Convert Inch to Classical Electron Radius
Convert inches to classical electron radii instantly. 1 inch = 9.013676e+12 classical electron radius — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Classical Electron Radius to Inch converter for the reverse conversion.
Units explained
Inch
An inch is an Imperial and US customary unit of length defined since 1959 as exactly 25.4 millimeters (0.0254 meters). It is still the standard small unit of length in the United States, the United Kingdom (informally), and a few other countries.
The inch derives from the Roman uncia (one-twelfth of a foot) and survived through Anglo-Saxon and medieval English measurement systems. Various definitions persisted regionally until the 1959 International Yard and Pound Agreement standardized the inch globally as exactly 25.4 mm.
Inches are used in the US and UK for body height, screen sizes (TVs, monitors, phones), tire sizes, plumbing, lumber, paper sizes (US Letter is 8.5 × 11 in), and most consumer product specifications in the United States.
Anglo-Saxon origin (predating 1066); standardized to 25.4 mm exactly by the International Yard and Pound Agreement of 1959, signed by the US, UK, Canada, Australia, New Zealand, and South Africa.
Classical Electron Radius
The classical electron radius is approximately 2.818×10⁻¹⁵ meters. It is the radius an electron would have if its mass were entirely electromagnetic and its charge distributed over its surface.
Defined classically in the early 20th century. The CODATA 2018 value of 2.8179403262×10⁻¹⁵ m is derived from the elementary charge, electron rest mass, and the Coulomb constant.
The classical electron radius appears in scattering theory (Thomson scattering cross-section), particle physics estimates, and historical electromagnetism. It is a calculational tool, not the actual size of an electron, which has no measured extent.
Concept dates to the early 20th-century classical electromagnetism; CODATA 2018 provides the current reference value.
Inch to Classical Electron Radius conversion formula
The relationship between inches and classical electron radii:
To convert inches to classical electron radii, multiply the value in inches by 9.013676e+12. To reverse, multiply classical electron radii by 1.109425e-13.
How to use this converter
Type a value into the calculator. The result in classical electron radii updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Classical Electron Radius to Inch converter for the reverse direction.
Step-by-step: convert inches to classical electron radii
- Write down the value in inches (in).
- Multiply that value by the factor 9.013676e+12.
- The product is the equivalent value in classical electron radii (rₑ).
- To reverse, multiply the classical electron radius value by 1.109425e-13.
Worked examples
Example 1 — Convert 1 in to rₑ:
1 × 9.013676e+12 = 9.013676e+12 rₑ
Example 2 — Convert 100 in to rₑ:
100 × 9.013676e+12 = 9.013676e+14 rₑ
Real-world example — Centimeter to wavelength scale
One inch equals 10 million classical electron radii. Physics curricula use this kind of conversion to relate everyday measurements to atomic and optical scales.
1 in × 9.013676e+12 = 9.013676e+12 rₑ
Real-world example — Small-scale to atomic-scale
One inch equals 10 million classical electron radii — useful for physics curricula that relate everyday measurements to atomic and optical scales.
1 in × 9.013676e+12 = 9.013676e+12 rₑ
Inch to Classical Electron Radius conversion table
Standard reference values for converting inches to classical electron radii:
| Inch [in] | Classical Electron Radius [rₑ] |
|---|---|
| 0.01 | 9.013676e+10 |
| 0.1 | 9.013676e+11 |
| 1 | 9.013676e+12 |
| 2 | 1.802735e+13 |
| 3 | 2.704103e+13 |
| 4 | 3.60547e+13 |
| 5 | 4.506838e+13 |
| 10 | 9.013676e+13 |
| 20 | 1.802735e+14 |
| 30 | 2.704103e+14 |
| 40 | 3.60547e+14 |
| 50 | 4.506838e+14 |
| 100 | 9.013676e+14 |
| 500 | 4.506838e+15 |
| 1000 | 9.013676e+15 |
Frequently asked questions
How many classical electron radii is 1 inch?
How do I convert inches to classical electron radii?
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How many classical electron radii is 100 inches?
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Metric / SI (18 units)
Imperial / US Customary (26 units)
Nautical (1 units)
Astronomical (9 units)
Atomic / Physics (6 units)
Typographic (3 units)
Sources & references
Conversion factor (1 in = 9.013676e+12 rₑ) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.