Ounces to Grams

Weight ounces, troy ounces, and what to do with fluid ounces.

Amount

Unit

Tip: you can type “8 oz flour” or “500 ml to oz”.

1 ounce (weight) =

28.3g

Reading this as weight ounces (oz) — what scales and food labels use.

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Details

Measures about 28.3 mL ·Ingredient

All units

lb: 0.0625
g: 28.3
kg: 0.0283
oz t: 0.911

How we got this

1 ounce (weight) × 28.349523125 g/oz = 28.349523 g

1 oz = 28.349523125 g. 1 lb = 453.59237 g. 1 troy oz = 31.1034768 g (international avoirdupois and troy definitions, NIST).

Density used: water, 1 g/mL. By definition close to 1 g/mL at room temperature. Source: NIST.

One ounce is 28.349523125 grams, exactly. This is the avoirdupois ounce, sixteen to the pound, the one on your kitchen scale and your mail scale. Recipes often round it to 28 g or 30 g. That is fine for a pinch of spice and drifts for baking: 8 oz at 28 g is 224 g, while the true figure is 226.8 g.

Two other ounces get confused with it. A troy ounce, used for precious metals, is 31.1035 g. A fluid ounce measures volume, so turning it into grams needs a density. The Which ounce table below lays all four out.

Quick answers

1 oz: 28.35 g
1 lb: 453.6 g
1 oz t: 31.1 g

Formula

g = oz × 28.349523125
oz = g ÷ 28.349523125
g = oz t × 31.1034768
oz t = g ÷ 31.1034768

Conversion table

oz to grams conversion table
Amount	oz to g	oz t to g
1	28.35	31.1
2	56.7	62.21
3	85.05	93.31
4	113.4	124.4
5	141.7	155.5
6	170.1	186.6
7	198.4	217.7
8	226.8	248.8
9	255.1	279.9
10	283.5	311
12	340.2	373.2
16	453.6	497.7
16.9	479.1	525.6
20	567	622.1
24	680.4	746.5
32	907.2	995.3
50	1,417	1,555
64	1,814	1,991
100	2,835	3,110

Which ounce?

Ounce	Exactly	Used for
Ounce (oz)	28.349523125 g	Food, mail, kitchen scales, the default meaning of a bare “oz”.
US fluid ounce (US fl oz)	29.5735295625 mL	US labels, bottles, cans. 16 of them make a US pint.
UK fluid ounce (UK fl oz)	28.4130625 mL	UK recipes, older imperial labels. 20 of them make a UK pint.
Troy ounce (oz t)	31.1034768 g	Gold, silver, platinum. About 10% heavier than the ounce on your kitchen scale.

Common amounts

8 oz cup 237 mL
12 oz can 355 mL
16.9 oz bottle 500 mL
20 oz bottle 591 mL
3.4 oz TSA 100 mL
1.7 oz perfume 50 mL
8 oz steak 227 g
1 oz gold 31.1 g

Questions

How many grams is 1 oz?

28.3495 g, or 28.35 g rounded.

How many grams is 4 oz?

113.40 g. That is one US stick of butter.

Is a gold ounce the same as a kitchen ounce?

No. Gold is sold by the troy ounce, 31.1035 g. A kitchen ounce is 28.3495 g, so a troy ounce is about 9.7% heavier.

How do I convert fluid ounces to grams?

Convert to mL first, then multiply by the density. Water is 1 g/mL, so 1 US fl oz of water is 29.57 g. Vegetable oil is about 0.92 g/mL, so about 27.2 g. Honey is about 1.42 g/mL, so about 42 g.