Ounces to Grams Converter
Convert weight between ounces, grams, pounds, and milligrams. Enter values for instant results with step-by-step formulas.
Reviewed by Manoj Kumar, Mathematics Educator
Formula
Grams = Ounces x 28.3495
Where 1 avoirdupois ounce equals exactly 28.349523125 grams, derived from the international pound definition of 0.45359237 kg divided by 16 ounces. For reverse: Ounces = Grams / 28.3495.
Worked Examples
Example 1: Recipe Conversion - Baking Ingredients
Problem:A recipe calls for 8 ounces of flour and 6 ounces of sugar. Convert to grams for a metric kitchen scale.
Solution:Flour: 8 oz x 28.3495 = 226.80 grams\nSugar: 6 oz x 28.3495 = 170.10 grams\nTotal weight: 14 oz = 396.89 grams\nNote: 8 oz = 0.5 pounds (half pound)\n6 oz = 0.375 pounds
Result:8 oz flour = 226.80 g | 6 oz sugar = 170.10 g | Total = 396.89 g
Example 2: Package Shipping Weight
Problem:A package weighs 350 grams. Convert to ounces and determine if it qualifies for First-Class Mail (max 13 oz).
Solution:Ounces = 350 / 28.3495 = 12.35 oz\nPounds = 12.35 / 16 = 0.772 lb\nMilligrams = 350,000 mg\nKilograms = 0.35 kg\n12.35 oz is under 13 oz limit for First-Class Mail
Result:350 g = 12.35 oz = 0.772 lb - qualifies for First-Class Mail
Frequently Asked Questions
What is the exact conversion factor between ounces and grams?
One avoirdupois ounce equals exactly 28.349523125 grams. This precise conversion factor is derived from the international yard and pound agreement of 1959, which defined one pound as exactly 0.45359237 kilograms. Since one pound contains 16 ounces, dividing 453.59237 grams by 16 gives the exact ounce-to-gram ratio. For most practical purposes, rounding to 28.35 grams per ounce introduces less than 0.002 percent error, which is sufficient for cooking, shipping, and everyday measurements. The reverse conversion is 1 gram equals 0.035274 ounces. It is important to distinguish avoirdupois ounces (used for general weight measurement) from troy ounces (used for precious metals) and fluid ounces (a volume measurement).
What is the difference between avoirdupois ounces and troy ounces?
Avoirdupois ounces and troy ounces are two different weight standards that cause frequent confusion. An avoirdupois ounce weighs 28.3495 grams and is the standard ounce used in everyday commerce, cooking, and shipping in the United States and United Kingdom. A troy ounce weighs 31.1035 grams and is used exclusively for measuring precious metals like gold, silver, and platinum. This means a troy ounce is approximately 9.7 percent heavier than a regular ounce. Confusingly, while there are 16 avoirdupois ounces in an avoirdupois pound, there are only 12 troy ounces in a troy pound, making a troy pound actually lighter than an avoirdupois pound. When buying gold or silver, prices are always quoted per troy ounce.
Why do recipes sometimes use ounces and sometimes grams?
Recipe measurements vary by country and culinary tradition. American recipes predominantly use ounces (weight) and cups (volume) because the US customary system remains the standard in home kitchens. European, Australian, and most other countries recipes use grams and milliliters because they adopted the metric system for cooking. Professional bakers and pastry chefs worldwide prefer weighing ingredients in grams regardless of country because weight measurements are far more precise and consistent than volume measurements. A cup of flour can vary from 120 to 160 grams depending on how it is scooped and packed, while 150 grams of flour is always 150 grams. This precision matters enormously in baking where small ratio changes can ruin the texture of bread, cakes, and pastries.
How do I convert recipe measurements from ounces to grams accurately?
For accurate recipe conversions, multiply the ounce value by 28.35 to get grams, then round to the nearest 5 grams for practical kitchen use. A digital kitchen scale that reads in both ounces and grams is the most reliable tool. Common baking conversions worth memorizing include: 1 ounce equals 28 grams, 4 ounces (quarter pound) equals 113 grams, 8 ounces (half pound) equals 227 grams, and 16 ounces (one pound) equals 454 grams. When converting volume measurements like cups to grams, you must know the specific ingredient because different ingredients have different densities. One cup of water weighs 236 grams, one cup of flour weighs about 120 grams, and one cup of sugar weighs about 200 grams. Always use ingredient-specific conversion charts for volume-to-weight conversions.
References
Reviewed by Manoj Kumar, Mathematics Educator · Editorial policy