Ounces to Grams Calculator
Enter weight in ounces
Result updates instantly
Exact Conversion
1 oz = 28.349523125 g
Formula
g = oz × 28.349523125
Common Cooking Conversions
| Ounces | Grams | Common Food Items |
|---|---|---|
| 0.5 oz | 14.17 g | Small spice packet |
| 1 oz | 28.35 g | Chocolate square |
| 2 oz | 56.70 g | Cheese portion |
| 4 oz | 113.40 g | Butter stick (¼ lb) |
| 8 oz | 226.80 g | Standard block cheese |
| 12 oz | 340.19 g | Soda can |
| 16 oz (1 lb) | 453.59 g | Package of pasta |
How This Ounces to Grams Calculator Works
Converting ounces to grams is essential for accurate cooking, baking, and food measurement. This calculator uses the exact international conversion factor to provide precise results instantly. The conversion is based on the international avoirdupois ounce, which is the standard ounce used for weight measurements in the United States and other countries.
Conversion Formula: The calculation follows this exact formula: Grams = Ounces × 28.349523125. This precise conversion factor is defined by international agreement and ensures accuracy for all applications, from cooking to scientific work.
Practical Example: If a recipe calls for 8 ounces of flour and you need to convert to grams: 8 oz × 28.349523125 = 226.796185 grams. The calculator displays this as 226.80 grams, rounded to two decimal places for readability while maintaining full precision internally.
Important Distinction: This calculator converts avoirdupois ounces (used for general weight) to grams. It does not convert troy ounces (used for precious metals) or fluid ounces (used for volume). For troy ounces, use 31.1034768 grams per ounce. For fluid ounces, use our fluid ounces to milliliters calculator.
When You Need to Convert Ounces to Grams
Cooking and Baking Accuracy
Recipes from different countries use different measurement systems. American recipes often list ingredients in ounces, while European, Australian, and Canadian recipes typically use grams. Accurate conversion ensures your baked goods rise properly, your sauces thicken correctly, and your dishes taste as intended.
Nutrition Tracking and Diet Planning
When tracking food intake for health or fitness goals, nutrition labels and databases often use grams for precise measurements. Converting ounces to grams helps you log accurate portion sizes, calculate exact calorie counts, and follow dietary guidelines that specify gram amounts.
Baking Tip: For the most accurate baking results, use a digital kitchen scale that measures in grams. Weight measurements are more precise than volume measurements because they aren’t affected by how ingredients settle or are packed.
Postal and Shipping Calculations
Postal services often charge based on weight brackets. In the US, packages are weighed in ounces and pounds, while international shipping and many other countries use grams and kilograms. Converting between these units helps you calculate correct postage and avoid additional fees.
Scientific and Laboratory Work
In scientific research and laboratory settings, precise measurements are critical. While most scientific work uses the metric system exclusively, some equipment or historical data may use ounces. Accurate conversion ensures experimental reproducibility and data consistency.
Country-Specific Measurement Practices
United States Usage
In the USA, ounces are commonly used for food packaging, cooking measurements, and postal weights. Most American kitchen scales can switch between ounces and grams, but recipes typically specify ounces for smaller quantities and pounds for larger amounts.
United Kingdom Usage
The UK officially uses the metric system, with grams as the standard unit. However, ounces persist in some contexts, particularly in older recipes, traditional markets, and when discussing portion sizes. Modern British recipes generally use grams exclusively.
Canada Usage
Canada uses the metric system officially, but due to proximity and trade with the US, ounces are frequently encountered on product labels, especially for imported goods. Canadian kitchens often need to convert between ounces and grams when using recipes from different sources.
Australia Usage
Australia uses the metric system exclusively for official purposes. Grams are standard for all weight measurements. Australians mainly need to convert ounces to grams when using American recipes or products, or when interpreting historical measurements.
Common Conversion Mistakes to Avoid
Mistake 1: Using 28 grams instead of 28.349523125 – While 28 grams per ounce is a common approximation, it creates a 1.2% error. For 16 ounces (1 pound), this gives 448 grams instead of the correct 453.592 grams – a 5.6 gram difference that matters in baking.
Mistake 2: Confusing fluid ounces with weight ounces – Fluid ounces measure volume, while ounces (avoirdupois) measure weight. They are not interchangeable. 8 fluid ounces of water weighs approximately 8.3 avoirdupois ounces (236.6 ml of water weighs 236.6 grams).
Mistake 3: Forgetting about troy ounces – Precious metals like gold and silver are measured in troy ounces (31.1034768 grams), not avoirdupois ounces (28.349523125 grams). Using the wrong conversion factor for jewelry or precious metals creates significant errors.
Frequently Asked Questions
Is 1 ounce exactly 28 grams?
No, 1 avoirdupois ounce equals exactly 28.349523125 grams. The approximation “28 grams per ounce” is close but not exact. For precise cooking, baking, or scientific work, use the exact conversion factor.
What’s the difference between fluid ounces and weight ounces?
Fluid ounces measure volume (like cups or milliliters), while weight ounces measure mass. They are different units for different purposes. 8 fluid ounces of water does weigh approximately 8.3 weight ounces, but this relationship varies for different substances.
How many ounces are in a pound?
There are 16 avoirdupois ounces in an avoirdupois pound. Therefore, 1 pound = 453.59237 grams. This calculator can be used for pound conversions by first converting pounds to ounces (multiply by 16), then converting ounces to grams.
Why do some recipes use ounces and others use grams?
American recipes typically use ounces and cups, while recipes from metric-using countries (most of Europe, Australia, etc.) use grams and milliliters. Professional chefs often prefer grams because weight measurements are more precise and consistent than volume measurements.
Can I convert directly from pounds to grams?
Yes, but it’s a two-step process: First convert pounds to ounces (multiply by 16), then convert ounces to grams (multiply by 28.349523125). Alternatively, use the direct conversion: 1 pound = 453.59237 grams.
Practical Examples for Different Users
Home Cook Example: An American following a British baking recipe needs to convert 6 ounces of butter to grams. Using this calculator: 6 oz × 28.349523125 = 170.0971875 grams (approximately 170.10 g). They can measure exactly 170 grams on their kitchen scale.
Student Example: A chemistry student needs to prepare 3.5 ounces of a compound for an experiment. The lab scale measures in grams. 3.5 oz × 28.349523125 = 99.2233309375 grams (approximately 99.22 g). They can weigh this precisely for their experiment.
Fitness Example: Someone tracking protein intake eats a 4-ounce chicken breast. To calculate exact protein content from nutrition databases (which use grams), they convert: 4 oz × 28.349523125 = 113.3980925 grams (approximately 113.40 g).
Small Business Example: A maker of handmade soap sells 2-ounce bars but needs to label them for international markets that require metric weights. 2 oz × 28.349523125 = 56.69904625 grams (approximately 56.70 g). They can label accordingly.
Quick Estimation: For mental math, you can approximate: ounces × 28 = grams. For more accuracy: ounces × 28.35 = grams. For baking precision, always use the exact conversion or this calculator.
Essential Cooking Weight Conversions
| Measurement | Ounces | Grams | Common Equivalents |
|---|---|---|---|
| 1 tablespoon flour | 0.25 oz | 7.09 g | ≈ ¼ oz |
| ¼ cup butter | 2 oz | 56.70 g | ½ stick butter |
| ½ cup sugar | 3.5 oz | 99.22 g | Granulated white sugar |
| 1 cup flour | 4.5 oz | 127.57 g | All-purpose flour |
| 1 cup brown sugar | 7.5 oz | 212.62 g | Packed brown sugar |
| 1 large egg | 1.75 oz | 49.61 g | Without shell |
| 1 stick butter | 4 oz | 113.40 g | ½ cup or 8 tablespoons |
| 1 package yeast | 0.25 oz | 7.09 g | Standard packet |
| 1 can tuna | 5 oz | 141.75 g | Drained weight |
| 1 chicken breast | 6-8 oz | 170-227 g | Boneless, skinless |
Understanding Different Ounce Systems
Avoirdupois Ounce
The avoirdupois ounce (abbreviated oz) is the standard ounce used in the United States for most weight measurements. It equals 1/16 of an avoirdupois pound and exactly 28.349523125 grams. This is the ounce used in cooking, postal services, and everyday weight measurements.
Troy Ounce
The troy ounce (abbreviated ozt) is used for precious metals like gold, silver, and platinum. One troy ounce equals exactly 31.1034768 grams. Troy ounces are heavier than avoirdupois ounces and are divided into 20 pennyweights rather than 16 parts.
Fluid Ounce
The fluid ounce (abbreviated fl oz) measures volume, not weight. In the US, 1 fluid ounce equals approximately 29.5735 milliliters. In the UK, 1 imperial fluid ounce equals approximately 28.4131 milliliters. Fluid ounces cannot be directly converted to grams without knowing the substance’s density.
Final Note: This calculator converts avoirdupois ounces (the standard cooking ounce) to grams with exact precision. For precious metals, use troy ounce conversion (1 ozt = 31.1034768 g). For liquids, use fluid ounce to milliliter conversion. All calculations happen instantly in your browser with no data transmitted.