The short answer is 1 ounce = 28.35 grams. That is the exact standard conversion between these two weight units, and it works the same way for flour, sugar, meat, produce or anything else you put on a scale — weight converts to weight with no ingredient involved. If you just need the number, you have it. The rest of this guide gives the full table, worked examples from real cooking, and the small details (rounding, scale settings, avoirdupois versus troy) that decide whether the conversion actually helps.

1 Ounce in Grams conversion table

Ounce Grams
1 ounce 28.35 grams
5 ounces 141.8 grams
10 ounces 283.5 grams
25 ounces 708.8 grams
50 ounces 1,418 grams
100 ounces 2,835 grams
250 ounces 7,088 grams
500 ounces 14,175 grams
1,000 ounces 28,350 grams

Quick reference:

  • 1 ounce = 28.35 grams
  • 10 ounces = 283.5 grams
  • 50 ounces = 1,418 grams
  • 250 ounces = 7,088 grams
  • 1,000 ounces = 28,350 grams

How to convert ounces to gramss

The method is multiplication by a fixed factor. To convert ounces to gramss, multiply by 28.35; to go the other way, divide by 28.35 (or multiply by 0.035). The factor is exact by definition: the international pound is defined as exactly 453.59237 g, the ounce as exactly 28.349523125 g, and the kilogram as exactly 1,000 g. The figures in the table are rounded for kitchen use — 28.35 g for an ounce, 453.59 g for a pound — and the rounding error is a fraction of a gram at the amounts cooks actually weigh. What matters more than the last decimal is the scale: use a digital kitchen scale, set it to the unit the recipe uses, tare the bowl, and weigh directly rather than converting in your head. One caution: the ounces on a kitchen scale are avoirdupois ounces (28.35 g). Troy ounces, used for precious metals, are 31.10 g and have no place in a kitchen — if a scale offers a troy setting, do not use it for food.

Why this conversion comes up

This conversion turns up whenever a recipe and a scale disagree. European and Australian recipes write grams and kilograms; American recipes write ounces and pounds; and many kitchen scales can be switched between the two with one button — if you know which reading to trust. It also turns up at the shops, where flour is sold by the kilogram and the recipe wants pounds, or meat is sold by the pound and the recipe wants grams. Weight is the most reliable way to measure baking ingredients, so getting the conversion right is worth more than getting a volume conversion right.

Worked examples

A loaf of bread

A bread recipe calls for 8 ounce of flour, and your scale reads in grams. 8 ounce is 226.8 grams. Bread is the recipe where this conversion matters most: 10 g of flour either way changes the hydration of the dough, so weigh to the converted number and do not round it to a convenient figure.

Scaling a cake for a crowd

A cake recipe serves eight and needs 16 ounce of sugar. You are making it for twenty, which is two and a half times the recipe: 32 ounce, or 907.2 grams. Convert the scaled amount in one step rather than converting and then multiplying, so the rounding happens once instead of twice.

Portioning meat for the week

You buy meat in a 4-ounce pack and portion it into grams servings for meal prep. 4 ounce is 113.4 grams, so you can see at a glance how many portions the pack gives you and whether to buy one pack or two. Weigh each portion rather than estimating — portions that look equal rarely are.

Practical guidance

Doubling and halving are where small errors become large ones. A rounding error of 10 ml in a single cup is nothing; the same error doubled across a party-sized batch is a noticeable difference in a sauce or a dough. Convert with the full factor, round only at the end, and write the converted amount on the recipe so you only do the arithmetic once.

Common mistakes to avoid

  1. Converting volume to weight without the ingredient. Converting volume to weight without the ingredient. Grams and ounces are weight; cups and millilitres are volume. The conversion between them depends on density, so there is no universal factor — check the ingredient table for flour, sugar, butter and the rest.
  2. Trusting a spring scale for small amounts. Trusting a spring scale for small amounts. Spring scales are inaccurate below about 50 g. For spices, yeast and baking powder, use a digital scale that reads to 1 g, or measuring spoons.
  3. Using troy ounces instead of avoirdupois ounces. Using troy ounces instead of avoirdupois ounces. Kitchen scales use avoirdupois ounces (28.35 g); troy ounces (31.10 g) are for precious metals. If your scale has a troy setting, make sure it is off before weighing food.
  4. Weighing with the bowl on the scale and forgetting to tare. Weighing with the bowl on the scale and forgetting to tare. The bowl's weight gets added to the ingredient, and everything after it is wrong. Tare the empty bowl, then add the ingredient.

Frequently asked questions

Is 1 ounce exactly 28.35 grams?

Yes, by international definition. The pound is defined as exactly 453.59237 g and the ounce as exactly 28.349523125 g, so the factor 28.35 is exact to the precision shown. The table rounds to a sensible number of decimals for kitchen use; the rounding error is a fraction of a gram at the amounts cooks actually weigh.

Should I weigh ingredients or use cups?

Weigh them, whenever the recipe allows it. Weight is more accurate than volume, especially for flour, which can vary by 20 g per cup depending on how it is measured. A digital kitchen scale that reads to 1 g costs less than a set of measuring cups and removes every conversion on this page from your cooking entirely.

How much should I round the result?

For soups, stews, roasts and everyday cooking, two significant figures are plenty — 28 g for an ounce, 454 g for a pound. For baking, keep one more figure (28.35 g, 453.59 g) because rounding five ingredients by a gram or two each can move a dough by 10 g. Round once, at the end, never at each step.

What is the difference between an ounce and a fluid ounce?

An ounce (oz) is a unit of weight — 28.35 g. A fluid ounce (fl oz) is a unit of volume — 29.57 ml. They are different quantities that happen to share a name, and they are only numerically close for water. Never substitute one for the other with oil, honey or flour, where the numbers diverge sharply.

Are kitchen ounces the same as troy ounces?

No. Kitchen scales use avoirdupois ounces (28.35 g). Troy ounces (31.10 g) are used for precious metals and gemstones. If your scale offers a troy setting, do not use it for food — it will overstate every weight by about 10%.

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