How to Convert Ounces to Grams

The Ounces to Grams Formula

One avoirdupois ounce (the standard ounce used in everyday life in the United States and United Kingdom) equals approximately 28.3495 grams. The precise value is 28.349523125 grams. The formula is:

grams = ounces × 28.3495

This conversion factor comes from the definition of the pound (1 lb = 453.59237 g exactly) divided by 16 ounces per pound. The avoirdupois ounce is different from the troy ounce (31.1035 g), which is used for precious metals, and from fluid ounces, which measure volume, not weight.

Step-by-Step Examples

Example 1: Converting 4 Ounces to Grams

• Step 1: Take the value in ounces: 4 oz.
• Step 2: Multiply by 28.3495: 4 × 28.3495 = 113.398.
• Result: 4 ounces equals approximately 113.4 grams.

Example 2: Converting 8 Ounces (Half a Pound) to Grams

• Step 1: Take the value: 8 oz.
• Step 2: Multiply: 8 × 28.3495 = 226.796.
• Result: 8 ounces equals approximately 226.8 grams.

Example 3: Converting 16 Ounces (1 Pound) to Grams

• Step 1: Take the value: 16 oz.
• Step 2: Multiply: 16 × 28.3495 = 453.592.
• Result: 16 ounces equals approximately 453.6 grams.

For instant results, use our weight converter.

Quick Reference Table

The Reverse Formula: Grams to Ounces

To convert grams to ounces, divide by 28.3495 or multiply by 0.03527:

ounces = grams × 0.03527

For example, 500 grams × 0.03527 = 17.64 ounces. Our weight converter handles both directions.

Quick Mental Math Trick

For a quick kitchen estimate, multiply ounces by 28 (or by 30 for even faster math and accept a ~6% overestimate). So 5 oz × 28 = 140 g (actual: 141.75 g). This is accurate enough for most cooking purposes. Alternatively, remember that 1 oz is approximately 28 g and scale from there.

Real-World Applications

Cooking and Baking

Precision matters in baking. European recipes list ingredients in grams, while American recipes use ounces and cups. A recipe calling for 200 grams of flour needs 7.05 ounces. When a US recipe asks for 6 ounces of chocolate chips, that is 170 grams. Using a kitchen scale set to grams provides the most accurate results for any recipe.

Shipping and Postage

International shipping carriers require weights in grams or kilograms. A letter weighing 2 ounces is 56.7 grams. USPS first-class mail limits are defined in ounces domestically but international services may quote limits in grams, making conversion essential for accurate postage.

Jewelry and Precious Metals

Precious metals use the troy ounce (31.1035 g), not the avoirdupois ounce. If gold is priced at a certain amount per troy ounce, you need the troy conversion for accurate cost calculations. A 14-karat gold necklace weighing 20 grams equals 0.643 troy ounces.

Nutrition Labels

US food labels list serving sizes in both grams and ounces. A 28-gram serving of chips is approximately 1 ounce. Understanding this conversion helps when tracking portion sizes across products from different countries.

Frequently Asked Questions

How many grams are in 1 ounce?

There are approximately 28.3495 grams in one avoirdupois ounce. For troy ounces (precious metals), the value is 31.1035 grams.

What is the difference between an avoirdupois ounce and a troy ounce?

The avoirdupois ounce (28.3495 g) is the standard ounce for everyday use. The troy ounce (31.1035 g) is about 10% heavier and is used exclusively for precious metals like gold, silver, and platinum.

How do I convert ounces to grams for a recipe?

Multiply the ounces by 28.3495 to get grams. For a quick estimate, multiply by 28. For example, 4 oz of butter equals about 113.4 grams.

Quick Reference Section

• Ounces to Grams: grams = oz × 28.3495
• Grams to Ounces: oz = grams × 0.03527
• Mental shortcut: Multiply ounces by 28 for a fast estimate
• Key anchor: 1 oz = 28.35 g, 16 oz = 1 lb = 453.59 g

For precise conversions, use our free weight converter.