Formula Used
Standard mass ounces use this formula:
grams = ounces × 28.349523125.
Troy ounces use this formula:
grams = ounces × 31.1034768.
Fluid ounces need density:
grams = fluid ounces × milliliters per fluid ounce × density.
US fluid ounces use 29.5735295625 mL.
UK fluid ounces use 28.4130625 mL.
How to Use This Calculator
Enter the ounce value in the first field.
Select the correct ounce type. Use standard ounces for normal weight conversion.
Use troy ounces for precious metals. Use fluid ounce modes only when density is known.
Choose decimal precision and rounding. Add batch values when you need several conversions at once.
Press calculate. The answer will appear below the header and above the form.
Example Data Table
| Input |
Mode |
Density |
Result |
| 1 oz |
Avoirdupois ounce |
Not needed |
28.3495 g |
| 2.5 oz |
Avoirdupois ounce |
Not needed |
70.8738 g |
| 1 oz |
Troy ounce |
Not needed |
31.1035 g |
| 8 fl oz |
US fluid ounce |
1 g/mL |
236.5882 g |
| 16 fl oz |
US fluid ounce |
1.42 g/mL |
671.9106 g |
Oz to Grams Conversion Guide
An oz to grams calculator helps when small weights must be converted with care.
Ounces are common in recipes, postage, product labels, and workshop notes.
Grams are common in science, nutrition, medicine, and global trade.
A precise converter avoids repeated manual work and lowers entry mistakes.
Why This Tool Is Useful
The standard ounce is called the avoirdupois ounce.
It is used for normal mass in many daily tasks.
One standard ounce equals 28.349523125 grams.
This fixed factor gives reliable results for food portions, parcels, powders, hardware, and craft materials.
The calculator also supports troy ounces.
A troy ounce is used for gold, silver, platinum, and other precious metals.
It equals 31.1034768 grams.
Fluid Ounce Support
Fluid ounces are different because they measure volume, not mass.
A volume can be changed into grams only when density is known.
Water is close to 1 gram per milliliter.
Oils, syrups, milk, alcohol, and honey use different densities.
This calculator lets you enter density for better fluid ounce estimates.
Advanced Options
Precision controls how many decimal places appear.
Rounding options help match kitchen scales, lab notes, or shipping rules.
Batch mode saves time when several ounce values must be converted together.
The export buttons create records for spreadsheets, reports, or printed notes.
Use the result table to compare the original value, selected mode, conversion factor, and final grams.
Check the selected ounce type before relying on the answer.
That step matters most for precious metals and liquid ingredients.
FAQs
How many grams are in one standard ounce?
One standard ounce equals 28.349523125 grams. This is the normal avoirdupois ounce used for food, shipping, body weight, and many household measurements.
Is a troy ounce the same as a regular ounce?
No. A troy ounce is heavier. One troy ounce equals 31.1034768 grams. It is mainly used for precious metals like gold and silver.
Can I convert fluid ounces directly to grams?
Only when density is known. Fluid ounces measure volume. Grams measure mass. The calculator uses density to estimate grams from US or UK fluid ounces.
What density should I use for water?
Use 1 g/mL for a practical water estimate. Exact density can change slightly with temperature, but 1 g/mL works well for everyday conversions.
Why does the calculator have rounding options?
Different tasks need different precision. Recipes may need fewer decimals. Lab work may need more. Rounding options help format the result for your use case.
What does batch conversion do?
Batch conversion lets you enter several ounce values at once. Separate values with commas, spaces, or new lines. Each value gets its own gram result.
Can I download the result?
Yes. After calculation, you can download the result as a CSV file or a PDF file. Both options appear below the result table.
Which ounce mode should I choose?
Choose standard ounce for normal weight. Choose troy ounce for precious metals. Choose a fluid ounce option only when converting liquid volume with density.