Ounces to Grams

1 ounce is exactly 28.349523125 grams, or about 28.3495 g. Enter ounces to convert: multiply by 28.349523125. Avoirdupois ounces, with a chart.

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Ounces (oz)

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Formula:grams = ounces × 28.349523125

How to Convert Ounces to Grams

grams = ounces × 28.349523125

1Multiply by 28.349523125Multiply the ounce figure by 28.349523125, the number of grams in one avoirdupois ounce.
2Do the mathFor 8 ounces: 8 × 28.349523125 = 226.796185, shown as 226.7962 after rounding to four decimal places.
3Read the result8 ounces is about 226.7962 grams.

Ounces to Grams Conversion Chart

Each gram figure is rounded to four decimals; the pound notes are exact definitions, shown here with the rounded display. For pounds and ounces, count each pound as 16 ounces and enter the total.

Ounces (oz) to Grams (g) reference values
Note	Ounces (oz)	Grams (g)
A quarter ounce	0.25	7.0874
A half ounce	0.5	14.1748
-	1	28.3495
-	2	56.699
-	3	85.0486
A quarter of a pound	4	113.3981
-	5	141.7476
-	6	170.0971
-	7	198.4467
Half a pound	8	226.7962
-	9	255.1457
-	10	283.4952
Three quarters of a pound	12	340.1943
-	14	396.8933
-	15	425.2428
One pound (exactly 453.59237 g)	16	453.5924
-	18	510.2914
-	32	907.1847

Unit Definitions

Ounces (oz)

One avoirdupois ounce (oz) is 1/16 of a pound in US customary and imperial use, and international agreement fixes it at exactly 28.349523125 grams.

Common uses

Food and ingredient weights
Postal and parcel weights
Everyday goods in the US

Grams (g)

Grams are the metric mass unit, with one thousand to the kilogram. Each avoirdupois ounce weighs exactly 28.349523125 g, so converting ounces to grams means multiplying by that figure.

Common uses

Food labels and ingredient weights
Small parcels and letters
Science and laboratory measurement

Ounces, Grams and Pounds-and-Ounces

Because 28.349523125 is exact, any rounding comes from the four-decimal display. A gram figure carries no approximation sign only when its product already has four decimals or fewer, as with 160 oz = 4535.9237 g.

The calculator takes ounces only. For pounds and ounces, count each pound as 16 ounces, add the remaining ounces and enter the total: 6 lb 6 oz is 102 ounces, which is about 2891.6514 g.

Practical Examples

Here are some real-world examples of ounces to grams conversions:

4 Ounces4 ounces is about 113.3981 grams, a quarter of a pound.
8 Ounces8 ounces is about 226.7962 grams, half a pound.
12 Ounces12 ounces is about 340.1943 grams, three quarters of a pound.
16 Ounces16 ounces is about 453.5924 grams; one pound is exactly 453.59237 g.

The Formula and the Exact Factor

An avoirdupois ounce is exactly 28.349523125 grams, so ounces turn into grams when multiplied by that number. The factor carries no uncertainty of its own; any shortfall in a result comes from a shortened factor or early rounding.

For 8 oz the exact answer is 226.796185 g, which the calculator shows as 226.7962 g. In the last column, each difference is the shortened-factor result less 226.796185.

Result for 8 oz with different rounded factors
Factor used	Result for 8 oz	Difference from exact (about)
28	224 g	−2.7962 g
28.3	226.4 g	−0.3962 g
28.35	226.8 g	+0.0038 g
28.3495	226.796 g	−0.0002 g
× 28.349523125 (exact factor)	226.796185 g	none (exact)

Worked Examples

Here the full 28.349523125 does the multiplying, and rounding happens once, at the end, half up, to four decimals, except where another precision is named.

A decimal value. 2.5 oz × 28.349523125 = 70.8738078125 g exactly, shown by the calculator as about 70.8738 g.

A larger value. 100 oz × 28.349523125 = 2834.9523125 g exactly. The calculator rounds that to 2834.9523 g.

Checking a result. Divide the grams by 28.349523125 to return to ounces: 226.7962 g ÷ 28.349523125 ≈ 8.000001 oz. The tiny gap from 8 comes from rounding 226.7962.

How Many Decimals to Keep

Four decimals appear in the result, though a printed label may need fewer. Here 8 oz is exactly 226.796185 g, and each error is the shortened figure less the exact figure.

8 oz shown at four, one and zero decimals
Decimals kept	Result	Error (about)
4	226.7962 g	+0.00002 g
1	226.8 g	+0.00382 g
0	227 g	+0.20382 g

Rounded grams are fine to report, but do not feed them into another calculation.

Common Mistakes

Dividing by the factor

Dividing by 28.349523125 turns grams into ounces. Applied to 8 it gives about 0.2822, far too small for a gram figure. An ounces-to-grams answer should be roughly 28 times larger than the ounces.

Rounding before checking back

Converting 226.8 g back to ounces gives about 8.00013 oz, and 227 g gives about 8.0072 oz. Each rounded step moves the result further from the 8 oz you began with.

Typing a short factor

Entering 28.3 in place of the full factor undershoots the answer before any rounding: the first table shows 226.4 g for 8 oz, about 0.4 g too low.

Frequently Asked Questions

How many grams are in 1 ounce?

One avoirdupois ounce is exactly 28.349523125 grams, which is about 28.3495 g when rounded to 4 decimal places. Everyday sources often shorten it to 28.35 g, and a few round it to 28 g; those are rounded values, not the exact figure.

How many grams are in a half ounce?

Half an ounce is exactly 14.1747615625 grams, shown here as about 14.1748 g. A quarter ounce is about 7.0874 g and an eighth of an ounce is about 3.5437 g.

How do I convert ounces to grams?

Multiply the number of ounces by 28.349523125. For 8 oz that is about 226.7962 g. For a rough mental figure, multiply by 28, which falls short of the exact result by about 1.2 percent.

How do I convert pounds and ounces to grams?

Use grams = (pounds × 453.59237) + (ounces × 28.349523125). For 6 lb 6 oz that is 2,721.55422 g plus 170.09713875 g, which is about 2,891.6514 g. The calculator above takes ounces only, so turn pounds into ounces first (1 lb is 16 oz); 6 lb 6 oz equals 102 ounces in total.

Does the ingredient matter when converting ounces to grams?

Not when the ounces are a measured weight: 4 oz of flour and 4 oz of butter are both about 113.3981 g. It matters only when you start from a volume such as cups or spoonfuls, because the same volume of different ingredients weighs different amounts.

What is the difference between a troy ounce and a regular ounce?

A troy ounce is exactly 31.1034768 g and is the unit for precious metals, while the regular avoirdupois ounce used for food and parcels is 28.349523125 g. The troy ounce is about 9.7 percent heavier, so use the avoirdupois figure for everyday goods.

Are fluid ounces the same as ounces by weight?

No. A fluid ounce measures volume, with one US fluid ounce being 29.5735295625 millilitres, while an ounce by weight measures mass. Turning a fluid ounce into grams needs the density of the liquid, so use the Volume Converter for volume units.

Sources

Based on 3 sources.

Displayed results are rounded to a maximum of 4 decimal places for readability (extended only in the rare case a nonzero value would otherwise display as “0”), and whole-number results are shown without unnecessary decimals. The conversion factor and formula above are the exact relationship - only the calculator's displayed output is rounded.

Need a different unit? Weight Converter supports many other unit conversions.