Free · Unit conversions
Ordinary & Troy Ounces to Grams
Convert grams and either avoirdupois or troy ounces using their separate exact mass definitions.
- Formula & worked example
- Private in your browser
- No signup
Calculator inputs
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How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
Private by default
Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.
Formula and method
One ordinary ounce is exactly 28.349523125 grams; one troy ounce is exactly 31.1034768 grams.
Grams = ounces × grams per selected ounce
Worked example
Enter these known values and leave the other values blank.
- Mass in selected ounce type
- 1 oz
- Mass in grams
- 28.35 g
Assumptions and limitations
- The ordinary ounce is avoirdupois, equal to one sixteenth of the international pound.
- A troy ounce is a separate unit commonly used for precious metals. Neither option is a fluid ounce.
- Zero and signed mass differences can be converted. Unit conversion does not determine material purity or value.
Common questions
Why does an ounce of bullion convert differently?
A quoted troy ounce uses 31.1034768 grams; an ordinary avoirdupois ounce uses 28.349523125 grams. Check the quoted unit.
Can I convert grams back to ounces?
Yes. Enter grams and choose the required ounce definition.
References
The calculation equations, inverse formulas, units, and input rules were imported from this source. Bookify provides the interface and equation solver.
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