oz to Grams Converter
Convert ounces to grams for American cooking, baking, and postal weight measurement.
How It Works
Formula: oz to g = value × 28.3495231
Example: 8 oz = 226.796185 g
Note: 1 avoirdupois ounce equals 28.3495 grams, the standard used in American cooking and everyday weight.
Common Uses
Quick Conversion Table
| oz | g |
|---|---|
| 1 | 28.3495 |
| 5 | 141.7476 |
| 10 | 283.4952 |
| 25 | 708.7381 |
| 50 | 1417 |
| 100 | 2835 |
| 150 | 4252 |
| 200 | 5670 |
Rounding Rule
Rounded to 4 decimal places
Error Margin
±0.01 g
Precision Guidance
For cooking, round to 1 gram. For nutrition labeling, keep 1 decimal place.
Common Mistakes
Do not confuse the avoirdupois ounce (28.35 g) with the troy ounce (31.10 g) used for gold and silver.
Frequently Asked Questions
What is 1 oz in grams?
1 avoirdupois ounce equals 28.3495 grams (1 oz = 28.3495231 g).
Is this the same ounce used in cooking?
Yes, American recipes use the avoirdupois ounce (28.35 g), not the troy ounce used for precious metals.
How do I convert 8 oz to grams?
Multiply 8 by 28.3495. The result is 226.8 grams, a common recipe portion.
Why use grams for baking?
Grams are more precise than ounces, which is why professional bakers weigh ingredients in grams.
Deep Dive Guide
Ounces to Grams: Convert Ounces to Grams for Cooking and Baking
Convert ounces to grams with the exact 28.3495 factor. Translate US recipe weights, portion sizes, and shipping values into metric grams.
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Exact Constants & Authoritative Sources
Every conversion on this page uses the fixed, internationally agreed constants below — drawn from NIST and the SI Brochure. No values are estimated or rounded as if exact. See the full list on our Sources & Standards page.
- EXACT1 pound (lb, avoirdupois) = 0.45359237 kilograms (exact)
- EXACT1 ounce (oz, avoirdupois) = 28.349523125 grams (exact, 1/16 lb)
- EXACT1 stone (st) = 6.35029318 kilograms (exact, 14 lb)
- EXACT1 short ton (US) = 907.18474 kilograms (exact, 2000 lb)
Common Pitfalls & How to Avoid Them
Mass vs. weight
The pound and kilogram are units of MASS, not force. On Earth, mass and "weight" read the same number in practice, but a 70 kg mass weighs less on the Moon. UnitFig converts mass; for scientific force you need newtons (1 lbf = 4.4482216152605 N, exact).
Avoirdupois vs. troy ounce
Cooking and body weight use the avoirdupois ounce (28.349523125 g). Gold and precious metals use the troy ounce (31.1034768 g). Never mix them — the error is about 10%.
Rounding the factor
Using 2.2 instead of the exact 2.20462262 overstates small errors at large values. For medical dosing or competition weight classes, keep the full factor or use a converter.
A unit-conversion reference site has no manufacturer-specific or device calibration parameters, so "layered tuning" does not apply here. The only real error-handling is input validation: the converter rejects non-numeric, empty, or out-of-range entries and shows a clear message, then falls back to exact constants above. No estimated or rounded figures are ever presented as exact.
Authoritative sources for this page
- NIST (U.S. National Institute of Standards and Technology) — NIST SP 330 — The International System of Units (SI), 2019 edition
Last Updated 2026 | This converter was reviewed for accuracy