Length · Unit Converter

Convert Square Femtometer to Square Attometer

Convert square femtometers to square attometers instantly. 1 square femtometer = 1000000.0000000001 square attometer — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Attometer to Square Femtometer 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 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.

Metric / SI

Square Attometer

What is a square attometer?

A square attometer is a metric unit of area equal to 10⁻³⁶ m². It is used in theoretical particle physics when discussing cross-sections at the sub-femtometer scale.

Origin of the square attometer

Derived by squaring the attometer (10⁻¹⁸ m). The atto- prefix was adopted by the CGPM in 1964 from the Danish 'atten' (eighteen), denoting 10⁻¹⁸.

Where it is used

Square attometers can appear in particle physics literature comparing extremely small interaction cross-sections, though more often barns (10⁻²⁸ m²) are used at this scale.

When and where it was developed

SI prefix atto- adopted in 1964; remains a defined unit, rarely used in practice.

Square Femtometer to Square Attometer conversion formula

The relationship between square femtometers and square attometers:

1 fm² = 1000000.0000000001 am²
1 am² = 1e-6 fm²

To convert square femtometers to square attometers, multiply the value in square femtometers by 1000000.0000000001. To reverse, multiply square attometers by 1e-6.

How to use this converter

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

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

  1. Write down the value in square femtometers (fm²).
  2. Multiply that value by the factor 1000000.0000000001.
  3. The product is the equivalent value in square attometers (am²).
  4. To reverse, multiply the square attometer value by 1e-6.

Worked examples

Example 1 — Convert 1 fm² to am²:
1 × 1000000.0000000001 = 1000000.0000000001 am²

Example 2 — Convert 100 fm² to am²:
100 × 1000000.0000000001 = 1e+8 am²

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 × 1000000.0000000001 = 2000000.0000000002 am²

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 attometers for direct comparison with another instrument's calibration data sheet.

800 fm² × 1000000.0000000001 = 8e+8 am²

Square Femtometer to Square Attometer conversion table

Standard reference values for converting square femtometers to square attometers:

Square Femtometer [fm²]Square Attometer [am²]
0.0110000
0.1100000
11000000.0000000001
22000000.0000000002
33000000.0000000005
44000000.0000000005
55000000.0000000009
101e+7
202e+7
303e+7
404e+7
505e+7
1001e+8
5005e+8
10001e+9

Frequently asked questions

How many square attometers is 1 square femtometer?
1 square femtometer equals 1000000.0000000001 square attometer.
How do I convert square femtometers to square attometers?
Multiply the value in square femtometers by 1000000.0000000001 to get square attometers.
How do I convert square attometers back to square femtometers?
Multiply the value in square attometers by 1e-6, or use the Square Attometer to Square Femtometer converter.
How many square attometers is 100 square femtometers?
100 square femtometers equals 1e+8 square attometers, because 100 × 1000000.0000000001 = 1e+8.

Convert Square Femtometer to other area units

Show all Square Femtometer conversions

Sources & references

Conversion factor (1 fm² = 1000000.0000000001 am²) verified against the following authoritative sources:

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