Convert Carbon-12 Atom Mass to Atomic Mass Unit
Convert carbon-12 atom mass to atomic mass unit instantly. 1 carbon-12 atom mass = 11.9999918099 atomic mass unit — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Atomic Mass Unit to Carbon-12 Atom Mass converter for the reverse conversion.
Units explained
Carbon-12 Atom Mass
The mass of a single carbon-12 atom is exactly 12 u by definition, about 1.9926E-26 kg.
The reference nuclide that defines the unified atomic mass scale.
The defining standard for the atomic mass unit.
Chosen as the mass standard by IUPAC and IUPAP in 1960-1961.
Atomic Mass Unit
One unified atomic mass unit (u) is defined as 1/12 the mass of a carbon-12 atom, about 1.6605E-27 kg.
Introduced to give atomic and molecular masses convenient numerical values.
Atomic, molecular, and nuclear physics and chemistry.
The unified (carbon-12) scale was adopted by IUPAC and IUPAP in 1960-1961.
Carbon-12 Atom Mass to Atomic Mass Unit conversion formula
The relationship between carbon-12 atom mass and atomic mass unit:
To convert carbon-12 atom mass to atomic mass unit, multiply the value in carbon-12 atom mass by 11.9999918099. To reverse, multiply atomic mass unit by 0.0833333902.
How to use this converter
Type a value into the calculator. The result in atomic mass unit updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Atomic Mass Unit to Carbon-12 Atom Mass converter for the reverse direction.
Step-by-step: convert carbon-12 atom mass to atomic mass unit
- Write down the value in carbon-12 atom mass (C-12).
- Multiply that value by the factor 11.9999918099.
- The product is the equivalent value in atomic mass unit (u).
- To reverse, multiply the atomic mass unit value by 0.0833333902.
Worked examples
Example 1 — Convert 1 C-12 to u:
1 × 11.9999918099 = 11.9999918099 u
Example 2 — Convert 100 C-12 to u:
100 × 11.9999918099 = 1199.9991809894 u
Real-world example — Wavelengths across the spectrum
Optical and atomic-scale phenomena are routinely cross-converted between sub-micron units. A photon of wavelength 800 carbon-12 atom mass can be re-expressed in atomic mass unit for direct comparison with another instrument's calibration data sheet.
800 C-12 × 11.9999918099 = 9599.9934479153 u
Real-world example — Molecular dimensions
The diameter of small molecular structures (around 2 carbon-12 atom mass) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.
2 C-12 × 11.9999918099 = 23.9999836198 u
Carbon-12 Atom Mass to Atomic Mass Unit conversion table
Standard reference values for converting carbon-12 atom mass to atomic mass unit:
| Carbon-12 Atom Mass [C-12] | Atomic Mass Unit [u] |
|---|---|
| 0.01 | 0.1199999181 |
| 0.1 | 1.199999181 |
| 1 | 11.9999918099 |
| 2 | 23.9999836198 |
| 3 | 35.9999754297 |
| 4 | 47.9999672396 |
| 5 | 59.9999590495 |
| 10 | 119.9999180989 |
| 20 | 239.9998361979 |
| 30 | 359.9997542968 |
| 40 | 479.9996723958 |
| 50 | 599.9995904947 |
| 100 | 1199.9991809894 |
| 500 | 5999.9959049471 |
| 1000 | 11999.9918098942 |
Frequently asked questions
How many atomic mass unit is 1 carbon-12 atom mass?
How do I convert carbon-12 atom mass to atomic mass unit?
How do I convert atomic mass unit back to carbon-12 atom mass?
How many atomic mass unit is 100 carbon-12 atom mass?
Popular weight unit conversions
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Metric / SI (18 units)
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Indian / South Asian (6 units)
Scientific / Atomic (8 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 C-12 = 11.9999918099 u) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.