An avoirdupois ounce is 1/16 pound.
Ounces to Attograms Converter — oz to ag
Convert Ounce (oz) to Attogram (ag) using the exact conversion factor (1 ounce = 2.834952e+19 attogram). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Ounces to Attograms converter
Converter
Mass/Weight Converter
Convert SI mass, imperial weight, jewelry, atomic, and astronomy mass units.
Context values
Some unit families need one extra value for a physically accurate result.
Attogram is 1e-18 gram units.
Result = input x 0.02834952313 / 1e-21.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Ounces to Attograms
Weight conversions between Ounce and Attogram come up constantly in everyday commerce, shipping, and cooking, since US packaging is usually labeled in pounds while most of the rest of the world uses kilograms. Ounce is typically associated with united States (cooking, postal, retail), while Attogram is typically associated with used in specialized scientific measurement, not everyday contexts.
Formula
attograms = ounces × 2.834952e+19
This factor comes from each unit's defined relationship to the category's base unit: 1 ounce equals 0.028349523125 base units, and 1 attogram equals 1e-21 base units, so dividing one by the other gives the direct ounce-to-attogram factor of 2.834952e+19.
Simple example
1 oz × 2.834952e+19 = 2.834952e+19 ag
1 ounce = 2.834952e+19 attograms.
Real-world example
50 oz × 2.834952e+19 = 1.417476e+21 ag
50 ounces = 1.417476e+21 attograms.
Conversion table
| Ounce (oz) | Attogram (ag) |
|---|---|
| 1 oz | 2.834952e+19 ag |
| 5 oz | 1.417476e+20 ag |
| 10 oz | 2.834952e+20 ag |
| 25 oz | 7.087381e+20 ag |
| 50 oz | 1.417476e+21 ag |
| 100 oz | 2.834952e+21 ag |
Reverse conversion: Attogram to Ounce
2.834952e+19 ag × 3.527396e-20 = 0.9999998898 oz
2.834952e+19 attograms = 0.9999998898 ounces.
ounces = attograms × 3.527396e-20
For a page dedicated to this direction, see Attogram to Ounce.
Ounce vs. Attogram
| Aspect | Ounce | Attogram |
|---|---|---|
| Family | US/imperial customary unit | SI derived (metric prefix) unit |
| Typical use | US cooking and recipe measurement (small quantities) | Nanotechnology and single-molecule mass measurement |
| Where it's used | United States (cooking, postal, retail) | Used in specialized scientific measurement, not everyday contexts |
Understanding the Ounce
Ounce (oz) measures mass. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. It is classified as a US/imperial customary unit.
Where it's used: United States (cooking, postal, retail) United Kingdom (informal/retail use)
Avoirdupois ounce vs. troy ounce. The everyday ounce (avoirdupois, 28.35 g) used for cooking and shipping is a different, smaller unit than the troy ounce (31.10 g) used for precious metals like gold and silver — this page uses the everyday avoirdupois ounce.
Uses of the Ounce today
- US cooking and recipe measurement (small quantities)
- US postal and shipping weight
- Precious metals (troy ounce, a related but distinct unit)
History of the Ounce
The ounce descends from the Roman 'uncia' (a twelfth part), inherited through medieval English weight systems; the avoirdupois ounce (for general goods, as opposed to the troy ounce for precious metals) became standard for everyday trade, fixed at exactly 28.349523125 g via the pound's 1959 international standardization.
Historical origin. Ounce was not the invention of a single named person; it developed through the process described above.
Understanding the Attogram
Attogram (ag) measures mass. An attogram is 10⁻¹⁸ grams (10⁻²¹ kilograms) — 'atto-' is the SI prefix for one quintillionth. It is classified as a SI derived (metric prefix) unit.
Where it's used: Used in specialized scientific measurement, not everyday contexts
Uses of the Attogram today
- Nanotechnology and single-molecule mass measurement
- Analytical chemistry at extremely small mass scales
- Comparing against atomic-scale mass units like the atomic mass unit
History of the Attogram
The attogram is simply the gram combined with the SI prefix 'atto-' (10⁻¹⁸), one of the small-scale metric prefixes introduced by the International Committee for Weights and Measures as part of the broader SI prefix system, not a unit with its own separate history.
Historical origin. Attogram was not the invention of a single named person; it developed through the process described above.
Ounce — sources
- NIST — International yard and pound (1959) — Basis for the modern ounce via the standardized pound.
Attogram — sources
- BIPM SI Brochure — SI prefixes — Defines 'atto-' as the prefix for 10⁻¹⁸.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many attograms are in 1 ounce?
1 ounce equals 2.834952e+19 attograms, using the exact defined conversion factor rather than an estimate.
How do I convert ounce to attogram?
Multiply the ounce value by 2.834952e+19. The converter above does this instantly to whatever precision you set.
How do I convert attogram back to ounce?
Use the reverse factor: 1 attogram equals 3.527396e-20 ounces. You can also use the swap control in the converter above to flip the direction instantly.
What is a ounce?
Ounce (oz) measures mass. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. It is classified as a US/imperial customary unit.
What is a attogram?
Attogram (ag) measures mass. An attogram is 10⁻¹⁸ grams (10⁻²¹ kilograms) — 'atto-' is the SI prefix for one quintillionth. It is classified as a SI derived (metric prefix) unit.
Is the ounce to attogram conversion exact?
Yes. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between avoirdupois ounce vs. troy ounce?
The everyday ounce (avoirdupois, 28.35 g) used for cooking and shipping is a different, smaller unit than the troy ounce (31.10 g) used for precious metals like gold and silver — this page uses the everyday avoirdupois ounce.
Where is the ounce still used today?
United States (cooking, postal, retail) United Kingdom (informal/retail use)