Ounces to Grams Converter

To convert ounces to grams, multiply by 28.349523125. 1 oz is 28.35 g, 1½ oz is 42.52 g, 4 oz is 113.4 g and 8 oz is 226.8 g. To go from grams to ounces, divide by the same number: 100 g is 3.527 oz. The factor is exact, because the ounce is defined as 1/16 of a pound and the pound as 453.59237 g.

Use this converter for recipes, postage, food labels, coffee doses or anything else weighed in ounces. Type whole numbers, decimals or fractions such as 3/4 or 1 1/2. The result also shows pounds and ounces, kilograms and troy ounces, and the 28 g rounding used on US nutrition labels so you can see why a label and your scale disagree.

How to use the oz to grams converter

1. Choose the direction: ounces to grams, grams to ounces, or the troy-ounce versions for gold and silver.
2. Type the amount. Fractions work: 1/2, 3/4, 1 1/2 or 1½.
3. Read the headline answer and the other units below it.
4. If your amount is in fluid ounces (a liquid measured by volume), stop: that's a different unit. Use mL to oz instead.
5. Copy the link to keep or share the result.

Ounces to grams formula

NIST Handbook 44, Appendix C defines the avoirdupois ounce as 1/16 of a pound, and the pound as 453.592 37 grams, which gives 1 oz = 28.349 523 125 g exactly. The UK Weights and Measures Act 1985 uses the same pound and ounce.

• grams = ounces × 28.349523125
• ounces = grams ÷ 28.349523125 (or grams × 0.03527396)
• grams = troy ounces × 31.1034768

For mental math, 28 g per ounce is within 1.3%, and "30 g" is within 6%. Use the full factor for anything you scale up: on 64 oz the 28 g shortcut is 22 g short.

1 oz to grams

1 ounce = 28.349523125 grams, which most people round to 28.35 g. A US nutrition label rounds 1 oz to 28 g, as 21 CFR 101.9 allows, so a label that says "1 oz (28 g)" is using the rounded figure.

1 1/2 oz to grams

1½ oz = 42.52 g. Work it as 1.5 × 28.349523125. If you are converting a cocktail recipe's "1½ oz", that is almost certainly fluid ounces of liquid, not weight: 1½ US fl oz is 44.36 mL. See mL to oz.

4 oz and 8 oz to grams

4 oz = 113.4 g (a quarter pound) and 8 oz = 226.8 g (half a pound). A stick of butter marked 4 oz is therefore about 113 g, and an 8 oz block of cheese about 227 g.

16 oz (1 lb) to grams

16 oz = 453.59237 g, exactly one pound. For larger weights, the kg to lbs converter handles pounds and kilograms directly.

100 grams to oz

100 g = 3.5274 oz, about 3½ ounces. 250 g is 8.818 oz and 500 g is 17.637 oz, a little over a pound (1 lb 1.64 oz).

Ounces to grams chart: 1 to 64 oz

Fractions of an ounce in grams

Grams to ounces chart: 1 to 1,000 g

Worked examples

A US recipe calls for 6 oz of chocolate

6 × 28.349523125 = 170.1 g. A 200 g bar covers it with 29.9 g to spare.

A European pack weighs 250 g

250 ÷ 28.349523125 = 8.818 oz. A US recipe asking for 8 oz needs 226.8 g, so the pack is 23.2 g more than enough.

A 1 oz silver coin

Bullion is weighed in troy ounces. The U.S. Mint lists its silver American Eagle at 1.000 troy oz (31.103 g). That is 31.1035 g, or 1.097 ordinary ounces, so a kitchen scale set to oz will read about 1.1 oz.

Converting a whole recipe to grams

Convert each ingredient from its exact ounce value, then round only at the end, to whatever your scale shows (usually 1 g). A bread recipe with 16 oz flour, 11 oz water and ⅓ oz salt becomes 454 g, 312 g and 9.4 g. If you round each ounce to 28 g first, the flour comes out 6 g light, enough to change the dough. Water in a recipe written by weight is weight ounces, so it converts with 28.35 too; if the recipe says "fl oz" or uses a measuring jug, it is volume and belongs in cups to mL.

Going the other way, a metric recipe in grams converts to ounces by dividing by 28.35. If your scale reads in ounces to one decimal, 250 g is 8.8 oz. For small amounts such as yeast or spices, grams give finer steps than ounces: 7 g of yeast is 0.25 oz, and a scale that rounds to 0.1 oz would show 0.2 oz, an error of up to 1.4 g.

Ounces, fluid ounces and troy ounces

Three different units share the word "ounce":

• Ounce (oz), avoirdupois: weight, 28.349523125 g. This is the everyday ounce on food, mail and body-weight scales. NIST notes that "ounce" with no qualifier means the avoirdupois ounce.
• Troy ounce (oz t): weight, 31.1034768 g, 480 grains. Used for precious-metal bullion; the U.S. Mint states its bullion coins' content in troy ounces.
• Fluid ounce (fl oz): volume, 29.5735 mL in the US and 28.4131 mL in the UK. It measures how much space a liquid takes, not how heavy it is.

To change fluid ounces into grams you need the liquid's density. For water, one US fluid ounce weighs about 29.55 g; honey or syrup weighs more, oil less. The weight per gallon calculator lists densities, and the mL to oz converter has a liquid-weight option.

Common mistakes

• Converting fluid ounces with 28.35. If the recipe is measuring a liquid in a jug, it means fluid ounces. Convert to mL instead.
• Using 30 g per ounce. It's 6% high. On a 16 oz (1 lb) amount, that's 26 g too much.
• Weighing gold with a kitchen ounce. A troy ounce is 2.754 g heavier than an ordinary ounce.
• Reading 1.5 lb as 1 lb 5 oz. 1.5 lb is 1 lb 8 oz (680.39 g). Pounds use 16 ounces, not 10.

Related converters

For body weight or larger items, use kg to lbs or stone to lbs. For recipes measured by volume, see cups to mL and grams to cups.

Frequently asked questions

Sources & method

• NIST Handbook 44 (2026), Appendix C: 1 ounce (avoirdupois) = 1/16 lb = 28.349 523 125 g; 1 lb = 453.592 37 g; 1 troy ounce = 480 grains = 31.103 476 8 g
• NIST SP 811, Appendix B.8: ounce (avoirdupois) = 28.349 52 g; ounce (troy or apothecary) = 31.103 48 g
• UK Weights and Measures Act 1985, Schedule 1: pound = 0.453 592 37 kg; ounce = 1/16 pound; ounce troy = 0.031 103 476 8 kg
• 21 CFR 101.9(b)(5)(viii): for nutrition labeling, 1 oz in weight means 28 g and 1 fl oz means 30 mL
• U.S. Mint: Bullion coin programs (American Eagle silver: 1.000 troy oz, 31.103 g)

Results are estimates for general information. Found an error? It helps everyone — see our methodology.