Instant · Precise · Universal
32 units available
6 categories total
To convert AU to km: multiply by 149,597,870.7. To convert AU to light-years: divide by 63,241.
1 AU = 149,597,870,700 m ≈ 149.598 Gm ≈ 499 light-seconds ≈ 8.317 light-minutes.
For example, 1 Astronomical Unit (AU) = 5.308766e+25 Electron Radius (Classical) (re).
| Astronomical Unit (AU) | Electron Radius (Classical) (re) |
|---|---|
| 0.1 | 5.308766e+24 |
| 0.5 | 2.654383e+25 |
| 1 | 5.308766e+25 |
| 2 | 1.061753e+26 |
| 5 | 2.654383e+26 |
| 10 | 5.308766e+26 |
| 25 | 1.327192e+27 |
| 50 | 2.654383e+27 |
| 100 | 5.308766e+27 |
| 500 | 2.654383e+28 |
| 1000 | 5.308766e+28 |
The astronomical unit is a unit of length approximating the mean Earth-Sun distance, defined as exactly 149,597,870,700 meters.
1 AU = 149,597,870,700 m ≈ 149.598 Gm ≈ 499 light-seconds ≈ 8.317 light-minutes.
To convert AU to km: multiply by 149,597,870.7. To convert AU to light-years: divide by 63,241.
Spacecraft mission planning, expressing planetary orbit sizes, and solar system scale models.
Light takes about 8 minutes and 20 seconds to travel 1 AU. Mars is about 1.52 AU from the Sun, Jupiter about 5.2 AU.
Thinking the AU is the exact Earth-Sun distance — Earth's actual distance varies from ~147 to ~152 Gm over the year due to orbital eccentricity.
AU makes the solar system manageable: Mercury ≈ 0.39 AU, Venus ≈ 0.72, Earth = 1, Mars ≈ 1.52, Jupiter ≈ 5.2, Saturn ≈ 9.5.
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.



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