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) = 8.302695e-24 Carat (ct).
| Atomic Mass Unit (u) | Carat (ct) |
|---|---|
| 0.1 | 8.302695e-25 |
| 0.5 | 4.151348e-24 |
| 1 | 8.302695e-24 |
| 2 | 1.660539e-23 |
| 5 | 4.151348e-23 |
| 10 | 8.302695e-23 |
| 25 | 2.075674e-22 |
| 50 | 4.151348e-22 |
| 100 | 8.302695e-22 |
| 500 | 4.151348e-21 |
| 1000 | 8.302695e-21 |
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 carat is a unit of mass used for gemstones and pearls, equal to exactly 200 milligrams (0.2 grams).
1 ct = 0.2 g = 200 mg = 0.007055 oz.
To convert carats to grams: multiply by 0.2. To convert grams to carats: multiply by 5.
Diamond grading and pricing, gemstone trade, pearl classification, and jewelry appraisal.
The Hope Diamond weighs 45.52 ct (9.1 g). The Cullinan Diamond, the largest gem-quality rough diamond ever found, was 3,106 ct (621 g).
Confusing carat (ct, mass) with karat (K, gold purity). 24K gold is pure gold; a 24-carat diamond weighs 4.8 g.
Carat = weight of a gem. Karat = purity of gold. They sound the same but measure completely different things.



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