# How to convert grams to oz?

Converts grams (g) to ounces (oz) and back, with the exact unit definitions.

- Page: https://www.acalculator.org/convert/grams-to-oz
- JSON spec: https://www.acalculator.org/convert/grams-to-oz.json
- Version: 6d79a8e9390b

## Default answer

Example with the default inputs (Grams (g) 1): 1 g = 0.035274 oz.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| value | Grams (g) | The amount in grams to convert. |
| result | Ounces (oz) | The same amount in ounces. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Grams (g) | The amount in grams to convert. |
| result | Ounces (oz) | The amount in ounces. |

## Method

oz = g × 0.0352739619496 (the same as g ÷ 28.349523125)

## Assumptions

- 1 gram = 0.0352739619496 ounces, from the exact definitions in NIST SP 811.
- Ounces here are avoirdupois ounces, a weight: 1 oz = 1/16 lb = 28.349523125 g. A US fluid ounce is a volume.
- Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up; an answer of 1 billion or more shows at most 15 significant digits.

## Worked examples

1. value = 1 gives result = 0.035274. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
2. value = 100 gives result = 3.527396. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
3. result = 16 gives value = 453.59237. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.

## FAQ

### How many ounces are in a gram?

1 gram is 0.035274 ounces, from the exact unit definitions (NIST SP 811).

### How do I convert grams to oz?

Multiply by 0.035274: oz = g × 0.0352739619496 (the same as g ÷ 28.349523125). For example, 1 g × 0.035274 = 0.035274 oz.

### How do I convert oz back to grams?

Multiply by 28.349523, or type the ounces into the second box and the converter works it out. 1 ounce is 28.349523 grams.

### Is an ounce here a weight or a volume?

A weight: the avoirdupois ounce, 1/16 of a pound (28.349523125 g exactly). A US fluid ounce (29.57 mL) measures volume, as on cups-to-ounces pages.

### What is 100 grams in ounces?

3.527396 oz: 100 ÷ 28.349523125.

### What is 500 g in ounces and pounds?

17.636981 oz, or 1.102311 lb: a pound is 16 oz, 453.59237 g exactly (NIST SP 811).

## Sources

- NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B.8: Factors for Units Listed Alphabetically (bold factors are exact), retrieved 2026-10-18. https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8
- NIST SP 811 (2008), footnotes to Appendix B: 1 lb = 0.45359237 kg exactly (footnote 22); 1 lbf = 4.4482216152605 N exactly with standard gravity, 9.80665 m/s² (footnote 23), retrieved 2026-10-18. https://www.nist.gov/pml/special-publication-811/nist-guide-si-footnotes