Ounces to Grams (oz to g)
One avoirdupois ounce is exactly 28.349523125 grams, so grams = ounces × 28.349523125: 1 oz is 28.349523125 g, 8 oz is 226.796185 g and 16 oz is 453.59237 g. This page opens on ounces into grams whatever the converter was last set to, answers as you type, and lists the same weight in milligrams, kilograms, pounds, stones and tonnes underneath, because a weight is easier to judge beside the units you already use. The ounce here is the avoirdupois ounce of food, post and kitchen scales, not the troy ounce that precious metals are priced in.
1 oz in every mass unit
Common questions
- How many grams are in an ounce?
- Exactly 28.349523125 g. An ounce is a sixteenth of the international pound, and that pound is defined as exactly 0.45359237 kg, so the factor is a definition rather than a measurement and the page prints all of its digits. Kitchen and postal work usually rounds it to 28.35 g, and recipes often use a flat 28 g. The Copy result button copies the figure without the digit grouping, so it pastes straight into a spreadsheet.
- What are 4, 8, 12 and 16 oz in grams?
- 4 oz is 113.3980925 g, 8 oz is 226.796185 g, 12 oz is 340.1942775 g and 16 oz is 453.59237 g. Sixteen ounces is one pound, which is why that last figure is the pound definition, 0.45359237 kg, written in grams. Type any of them into the field and the answer appears without a button press.
- Is an ounce the same as a fluid ounce?
- No. A fluid ounce measures volume, so it converts to millilitres rather than grams: one US fluid ounce is 29.5735295625 mL and one imperial fluid ounce is 28.4130625 mL. Both are here under the Volume category on the strip above the converter, chosen from the unit menu. Water is close enough that a US fluid ounce of it weighs about 29.6 g, but flour, sugar and oil are not water, and the two ounces are not interchangeable.
- What about a troy ounce of gold or silver?
- A troy ounce is a different unit, 31.1034768 g, about 10% heavier than the avoirdupois ounce, and it is used only for precious metals. It is deliberately not in the mass list here, because converting a bullion weight with the 28.349523125 factor gives the wrong number and a page that offers both ounces under one name invites exactly that mistake.
- How do I convert grams back to ounces?
- Press the swap button between the two fields and the pair reverses to grams into ounces, or divide by 28.349523125. The page shows 100 g as 3.52739619496 oz and 500 g as 17.6369809748 oz, to twelve significant digits, so a chained conversion does not come back as 0.99999999 of what you started with.
- Why does it show pounds and kilograms too?
- Because an ounce is usually being compared with something. Under the answer the same weight is listed in milligrams, grams, kilograms, tonnes, pounds, stones and US short tons, each with its own Copy button, and one switch adds the three rarer ones: long tons, carats and grains.
- Does anything I type leave my browser?
- No. The conversion is one multiplication done in the page, with no upload and no account. The number you typed is kept in your own browser storage so the field is where you left it next time, the Start over button at the top of the page clears it, and opening this page on ounces to grams does not overwrite the pair the main converter remembers.
Conversion factors are the exact legal definitions where one exists. An inch is exactly 2.54 cm and a pound exactly 0.45359237 kg, so those conversions are exact rather than approximate. Temperature uses offsets rather than factors, and that is shown in the working.