Instant · Precise · Universal
34 units available
6 categories total
To convert Da to kg: multiply by 1.6605390666 × 10⁻²⁷. 1 kDa = 1,000 Da.
1 Da = 1 u = 1.6605390666 × 10⁻²⁷ kg. Proteins range from ~5 kDa to >1,000 kDa.
For example, 1 Dalton (Da) = 1 Atomic Mass Unit (u).
| Dalton (Da) | Atomic Mass Unit (u) |
|---|---|
| 0.1 | 0.1 |
| 0.5 | 0.5 |
| 1 | 1 |
| 2 | 2 |
| 5 | 5 |
| 10 | 10 |
| 25 | 25 |
| 50 | 50 |
| 100 | 100 |
| 500 | 500 |
| 1000 | 1000 |
The dalton is a unit of mass equal to one unified atomic mass unit (1/12 of a carbon-12 atom), approximately 1.661 × 10⁻²⁷ kg.
1 Da = 1 u = 1.6605390666 × 10⁻²⁷ kg. Proteins range from ~5 kDa to >1,000 kDa.
To convert Da to kg: multiply by 1.6605390666 × 10⁻²⁷. 1 kDa = 1,000 Da.
Protein molecular weights (hemoglobin ≈ 64.5 kDa), DNA fragment sizing, and antibody characterization.
Titin, the largest known protein, has a molecular weight of about 3,800 kDa (3.8 MDa). The average protein is ~40–50 kDa.
The dalton and u are identical — they're just preferred in different fields (Da in biology, u in chemistry/physics).
If a paper says a protein is '50 kDa,' that's 50,000 atomic mass units — about 50,000 hydrogen atoms' worth of mass.
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).



© 2026 UntangleTools. All Rights Reserved.