Grams to Ounces Converter

How to use this tool

Type a number, pick the unit it is in, pick the unit you want, and read the answer. Swap flips the two around and carries the result across, so you can chase a figure back and forth without retyping it. The Decimals box only changes what is shown; the arithmetic underneath always runs at full precision.

The unit list covers more than the two in the title because the question is rarely only about grams and ounces. Pounds and ounces reads out the way a kitchen or bathroom scale shows it, as a whole number of pounds plus a remainder. Stones and pounds does the same for body weight in Britain and Ireland. Sticks of butter is there because American recipes assume them and nobody outside America has one. Troy ounces and grains are there because they are what catches people out, and keeping them visible is better than pretending an ounce is always an ounce.

The green panel answers the question that actually costs people a baking session. Type a number of fluid ounces, pick what is in them, and it tells you what that weighs. For water the two numbers nearly agree and everyone gets away with it. For flour they are off by half.

Why this conversion is exact

Most unit conversions are measurements of something physical and carry an uncertainty with them. This one does not. In 1959 the United States, the United Kingdom, Canada, Australia, New Zealand and South Africa signed the international yard and pound agreement, which defined the pound as exactly 0.45359237 kilograms. Not approximately. Exactly, by agreement, with no error bar.

Everything else falls out of that one line. An avoirdupois ounce is a sixteenth of a pound, so it is 453.59237 divided by 16, which is 28.349523125 grams. A grain is a seven thousandth of a pound, which is 0.06479891 grams exactly. A stone is 14 pounds, 6.35029318 kilograms. A US stick of butter is a quarter pound, 113.398093 grams, usually printed on the wrapper as 113 g. None of those figures will ever change, and any calculator that disagrees with them has rounded somewhere it should not have.

That is worth knowing because it tells you where the uncertainty in a recipe actually lives. It is never in the gram to ounce step. It is in the scale you are using, in whether the recipe meant weight or volume, and in whether the author measured the flour the same way you do.

The fluid ounce, which is not an ounce

An ounce is a weight. A fluid ounce is a volume. They share a word for historical reasons, and they nearly coincide for water, which is exactly why the confusion survives: 8 fluid ounces of water weighs 8.3 ounces, close enough that nobody notices anything is wrong. Then the same person measures 8 fluid ounces of flour, gets 4.2 ounces of it, and wonders why the dough is wet.

The rule is simple once you see it. If the ingredient is a liquid and the recipe is American, ounces almost certainly means fluid ounces and you want the jug. If the ingredient is a solid, ounces means weight and you want the scale. If the recipe is British or Australian and gives both, the fluid ones will be labelled. And if a recipe gives flour in ounces, it is a weight every time, because nobody sensible measures flour by volume in a jug.

There is a second layer to this. The US fluid ounce is 29.5735 millilitres and the UK imperial fluid ounce is 28.4131, so they are not the same either. The UK one is the smaller, which catches people who know that the UK gallon and pint are the larger. The explanation is that a UK pint holds 20 fluid ounces while a US pint holds 16, so the UK pint is bigger even though its ounce is smaller.

Grams to ounces at a glance

Exact conversions for the gram figures that come up most in recipes and on packaging, with the pounds and ounces reading and the stick equivalent for American recipes.

Exact conversions using the defined ounce of 28.349523125 grams. Each gram figure in the first column is a link that opens the converter on it.

The troy ounce, and why gold is different

Two systems of weight came out of medieval Europe and both survived. Avoirdupois, the one you use for everything, has 16 ounces to the pound and 437.5 grains to the ounce. Troy, used for precious metals and gemstones, has 12 ounces to the pound and 480 grains to the ounce. They agree that a grain is exactly 0.06479891 grams, which means the troy ounce is 31.1034768 grams against 28.349523125, about 9.7 percent heavier.

This matters whenever a price is quoted per ounce. Gold, silver, platinum and palladium are all quoted per troy ounce, so a spot price of two thousand an ounce is two thousand for 31.1 grams, not for 28.35. Convert with the kitchen ounce and your valuation is nearly ten percent light. The same applies in reverse when someone weighs jewellery on a kitchen scale and reads ounces off it.

The troy pound is where it gets genuinely strange. Twelve troy ounces make a troy pound, which is 373.24 grams, so a troy pound is lighter than an ordinary pound even though a troy ounce is heavier. It is not in practical use any more, which is probably for the best.

A worked check you can repeat on paper

Start with 250 grams. An ounce is 28.349523125 grams, so 250 divided by 28.349523125 is 8.81849 ounces. In pounds that is 250 divided by 453.59237, which is 0.55116, so zero pounds and 8.82 ounces. In sticks of butter it is 250 divided by 113.398093, which is 2.2046, so a 250 gram European block is a shade over two and a fifth American sticks.

Now the other way. 8 ounces is 8 times 28.349523125, which is 226.796185 grams, and that is exactly half a pound because 8 is half of 16. Two sticks of butter, in other words. A recipe asking for 8 oz of butter and a recipe asking for two sticks are asking for the same thing, and both come to 227 grams once you round sensibly.

And the check that ties the systems together: a pound is 7,000 grains and an ounce is 437.5, and 437.5 times 16 is 7,000, so the grain, the ounce and the pound agree. A troy ounce is 480 grains, so 480 divided by 437.5 is 1.0971, which is where the 9.7 percent comes from.

Mistakes that catch people out

Reading ounces as fluid ounces. The big one. For flour it is off by more than half; for honey it is off the other way.

Using the kitchen ounce for gold. Precious metals are priced per troy ounce, 9.7 percent heavier. A valuation done with the wrong ounce is wrong by that much.

Assuming a UK fluid ounce equals a US one. 28.4131 against 29.5735 millilitres. A UK pint is 20 of them, a US pint is 16.

Treating 28 as close enough in bulk. Fine for a few ounces. Over ten pounds the error from using 28 instead of 28.35 is about two ounces.

Confusing a European butter block with two sticks. A 250 gram block is 2.2 sticks. A recipe wanting two sticks wants 227 grams, so most of a block but not all of it.

Forgetting that a stone is 14 pounds, not 10. A common slip for anyone converting a British body weight for the first time. 12 stone is 168 pounds, which is 76.2 kilograms.

Popular weight conversions

The figures people look up most. Each opens the converter on that conversion with its own address.

Grams to ounces

Ounces to grams

Pounds and kilograms

The way a scale reads it

Butter, troy and grains

How this was checked

Every factor was entered from its legal definition rather than a rounded value, and the set was then checked for internal consistency in Node. Sixteen ounces returns exactly one pound. Seven thousand grains returns exactly one pound. Four hundred and thirty seven point five grains returns exactly one ounce. Four sticks of butter returns exactly one pound. Fourteen pounds returns exactly one stone. Every one of those came back exact to twelve significant figures rather than close, which is what you should expect when the underlying numbers are definitions.

Round trips were checked in both directions for every unit pair, so converting grams to troy ounces and back returns the starting figure without drift. The pounds and ounces reading was checked at the boundaries, where a value a fraction under a whole pound must not display as sixteen ounces, and the stones and pounds reading likewise at fourteen. The fluid ounce panel was checked against published densities, and water comes out at 8.35 ounces for 8 US fluid ounces, which is the figure the arithmetic demands. The live page was then opened at every address linked above and each was checked for a distinct title, the right headline, charts that rendered, and clean CSV, image and print output containing only that conversion, at desktop, tablet and phone widths.

Common questions

How many grams are in an ounce?

Exactly 28.349523125 grams. That is not a measurement or an approximation, it is a definition: the international yard and pound agreement of 1959 fixed the pound at exactly 0.45359237 kilograms, and an ounce is one sixteenth of a pound. Divide 453.59237 by 16 and you get 28.349523125. For kitchen work 28.35 is close enough, and for mental arithmetic 28 will do, but the exact figure is what every conversion on this page uses.

How many ounces are in a pound?

Sixteen, in the avoirdupois system that everybody uses for food, post and body weight. That makes a pound 453.59237 grams and half a pound 226.8 grams, which is why an American recipe calling for 8 oz of something wants about 227 grams. The troy system used for precious metals has twelve troy ounces to a troy pound, and since a troy ounce is also heavier, the two pounds are not the same thing at all: a troy pound is 373.24 grams, noticeably lighter than an ordinary one.

What is 250 grams in ounces?

8.82 ounces, or 8 ounces and 13 grams if you prefer it that way round. 250 grams is a common European block size for butter and a common figure in metric recipes, and it comes out awkwardly in ounces precisely because the two systems were never designed to line up. The table on this page gives the values either side of it so you can see whether rounding to 8.8 or to 9 matters for what you are doing.

Is a fluid ounce the same as an ounce?

No, and this is the error that ruins more recipes than any other. An ounce is a weight, 28.35 grams. A fluid ounce is a volume, 29.5735 millilitres in the United States. They only appear to agree because water happens to have a density near one, so 8 fluid ounces of water weighs 8.3 ounces. For anything else they come apart fast: 8 fluid ounces of flour weighs 4.2 ounces and 8 fluid ounces of honey weighs 11.9. If a recipe says 8 oz of flour it means the scale, not the measuring jug.

Why is a troy ounce different from a normal ounce?

Because the two systems agreed on the grain and then disagreed about how many make an ounce. Both define the grain as exactly 0.06479891 grams. The avoirdupois ounce is 437.5 grains and the troy ounce is 480, so the troy ounce is 31.1034768 grams, about 9.7 percent heavier. Troy survives only for precious metals and gemstones, which is why a gold price quoted per ounce is per troy ounce. Converting a bullion weight with the kitchen ounce gets you a number that is wrong by nearly a tenth.

How many grams is a stick of butter?

113.4 grams, because an American stick is a quarter pound, exactly 4 ounces. Two sticks are half a pound, 226.8 grams, and four sticks are a full pound, 453.6. European butter usually comes in 250 gram blocks, which is 2.2 sticks, so a recipe asking for two sticks needs slightly less than a whole block. The wrapper on a US stick is marked in tablespoons as well: eight tablespoons to a stick, which is half a cup.

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• NIST on units of mass: the official US reference for the definitions this page uses.