US Cups vs Metric Cups: What Is the Difference?

4 min read•March 15, 2024•Reviewed: June 1, 2026

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

Not all cups are the same size. A US legal cup is 236.588 mL, while the metric cup used in Australia, Canada, and New Zealand is exactly 250 mL — about 5.5% larger. When following a recipe from a different country, using the wrong cup size means every volume-measured ingredient is off by that same margin.

For most cooking — soups, stews, salad dressings — a 5.5% difference is imperceptible. But in baking, where ingredient ratios determine texture and rise, it can mean the difference between light and dense results, especially in large batches.

The Size Difference

US cup      = 236.588 mL  (8 US fl oz)
Metric cup  = 250.000 mL  (used in AU, CA, NZ, most of the world)
UK (old)    = 284.131 mL  (½ imperial pint — rarely used now)

The difference:
  1 metric cup = 1.0567 US cups  (about 1 US cup + 1 tbsp)
  1 US cup     = 0.9463 metric cups

Quick practical adjustment:
  Metric recipe → US measures: subtract about 1 tablespoon per cup
  US recipe → metric measures: add about 1 tablespoon per cup

When Does It Actually Matter?

For cooking with forgiving recipes — pasta water, soup broth, marinades — the 13 mL difference per cup is negligible. Even doubling a recipe with the wrong cup size rarely causes a noticeable difference in these contexts.

Baking is where cup size matters most. In a simple cake calling for 2 cups of flour, using a metric cup adds about 26 mL more flour (roughly 2–3% more by weight). Over 4 cups of flour in a bread recipe, that extra flour adds up to about a quarter cup — enough to affect texture noticeably. For precise baking, use a kitchen scale with grams.

The Old UK Cup

The UK historically used a cup equal to half an imperial pint — 284 mL. This is quite different from both the US and metric cups. British recipes from before the 1970s occasionally referenced this measure, but it has since been largely replaced by metric measurements (grams and milliliters) in published UK cookbooks. If you see a cup measurement in a modern UK recipe, it almost certainly refers to the metric 250 mL cup.

Quick Tips

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Always check the recipe's country of origin. Australian and Canadian recipes use 250 mL cups; most US recipes use 236.6 mL.
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The simplest solution: use a kitchen scale for dry ingredients and a graduated measuring cup (with mL markings) for liquids.
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For most baking, the 1-tablespoon-per-cup adjustment gets you close enough. But for precision (bread, macarons, soufflés), use grams.
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Cooking apps and websites sometimes quietly change cup measures when displaying international recipes — always verify which cup size the original recipe used.

Frequently Asked Questions

Does Canada use a US cup or a metric cup?

Canada officially uses a metric cup of 250 mL. Most Canadian cookbooks and measuring cups sold in Canada use the 250 mL metric cup. However, because the US is Canada's closest neighbor and many US recipes circulate widely, some Canadian home cooks use US measuring cups without realizing the small difference.

How much difference does 250 mL vs 236 mL make in a recipe?

The difference is about 14 mL (roughly 1 tablespoon) per cup. For 1–2 cups, this is usually negligible in cooking. In baking with 3+ cups of flour, the cumulative difference (30–40 mL, equivalent to about 15–20 grams of flour) can affect the final texture. The more precise the recipe (bread, pastry, cake), the more likely the discrepancy matters.

What cup size does the UK use in modern recipes?

Modern UK recipes have largely moved away from cup measurements in favor of metric weights (grams) and volumes (mL). When cups do appear in contemporary UK or European recipes, they typically mean the 250 mL metric cup. The old imperial half-pint cup (284 mL) is now rarely seen.

Should I use a US measuring cup or a metric measuring cup?

Use whatever matches the recipe's country of origin. Ideally, use the same type of measuring cup the recipe author used. Even better: weigh dry ingredients in grams using a kitchen scale — this eliminates cup-size uncertainty entirely and gives more consistent results.

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