Convert Ounce to Gram
Convert ounces to grams instantly. 1 ounce = 28.3495231 gram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Gram to Ounce converter for the reverse conversion.
Units explained
Ounce
The (avoirdupois) ounce (oz) equals one-sixteenth of a pound, about 28.35 grams.
From Latin 'uncia', meaning a twelfth part.
US food portions, postal weights, and boxing weight classes.
Standardized as 1/16 of the international pound from 1959.
Gram
The gram (g) equals one-thousandth of a kilogram.
From Late Latin 'gramma', a small weight or scruple.
The everyday metric unit for food, medicine, and small objects.
Defined in 1795 as the mass of one cubic centimeter of water at melting point.
Ounce to Gram conversion formula
The relationship between ounces and grams:
To convert ounces to grams, multiply the value in ounces by 28.3495231. To reverse, multiply grams by 0.035273962.
How to use this converter
Type a value into the calculator. The result in grams updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Gram to Ounce converter for the reverse direction.
Step-by-step: convert ounces to grams
- Write down the value in ounces (oz).
- Multiply that value by the factor 28.3495231.
- The product is the equivalent value in grams (g).
- To reverse, multiply the gram value by 0.035273962.
Worked examples
Example 1 — Convert 1 oz to g:
1 × 28.3495231 = 28.3495231 g
Example 2 — Convert 100 oz to g:
100 × 28.3495231 = 2834.95231 g
Real-world example — Postcard and small-object dimensions
A postcard is about 5 ounces wide. Converting to grams is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 oz × 28.3495231 = 141.7476155 g
Real-world example — Ruler-scale measurements
A 30-ounce school ruler converts cleanly to grams — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 oz × 28.3495231 = 850.485693 g
Real-world example — Hardware-scale dimensions
A 10-ounce fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between ounces and grams daily when mixing metric and imperial tools.
10 oz × 28.3495231 = 283.495231 g
Ounce to Gram conversion table
Standard reference values for converting ounces to grams:
| Ounce [oz] | Gram [g] |
|---|---|
| 0.01 | 0.283495231 |
| 0.1 | 2.83495231 |
| 1 | 28.3495231 |
| 2 | 56.6990462 |
| 3 | 85.0485693 |
| 4 | 113.3980924 |
| 5 | 141.7476155 |
| 10 | 283.495231 |
| 20 | 566.990462 |
| 30 | 850.485693 |
| 40 | 1133.980924 |
| 50 | 1417.476155 |
| 100 | 2834.95231 |
| 500 | 14174.76155 |
| 1000 | 28349.5231 |
Frequently asked questions
How many grams is 1 ounce?
How do I convert ounces to grams?
How do I convert grams back to ounces?
How many grams is 100 ounces?
Popular weight unit conversions
Convert Ounce to other weight units
Show all Ounce conversions
Metric / SI (18 units)
Avoirdupois (14 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 oz = 28.3495231 g) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.