Length · Unit Converter

Convert Centimeter to Classical Electron Radius

Convert centimeters to classical electron radii instantly. 1 centimeter = 3.548691e+12 classical electron radius — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Classical Electron Radius to Centimeter converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Girish V Kulkarni Ph.D.
Length category 2 min read Published Last reviewed Updated

Units explained

Metric / SI

Centimeter

What is a centimeter?

A centimeter is a metric unit of length equal to one hundredth of a meter (1/100 m). It is one of the most commonly used SI sub-units in daily life, especially for measuring small objects, body dimensions, paper sizes, and short distances.

Origin of the centimeter

The centimeter emerged from the French metric system established by the French Academy of Sciences in 1793. The metric system introduced decimal-based prefixes (milli-, centi-, deci-, deca-, hecto-, kilo-) to create proportional sub-units of the meter.

Where it is used

Centimeters are the standard unit for everyday measurement in nearly every country outside the United States. They are used for body height, clothing sizes, rainfall, paper formats (A4 is 21 × 29.7 cm), screen dimensions, and most consumer product specifications.

When and where it was developed

Developed in France during the late 18th century as part of the metric system designed by the French Academy of Sciences. Formally adopted in France in 1795 and ratified internationally through the Metre Convention signed in Paris in 1875.

Atomic / Physics

Classical Electron Radius

What is a 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.

Origin of the classical electron radius

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.

Where it is used

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.

When and where it was developed

Concept dates to the early 20th-century classical electromagnetism; CODATA 2018 provides the current reference value.

Centimeter to Classical Electron Radius conversion formula

The relationship between centimeters and classical electron radii:

1 cm = 3.548691e+12 rₑ
1 rₑ = 2.81794e-13 cm

To convert centimeters to classical electron radii, multiply the value in centimeters by 3.548691e+12. To reverse, multiply classical electron radii by 2.81794e-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 Centimeter converter for the reverse direction.

Step-by-step: convert centimeters to classical electron radii

  1. Write down the value in centimeters (cm).
  2. Multiply that value by the factor 3.548691e+12.
  3. The product is the equivalent value in classical electron radii (rₑ).
  4. To reverse, multiply the classical electron radius value by 2.81794e-13.

Worked examples

Example 1 — Convert 1 cm to rₑ:
1 × 3.548691e+12 = 3.548691e+12 rₑ

Example 2 — Convert 100 cm to rₑ:
100 × 3.548691e+12 = 3.548691e+14 rₑ

Real-world example — Small-scale to atomic-scale

One centimeter equals 10 million classical electron radii — useful for physics curricula that relate everyday measurements to atomic and optical scales.

1 cm × 3.548691e+12 = 3.548691e+12 rₑ

Real-world example — Centimeter to wavelength scale

One centimeter equals 10 million classical electron radii. Physics curricula use this kind of conversion to relate everyday measurements to atomic and optical scales.

1 cm × 3.548691e+12 = 3.548691e+12 rₑ

Centimeter to Classical Electron Radius conversion table

Standard reference values for converting centimeters to classical electron radii:

Centimeter [cm]Classical Electron Radius [rₑ]
0.013.548691e+10
0.13.548691e+11
13.548691e+12
27.097382e+12
31.064607e+13
41.419476e+13
51.774346e+13
103.548691e+13
207.097382e+13
301.064607e+14
401.419476e+14
501.774346e+14
1003.548691e+14
5001.774346e+15
10003.548691e+15

Frequently asked questions

How many classical electron radii is 1 centimeter?
1 centimeter equals 3.548691e+12 classical electron radius.
How do I convert centimeters to classical electron radii?
Multiply the value in centimeters by 3.548691e+12 to get classical electron radii.
How do I convert classical electron radii back to centimeters?
Multiply the value in classical electron radii by 2.81794e-13, or use the Classical Electron Radius to Centimeter converter.
How many classical electron radii is 100 centimeters?
100 centimeters equals 3.548691e+14 classical electron radii, because 100 × 3.548691e+12 = 3.548691e+14.

Convert Centimeter to other length units

Show all Centimeter conversions
Metric / SI (17 units)
Imperial / US Customary (27 units)
Nautical (1 units)
Astronomical (9 units)
Atomic / Physics (6 units)
Typographic (3 units)

Sources & references

Conversion factor (1 cm = 3.548691e+12 rₑ) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.