How to Convert Ounces to Grams – 1 Step Conversion

How to Convert Ounces to Grams
To convert ounces to grams simply multiply the number of ounces by 28.35.

See how to convert ounces to grams in one easy step. Or, just look up the ounce to gram conversion in a table.

About Ounces and Grams

Ounces (oz) and grams (g) are two units of mass or weight. You’ll encounter them in cooking, postage, medicine, and in the lab. This type of ounce is the avoirdupois ounce. In contrast, the fluid ounce is a unit of volume, while the troy ounce is a mass unit for precious metals. Meanwhile, the gram is an SI or metric unit of mass.

Ounces to Grams Conversion Formula

The conversion formula or conversion factor is simple:

  • 1 ounce (oz) = 28.349523125 grams (g)
  • Rounded: 1 oz = 28.35 g or 1 oz = 28.3 g or 1 oz = 28 g
  • 1 gram (g) = 0.035274 ounces (oz)

How to Convert Ounces to Grams

All you do to convert ounces to grams is multiply the ounces by 28.35 (or however many significant digits you need).

For example, let’s convert 12 ounces to grams:

grams = 12 ounces x 28.35 grams/ounce = 340.2 or 340 grams

Look Up Ounces to Grams in a Table

Rather than do the math, simply look up common ounces to grams conversions:

OuncesGrams (Rounded)
or 0.125 ounces3.5 grams
¼ or 0.25 ounces7 grams
½ or 0.5 ounces14 grams
1 ounce28 grams
2 ounces57 grams
4 ounces (¼ pound)113 grams
6 ounces170 grams
8 ounces (½ pound)227 grams
16 ounces (1 pound)454 grams
32 ounces (2 pounds)907 grams


  • Barbrow, L.E.; Judson, L. V. (1976). Weights and Measures of the United States. National Bureau of Standards Special Publication 447.
  • Çengel, Yunus A.; Boles, Michael A. (2002). Thermodynamics: An Engineering Approach (8th ed.). McGraw Hill. ISBN 9780073398174.
  • National Institute of Standards and Technology. (2008). Guide for the Use of the International System of Units (SI).
  • Young, Hugh D; Freedman, Roger A. (2012). University Physics (13th ed.). Pearson Education Inc. ISBN 978-0-321-69686-1.