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What Is a Cup? UK Guide to Cup Measurements in Cooking

Published January 2026 • 3 min read • Cooking

Quick Answer

A cup is a volume measurement used in cooking. 1 US cup = 240ml. 1 UK imperial cup = 284ml. Most modern recipes use US cups. In the UK, we typically measure in grams (weight) and millilitres (volume) instead.

If you've ever followed an American recipe, you've seen measurements like "1 cup of flour" or "½ cup of sugar." But what exactly is a cup, and how does it compare to UK measurements?

What Is a Cup Measurement?

A cup is a standardised volume measurement used primarily in the United States, Canada, and Australia for cooking and baking. It measures how much space an ingredient takes up, not how much it weighs.

Key facts:

When you see "cup" in a recipe without specification, it usually means a US cup (240ml).

US Cup vs UK Cup: What's the Difference?

Measurement Volume (ml) Where Used
US Cup 240ml United States, most online recipes
UK Imperial Cup 284ml Old British cookbooks (rarely used today)
Metric Cup 250ml Australia, New Zealand

Important: The UK imperial cup (284ml) is outdated. Modern UK recipes use grams and millilitres instead. If you're following an American recipe, assume it's a US cup (240ml).

Why Don't We Use Cups in the UK?

The UK adopted the metric system for cooking in the 1960s-70s. We now measure:

Why grams are better:

How to Convert Cups to UK Measurements

For Liquids (Easy)

Liquids have a direct volume conversion:

For Dry Ingredients (Varies by Ingredient)

You need to convert to grams, and the conversion depends on density:

Ingredient 1 Cup (g)
Flour 125g
Sugar (granulated) 200g
Butter 227g
Rice (uncooked) 185g
Oats 90g

See our complete guide: How Many Grams Is 1 Cup?

Do You Need Measuring Cups?

In the UK: No. Use digital kitchen scales instead (£10-15 on Amazon). They're more accurate and work for all ingredients.

If you cook from US recipes often: You can buy US measuring cup sets on Amazon UK for convenience, but it's still more accurate to convert to grams.

How to Use Measuring Cups Properly

If you do use cups:

  1. Spoon dry ingredients into the cup — don't scoop from the bag (this compacts and adds extra)
  2. Level off with a knife — scrape excess off the top for accuracy
  3. Don't pack ingredients unless the recipe says "packed" (e.g., packed brown sugar)
  4. For liquids: Fill to the line and check at eye level

Cup Fractions Explained

Recipes often use fractions of a cup. Here's what they mean in ml:

Fraction US Cup (ml) Tablespoons
1 cup 240ml 16 tbsp
¾ cup 180ml 12 tbsp
⅔ cup 160ml 11 tbsp
½ cup 120ml 8 tbsp
⅓ cup 80ml 5 tbsp
¼ cup 60ml 4 tbsp
⅛ cup 30ml 2 tbsp

Common Questions

Is a mug the same as a cup?

No. A standard mug holds 250-350ml, while a US cup is exactly 240ml. Don't use a mug for recipe measurements.

Can I use a measuring jug instead of cups?

Yes! UK measuring jugs show millilitres. Just use the conversions above (1 cup = 240ml).

Why do American recipes use cups instead of grams?

The US never adopted the metric system, so they measure volume (cups) for both liquids and solids. It's less accurate but more convenient for home cooks without scales.

What's the difference between dry and liquid measuring cups?

In the US, they sell separate cups for dry (scoopable, level top) and liquid (transparent jug with spout) ingredients. In the UK, we just use one measuring jug for liquids and scales for solids.

Tips for Following American Recipes in the UK

  1. Convert cups to grams using our conversion tables
  2. Use digital scales for all dry ingredients
  3. Use a measuring jug for liquids (1 cup = 240ml)
  4. Watch out for UK/US ingredient name differences:
    • US "all-purpose flour" = UK plain flour
    • US "confectioners' sugar" = UK icing sugar
    • US "heavy cream" = UK double cream

For Calorie Tracking: Use Grams

If you're tracking nutrition with an app like NutraSafe, always measure in grams. UK food labels show nutrition per 100g, making it easy to calculate:

Example: If you eat 50g of oats:

Cup measurements make nutrition tracking less accurate because volume varies.

Final Thoughts

A cup is simply a volume measurement (240ml for US recipes). In the UK, we prefer grams for dry ingredients and millilitres for liquids because they're more accurate and consistent.

If you're following American recipes, use our cup-to-gram conversion guide or invest in digital kitchen scales for perfect results every time.

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Last updated: February 2026