mL) and the "US Customary Cup" (used in recipes, 236.588 mL). In practice, this 1.4% difference rarely matters.

Tablespoons and Teaspoons

These small units seem universal but aren't:

The Australian tablespoon (20 mL) is a famous trap. If a US recipe calls for 3 tablespoons (44.4 mL) and you use 3 Australian tablespoons (60 mL), you've added 35% more — enough to ruin a baking recipe.

Key equivalents to memorise:

• 1 US cup = 16 US tablespoons = 48 US teaspoons
• 3 US teaspoons = 1 US tablespoon
• 2 US tablespoons = 1 US fluid ounce

Fluid Ounces: US vs UK

A fluid ounce is not the same size on both sides of the Atlantic:

• US fluid ounce = 29.574 mL
• UK (imperial) fluid ounce = 28.413 mL

The US fluid ounce is ~4% larger. This also means pints and gallons differ: a US pint (16 fl oz = 473 mL) is smaller than an imperial pint (20 fl oz = 568 mL). British pub-goers get about 20% more beer per pint.

Complete Volume Conversion Chart

Why Bakers Prefer Weight

Professional bakers and most European recipes use weight (grams) rather than volume (cups). Here's why:

• Accuracy: 1 cup of flour can weigh anywhere from 120 g to 160 g depending on how you scoop it. 150 g is always 150 g.
• Scaling: Doubling a recipe is trivial with weights — just multiply. With cups, you end up with awkward fractions.
• Fewer dishes: Weigh everything into a single bowl on a scale instead of dirtying multiple measuring cups.
• Consistency: Recipes turn out the same every time regardless of how tightly you pack the ingredient.

Common Ingredient Weights per US Cup

Because ingredient densities vary, "1 cup" weighs differently for each item:

Notice how 1 cup of flour can range from 125 g to 160 g — a 28% difference! This is the single biggest reason baking recipes fail. The "spoon and level" method (spooning flour into the cup, then levelling with a knife) gives the most consistent result around 125 g.

Recipe Conversion Tips

1. Identify the origin country. Is it an American, Australian, or British recipe? This tells you which cup size applies.
2. Convert liquids directly. Water, milk, and other liquids convert straightforwardly between volume systems using our cooking converter.
3. Use weight for dry ingredients. Look up the ingredient's weight per cup and convert to grams for accuracy.
4. Watch the tablespoon trap. If converting an Australian recipe, remember their tablespoon is 20 mL, not 15 mL.
5. Temperature matters too. US recipes use Fahrenheit; most others use Celsius. Use our temperature converter for oven settings.
6. Don't stress about small amounts. The difference between a US teaspoon (4.93 mL) and a metric teaspoon (5 mL) is negligible for most recipes.