How Many Grams in an Ounce? (Weight Conversion Chart)

Quick Answer: 1 Ounce = 28.3495 Grams

One avoirdupois ounce — the standard ounce used in the United States and United Kingdom for everyday measurements — equals exactly 28.349523125 grams. For most practical purposes, rounding to 28.35 grams per ounce is perfectly accurate. This conversion applies to food, body weight, postal measurements, and any general weight measurement that uses ounces.

The important exception is precious metals, which use the troy ounce. One troy ounce equals 31.1035 grams — about 10 percent heavier than a standard ounce. We will cover the troy ounce in detail later in this article.

Complete Ounce to Gram Conversion Table (1 to 16 oz)

The following table provides precise conversions for every ounce from 1 to 16 (one full pound), along with fractional ounce conversions that are commonly needed in cooking and baking:

For conversions beyond this table, simply multiply the number of ounces by 28.3495. For example, 24 ounces equals 24 times 28.3495, which is 680.4 grams. Use our unit converter for instant conversions between any weight units.

Troy Ounce vs. Avoirdupois Ounce

One of the most common sources of confusion in weight measurement is the existence of two different types of ounces. Understanding when each applies is crucial for accurate conversions.

The Avoirdupois Ounce (Standard Ounce)

The avoirdupois system is the standard weight measurement system used in the United States and for most purposes in the United Kingdom. The word "avoirdupois" comes from the Old French "aveir de peis," meaning "goods of weight." In this system:

• 1 ounce = 28.3495 grams
• 16 ounces = 1 pound
• 1 pound = 453.592 grams
• 2,000 pounds = 1 short ton

This is the ounce you encounter in grocery stores, on nutrition labels, at the post office, and in everyday life. When someone says "ounce" without any qualifier, they almost always mean the avoirdupois ounce.

The Troy Ounce (Precious Metals)

The troy ounce is used exclusively for measuring precious metals — gold, silver, platinum, and palladium. The troy system is named after Troyes, France, a medieval trading center where this measurement standard was widely used. In the troy system:

• 1 troy ounce = 31.1035 grams
• 12 troy ounces = 1 troy pound
• 1 troy pound = 373.242 grams

Note that a troy pound has only 12 ounces (not 16), and each troy ounce is heavier than a regular ounce. This means a troy pound (373.2 g) is actually lighter than a regular pound (453.6 g), even though each individual troy ounce is heavier. This can be confusing, which is why precious metals are almost always quoted in troy ounces, never troy pounds.

Side-by-Side Comparison

When you see gold priced at "1,900 per ounce," that refers to a troy ounce (31.1 grams), not a standard ounce (28.3 grams). This distinction matters — confusing the two would mean a 9.7 percent error in your calculations.

Ounces to Grams in Cooking and Baking

Cooking and baking are the most common everyday contexts where ounce-to-gram conversions are needed. This is especially true when following recipes from different countries, since most of the world uses the metric system.

Why Grams Are Better for Baking

Professional bakers overwhelmingly prefer measuring ingredients by weight in grams rather than by volume in cups. The reason is precision: a cup of flour can weigh anywhere from 120 to 160 grams depending on how it is scooped, whether it is sifted, humidity, and the type of flour. By contrast, 150 grams of flour is always 150 grams of flour, regardless of how you scoop it into the bowl. For delicate baked goods where ingredient ratios are critical — such as macarons, souffles, and pastry — weighing in grams is the difference between success and failure.

Common Dry Ingredient Conversions

The following table shows ounce and gram equivalents for common baking ingredients. Note that these conversions are by weight, not volume. Since different ingredients have different densities, one cup of each ingredient weighs a different amount:

For quick and accurate conversions while cooking, use our cooking measurement converter or our weight converter tool.

Precious Metals: Grams and Troy Ounces

For investors, jewelers, and anyone buying or selling precious metals, understanding the relationship between grams and troy ounces is essential. The following table shows current approximate values (as of early 2026) to illustrate why precision matters:

As the table illustrates, confusing a troy ounce with an avoirdupois ounce when buying gold would mean overpaying by approximately 9.7 percent per unit. On a single troy ounce of gold at 2,900, that error would cost roughly 259. For large purchases or institutional trades, the financial impact of using the wrong ounce type can be enormous.

Gold Weight Units Around the World

While troy ounces are the international standard for gold trading, different cultures and markets use various weight units for gold:

• Tola: Used in India and South Asia, 1 tola = 11.664 grams
• Baht: Used in Thailand, 1 baht = 15.244 grams
• Tael (Liang): Used in China and East Asia, 1 tael = 37.429 grams (varies by region)
• Mithqal: Used in parts of the Middle East, 1 mithqal = 4.608 grams
• Mesghal: Used in Iran, 1 mesghal = 4.608 grams

Gram to Ounce Conversion Table

For conversions going the other direction — grams to ounces — here is a useful reference table. To convert grams to ounces, divide by 28.3495:

Fluid Ounces vs. Weight Ounces: A Critical Distinction

One of the most common measurement mistakes is confusing fluid ounces (a unit of volume) with ounces (a unit of weight). These are completely different measurements that happen to share a name.

• Ounce (oz): A unit of weight equal to 28.3495 grams. Measures how heavy something is.
• Fluid ounce (fl oz): A unit of volume equal to approximately 29.574 milliliters (US) or 28.413 milliliters (Imperial). Measures how much space a liquid occupies.

For water, 1 fluid ounce weighs very close to 1 ounce (since water's density is approximately 1 g/mL), which is the historical reason the two units share a name. But for other substances, the weight and volume ounces can differ dramatically. For example, 1 fluid ounce of honey weighs about 1.5 ounces because honey is denser than water. And 1 fluid ounce of cooking oil weighs about 0.95 ounces because oil is less dense than water.

In cooking, this distinction matters most with dense liquids (honey, molasses, corn syrup) and light dry ingredients (flour, cocoa powder). When a recipe specifies "ounces," look for context clues — dry ingredients are typically measured by weight, while liquids are measured by volume.

Complete Metric Weight Conversion Table

For comprehensive reference, here is a table converting between all the most commonly used weight units:

Quick Mental Math for Ounce-Gram Conversions

When you need to convert ounces to grams in your head without a calculator, here are some helpful mental math tricks:

• Rough estimate: Multiply ounces by 28. This is accurate to within 1.2 percent and works well for quick kitchen conversions. For example, 6 oz times 28 = 168 grams (actual: 170.1 g).
• More precise: Multiply ounces by 28, then add one-third of the ounce value. For example, 6 oz: 168 + 2 = 170 grams (almost exactly right).
• Quarter-pound reference: Memorize that 4 oz = 113 g and 8 oz = 227 g. Use these as anchor points for nearby values.
• Grams to ounces shortcut: Divide grams by 30 for a quick estimate. For example, 150 g divided by 30 = 5 oz (actual: 5.29 oz). This underestimates slightly but is good enough for most purposes.

Frequently Asked Questions