How to Convert Grams to Ounces: Formula, Chart & the Fluid-Ounce Trap

To convert grams to ounces, divide the grams by 28.3495 — that formula (ounces = grams ÷ 28.3495) is exact for the avoirdupois ounce used in cooking and shipping. 100 grams is 3.53 ounces; 250 grams of flour is 8.82 ounces. Try it in our free unit converter. Worked examples, the reverse formula, and the fluid-ounce trap are below.

The grams-to-ounces formula: divide by 28.3495

The conversion is a single division: ounces = grams ÷ 28.3495. That is the formula to memorize, and it is exact to four decimal places — more precision than any kitchen scale or postage meter can use. 100 grams of chocolate is 100 ÷ 28.3495 = 3.527 oz, usually stated as 3.5 oz. A 500-gram package is 500 ÷ 28.3495 = 17.64 oz, just over a pound. A 28-gram serving — the standard US nutrition-label serving size — is 28 ÷ 28.3495 = 0.99 oz, which is why labels call it 'about 1 oz'. The formula works for any weight, from milligrams of medicine to kilograms of freight. One multiplication-free division, every time. And because 28.3495 is a defined constant (more on that below), the answer is the same on every calculator on Earth — this conversion has no 'close enough' versions.

Why 28.3495: the avoirdupois ounce, defined

The number is not measured; it is derived. The international pound is defined as exactly 0.45359237 kilograms — a legal definition, like the 2.54 cm inch. The avoirdupois ounce is exactly one-sixteenth of that pound: 0.45359237 ÷ 16 = 0.028349523125 kg, which is 28.349523125 grams. Round to four decimals and you get 28.3495. That is the whole story — the factor cannot be 'updated' by better measurements because it is fixed by definition. Two traps to avoid. First, 'ounce' here always means the avoirdupois ounce (16 per pound), used for food, body weight, and goods. The troy ounce (31.1035 grams) belongs to precious metals — if you are weighing gold or silver, you need a different number entirely. Second, this is a weight ounce, not a fluid ounce — a distinction that ruins recipes, covered in its own section below.

Worked examples: recipes, postage, and jewelry

Recipes: a European recipe calls for 250 g flour — 250 ÷ 28.3495 = 8.82 oz, just over half a pound. 200 g of butter is 200 ÷ 28.3495 = 7.05 oz, about two sticks plus a tablespoon. 30 g of cocoa is 30 ÷ 28.3495 = 1.06 oz. Postage and shipping: USPS First-Class letter rates step at ounce boundaries, and the 3.5 oz limit for the letter rate is 3.5 × 28.3495 = 99.2 g. A 13-ounce First-Class package ceiling is 13 × 28.3495 = 368.5 g. Jewelry and small goods: a 5-gram gold pendant is 5 ÷ 28.3495 = 0.18 avoirdupois oz — but jewelers quote troy ounces, where it is 5 ÷ 31.1035 = 0.16 troy oz; use the wrong ounce and your valuation is off by 10%. In every case the pattern is the same: divide, then round to match your measuring device. A kitchen scale reading whole grams cannot justify an answer to two decimal places.

The reverse formula: ounces to grams

Going the other way, grams = ounces × 28.3495. A 16-ounce (one-pound) bag of coffee is 16 × 28.3495 = 453.6 g. An 8-ounce steak is 8 × 28.3495 = 226.8 g. A 12-ounce soda can's contents by weight would be 340 g — but note that cans are labeled in fluid ounces, which is a volume measure and a different conversion (see the trap section). The reverse formula round-trips perfectly: convert 100 g to 3.5274 oz, multiply back by 28.3495, and you land on 100 g exactly, because you are multiplying and dividing by the same defined constant. The only error ever introduced is rounding you do in the middle — so keep full precision through multi-step chains and round only the final answer. Converting ounce values often? Our free unit converter handles both directions in one tap.

Grams to ounces conversion chart

Memorize the anchors and you will rarely need a calculator. 1 g = 0.035 oz (a paperclip weighs about a gram). 10 g = 0.35 oz. 28.35 g = 1 oz — the single most useful anchor; 28 g is the standard serving size for a reason. 50 g = 1.76 oz. 100 g = 3.53 oz (a small chocolate bar). 250 g = 8.82 oz (half a pound is 226.8 g, so 250 g is 'half a pound plus a bit'). 500 g = 17.64 oz (just over a pound). 1,000 g = 35.27 oz (2.2 lb). Going the other way: 1 oz = 28.35 g, 4 oz = 113.4 g (a stick of butter is 113 g), 8 oz = 226.8 g, 16 oz = 453.6 g (one pound). Print the 28.35 anchor on a sticky note inside a kitchen cabinet and 90% of recipe conversions become one mental division — or skip the math and use the converter.

Weight ounces vs fluid ounces: the trap that ruins recipes

Here is the mistake that sinks conversions: an ounce of weight and a fluid ounce are different units. The weight ounce (28.3495 g) measures mass. The fluid ounce (29.5735 ml) measures volume. They share a name and nothing else. Water is the lucky exception: 1 fluid ounce of water weighs almost exactly 1 ounce, because water's density is 1 g/ml. Everything else diverges. 8 fluid ounces of honey weighs about 12 ounces (honey is dense); 8 fluid ounces of flour weighs about 4.3 ounces (flour is fluffy). So when a recipe says '8 oz of flour', it usually means weight — 226.8 g. When it says '8 fl oz of milk', it means volume — 236.6 ml. Our guide on converting milliliters to ounces covers the fluid side in full, and our fluid ounces to liters converter handles volume conversions instantly. The rule: solids convert with 28.3495; liquids convert with 29.5735 — and never mix them.

How many ounces in a gram — and when the answer matters

One gram is 0.03527 ounces — roughly three-hundredths of an ounce. The number is tiny, which is exactly why it matters in the domains that weigh in grams: medication dosing (a 500 mg tablet is 0.018 oz — nobody doses medicine in ounces, which is the point), postage (a 5-gram overage on a letter can tip it into the next ounce bracket and double the postage), jewelry (a gram of gold is worth real money, and the avoirdupois-vs-troy distinction changes the price), and nutrition labels (that '28 g = about 1 oz' serving is the number Americans actually read). For these small quantities, the common shortcut '30 grams ≈ 1 ounce' is dangerous — it is off by nearly 6%, enough to misdose, misprice, or mislabel. Use the full 28.3495 for anything under 100 grams; the arithmetic is no harder and the answer is honest.

Quick estimates and spreadsheet conversions

For rough kitchen work, the ÷30 shortcut (30 g ≈ 1 oz) is fine — it errs by about 6% on the high side, invisible in a stew. For baking, where ratios matter, use 28.35. In Excel or Google Sheets, put grams in column A and use =A1/28.3495 in B1, filled down; the reverse is =A1*28.3495. The native =CONVERT(A1,"g","ozm") also works ("ozm" is the avoirdupois ounce code — do not use "oz", which means fluid ounce in CONVERT's vocabulary, a perfect illustration of the trap above). Format results to one decimal for kitchen use. And when the conversion is volume rather than weight — liters of stock, gallons of paint — our liters to gallons converter is the right tool. Everything lives on the ToolNest homepage: 130+ free converters, one tap each. Related guides: milliliters to ounces and kilograms to pounds.