Convert Grams (g) to Ounces (oz)

What Is a Gram?

The gram (g) is a metric unit of mass equal to one thousandth of a kilogram. It is widely used for measuring small quantities — food labeling, chemistry, laboratory work, and cooking. Although not an SI base unit, it is fully compatible with the SI system.

What Is an Ounce?

The ounce (oz) is a unit of mass equal to one sixteenth of a pound in the avoirdupois system. It is defined exactly as 28.349523125 grams. The ounce is used in the US and UK for food portions, postal items, and small packages. (Note: this is the avoirdupois ounce, not the troy ounce used for precious metals.)

Grams to Ounces Formula

The conversion factor is exact:

ounces = grams × 0.03527396195 exact

Or equivalently: ounces = grams ÷ 28.349523125. This comes from the definition of the avoirdupois ounce.

Worked Example

Convert 250 g (a common baking quantity) to ounces:

1. Divide: 250 ÷ 28.35 = 8.82 oz

Quick Estimation

For mental math, divide grams by 28 (within 1.2% accuracy). Common baking conversions: 100 g ≈ 3.5 oz, 250 g ≈ 8.8 oz, 500 g ≈ 17.6 oz.

Common Use Cases

• Cooking and baking: European recipes use grams; US recipes use ounces. A kitchen scale showing both eliminates conversion errors.
• Food packaging: US nutrition labels show ounces; most countries use grams. A "6 oz" yoghurt = 170 g.
• Postal services: USPS charges by the ounce. A 50 g letter ≈ 1.76 oz.
• Precious metals: Gold uses troy ounces (31.1 g), not avoirdupois ounces (28.35 g). This converter uses avoirdupois.