How to Convert Ounces to Grams

Ounces and grams are both units of mass used in everyday life, but they belong to different measurement systems. Ounces are part of the imperial system, while grams are part of the metric system. Converting between them accurately is essential in cooking, shipping, jewelry, and science.

The exact conversion factor is 1 ounce = 28.3495 grams. For most practical purposes, rounding to 28.35 g/oz gives you accuracy within a fraction of a percent.

The Conversion Formula

Grams = Ounces Γ— 28.3495

To go the other direction:

Ounces = Grams Γ· 28.3495

Step-by-Step Example

You have 5.5 ounces of flour and need the gram equivalent for a metric recipe.

  1. Start with the ounce value: 5.5 oz
  2. Multiply by the conversion factor: 5.5 Γ— 28.3495
  3. Result: 155.92 grams

Common Ounce to Gram Conversions

OuncesGrams (approx)
0.5 oz14.17 g
1 oz28.35 g
2 oz56.70 g
4 oz113.40 g
8 oz226.80 g
16 oz453.59 g

Why the Difference Between Fluid Ounces and Weight Ounces Matters

A common mistake is confusing fluid ounces (a volume measure) with weight ounces (a mass measure). The conversion above applies only to weight ounces. Fluid ounces depend on the density of the substance being measured, so 1 fl oz of water weighs approximately 29.57 grams, while 1 fl oz of honey weighs more.

Practical Tips

  • In baking, always use weight measurements for precisionβ€”grams are far more accurate than cups or volume measures.
  • A standard kitchen postal scale accurate to 1 g is ideal for recipe conversions.
  • Precious metals like gold are typically measured in troy ounces (1 troy oz = 31.10 grams), which differ from the standard avoirdupois ounce.

Use our oz-to-grams converter to get instant results for any value.