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) = 1.660539e-18 Microgram (µg).
| Atomic Mass Unit (u) | Microgram (µg) |
|---|---|
| 0.1 | 1.660539e-19 |
| 0.5 | 8.302695e-19 |
| 1 | 1.660539e-18 |
| 2 | 3.321078e-18 |
| 5 | 8.302695e-18 |
| 10 | 1.660539e-17 |
| 25 | 4.151348e-17 |
| 50 | 8.302695e-17 |
| 100 | 1.660539e-16 |
| 500 | 8.302695e-16 |
| 1000 | 1.660539e-15 |
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 microgram is a unit of mass equal to 10⁻⁶ grams or 10⁻⁹ kilograms — one millionth of a gram.
1 µg = 10⁻⁶ g = 10⁻⁹ kg = 0.001 mg = 1,000 ng.
To convert µg to mg: divide by 1,000. To convert µg to grams: divide by 1,000,000.
Vitamin dosages (e.g., vitamin B12: 2.4 µg/day), drug formulations, and food additive regulations.
The recommended daily intake of vitamin D is 15 µg (600 IU) — an incredibly tiny yet vital amount for bone health.
Confusing µg with mg — a 1,000× error. In medicine, this can be life-threatening. Always double-check the prefix.
In medical contexts, 'mcg' = 'µg'. If a prescription says '200 mcg', that's 0.2 mg or 0.0002 g.



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