The unified atomic mass unit is used in atomic physics.
Atomic mass units to Yoctograms Converter — u to yg
Convert Atomic mass unit (u) to Yoctogram (yg) using the exact conversion factor (1 atomic mass unit = 1.660539067 yoctogram). See the formula, worked examples, conversion table, history, and common uses.
Atomic mass units to Yoctograms 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.
Yoctogram is 1e-24 gram units.
Result = input x 1.66053907e-27 / 1e-27.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Atomic mass units to Yoctograms
Weight conversions between Atomic mass unit and Yoctogram 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. Atomic mass unit is most often used for expressing atomic and molecular masses in chemistry.
Formula
yoctograms = atomic mass units × 1.6605390666
This factor comes from each unit's defined relationship to the category's base unit: 1 atomic mass unit equals 1.660539e-27 base units, and 1 yoctogram equals 1e-27 base units, so dividing one by the other gives the direct atomic mass unit-to-yoctogram factor of 1.6605390666.
Simple example
1 u × 1.660539067 = 1.660539067 yg
1 atomic mass unit = 1.660539067 yoctograms.
Real-world example
50 u × 1.660539067 = 83.02695333 yg
50 atomic mass units = 83.02695333 yoctograms.
Conversion table
| Atomic mass unit (u) | Yoctogram (yg) |
|---|---|
| 1 u | 1.660539067 yg |
| 5 u | 8.302695333 yg |
| 10 u | 16.60539067 yg |
| 25 u | 41.51347667 yg |
| 50 u | 83.02695333 yg |
| 100 u | 166.0539067 yg |
Reverse conversion: Yoctogram to Atomic mass unit
1.660539067 yg × 0.6022140762 = 1 u
1.660539067 yoctograms = 1 atomic mass units.
atomic mass units = yoctograms × 0.602214076208
For a page dedicated to this direction, see Yoctogram to Atomic mass unit.
Understanding the Atomic mass unit
Atomic mass unit (u) measures mass. The unified atomic mass unit is defined as exactly 1/12 the mass of a carbon-12 atom, approximately 1.6605390666 × 10⁻²⁷ kg. It is classified as a Non-SI unit accepted for use with SI (scientific).
Where it's used: Used internationally in chemistry and physics, not a general-public unit
Uses of the Atomic mass unit today
- Expressing atomic and molecular masses in chemistry
- Nuclear and particle physics mass calculations
- Molecular weight tables and mass spectrometry
History of the Atomic mass unit
Atomic mass scales existed before international standardization, using either oxygen-16 or natural oxygen as a reference. In 1961, the International Union of Pure and Applied Chemistry (IUPAC) and physicists agreed on a unified scale based on carbon-12, ending decades of divergent chemistry and physics mass scales.
The unified atomic mass unit (u), also called the dalton (Da) in SI-adjacent contexts, is now tied to the carbon-12 standard and remains the base unit for atomic and molecular mass tables used across chemistry and physics.
Historical origin. Atomic mass unit was not the invention of a single named person; it developed through the process described above.
Understanding the Yoctogram (yg)
Yoctogram is 1e-24 gram units.
Atomic mass unit — sources
- BIPM SI Brochure — Non-SI units accepted for use with SI — Lists the unified atomic mass unit and its carbon-12 definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many yoctograms are in 1 atomic mass unit?
1 atomic mass unit equals 1.660539067 yoctograms, using the exact defined conversion factor rather than an estimate.
How do I convert atomic mass unit to yoctogram?
Multiply the atomic mass unit value by 1.660539067. The converter above does this instantly to whatever precision you set.
How do I convert yoctogram back to atomic mass unit?
Use the reverse factor: 1 yoctogram equals 0.6022140762 atomic mass units. You can also use the swap control in the converter above to flip the direction instantly.
What is a atomic mass unit?
Atomic mass unit (u) measures mass. The unified atomic mass unit is defined as exactly 1/12 the mass of a carbon-12 atom, approximately 1.6605390666 × 10⁻²⁷ kg. It is classified as a Non-SI unit accepted for use with SI (scientific).
What is a yoctogram?
Yoctogram (yg) is a unit of mass/weight.
Is the atomic mass unit to yoctogram conversion exact?
Yes. The unified atomic mass unit is defined as exactly 1/12 the mass of a carbon-12 atom, approximately 1.6605390666 × 10⁻²⁷ kg. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the atomic mass unit still used today?
Used internationally in chemistry and physics, not a general-public unit