US Cups vs Metric Cups: What's the Difference?

5 min read•June 1, 2026•Reviewed: June 1, 2026

✓Reviewed by Apex Conversion Editorial Team · Last reviewed June 1, 2026

Not all cups are created equal. A standard US measuring cup holds exactly 236.588 mL (8 US fluid ounces). A metric cup — used in Australia, New Zealand, and Canada — holds 250 mL. That is a 5.7% difference. For most cooking it is negligible, but in baking — where ratios of flour, liquid, and leavening must be precise — the discrepancy can affect texture and rise.

The situation gets more complicated: older UK recipes use an informal 'cup' based on half an imperial pint (284 mL), and Japanese recipes use a 200 mL cup. If you are following a recipe from another country, knowing which cup size they meant is the first step to getting the recipe right.

Cup Size Reference by Country

US cup:        236.588 mL  (8 US fl oz)  — used in United States
Metric cup:    250 mL      (exact)        — Australia, NZ, Canada
Imperial cup:  284.131 mL  (½ imp pint)  — older UK recipes
Japanese cup:  200 mL      (exact)        — Japan

Converting between US and metric cup:
  1 US cup = 236.6 mL = 0.946 metric cups
  1 metric cup = 250 mL = 1.057 US cups
  4 US cups = 946 mL ≈ 3.785 metric cups
  4 metric cups = 1000 mL = 4.227 US cups

When the Difference Matters

For cooking savory dishes (soups, stews, sauces), a 5.7% difference in liquid measurement will not change the outcome. The recipe is forgiving enough. For baking — cakes, bread, cookies, pastry — precision matters. Using an Australian recipe that calls for '2 cups of flour' with a US cup gives you 473 mL of flour instead of 500 mL. That 5.4% reduction could affect texture, but most recipes have enough tolerance to absorb it.

The most reliable solution for baking is to use weight (grams or ounces) rather than volume measures. A recipe that says '250 g of flour' is unambiguous, regardless of which country published it or which measuring tools you have. If you must use cups, note the recipe's country of origin: look for whether the recipe is from Australia/NZ (250 mL cup) or the US (236.6 mL cup).

How to Adapt Across Cup Sizes

If you have Australian recipes and US measuring cups: for every 1 metric cup the recipe calls for, use 1 US cup plus about 1 tablespoon (15 mL). This brings 236.6 + 14.8 = 251.4 mL — very close to 250 mL. For 2 cups: 2 US cups + 2 tablespoons. For ½ cup: ½ US cup + 1½ teaspoons.

If you have US recipes and metric cups: for every 1 US cup, use 1 metric cup minus about 1 tablespoon (15 mL). So 250 − 15 = 235 mL, very close to 236.6 mL. Alternatively, just use the metric cup as-is — for most recipes, the ~13 mL shortfall per cup (5.7%) falls within measurement error and will not affect the outcome. Invest in a kitchen scale for precision baking.

Frequently Asked Questions

How many mL is 1 cup?

In the US: 1 cup = 236.588 mL (approximately 237 mL). In Australia, New Zealand, and Canada: 1 metric cup = 250 mL exactly. In older UK recipes: 1 cup ≈ 284 mL (half imperial pint). When in doubt, the recipe's country of origin tells you which cup size to use.

Can I use a metric cup for US recipes?

Yes, for most recipes. A metric cup is about 13 mL larger than a US cup — roughly 5.7% more. For casual cooking, this difference is unnoticeable. For precise baking, weigh ingredients in grams for best results. A kitchen scale eliminates this ambiguity entirely.

Why does Canada use a metric cup if it adopted the metric system?

Canada officially adopted metric in the 1970s, but the 250 mL metric cup was already in common use. Canadian standards settled on 250 mL as the cup size, which aligns neatly with metric measurement (1/4 of a liter). US standards kept the older 236.6 mL (8 fl oz) cup because the fluid ounce system was already established.

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