Convert Square Femtometer to Square Yoctometer
Convert square femtometers to square yoctometers instantly. 1 square femtometer = 1e+18 square yoctometer — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Yoctometer to Square Femtometer converter for the reverse conversion.
Units explained
Square Femtometer
A square femtometer is a metric unit of area equal to 10⁻³⁰ m². It is used in nuclear and particle physics to describe interaction cross-sections at the nuclear scale.
Derived by squaring the femtometer (10⁻¹⁵ m), historically known as the fermi after physicist Enrico Fermi.
Square femtometers are equivalent to 0.01 barn. They appear in particle physics literature comparing strong interaction cross-sections and hadron sizes.
Femtometer adopted into SI in 1964; the fermi nomenclature predates this from mid-20th century nuclear physics.
Square Yoctometer
A square yoctometer is a metric unit of area equal to one square yoctometer (10⁻²⁴ m × 10⁻²⁴ m = 10⁻⁴⁸ m²). It is the smallest SI prefix-derived area unit defined and exists primarily for theoretical completeness.
Derived by squaring the yoctometer (10⁻²⁴ m), which uses the SI prefix yocto- adopted by the CGPM in 1991. The yocto- prefix originates from the Latin 'octo' (eight), referring to the 10⁸ thousand-grouping in the power-of-thousand scheme.
Square yoctometers have no current practical application. The yoctometer scale itself lies far below any physically measurable length, including the Planck length. The unit is included for SI catalogue completeness.
SI prefix yocto- adopted in 1991; square area defined by mathematical squaring.
Square Femtometer to Square Yoctometer conversion formula
The relationship between square femtometers and square yoctometers:
To convert square femtometers to square yoctometers, multiply the value in square femtometers by 1e+18. To reverse, multiply square yoctometers by 1e-18.
How to use this converter
Type a value into the calculator. The result in square yoctometers updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Square Yoctometer to Square Femtometer converter for the reverse direction.
Step-by-step: convert square femtometers to square yoctometers
- Write down the value in square femtometers (fm²).
- Multiply that value by the factor 1e+18.
- The product is the equivalent value in square yoctometers (ym²).
- To reverse, multiply the square yoctometer value by 1e-18.
Worked examples
Example 1 — Convert 1 fm² to ym²:
1 × 1e+18 = 1e+18 ym²
Example 2 — Convert 100 fm² to ym²:
100 × 1e+18 = 1e+20 ym²
Real-world example — Molecular dimensions
The diameter of small molecular structures (around 2 square femtometers) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.
2 fm² × 1e+18 = 2e+18 ym²
Real-world example — Wavelengths across the spectrum
Optical and atomic-scale phenomena are routinely cross-converted between sub-micron units. A photon of wavelength 800 square femtometers can be re-expressed in square yoctometers for direct comparison with another instrument's calibration data sheet.
800 fm² × 1e+18 = 8e+20 ym²
Square Femtometer to Square Yoctometer conversion table
Standard reference values for converting square femtometers to square yoctometers:
| Square Femtometer [fm²] | Square Yoctometer [ym²] |
|---|---|
| 0.01 | 1e+16 |
| 0.1 | 1e+17 |
| 1 | 1e+18 |
| 2 | 2e+18 |
| 3 | 3e+18 |
| 4 | 4e+18 |
| 5 | 5e+18 |
| 10 | 1e+19 |
| 20 | 2e+19 |
| 30 | 3e+19 |
| 40 | 4e+19 |
| 50 | 5e+19 |
| 100 | 1e+20 |
| 500 | 5e+20 |
| 1000 | 1e+21 |
Frequently asked questions
How many square yoctometers is 1 square femtometer?
How do I convert square femtometers to square yoctometers?
How do I convert square yoctometers back to square femtometers?
How many square yoctometers is 100 square femtometers?
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Metric / SI (15 units)
Imperial / US Customary (3 units)
Sources & references
Conversion factor (1 fm² = 1e+18 ym²) 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 Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.