How Much Does an Ounce Weigh? Grams, Pounds + Conversion Tables (Quick Answer)

One ounce weighs 28.35 grams if you’re talking about the everyday, avoirdupois ounce used for food, shipping, and body weight in the United States.

But if you’re weighing gold, silver, or another precious metal, the math changes a troy ounce weighs 31.10 grams, which is heavier than the standard ounce measurement most people know.

This guide breaks down exactly how much an ounce weighs in grams, pounds, kilograms, and milliliters, with full conversion tables you can bookmark and use anytime.

Quick Reference

Before we get into the details, here’s the fast answer for anyone who just needs the numbers.

Unit	Equals
1 ounce (avoirdupois)	28.35 grams
1 ounce (avoirdupois)	1/16 pound
1 troy ounce	31.10 grams
1 fluid ounce (US)	29.57 milliliters (volume, not weight)
1 pound	16 ounces = 453.59 grams
1 kilogram	35.27 ounces

Keep this table handy nearly every question in this article traces back to one of these six conversions.

How Much Does an Ounce Weigh in Grams

This is the question most people are really asking: how much does an ounce weigh in grams? The precise answer is 28.34952 grams, which is almost always rounded to 28.35 grams in everyday use. This is the avoirdupois ounce the standard ounce used in the US for food packaging, mail, and body weight.

The formula is simple:

grams = ounces × 28.3495

So if a recipe calls for 3 ounces of flour, you’d multiply 3 by 28.3495 to get roughly 85 grams. For most kitchen and shipping purposes, rounding to 28.35 grams per ounce is accurate enough. Jewelers, chemists, and anyone working with fine tolerances should use the full 28.34952-gram figure instead of rounding early, since small errors compound over larger quantities.

How Much Does an Ounce Weigh in Kg

Grams are useful for small amounts, but once you’re talking about a pound or more, kilograms make more sense. One ounce equals 0.02835 kilograms. That’s a small number on its own, which is exactly why ounces stay in grams for most everyday comparisons but it matters when you’re converting a bulk shipment or a body weight figure into the metric system.

Ounces	Kilograms
1 oz	0.028 kg
4 oz	0.113 kg
8 oz	0.227 kg
16 oz (1 lb)	0.454 kg

You’ll notice 16 ounces lands right at 0.454 kilograms, which lines up with the standard pound-to-kilogram conversion. That consistency is a good way to double-check your math when converting larger ounce weights.

Ounces to Grams

Here’s the full ounces to grams conversion chart, covering the amounts people search for most in cooking, shipping, and general measurement.

Ounces	Grams
0.5	14.17
1	28.35
2	56.70
4	113.40
5	141.75
8	226.80
10	283.50
16 (= 1 lb)	453.59

Rule of thumb: multiply the ounce figure by 28.35 to get grams, and divide a gram figure by 28.35 to get back to ounces. This single formula covers the vast majority of gram conversion needs you’ll run into.

How Much Does an Ounce Weigh in Pounds

One ounce equals 1/16 of a pound, or 0.0625 pounds. That fraction comes from the avoirdupois system, where 16 avoirdupois ounces make up 1 avoirdupois pound. It’s worth noting this only applies to the standard ounce the troy system works differently, with 12 troy ounces to a troy pound, though the troy pound itself is rarely used today outside of historical contexts.

Understanding this 1/16 relationship is the key to almost every ounces-to-pounds conversion you’ll ever need to do.

Ounces to Pounds

Use this chart whenever you need to convert ounces to pounds quickly.

Ounces	Pounds
1	0.0625
2	0.125
4	0.25
8	0.5
12	0.75
16	1
32	2

The formula: pounds = ounces ÷ 16. This comes up constantly with shipping weights, grocery labels, and body weight, since the US almost always expresses larger weights in pounds and ounces together (like “8 pounds, 6 ounces”) rather than switching to a decimal.

Avoirdupois vs Troy Ounce

This is where most of the confusion around ounce weight actually starts. There isn’t just one kind of ounce there are two, and they are not interchangeable.

The avoirdupois ounce is the everyday ounce measurement Americans use for food, shipping, and body weight. It’s part of the broader avoirdupois weight system, and it equals 28.35 grams.

The troy ounce, by contrast, is a separate unit used almost exclusively for precious metals like gold, silver, platinum, and palladium. A troy ounce equals 31.10 grams, which makes it about 10% heavier than the avoirdupois ounce. The troy weight system traces back to the medieval trading town of Troyes, France, and it survived for one reason: the bullion trade never switched away from it.

Here’s a side-by-side comparison:

Type	Weight	Common Use
Avoirdupois ounce	28.35 grams	Food, shipping, body weight, everyday goods
Troy ounce	31.10 grams	Gold, silver, platinum, palladium

There’s an old saying that captures this perfectly:

“An ounce of gold weighs more than an ounce of feathers.”

That statement sounds like a riddle, but it’s technically true. Gold is measured in troy ounces, while feathers (and nearly everything else) are measured in avoirdupois ounces. Since a troy ounce weighs more, an ounce of gold really does outweigh an ounce of feathers on a scale. If you ever see gold, silver, or another precious metal priced “per ounce,” assume it means the troy ounce unless stated otherwise the entire bullion measurement industry runs on this standard.

Ounce vs Fluid Ounce

Another common mix-up: an ounce and a fluid ounce are not the same thing, and they don’t measure the same property.

Ounce (oz) measures weight. One ounce equals 28.35 grams.
Fluid ounce (fl oz) measures volume. One US fluid ounce equals 29.57 milliliters.

These two units happen to land close together when you’re measuring water, since water is a fairly standard density. Eight fluid ounces of water weighs almost exactly 8.3 ounces. But that relationship falls apart fast with anything less dense than water. Eight fluid ounces of flour, for example, weighs only about 4.5 ounces roughly half what the fluid ounce number would suggest.

This is precisely why baking recipes that list ingredients by weight (in ounces or grams) tend to turn out more consistent than recipes that rely on cup or fluid ounce measurements. Volume measurements are sensitive to how tightly an ingredient is packed; weight measurements are not.

How Much Is an Ounce to Ml

For anyone converting liquid volume, one US fluid ounce equals 29.57 milliliters. It’s worth flagging that the UK and other countries using the Imperial system define a fluid ounce slightly differently, at 28.41 milliliters a small but real difference if you’re following a recipe or product label from outside the US.

Fluid Ounces (US)	Milliliters
1 fl oz	29.57 ml
2 fl oz	59.15 ml
4 fl oz	118.29 ml
8 fl oz	236.59 ml
16 fl oz	473.18 ml

How Much Is One Ounce of Liquid

When people ask “how much is one ounce of liquid,” they’re usually asking about the fluid ounce, not the weight ounce and the answer is 29.57 milliliters for the US standard. But it’s worth remembering that the weight of that liquid still depends on what it is. Water weighs close to 28.35 grams per fluid ounce, but oil, honey, and syrup are denser or lighter, so their actual weight per fluid ounce will vary. If a recipe or label lists a liquid ingredient by weight instead of volume, that’s usually the more accurate measurement to trust.

What Weighs 1 Ounce of Gold

Since gold is priced and traded in troy ounces, it’s worth being specific here: one troy ounce of gold weighs 31.1035 grams, not the 28.35 grams you’d get from a standard avoirdupois ounce. This distinction matters enormously in the precious metals market mixing up the two ounce types when buying or valuing gold, silver, or platinum can lead to a real miscalculation in value.

For context, here are a few everyday items that weigh close to a standard (avoirdupois) ounce, which can help make an abstract number feel more concrete:

A slice of sandwich bread
About 28 standard paperclips
A pencil
A slice of American cheese

None of these weigh a troy ounce, though that unit is reserved almost entirely for precious metals and gunpowder, a holdover from its historical use in the bullion trade.

How Much Does an Ounce Weigh in Pounds

To reinforce the earlier answer in a different context: an ounce weighs 0.0625 pounds, or exactly 1/16 of a pound, in the avoirdupois system used across the US for everyday weight. This is the same ratio behind why a standard US pound splits cleanly into 16 ounces on food labels, shipping forms, and kitchen scales.

What Does a Half Ounce Weigh

A half ounce is a common real-world quantity, especially in retail contexts like spices, jewelry, and precious metals so it’s worth its own answer. A half ounce weighs 14.17 grams using the avoirdupois system, or 15.55 grams using the troy system. The gap between those two numbers is small in absolute terms, but it’s the same roughly 10% difference you’ll see at any ounce fraction, since troy weight is consistently heavier than avoirdupois weight across the board.

How Much Is One Ounce in a Cup

This one trips people up because it mixes a weight-style question with a volume-based unit. A standard US cup equals 8 fluid ounces by volume that part is fixed. But how much a cup weighs in ounces depends entirely on what’s in it, because cups measure volume, not weight.

Ingredient	Weight per Cup (approx.)
Water	8 oz
Granulated sugar	7 oz
All-purpose flour	4.5 oz
Butter	8 oz

As the table shows, a cup of flour and a cup of butter both take up the same volume, but they don’t weigh the same amount. This is the same density issue covered earlier in the ounce vs fluid ounce comparison and it’s the single biggest reason bakers who care about consistency measure by weight instead of by cup.

Common Uses

Ounce measurements show up constantly in daily American life, often without much thought but the type of ounce being used changes depending on the situation.

Cooking and Baking

Most US recipes lean on volume measurements like cups and tablespoons, but professional bakers and serious home cooks increasingly weigh ingredients in ounces or grams instead. A kitchen scale that switches between grams and ounces is one of the cheapest upgrades you can make for consistent results, since it removes the guesswork that comes with packing, scooping, and leveling.

Shipping

USPS, UPS, and FedEx all price small packages by weight in ounces before switching over to pounds at the 16-ounce mark. Knowing your package’s ounce weight ahead of time rather than guessing at the counter can save you from an unexpected shipping surcharge.

Precious Metals

As covered earlier, gold, silver, platinum, and palladium are all sold and priced in troy ounces, not the standard avoirdupois ounce. If you ever see a coin or bar labeled “1 oz,” it’s referring to 31.10 grams, not 28.35 grams a distinction that matters a great deal when you’re calculating value.

Body Weight (International)

The US is one of the few countries that still measures body weight in pounds and ounces rather than kilograms and grams. A newborn described as “7 pounds, 4 ounces,” for example, weighs about 3.29 kilograms a conversion that comes up often for anyone communicating body weight figures across countries.

Where Does the Word “Ounce” Come From

The word “ounce” has a long history that traces back to the Latin word uncia, referring to a twelfth part originally a twelfth of a Roman pound. Over time, uncia evolved into the Italian onza, which is where the modern abbreviation “oz” actually comes from. It isn’t short for any English word at all; it’s a holdover from that Italian spelling. The unit itself dates back to Roman times, making it one of the oldest weight measurements still in everyday use today.

How Many Grams Are in an Ounce of Common Foods

Since so many ounce questions come from the kitchen, here’s a quick reference for specific ingredients:

Chocolate: about 28.35 grams per ounce
Butter: about 28 grams per ounce
Chicken (raw, boneless): about 28 grams per ounce
Sugar: commonly cited around 25–28 grams per ounce depending on how tightly it’s packed
Protein powder: about 28 grams per ounce, though “grams of protein” per scoop is a separate nutritional figure, not a weight conversion

In nearly all of these cases, the standard 28.35-gram conversion holds the small variations you’ll see online usually come from ingredient density and how the ounce was measured (scooped vs. leveled vs. weighed).

How to Convert Grams and Ounces (Formula and Steps)

Converting between the two units is straightforward once you know the formula:

Grams to ounces: multiply grams by 0.035274
Ounces to grams: multiply ounces by 28.3495

To do it manually, follow these three steps:

Identify the weight you’re starting with (in ounces or grams).
Multiply it by the correct conversion factor above.
Round the result to two decimal places for practical use.

For anything requiring high precision jewelry, lab work, precious metals skip the rounding and use the full 28.34952 figure instead.

How to Measure an Ounce Without a Scale

A kitchen scale is always the most accurate option, but it isn’t the only one. If you don’t have one on hand, here are a few reliable substitutes:

Tablespoons: 2 tablespoons of a liquid roughly equal 1 fluid ounce.
Cups: 1 ounce is roughly 1/8 of a cup for liquids (since 8 fluid ounces make a cup).
Common object comparisons: a slice of bread or a handful of about 28 paperclips is a rough stand-in for 1 avoirdupois ounce when you just need a ballpark.

None of these methods will match the accuracy of a scale, especially for dry, dense, or fluffy ingredients, but they’re useful in a pinch.

Frequently Asked Questions

How much does an ounce weigh in grams?

An avoirdupois ounce weighs 28.35 grams. A troy ounce weighs 31.10 grams.

How many ounces are in a pound?

There are 16 ounces in a standard avoirdupois pound.

Is a fluid ounce the same as a weight ounce?

No. A fluid ounce measures volume; a weight ounce measures mass.

Why is a troy ounce heavier than a regular ounce?

The troy system developed separately for precious metals and was never standardized down.

What does “oz” stand for?

It comes from the Italian word onza, not an English abbreviation.

How much does a half ounce weigh?

14.17 grams (avoirdupois) or 15.55 grams (troy).

How many grams are in an ounce of gold?

31.1035 grams, since gold is measured in troy ounces.

What weighs 1 ounce?

A slice of bread or 28 paperclips.

Does 16 oz make 1 lb?

Yes, 16 avoirdupois ounces equal exactly 1 pound.

How much does 1 oz weigh in grams?

28.35 grams, the standard avoirdupois conversion.

Does 30 grams equal 1 oz?

Close, but no 1 oz is 28.35 grams.

Conclusion

The short answer to “how much does an ounce weigh” is 28.35 grams for the everyday avoirdupois ounce, or 31.10 grams for the troy ounce used in precious metals. That single distinction avoirdupois vs. troy is responsible for almost every point of confusion around ounce weight, whether you’re converting a recipe, weighing a shipment, or pricing gold. The most useful habit you can build is asking which ounce you’re actually dealing with before you do the math. Once you know that, every other conversion in this guide grams, pounds, kilograms, milliliters, or cups is just a matter of applying the right formula.

John Wick

Hi, I’m John Wick, the admin at Magazineaura.com. I make measurements simple and easy to understand, from bed sizes to everyday length conversions. Clear guides. Accurate dimensions. No confusion.