Instant · Precise · Universal
34 units available
6 categories total
To convert u to kg: multiply by 1.6605390666 × 10⁻²⁷. To convert u to MeV/c²: multiply by 931.494.
1 u = 1.6605390666 × 10⁻²⁷ kg = 1/Nₐ grams ≈ 931.494 MeV/c².
For example, 1 Atomic Mass Unit (u) = 0.9927760979 Proton Mass (mp).
| Atomic Mass Unit (u) | Proton Mass (mp) |
|---|---|
| 0.1 | 0.09927760979 |
| 0.5 | 0.4963880489 |
| 1 | 0.9927760979 |
| 2 | 1.985552196 |
| 5 | 4.963880489 |
| 10 | 9.927760979 |
| 25 | 24.81940245 |
| 50 | 49.63880489 |
| 100 | 99.27760979 |
| 500 | 496.3880489 |
| 1000 | 992.7760979 |
The atomic mass unit (unified) is defined as 1/12 the mass of a carbon-12 atom, approximately 1.661 × 10⁻²⁷ kilograms.
1 u = 1.6605390666 × 10⁻²⁷ kg = 1/Nₐ grams ≈ 931.494 MeV/c².
To convert u to kg: multiply by 1.6605390666 × 10⁻²⁷. To convert u to MeV/c²: multiply by 931.494.
Molecular weight calculations, mass spectrometry data interpretation, and chemical stoichiometry.
A proton has a mass of ~1.007 u, a neutron ~1.009 u. The discrepancy from 1.000 reflects nuclear binding energy.
Confusing 'amu' (the old, obsolete term) with 'u' (the unified standard). Also, forgetting that 1 u ≠ 1 gram.
Think of u as 'approximately the mass of one proton or neutron.' Carbon-12 = 12 u exactly (by definition).
The proton mass is the rest mass of a proton, approximately 1.673 × 10⁻²⁷ kilograms or about 938.3 MeV/c².
mp ≈ 1,836 × mₑ ≈ 1.00728 u. About 0.1% heavier than a neutron.
To convert proton masses to kg: multiply by 1.67262192369 × 10⁻²⁷.
Nuclear energy calculations, radiation therapy dosimetry, and proton beam therapy for cancer.
A proton's mass is mostly from the kinetic energy of quarks and gluons (via E=mc²), not from the quark masses themselves (~1%).
Assuming quarks make up most of the proton's mass — quarks contribute only ~1%. The rest is binding energy.
The proton:electron mass ratio (1,836:1) is a fundamental number in physics. It determines atomic structure.



© 2026 UntangleTools. All Rights Reserved.