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Ounces to grams (oz to g)

To convert ounces to grams (oz to g): one ounce is 28.349523 grams, so 12 oz is 340.194 g.

Swap units: g to oz

In grams340.194 g

Conversion factor Exact by definition. The inch has been exactly 2.54 cm and the pound exactly 0.45359237 kg since the 1959 international yard and pound agreement, so these are not measurements that can drift.
1 ounce = 28.34952313 grams
The other way
1 gram = 0.0352739619 ounces
Working
12 x 28.34952313 = 340.194
12 oz in every unit
340,194 mg 340.19 g 0.34019 kg 0.00034019 t 12 oz 0.75 lb 0.053571 st 0.000375 ton 5,250 gr 218.75 dwt 10.938 oz t 0.91146 lb t
ounces to grams
ozg
128.3495
256.699
5141.748
10283.495
25708.738
501,417.48
1002,834.95

How the Unit Converter works

One ounce is exactly 28.34952313 grams. That is a definition rather than a measurement: the imperial and US customary units were fixed against metric ones by the 1959 international yard and pound agreement, so this factor does not drift and will not be revised.

Worked through: 8 oz x 28.3495231 = 226.796 g.

Going the other way, one gram is 0.0352739619 ounces.

To convert without a calculator, multiply by 28.35. Rounding that to 28 is within 1.2% for most purposes.

An avoirdupois ounce, which is the ordinary one at 28.35 g. A TROY ounce, used only for precious metals, is 31.1035 g, about 10% heavier. Gold quoted per ounce is always troy, and confusing the two misprices a trade by a tenth.

Precision is worth matching to the input. A measurement given as 1 oz carries one or two significant figures, and reporting its conversion to six implies a precision the original never had.

Unit Converter FAQ

How many grams are in a ounce?

28.349523. That is exact by definition: the 1959 international yard and pound agreement fixed it, and it does not change.

What is 12 oz in grams?

340.194 g. Multiply by 28.349523: 8 oz x 28.3495231 = 226.796 g.

How do I convert grams back to ounces?

Divide by 28.349523, or equivalently multiply by 0.035273962. One gram is 0.035273962 ounces. The two factors are reciprocals, so you only need to remember one of them.

Is there anything to watch out for with this conversion?

An avoirdupois ounce, which is the ordinary one at 28.35 g. A TROY ounce, used only for precious metals, is 31.1035 g, about 10% heavier. Gold quoted per ounce is always troy, and confusing the two misprices a trade by a tenth.

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