Instant · Precise · Universal
32 units available
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To convert to meters: multiply by 2.8179403262 × 10⁻¹⁵.
re = e²/(4πε₀mec²) ≈ 2.8179 × 10⁻¹⁵ m, where e is electron charge and me is electron mass.
For example, 1 Electron Radius (Classical) (re) = 0.000002817940326 Nanometer (nm).
| Electron Radius (Classical) (re) | Nanometer (nm) |
|---|---|
| 0.1 | 2.817940e-7 |
| 0.5 | 0.000001408970163 |
| 1 | 0.000002817940326 |
| 2 | 0.000005635880652 |
| 5 | 0.00001408970163 |
| 10 | 0.00002817940326 |
| 25 | 0.00007044850815 |
| 50 | 0.0001408970163 |
| 100 | 0.0002817940326 |
| 500 | 0.001408970163 |
| 1000 | 0.002817940326 |
The classical electron radius is a theoretical length scale derived from the electron's charge and mass, approximately 2.818 × 10⁻¹⁵ meters.
re = e²/(4πε₀mec²) ≈ 2.8179 × 10⁻¹⁵ m, where e is electron charge and me is electron mass.
To convert to meters: multiply by 2.8179403262 × 10⁻¹⁵.
Used in calculating X-ray and gamma-ray scattering probabilities off electrons (Thomson and Compton scattering).
Despite its name, the electron is a point particle in quantum theory — the 'classical radius' is a theoretical construct, not the electron's actual size.
Assuming this is the actual physical size of the electron — quantum mechanics shows the electron has no measurable size.
Think of it as the scale at which classical electromagnetic self-energy equals the electron's mass-energy.
The nanometer is a unit of length equal to 10⁻⁹ meters, or one billionth of a meter.
1 nm = 10⁻⁹ m = 10 Å = 1,000 pm = 10⁻³ µm. One micrometer equals 1,000 nanometers.
To convert nm to meters: multiply by 10⁻⁹. To convert nm to micrometers: divide by 1,000.
Semiconductor chip feature sizes (5 nm, 3 nm transistors), UV light wavelengths, virus dimensions, and thin-film coatings.
A human hair is about 80,000–100,000 nm thick. The COVID-19 virus is approximately 100 nm in diameter.
Confusing nanometers with micrometers — they differ by a factor of 1,000. Be careful with nm vs. µm in specs.
Visible light wavelengths (380–700 nm) are a great anchor: red light ≈ 700 nm, violet light ≈ 380 nm.



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