Ounce to Gram Converter

Convert ounces to grams and grams to ounces instantly. Free, accurate, and works entirely in your browser.

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Ounces (oz)Grams (g)

What is the Ounce to Gram Converter?

This tool converts between ounces (oz) and grams (g) — two of the most commonly used weight units in cooking, fitness, shipping, and science. The ounce is part of the US customary and imperial systems, while the gram is the metric standard used by virtually every country in the world. Whether you are scaling a recipe, tracking your daily protein intake, or calculating postage costs, this converter makes switching between the two systems effortless.

The avoirdupois ounce — the type used in this converter — is defined as exactly 28.349523125 grams according to international agreement. This standard was formalized in 1959 when English-speaking nations unified their definitions.

How to Use This Converter

  1. Enter a value: Type the weight you want to convert in the "From" field. Start with 1 to see how many grams are in an ounce.
  2. Select direction: Choose oz or g as your starting unit and the unit you want to convert to.
  3. Read the result: The converted value appears instantly. Use the ⇅ button to swap units at any time.

You can click any preset button for common values like 1 oz, 4 oz, 8 oz, or 16 oz. Adjust precision from 2 to 8 decimal places, and use the reference table for quick lookups of frequently converted values.

The Conversion Formula

The math is simple. Since 1 ounce = 28.349523125 grams:

For practical purposes, most people round to 1 oz = 28.35 g. This converter uses the full standard value internally but displays results rounded to your chosen precision.

Real-World Applications

Cooking and Baking

Recipes from different countries use different units. A US recipe might call for 8 oz of flour, while a European recipe specifies 225 g. These are nearly identical (8 oz = 226.8 g), but small differences matter in baking where precision affects texture and rise. Common conversions include 1 cup of butter (8 oz = 227 g) and 1 cup of sugar (7 oz = 198 g).

Fitness and Nutrition

Food labels in the US list serving sizes in both ounces and grams, but tracking apps typically use grams. If your protein powder recommends a 2 oz scoop, that is 56.7 g. Macro tracking — where every gram of protein, carbs, and fat counts — requires accurate conversion between the two systems.

Shipping and Postage

Postal rates around the world are calculated by weight, but different carriers use different units. USPS uses ounces for domestic mail but grams for international parcels. A package weighing 16 oz (1 lb) is 453.6 g. Accurate conversion prevents overpaying for postage or having packages returned for insufficient postage.

Science and Pharmacy

Laboratory measurements and pharmaceutical dosages demand high precision. While most scientific work uses the metric system, older equipment and US-manufactured supplies may be calibrated in ounces. Converting accurately is essential for reproducible results and safe medication dosing.

Why This Conversion Matters

The ounce-gram relationship is one of the most commonly needed weight conversions because it bridges the US customary system and the metric system. While the metric system is the global standard for science, medicine, and most of the world's population, the US continues to use ounces for everyday measurements like food, mail, and body weight. This dual-system reality means that anyone working across borders — whether shipping products, publishing recipes, or collaborating on research — needs a reliable way to convert between the two.

The avoirdupois system, from which the ounce comes, dates back to medieval England. The pound (16 oz) has been defined in relation to the kilogram since 1959, creating an unbroken chain of traceability from your measurement to the international prototype.

Frequently Asked Questions

How do I convert ounces to grams?

Multiply the ounce value by 28.3495. For example, 4 oz × 28.3495 = 113.4 g.

How many grams in 1 ounce?

There are exactly 28.349523125 grams in 1 avoirdupois ounce.

What is 8 oz in grams?

8 ounces equals 226.8 grams. This is half a pound in the imperial system.

How do I convert grams to ounces?

Divide the gram value by 28.3495. For example, 100 g ÷ 28.3495 = 3.527 oz.

Is this converter accurate?

Yes, it uses the exact international avoirdupois standard of 1 oz = 28.349523125 g, with adjustable decimal precision.

Is this a fluid ounce or a weight ounce?

This converter uses the avoirdupois ounce, which measures weight/mass. Fluid ounces measure volume and are a completely different unit.

Is my data safe when using this converter?

Yes. All calculations happen locally in your browser. No data is sent to any server or stored anywhere.

Do I need to create an account?

No. The tool is completely free with no signup, no registration, and no limits. Just open the page and start converting.

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