The avoirdupois ounce equals 1/16 of a pound or exactly 28.349523125 grams.
Definition & Scientific Metrology
The ounce (avoirdupois) is a small imperial weight unit used in cooking recipes, packaged goods, parcel postage, and archery/fabric weights. Note: distinct from fluid ounces (volume) and troy ounces (precious metals).
SI Kilogram Base Factor
1 oz =
0.028349523125 kgOrigins & Historical Evolution
Derived from the Roman uncia, meaning "one-twelfth" part of a Roman pound.
1 Ounce in Other Mass Units
Direct standard conversion equivalents for 1 oz:
| Target Unit | Equivalent Value | Multiplier Equation |
|---|---|---|
| Grams (g) | 28.35 | 1 oz × 28.349523 |
| Pounds (lbs) | 0.063 | 1 oz × 0.0625 |
| Kilograms (kg) | 0.028 | 1 oz × 0.0283495 |
| Milligrams (mg) | 28,349.523 | 1 oz × 28349.523 |
Common Real-World Applications
- Culinary recipes and spices
- Postal envelopes and small parcel mail rates
- Packaged retail snack foods
- Boxing glove weights (e.g. 12 oz, 16 oz)
Did You Know?
Interesting Metrology Facts
A standard slice of whole wheat bread weighs approximately 1 ounce (28g).
A Troy ounce (31.1035g) used for gold is heavier than a standard avoirdupois ounce (28.3495g).
Measurement Standards & Accuracy
Standard MultipliersFactors based on the 1959 International Yard and Pound Agreement and NIST SP 811.
Sources
- BIPM International Metrology Treaty
- NIST Guide for SI Units
- ISO 80000-4 Quantities and Units — Mass
Accuracy & Policy
Standard Exact Multipliers (e.g., 1 lb = 0.45359237 kg)
Related Tools & Resources for Ounce
Discover calculation widgets, unit comparisons, and printable lookup sheets for oz:
Unit Converters
Kilograms to Ounces Converter (kg to oz)Kilograms to Ounces with formula oz = kg × 35.27396
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Ounces to Kilograms Converter (oz to kg)Ounces to Kilograms with formula kg = oz × 0.0283495
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Pounds to Ounces Converter (lbs to oz)Pounds to Ounces with formula oz = lbs × 16
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Ounces to Pounds Converter (oz to lbs)Ounces to Pounds with formula lbs = oz ÷ 16
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Grams to Ounces Converter (g to oz)Grams to Ounces with formula oz = g ÷ 28.3495
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Ounces to Grams Converter (oz to g)Ounces to Grams with formula g = oz × 28.3495
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Unit Encyclopedia
Calculators
Weight Difference Calculator (Absolute & Percentage Gap)Weight Difference Calculator (Absolute & Percentage Gap) calculation tool
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Weight Percentage Calculator (Mass Proportion & Share Tool)Weight Percentage Calculator (Mass Proportion & Share Tool) calculation tool
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Weight Increase Calculator (Gain & Percentage Growth)Weight Increase Calculator (Gain & Percentage Growth) calculation tool
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Conversion Charts
Comparisons
Grams vs Ounces: Kitchen, Baking & Precision Weight Comparison1 ounce equals 28.3495 grams. In pastry and bread making, weighing in grams eliminates the rounding errors associated with fractional ounces.
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Ounce vs Gram: Understanding When to Use Each Unit1 ounce equals 28.3495 grams. In modern kitchen culinary work, converting to grams ensures reliable consistency regardless of recipe origins.
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Guides & Formulas
How to Convert Kilograms to Pounds (kg to lbs): Step-by-Step GuideConversion guide & practical formula
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How to Convert Pounds to Kilograms (lbs to kg): The Complete GuideConversion guide & practical formula
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How to Convert Grams to Ounces (g to oz): Baking & Kitchen GuideConversion guide & practical formula
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