Calcometry

Oz to Grams Converter

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Convert weight ounces to grams (and back) instantly. 1 avoirdupois oz = 28.349523125 g — not fluid ounces.

Ounces

oz

Grams

g

1 oz = 28.3495 g

Convert Ounces

Quick presets

Grams

226.8 g

8 oz = 226.8 g

1 oz
28.3495 g
4 oz
113.4 g
8 oz
226.8 g
16 oz
453.59 g
32 oz
907.18 g
100 oz
2,834.95 g
500 oz
14,175 g

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Ounces vs grams

This converter turns weight ounces into grams — the kind of ounce on nutrition labels, postal scales, and kitchen packages, not fluid ounces for liquids. In US recipes and shipping, ounces are common; grams are the metric standard on scales and labels almost everywhere else. One weight (avoirdupois) ounce equals exactly 28.349523125 grams.

Worked example: an “8 oz” chocolate bar is 8 × 28.349523125 ≈ 226.8 g. A 5 oz serving on a US label is about 142 g. For baking, weighing in grams on a kitchen scale usually beats scooping by volume once the recipe gives a weight.

Caveat: fluid ounces measure volume (about 29.6 mL for a US fl oz of water-like liquid). A cup of flour and a cup of water do not weigh the same in ounces. USPS prices by pounds and ounces; international customs forms often want kilograms — convert the total package weight before you fill them out.

Round-trip sanity check: 16 oz × 28.349523125 = 453.592 g (one pound); divide by 28.349523125 to recover 16 oz. Do not use fluid ounces here — 16 fl oz of honey weighs more than 16 oz of water by volume confusion.

Common questions

Are fluid ounces and weight ounces the same?

No. This tool converts weight ounces (avoirdupois oz). US fluid ounces measure volume (about 29.6 mL each for water-like liquids). A cup of flour and a cup of water weigh different ounces — volume and weight ounces are different units.

My recipe lists 8 oz of chocolate — is that the same as an “8 oz bar”?

Usually yes for US packaging: an “8 oz bar” means 8 weight ounces (about 227 g). Always check whether the recipe means weight or volume — “8 oz of cream cheese” by weight differs from “1 cup” by volume.

How do I convert US nutrition labels (oz) to grams?

Multiply ounces by 28.35 for a close gram estimate. Example: a 5 oz serving → about 142 g. Labels often round; use grams on kitchen scales for baking where precision matters.

Does the USPS use ounces or grams for stamps and parcels?

USPS retail pricing is in pounds and ounces. International forms may ask for kilograms — convert the total package weight before filling customs declarations to avoid rounding errors at the counter. Round-trip: 1 lb = 16 oz = 453.592 g.