Convert Ounces (oz) to Grams (g)
1 ounce equals 28.3495 grams.
Ounce to Gram Converter
What Is an Ounce?
The ounce (oz) is a unit of mass in the imperial and US customary systems. One ounce equals 1/16 of a pound. It is commonly used for food packaging, postal weight, and small measurements in the US and UK.
What Is a Gram?
The gram (g) is a metric unit of mass equal to 1/1,000 of a kilogram. It is the standard small-mass unit worldwide, used in cooking, science, medicine, and everyday commerce.
Ounces to Grams Formula
The conversion factor is exact:
grams = ounces × 28.349523125 exact
This factor is exact by definition: 1 pound = 0.45359237 kg exactly (1959 International Agreement), and 1 oz = 1/16 lb, so 1 oz = 0.45359237/16 × 1000 = 28.349523125 g.
Worked Example
Convert 8 oz (a typical steak) to grams:
- Multiply: 8 × 28.3495 = 226.8 g
Quick Estimation
Multiply ounces by 28 for a quick approximation. 8 oz × 28 = 224 g (actual: 226.8 g — within 1.2%).
Common Use Cases
- Recipe conversions: US recipes use ounces; metric countries use grams. A recipe calling for 6 oz of chocolate = 170 g.
- Food packaging: US nutrition labels show serving sizes in ounces. Converting to grams helps compare with international products.
- Postal and shipping: Small parcels weighed in ounces (US) must be converted to grams for international shipping labels.
- Precious metals: Note that troy ounces (31.1035 g) differ from avoirdupois ounces (28.3495 g). This converter uses avoirdupois ounces.
Frequently Asked Questions
How many grams are in 1 ounce?
Exactly 28.349523125 grams. For quick estimates, use 28.35 g or simply round to 28 g.
Is a troy ounce the same as a regular ounce?
No. A troy ounce (used for precious metals) equals 31.1035 g, while an avoirdupois ounce (everyday use) equals 28.3495 g. This converter uses the avoirdupois ounce.
How do I convert ounces to grams without a calculator?
Multiply by 28 for a quick estimate (within 1.2%). For better accuracy, multiply by 28 and add 1.2%. Example: 4 oz × 28 = 112 g (exact: 113.4 g).
What common foods weigh about 1 ounce?
A slice of bread (≈ 1 oz / 28 g), a handful of almonds (about 23 nuts), or one standard cheese slice. A AA battery weighs about 0.8 oz (23 g).
Common Ounce to Gram Conversions
Ounces to grams Conversion Table
Reference table with common ounces to grams conversions. All values calculated with high precision.
Ounces to Grams Table
1 to 100000
Grams to Ounces Table
100 to 10000000
Looking for the reverse? Convert Gram to Ounce
Related Weight (Mass) Converters
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Need a combined format?
- Kg to Pounds and Ounces — combined lb + oz format
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- G-force to m/s² — Force = mass × acceleration (F = ma)
