Serious cooking — especially baking — is all about precision. Volume measurements like "1 cup flour" can vary by 20% or more depending on how tightly packed it is. Weight-based measuring gives you a repeatable, accurate starting point. Here's how to navigate between the ounce, pound, and gram worlds with confidence.

The key conversions

  • 1 oz = 28.35 g (weight, not fluid)
  • 1 lb = 16 oz = 453.6 g ≈ 454 g
  • 1 kg = 1000 g = 2.205 lb = 35.27 oz
  • 100 g = 3.53 oz

The critical distinction: ounce can mean weight (28.35 g) or volume (29.57 ml, also called a "fluid ounce"). These are different things. A fluid ounce of honey weighs more than a fluid ounce of milk. Always check whether a recipe specifies oz by weight or fl oz by volume.

US baking measurements (by weight)

Many US recipes use volume, but modern baking is increasingly weight-based. Standard conversions:

  • 1 cup all-purpose flour = 120–125 g
  • 1 cup bread flour = 130 g
  • 1 cup cake flour = 115 g
  • 1 cup granulated sugar = 200 g
  • 1 cup brown sugar (packed) = 220 g
  • 1 cup powdered sugar = 120 g
  • 1 cup butter = 227 g (2 sticks)
  • 1 cup milk = 240 g
  • 1 cup water = 237 g
  • 1 egg (large, shelled) = 50 g

Note: Published "cup weights" vary by source. The King Arthur Baking conventions are widely used.

Meat and protein (grocery store)

US grocery stores sell meat by the pound. European stores sell by 100 g or kg.

  • 1 lb of meat = 454 g
  • 1/2 lb = 227 g
  • 1/4 lb = 113 g
  • 2 lb = 907 g
  • 5 lb = 2.27 kg

A typical serving of cooked meat or fish is about 3 oz (85 g). A "quarter-pounder" burger is 4 oz raw (113 g), reducing to about 3 oz cooked.

European recipe conversions

A French or German recipe calls for 500 g of flour. How much is that? 500 / 454 ≈ 1.1 lb ≈ 17.6 oz. Or in cups of all-purpose flour: 500 / 120 ≈ 4.17 cups.

British recipes sometimes use both metric and imperial: "200 g (7 oz)". The approximation is fine for most cooking. For baking, use the exact gram value if possible.

Scaling recipes

Weights scale linearly. A recipe for 2 servings calling for 200 g flour scales to 6 servings by tripling: 600 g. Volume measurements scale less cleanly because of cup-packing variations.

Kitchen scales: the game-changer

A digital kitchen scale costs $15–30 and changes baking forever. Benefits:

  • Consistent results recipe-to-recipe
  • Fewer dishes (measure into the mixing bowl)
  • Easy scaling up or down
  • Direct use of any international recipe

Most kitchen scales toggle between oz and g with a button. The "tare" function (zero out a container's weight) is essential.

Converting a recipe from volume to weight

Take a US recipe calling for 2 1/4 cups flour, 1 cup sugar, 1/2 cup butter. Convert:

  • 2 1/4 cups flour: 2.25 × 120 = 270 g
  • 1 cup sugar: 200 g
  • 1/2 cup butter: 114 g

Now the recipe is reproducible by anyone with a scale, anywhere in the world.

Fluid vs dry measuring: do not mix

Water and milk weigh approximately 1 g per milliliter, so 1 cup ≈ 240 g ≈ 240 ml. But a cup of honey or syrup weighs more (340 g). And a cup of flour weighs much less (120 g) because flour contains air. Always use weight for dry ingredients; fluids can use either.

US-to-metric fast references

  • 1 oz ≈ 28 g
  • 4 oz ≈ 113 g
  • 8 oz (1/2 lb) ≈ 227 g
  • 16 oz (1 lb) ≈ 454 g
  • 32 oz (2 lb) ≈ 907 g

Why bakers obsess over weight (and cooks shrug)

The reason baking demands weight while sautéing tolerates volume comes down to chemistry. Bread, cake, and pastry recipes work because the ratio of flour to liquid to fat to leavening sits inside narrow tolerances — too much flour and the crumb turns dense; too little and the loaf collapses. A 10% error in flour weight (one cup measured loose vs packed) is enough to ruin a cake. Savory cooking is more forgiving: an extra splash of olive oil or a heavy hand with onions doesn't break a stir-fry. So the rule of thumb in pro kitchens: bakers weigh, cooks taste.

This is also why "by feel" baking advice from experienced bakers translates poorly to home kitchens. They've internalized the right hydration percentages over thousands of loaves. A scale and a recipe in grams gets a beginner to consistent results without years of practice.

International recipe pitfalls

A few traps when converting between recipe traditions:

  • Australian cup: 250 ml, not the US 240 ml. A meaningful 4% difference for liquids.
  • UK Imperial pint: 568 ml, vs the US pint at 473 ml — a 20% gap. UK ounces and US ounces match for weight but not volume.
  • Stones: a UK weight unit equal to 14 lb (6.35 kg). Sometimes appears in old British cookbooks for things like potato yields.
  • Cup of butter: US recipes use 227 g per cup. European butter is sold in 250 g blocks. Recipes from Germany, France, or Italy almost never use cups for fats — they specify grams directly.

Hydration percentages and baker's math

Sourdough and artisan bread recipes often use "baker's percentages": flour is always 100%, and every other ingredient is expressed as a percentage of flour weight. A 70% hydration loaf with 500 g flour needs 350 g water. This makes scaling trivial — multiply every percentage by your flour amount. It's also why a kitchen scale showing grams (not the lower-resolution ounces) is non-negotiable for serious bread bakers. A 5 g salt difference matters when total dough weight is 850 g.

The converter

Our weight converter handles every kitchen weight unit — grams, kilograms, ounces, pounds — with one click. Paste in a weight, get every representation. Use it while reading recipes, while converting to fit your scale's units, or while translating grandmother's pound-based recipe to modern metric. Accuracy in the kitchen starts with accuracy in measurement. Use the tool; make better food.