Ounces to Grams Converter
Convert ounces to grams instantly. Type any oz value and get the exact gram equivalent. Includes a common weights table, formula, and food and cooking examples.
Built and maintained by Will Henschell, Data Scientist. Editorial policy.
Grams (g)
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Common Ounces to Grams Conversions
| ounces (oz) | grams (g) | Note |
|---|---|---|
| 0.5 oz | 14.175 g | ½ oz |
| 1 oz | 28.35 g | 1 oz |
| 2 oz | 56.7 g | 2 oz |
| 3.527 oz | 99.99 g | ≈ 100 g |
| 4 oz | 113.4 g | ¼ lb |
| 8 oz | 226.8 g | ½ lb |
| 12 oz | 340.19 g | ¾ lb |
| 16 oz | 453.59 g | 1 lb |
The Ounces-to-Grams Formula
1 avoirdupois ounce is defined as exactly 28.349523125 grams (= 1/16 pound, and 1 lb = 0.45359237 kg). To convert ounces to grams, multiply by 28.3495. For a quick mental estimate, multiply by 28 — accurate within 0.2%. Key benchmarks: 1 oz ≈ 28.35 g; 4 oz = 113.4 g; 8 oz (½ lb) = 226.8 g; 16 oz (1 lb) = 453.6 g. Note: a troy ounce (used for precious metals) = 31.1035 g — about 9.7% heavier. This converter uses the avoirdupois ounce used for food and everyday weight.
Ounces in Food and Cooking
US recipes and product labels specify weight in ounces and pounds. A standard can of tuna is 5 oz (142 g). A chicken breast is typically 4–8 oz (113–227 g). A stick of butter is 4 oz (113 g). Nutrition labels list serving sizes in both ounces and grams: a 1.5 oz serving of cheese = 42.5 g. International recipes, particularly European ones, list ingredients by grams. When baking, precision matters: even a ½ oz difference in flour can affect results — a kitchen scale in grams is more accurate than US volume measurements.
Troy Ounces vs. Avoirdupois Ounces
Two different 'ounces' exist in common use. The avoirdupois ounce (used for food, body weight, postal scales) = 28.3495 g. The troy ounce (used for precious metals: gold, silver, platinum) = 31.1035 g — about 9.7% heavier. A gold price quoted per troy ounce involves a heavier unit than a food ounce. This matters when buying or selling bullion: a 1 troy oz gold bar weighs 31.1 g, not 28.3 g. All grocery, cooking, and body-weight ounces are avoirdupois.
Frequently Asked Questions
How many grams is 1 ounce?
1 avoirdupois ounce equals exactly 28.349523125 grams, commonly rounded to 28.35 g. Note: 1 troy ounce (precious metals) = 31.1035 g.
How do I convert ounces to grams?
Multiply ounces by 28.3495. For a quick estimate, multiply by 28. Example: 4 oz × 28.3495 = 113.4 g.
What is 8 ounces in grams?
8 oz × 28.3495 = 226.8 grams. 8 ounces is also ½ pound — a common portion size for meat and produce.
What is the difference between a troy ounce and a regular ounce?
A troy ounce = 31.1035 g; an avoirdupois ounce = 28.3495 g. Troy ounces are used for precious metals only. All food and everyday weight uses avoirdupois ounces.