Length · Unit Converter

Convert Square Yoctometer to Square Femtometer

Convert square yoctometers to square femtometers instantly. 1 square yoctometer = 1e-18 square femtometer — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Femtometer to Square Yoctometer 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

Square Yoctometer

What is a 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.

Origin of the square yoctometer

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.

Where it is used

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.

When and where it was developed

SI prefix yocto- adopted in 1991; square area defined by mathematical squaring.

Metric / SI

Square Femtometer

What is a 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.

Origin of the square femtometer

Derived by squaring the femtometer (10⁻¹⁵ m), historically known as the fermi after physicist Enrico Fermi.

Where it is used

Square femtometers are equivalent to 0.01 barn. They appear in particle physics literature comparing strong interaction cross-sections and hadron sizes.

When and where it was developed

Femtometer adopted into SI in 1964; the fermi nomenclature predates this from mid-20th century nuclear physics.

Square Yoctometer to Square Femtometer conversion formula

The relationship between square yoctometers and square femtometers:

1 ym² = 1e-18 fm²
1 fm² = 1e+18 ym²

To convert square yoctometers to square femtometers, multiply the value in square yoctometers by 1e-18. To reverse, multiply square femtometers by 1e+18.

How to use this converter

Type a value into the calculator. The result in square femtometers 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 Femtometer to Square Yoctometer converter for the reverse direction.

Step-by-step: convert square yoctometers to square femtometers

  1. Write down the value in square yoctometers (ym²).
  2. Multiply that value by the factor 1e-18.
  3. The product is the equivalent value in square femtometers (fm²).
  4. To reverse, multiply the square femtometer value by 1e+18.

Worked examples

Example 1 — Convert 1 ym² to fm²:
1 × 1e-18 = 1e-18 fm²

Example 2 — Convert 100 ym² to fm²:
100 × 1e-18 = 1e-16 fm²

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 yoctometers can be re-expressed in square femtometers for direct comparison with another instrument's calibration data sheet.

800 ym² × 1e-18 = 8e-16 fm²

Real-world example — Molecular dimensions

The diameter of small molecular structures (around 2 square yoctometers) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.

2 ym² × 1e-18 = 2e-18 fm²

Square Yoctometer to Square Femtometer conversion table

Standard reference values for converting square yoctometers to square femtometers:

Square Yoctometer [ym²]Square Femtometer [fm²]
0.011e-20
0.11e-19
11e-18
22e-18
33e-18
44e-18
55e-18
101e-17
202e-17
303e-17
404e-17
505e-17
1001e-16
5005e-16
10001e-15

Frequently asked questions

How many square femtometers is 1 square yoctometer?
1 square yoctometer equals 1e-18 square femtometer.
How do I convert square yoctometers to square femtometers?
Multiply the value in square yoctometers by 1e-18 to get square femtometers.
How do I convert square femtometers back to square yoctometers?
Multiply the value in square femtometers by 1e+18, or use the Square Femtometer to Square Yoctometer converter.
How many square femtometers is 100 square yoctometers?
100 square yoctometers equals 1e-16 square femtometers, because 100 × 1e-18 = 1e-16.

Convert Square Yoctometer to other area units

Show all Square Yoctometer conversions

Sources & references

Conversion factor (1 ym² = 1e-18 fm²) verified against the following authoritative sources:

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