Free Calculator · Published October 2026
Ounces to Grams: Multiply by 28.34952
One avoirdupois ounce is 28.34952 grams on the printed NIST line. Two ounces are 56.69904 grams.
Write ounces and grams on the same chemical note before anyone treats the number as a fluid ounce or a pound.
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Book a DemoHow Ounces to Grams Uses 28.34952
This converter follows one row on the NIST Guide to the SI, Appendix B.8. The avoirdupois ounce row multiplies by 2.834 952 and E+01 to reach grams. A pound stated in kilograms stays on pounds to kilograms.
Avoirdupois ounces, or grams of that mass.
All calculations are estimates based on historical information and should be verified by the user.
Important: All calculator results are ballpark estimates
All calculations are estimates based on historical information and should be verified by the user. This tool is provided as a free service for planning purposes only and is not a substitute for a professional assessment, a supplier quote, or applicable local code requirements.
What Are Ounces to Grams Using?
Ounces to grams multiply by 28.34952. The result is a mass label. It does not say how much chemical to feed, how much a bag should weigh, or whether a sample passed a lab. Write avoirdupois ounce next to the factor so the next visit does not swap in a fluid ounce.
One factor, both directions
The NIST table prints 2.834 952 in the multiply-by column and E+01 in the exponent column. Read together, that is 28.34952 grams in one avoirdupois ounce. This page uses 28.34952 so an ounce round-trips through grams. It does not build the result from the pound row.
One gram divided by 28.34952 is the reverse ounce count, shown at five decimals on the worked table. The engine divided by 28.34952. It did not use 0.4535924.
Common ounce masses
Each row multiplies by 28.34952 and shows five decimal places. These are not recommended scoop sizes.
| Ounces | Grams |
|---|---|
| 1 | 28.34952 |
| 2 | 56.69904 |
| 5 | 141.74760 |
| 10 | 283.49520 |
| 16 | 453.59232 |
Worked examples
One ounce is 28.34952 grams. Two ounces are 56.69904 grams. Sixteen ounces are 453.59232 grams at five decimals. The reverse of one gram divides by 28.34952.
| Case | Ounces | Grams |
|---|---|---|
| 1 ounce | 1.00000 | 28.34952 |
| 2 ounces | 2.00000 | 56.69904 |
| 16 ounces | 16.00000 | 453.59232 |
| 1 gram | 0.03527 | 1.00000 |
An ounce is not a pound and not a fluid ounce
Pounds stated as kilograms, using 0.4535924, stay on pounds to kilograms. A U.S. fluid ounce stated as milliliters, using 29.57353, stays on fluid ounces to milliliters. A feed calculation that starts from a flow stays on the chemical feed rate calculator. This page has no 0.4535924 and no 29.57353.
What to write on the job ticket
Write five lines before the number leaves this page. A later visit should not have to guess which ounce was used.
- The entered value, and whether it was ounces or grams.
- The factor, 28.34952, named as the NIST avoirdupois ounce line.
- Both results, at five decimals.
- Which bag, tag, or sheet the mass came from.
- A note that the pound row and the fluid-ounce row were not applied, and that the factor was not called exact.
What stays off this mass
Sixteen avoirdupois ounces are one pound in ordinary speech. The product 453.59232 grams is this row times 16. It is not a second fetch of the pound-to-kilogram line, and this page does not call the two rows the same number.
A water treatment dealer who saves the 28.34952 note will not swap in a fluid ounce and call the result grams. This conversion does not size a softener and does not say a sample passed a county rule. A private-well lab sheet is still the well water testing guide.
Frequently Asked Questions
How do ounces to grams use 28.34952?
Multiply avoirdupois ounces by 28.34952. That is the NIST Appendix B.8 row for an ounce into a gram, printed as 2.834 952 E+01. Divide grams by the same factor to go back. The factor is not called exact, because boldface was not preserved.
Is 28.34952 the pound factor?
No. The avoirdupois pound row on the same NIST page is a different line, used by the pounds to kilograms converter. Sixteen times 28.34952 is not that pound factor. This page does not switch rows.
Does ounces to grams use a fluid ounce?
No. A U.S. fluid ounce is a volume. It stays on the fluid ounces to milliliters converter. This page converts an avoirdupois ounce, which is a mass.
What is 1 ounce in grams?
One avoirdupois ounce is 28.34952 grams. Two ounces are 56.69904 grams. Sixteen ounces are 453.59232 grams at five decimals. Those products use the printed NIST factor.
Is this a chemical dose?
No. The result is a unit change for a mass you typed. It is not a feed rate, a removal percent, or a pass line on a lab sheet.
Save 28.34952 Next to the Mass
The ounces, the grams, and the NIST line belong on the customer record.
Get a Free DemoAll calculations are estimates based on historical information and should be verified by the user. This tool is provided as a free service for planning purposes only and is not a substitute for a professional assessment, a supplier quote, or applicable local code requirements.